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Taiga Plains Ecozone+ Evidence for Key Findings Summary

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Canadian Biodiversity: Ecosystem Status and Trends 2010

Evidence for Key Findings Summary Report No. 13
Published by the Canadian Councils of Resource Ministers

Document Information

Cover photo

Library and Archives Canada Cataloguing in Publication

Taiga Plains Ecozone+ evidence for key findings summary.

Issued also in French under title:
Sommaire des éléments probants relativement aux constatations clés pour l'écozone+ de la taiga des plaines.
Electronic monograph in PDF format.
ISBN 978-1-100-22400-8
Cat. no.: En14-43/0-13-2013E-PDF

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Cover photo: boreal caribou, Gwich’in Settlement Area. Photo by John A. Nagy, provided by Government of the Northwest Territories (GNWT)

This report should be cited as:
ESTR Secretariat. 2013. Taiga Plains Ecozone+ evidence for key findings summary. Canadian Biodiversity: Ecosystem Status and Trends 2010, Evidence for Key Findings Summary Report No. 13. Canadian Councils of Resource Ministers. Ottawa, ON. vii + 109 p. Technical Reports

© Her Majesty the Queen in Right of Canada, 2013
Aussi disponible en français

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Preface

The Canadian Councils of Resource Ministers developed a Biodiversity Outcomes FrameworkReference 1 in 2006 to focus conservation and restoration actions under the Canadian Biodiversity Strategy.Reference 2 Canadian Biodiversity: Ecosystem Status and Trends 2010Reference 3 was the first report under this framework. It presents 22 key findings that emerged from synthesis and analysis of background technical reports prepared on the status and trends for many cross-cutting national themes (the Technical Thematic Report Series) and for individual terrestrial and marine ecozones+ of Canada (the Ecozone+ Status and Trends Assessments). More than 500 experts participated in data analysis, writing, and review of these foundation documents. Summary reports for each terrestrial Ecozone+ present Ecozone+-specific evidence related to each of the 22 national key findings (the Evidence for Key Findings Summary Report Series). Together, the full complement of these products constitutes the 2010 Ecosystem Status and Trends Report (ESTR):

2010 Ecosystem Status and Trends Report (ESTR)
Graphic of 2010 ecosystem status and trends report instead. Please review all sections with images and update alt tag accordingly

This report, Taiga Plains Ecozone+ Evidence for Key Findings Summary, presents evidence from the Taiga Plains Ecozone+ Status and Trends Assessment related to the 22 national key findings and is therefore not a comprehensive assessment of all ecosystem-related information. The level of detail presented on each key finding varies and important issues or datasets may have been missed. As in all ESTR products, the time frames over which trends are assessed vary – both because time frames that are meaningful for these diverse aspects of ecosystems vary and because the assessment is based on the best available information, which is over a range of time periods.

There have been extensive environmental impact assessments conducted in this Ecozone+ in relation to oil and gas exploration and transportation proposals. The baseline studies conducted for the Mackenzie Gas ProjectReference 4 are a source of compiled research and monitoring for parts of the Taiga Plains Ecozone+. Some results from this work have been included, but the scope and timing of the report precluded extensive use of this resource.

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Ecological classification system – ecozones+

A slightly modified version of the Terrestrial Ecozones of Canada, described in the National Ecological Framework for Canada,Reference 5 provided the ecosystem-based units for all reports related to this project. Modifications from the original framework include: adjustments to terrestrial boundaries to reflect improvements from ground-truthing exercises; the combination of three Arctic ecozones into one; the use of two ecoprovinces – Western Interior Basin and Newfoundland Boreal; the addition of nine marine ecosystem-based units; and, the addition of the Great Lakes as a unit. This modified classification system is referred to as “ecozones+” throughout these reports to avoid confusion with the more familiar “ecozones” of the original framework.Reference 6 Changes made for the Taiga Plains, based on ground-truthing: (1) reduce the area along its boundary with the Taiga Cordillera Ecozone+, (2) extend the area along its boundary with the Arctic Ecozone+ and, (3) move the southeastern boundary to include lands formerly considered part of the Taiga Shield.

Ecological classification system – ecozones+
Map
Long description for Ecological classification system – ecozones+

This map of Canada shows the ecological classification framework for the Ecosystem Status and Trends Report, named “ecozones+”. This map shows the distribution of 15 terrestrial ecozones+ (Atlantic Maritime; Newfoundland Boreal; Taiga Shield; Mixedwood Plains; Boreal Shield; Hudson Plains; Prairies; Boreal Plains; Montane Cordillera; Western Interior Basin; Pacific Maritime; Boreal Cordillera; Taiga Cordillera; Taiga Plains; Arctic), two large lake ecozones+ (Great Lakes; Lake Winnipeg), and nine marine ecozones+ (North Coast and Hecate Strait; West Coast Vancouver Island; Strait of Georgia; Gulf of Maine and Scotian Shelf; Estuary and Gulf of St. Lawrence; Newfoundland and Labrador Shelves; Hudson Bay, James Bay and Fox Basin; Canadian Arctic Archipelago; Beaufort Sea).

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Acknowledgements

This report has been written by the ESTR Secretariat with significant assistance from Anne Gunn and Joan Eamer. It is based on the report, Taiga Plains Ecozone+ Status and Trends Assessment.

Additional reviews of this summary report were provided by scientists and resource managers from relevant provincial and federal government agencies, as well as one external expert review. Further information about this Ecozone+ can be found in the associated supplementary material, taken from the draft Technical Ecozone+ Report. Contributions to the Taiga Plains Ecozone+ Status and Trends Assessment are listed below.

Taiga Plains Ecozone+ Status and Trends AssessmentReference 7 (Technical Ecozone+ Report) acknowledgments

Lead authors
Anne Gunn, Joan Eamer, and Suzanne Carrière
Contributing authors, specific sections or topics
Northwest Territories ecozone classification: B. Oosenbrug
Protected areas: Jean-Francois Gobeil, Robert Helie and Robert Vanderkam
Authors of ESTR Thematic Technical Reports from which material is drawn
Large-scale climate oscillations influencing Canada, 1900-2008: B. Bonsal and A. ShabbarReference 8
Canadian climate trends, 1950-2007: X. Zhang, R. Brown, L. Vincent, W. Skinner, Y. Feng and E. MekisReference 9
Trends in large fires in Canada, 1959-2007: C.C. Krezek-Hanes, F. Ahern, A. Cantin and M.D. FlanniganReference 10
Wildlife pathogens and diseases in Canada: F.A. LeightonReference 11
Trends in permafrost conditions and ecology in northern Canada: S. SmithReference 12
Monitoring ecosystems remotely: a selection of trends measured from satellite observations of Canada: F. Ahern, J. Frisk, R. Latifovic and D. PouliotReference 13
Climate-driven trends in Canadian streamflow, 1961-2003: A. Cannon, T. Lai and P. WhitfieldReference 14
Biodiversity in Canadian lakes and rivers: W.A. Monk and D.J. BairdReference 15

Review conducted by scientists, traditional knowledge specialists, and renewable resource and wildlife managers from provincial (BC only), territorial, and federal government agencies, and from wildlife co-management boards through a review process recommended by the ESTR Steering Committee. Substantial changes to the report were made as a result of this process.

Direction provided by the ESTR Steering Committee composed of representatives of federal, provincial and territorial agencies.

Editing, synthesis, technical contributions, maps and graphics, and report production by the ESTR Secretariat.

Aboriginal Traditional Knowledge compiled from publicly available sources by Donna D. Hurlburt.

Figure 1. Overview map of the Taiga Plains Ecozone+
Map
Long description for Figure 1.

This overview map of the Taiga Plains Ecozone+ shows the locations of cities/towns and bodies of water referred to in the report.  The ecozone+ extends from the Mackenzie River Delta at the Yukon border along the western side of the Northwest Territories and down into the northeast corner of BC and northwest Alberta.  Villages and towns pictured on the map include Aklavik, Inuvik, Fort McPherson and Tsiigehtchic near the Mackenzie delta, Fort Good Hope, Norman Wells, Fort Simpson, Fort Providence and Fort Smith in the Northwest Territories, Fort Nelson in BC and Hay Lake in Alberta. Yellowknife and Wrigley, NWT are pictured, but fall just outside the boundaries of the ecozone+.  Half of Great Slave Lake and all of Great Bear Lake fall within the boundaries of the Taiga Plains Ecozone+.  From northwest to southeast, the major rivers depicted on the map are the Arctic Red River, the Mackenzie River, the Liard River, the Hay River and the Slave River.  All-weather roads on the map are typically restricted to the southern half of the ecozone+, with access to northern areas by winter road, except the Dempster Highway that runs to Inuvik and Fort McPherson from the Yukon.

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List of Figures

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Ecozone+ Basics

The Taiga Plains ecozone+ is the large extent of boreal forest sweeping from the Arctic coast south along the Mackenzie River. The ecozone+ with its extensive peatlands, wetlands and intact blocks of forest provides important habitat for wildlife, especially waterfowl, endangered whooping cranes, the threatened wood bison, and caribou, including the threatened boreal caribou. The footprint from human development is greatest in the south (especially northeastern BC), along parts of the Mackenzie Valley, and around Inuvik. Oil and gas projects and pipelines, existing and potential, are the focus of industry and economic development, though hunting, fishing, trapping, and berry gathering remain very important to residents. Climate change is apparent in the ecozone+, with an average increase of 2°C year-round and over 5°C in winter since 1950 and corresponding changes in growing season, permafrost, and river ice.

Table 1. Taiga Plains ecozone+ overview.
Area604,628 km2 (6.2% of Canada)
TopographyExtended plains and a few isolated, low-elevation plateaus.

Landscape modified by rivers that have cut deep gorges and created meandering channels and ox-bow lakes.
ClimateStrong north-south gradient, with Growing Degree Days about double in the south compared to the northReference 16.

Precipitation relatively low as are both summer rainfall and evapotranspiration rates. Snow pack accumulates mostly in the fall, with typically light snow from December to MarchReference 16.
River basinsDrainage to the Arctic Ocean through the Mackenzie River Basin, including through Great Slave and Great Bear lakes.
GeologyUnderlain by sedimentary rocks with horizontal layers of sandstones, shales, conglomerates, and limestoneReference 17

Retreating ice sheets from the last ice age deposited till over most of the ecozone+ (Figure 2).
Land Cover68% forest; 20% shrub cover (Figure 3)

North: vegetation open with stunted stands of white spruce

Further south: more closed canopy forests – species include black and white spruce, jack pine, Alaska paper birch, aspen, and balsam poplarReference 13
PermafrostNorth: continuous permafrost over shallow active layer

Central: extensive discontinuous permafrost

South: sporadic permafrost
SettlementPopulation increased 36% from 1971 to 2006 (Figure 4).

9 communities with populations over 600 (Table 2); 7 smaller communities in NWT and additional small population centres in Indian reserves in BC.
EconomyHistorical and current economy centred on: 1) wildlife and fish abundance, 2) oil and gas reserves, 3) transportation (including pipelines).
DevelopmentRoads are in the north and south portions of the ecozone+ (Figure 1).
Additional minor roads and linear features are mainly related to access to oil and gas or, in the southern part of the ecozone+, forestry.

Industrial development is primarily oil and gas exploration and development, focused on the Mackenzie Delta and parts of the Mackenzie Valley. Major pipelines and associated infrastructure extending the length of the ecozone+ along the Mackenzie Valley are proposed and were approved in 2010 to proceed to the permit application stageReference 18.
National/global significanceLower portion of Mackenzie River, longest river in Canada, draining 20% of the nationReference 19.

Ramsar sites (wetlands of international significance): Hay-Zama Lakes and Whooping Crane breeding wetlandsReference 20.

World Heritage Site: Wood Buffalo National ParkReference 21

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Jurisdictions: Mainly within the Northwest Territories; extends into northeast BC and northwest Alberta and includes a very small section of southeastern Yukon (Figure 1). Four settled land claims with jurisdiction in the ecozone+: Inuvialuit, Gwich’in, Sahtu, and Tlicho, plus the Deh Cho Interim Measures Agreement.

Figure 2. Surficial materials, Taiga Plains Ecozone+
Map
Source: based on data from Geological Survey of Canada, 1994Reference 17
Long description for Figure 2

This map shows the distribution of surficial materials in the Taiga Plains Ecozone+. The majority of the ecozone+ is covered with till blanket, with some large areas of till veneer in the north. In the river drainages there tends to be a mix of coarse and fine grained glaciolacustrine deposits, with a large alluvial deposit in the Mackenzie Delta.

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Figure 3. Land cover, Taiga Plains Ecozone+
Map
Source: data for ecozone+ provided by authors of Ahern et al., 2011Reference 13
Long description for Figure 3

This graphic depicts a map and stacked bar graph of land cover classification in the Taiga Plains Ecozone+. This ecozone+ is heavily dominated by forest (68%), with substantial shrublands (20%) in the Mackenzie River Delta and south of Great Slave Lake. Fire scars, accounting for only 6% of the land cover, are concentrated near the shrubland areas in the Mackenzie Delta, and south and west of Great Slave Lake. A minimal amount of low vegetation and barren ground (6%) is found in the west-central part of the ecozone+, and agricultural land (<1%) is centred around Hay Lake, Alberta. A small map showing the location of the Taiga Plains Ecozone+ in Canada is located in the top right corner.

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Figure 4. Human population trends, Taiga Plains Ecozone+, 1971-2006
Graph
Source: population data for the ecozone+ compiled from Statistics Canada 2000Reference 23 and census reports for Wrigley, Fort Resolution, Fort Smith and Inuvik.
Long description for Figure 4

This bar graph depicts the following information:

Human population trends, Taiga Plains Ecozone+, 1971-2006.
YearNumber of people
197120,910
197623,641
198124,160
198626,200
199127,456
199630,092
200126,165
200628,435

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Table 2. Main communities and their 2006 populations
CommunityPopulation
Fort Nelson BC4,514
Hay River NT3,648
Inuvik NT3,484
Fort Smith NT2,364
Fort Simpson NT1,216
Hay Lake 209 Indian Reserve AB951
Fort McPherson NT776
Norman Wells NT761
Fort Providence NT727

Source: Statistics Canada, 2009Reference 24

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Key Findings at a Glance: National and Ecozone+ Level

Table 3 presents the national key findings from Canadian Biodiversity: Ecosystem Status and Trends 2010Reference 3 together with a summary of the corresponding trends in the Taiga Plains ecozone+. Topic numbers refer to the national key findings in Canadian Biodiversity: Ecosystem Status and Trends 2010. Topics that are greyed out were identified as key findings at a national level but were either not relevant or not assessed for this ecozone+ and do not appear in the body of this document. Evidence for the statements that appear in this table is found in the subsequent text organized by key finding. See the Preface on page i.

Table 3. Key findings overview

3.1 Theme: Biomes
Themes and TopicsKey Findings: NationalKey findings: Taiga Plains Ecozone+
1. ForestsAt a national level, the extent of forests has changed little since 1990; at a regional level, loss of forest extent is significant in some places. The structure of some Canadian forests, including species composition, age classes, and size of intact patches of forest, has changed over longer time frames.Boreal forest is the dominant ecosystem type in the Taiga Plains. Fragmentation from roads and other linear development, resulting in loss of large intact blocks of forest, is most evident in northeastern British Columbia (B.C.). Climate-related changes in the treeline zone at the north of the ecozone+ include increased shrub growth, a small net increase in tree cover resulting from increased conifer cover at the northern part of the treeline zone balanced with reduction in coniferous forest in the south of the zone (1985-2006), and reduced growth rates, likely due to drought stress, of the majority of white spruce trees since the 1930s.
2. GrasslandsNative grasslands have been reduced to a fraction of their original extent. Although at a slower pace, declines continue in some areas. The health of many existing grasslands has also been compromised by a variety of stressors.Not relevant
3. WetlandsHigh loss of wetlands has occurred in southern Canada; loss and degradation continue due to a wide range of stressors. Some wetlands have been or are being restored.Wetlands are diverse and widespread in the ecozone+ and are vulnerable to anthropogenic threats including climate change. Periodic spring flooding along the Mackenzie River Basin, which maintains the diversity of delta lakes, has been shown to be more related to climate variables than to the influence of the upstream W.A.C. Bennett dam. There are, however, indications that spring flooding may be less frequent. Delta lakes are affected by the longer ice-free season but also by increased erosion from permafrost slumping, which causes abrupt changes in water quality.
4. Lakes and riversTrends over the past 40 years influencing biodiversity in lakes and rivers include seasonal changes in magnitude of stream flows, increases in river and lake temperatures, decreases in lake levels, and habitat loss and fragmentation.The most widespread hydrological change is a trend to increased minimum and winter flows, both in the Mackenzie River as a whole (including tributaries upstream of the Taiga Plains) and in several smaller rivers monitored within the ecozone+. While upstream tributaries to the Mackenzie River are generally exhibiting trends to earlier peak flows, there is no clear trend in timing at most sites on smaller watercourses within the ecozone+. There are indications of a trend to increased streamflow variability within the ecozone+, with implications for riparian habitat.
5. CoastalCoastal ecosystems, such as estuaries, salt marshes, and mud flats, are believed to be healthy in less-developed coastal areas, although there are exceptions. In developed areas, extent and quality of coastal ecosystems are declining as a result of habitat modification, erosion, and sea-level rise.Not Relevant (coastal region just to the north of this ecozone+ is in the Arctic ecozone+)
6. MarineObserved changes in marine biodiversity over the past 50 years have been driven by a combination of physical factors and human activities, such as oceanographic and climate variability and overexploitation. While certain marine mammals have recovered from past overharvesting, many commercial fisheries have not.Not relevant
7. Ice across biomesDeclining extent and thickness of sea ice, warming and thawing of permafrost, accelerating loss of glacier mass, and shortening of lake-ice seasons are detected across Canada’s biomes. Impacts, apparent now in some areas and likely to spread, include effects on species and food webs.Changes in permafrost, well documented for this ecozone+, include: increased temperatures of permafrost, changes in active layer depth, reduction of the continuous permafrost zone, and thawing of discontinuous permafrost in some areas. This has resulted in landscape changes, including loss of frozen peat plateaus. River ice within the Mackenzie Basin shows trends to earlier break-up; datasets are poor for both river and lake ice within the ecozone+.

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3.2 Theme: Human/Ecosystem Interactions
Themes and TopicsKey Findings: NationalKey findings: Taiga Plains Ecozone+
8. Protected areasBoth the extent and representativeness of the protected areas network have increased in recent years. In many places, the area protected is well above the United Nations 10% target. It is below the target in highly developed areas and the oceans.In 2009, 5.6% of the ecozone+ had a high level of protection, by far the largest protected area being Wood Buffalo National Park, established in 1922. There was little change in protected areas from 1922 to the early 2000s when several, mainly quite small, protected areas were established. Candidate protected areas have been identified for the Mackenzie Valley in response to the proposed pipeline development. The aim is to maintain ecological integrity by developing buffer zones and connecting wildlife corridors through a network of protected areas.
9. StewardshipStewardship activity in Canada is increasing, both in number and types of initiatives and in participation rates. The overall effectiveness of these activities in conserving and improving biodiversity and ecosystem health has not been fully assessed.Stewardship in the ecozone+ is associated with aboriginal cultural and spiritual values, incorporated into land-use planning through, for example, community conservation plans. Public-private sector partnerships and national and international initiatives also contribute to stewardship of ecosystems.
10. Invasive non-native speciesInvasive non-native species are a significant stressor on ecosystem functions, processes, and structure in terrestrial, freshwater, and marine environments. This impact is increasing as numbers of invasive non-native species continue to rise and their distributions continue to expand.There is some incursion of non-native plant species, especially along roadways, in the Taiga Plains, with only a few being moderately invasive. An invasive non-native forest insect, the larch sawfly, has spread to the ecozone+, with regionally significant outbreaks in the 1990s. Increasing access, development, and climate change are liable to increase the rate of introduction and spread of non-native species in terrestrial and aquatic environments.
11. ContaminantsConcentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.Some legacy contaminants are declining in fish in the ecozone+ but the trends are not clear or consistent with, for example, DDTs increasing in recent years in Mackenzie River burbot. Brominated flame retardants in fish increased sharply up to the mid-2000s and then dropped, based on limited sampling. Mercury levels are naturally high in the Mackenzie Basin and have increased in fish, including in the Mackenzie River and Great Slave Lake within the ecozone+. Changes in aquatic ecology related to climate change may be either accentuating or masking trends in some contaminants.
12. Nutrient loading and algal bloomsInputs of nutrients to both freshwater and marine systems, particularly in urban and agriculture-dominated landscapes, have led to algal blooms that may be a nuisance and/or may be harmful. Nutrient inputs have been increasing in some places and decreasing in others.Not considered to be a concern for this ecozone+
13. Acid depositionThresholds related to ecological impact of acid deposition, including acid rain, are exceeded in some areas, acidifying emissions are increasing in some areas, and biological recovery has not kept pace with emission reductions in other areas.Not considered to be a concern for this ecozone+
14. Climate changeRising temperatures across Canada, along with changes in other climatic variables over the past 50 years, have had both direct and indirect impacts on biodiversity in terrestrial, freshwater, and marine systems.The Taiga Plains ecozone+ has experienced some of the greatest increases in temperature of any Canadian region since 1950 – with the annual mean temperature increasing over 2°C and winter temperatures rising about 5°C at all stations since 1950. This warming has translated into some clear ecosystem trends, such as changes to permafrost landscapes and increases in terrestrial primary productivity. There are indications of other emerging, climate-related trends, such as the northward movement of some forest insect pests.
15. Ecosystem servicesCanada is well endowed with a natural environment that provides ecosystem services upon which our quality of life depends. In some areas where stressors have impaired ecosystem function, the cost of maintaining ecosystem services is high and deterioration in quantity, quality, and access to ecosystem services is evident.Provisioning services of the ecozone+ include harvest of fish, wildlife, and plants, of cultural, spiritual, nutritional, and economic importance. Reliance on these provisioning services is high and not declining, especially in rural communities. Quality of these services generally remains high, with the exception of declines in barren-ground caribou, leading to harvest restrictions and reduced harvest success in some communities.
3.3 Theme: Habitat, Wildlife, and Ecosystem Processes
16. Agricultural landscapes as habitatThe potential capacity of agricultural landscapes to support wildlife in Canada has declined over the past 20 years, largely due to the intensification of agriculture and the loss of natural and semi-natural land cover.Not relevant
17. Species of special economic, cultural, or ecological interestMany species of amphibians, fish, birds, and large mammals are of special economic, cultural, or ecological interest to Canadians. Some of these are declining in number and distribution, some are stable, and others are healthy or recovering.The Taiga Plains ecozone+ is important nationally for boreal woodland caribou, who are dependent upon intact blocks of mature boreal forest. Trends are unknown for half of the populations; populations in the more fragmented, southern part of the ecozone+ are decreasing, although one population is reported as being stable. Bluenose-West barren-ground caribou have declined precipitously in recent years. Several waterfowl species that breed in the ecozone+ are declining; causes are not clear. The Taiga Plains is home to most of the global populations of two iconic species that were nearly driven to extinction in the early 20th century and are still considered at risk: the whooping crane and the wood bison.
18. Primary productivityPrimary productivity has increased on more than 20% of the vegetated land area of Canada over the past 20 years, as well as in some freshwater systems. The magnitude and timing of primary productivity are changing throughout the marine system.Overall, primary productivity increased on 22.7% and decreased on 1.5% of the land area of the Taiga Plains from 1985 to 2006. Increased primary productivity was mainly in the north part of the ecozone+, where studies show increased growth of shrubs along with some impairment of growth of lichens and of some white spruce. The large fires characteristic of the ecozone+ influence primary productivity but do not account for the overall increase.
19. Natural disturbancesThe dynamics of natural disturbance regimes, such as fire and native insect outbreaks, are changing and this is reshaping the landscape. The direction and degree of change vary.Natural disturbances in the Taiga Plains show signs of change related to climate. On a decadal basis, the area of forest burned increased from the 1960s then declined again in the most recent decade, though data are incomplete for this latter decade. There are indications of a trend to more fires earlier in the season, a pattern consistent with the observed temperature trends. The main forest insect pest, spruce budworm, is endemic in the southern part of the ecozone+ and there are indications that it may be moving northward. Both the forest tent caterpillar and the mountain pine beetle, relatively new to the ecozone+, show signs of becoming more abundant and expanding northward.
Wildlife disease and parasites
(ecozone+-specific key finding)
-Wildlife disease is of importance to the Taiga Plains ecozone+ for ecological, economic, and human health reasons. Bovine tuberculosis and brucellosis affect a high percentage of wood bison and present risks to human health and to economic activities. There is emerging evidence and growing concern that some wildlife diseases and parasites (including anthrax, ungulate parasites, and viruses and funguses affecting frogs) may be increasing in prevalence and/or range, or may do so in the future, in response to warmer weather and changes in wildlife species distribution.
20. Food websFundamental changes in relationships among species have been observed in marine, freshwater, and terrestrial environments. The loss or reduction of important components of food webs has greatly altered some ecosystems.There is little information on changes in food webs in the Taiga Plains. Abundance of many mammals in the Taiga Plains is cyclic, driven or influenced by food web effects as well as drivers like climate. Changes in small mammal cycles have been reported in other northern regions, and a recent dampening of snowshoe hare and lynx cycles is noted in the NWT. Northern tundra caribou wintering in the Taiga Plains have declined in abundance which may reflect a low period on a population cycle. Declining boreal caribou populations in the south of the ecozone+ may be affected by changes in predator-prey dynamics related to habitat alteration.
21. Biodiversity monitoring, research, information management, and reportingLong-term, standardized, spatially complete, and readily accessible monitoring information, complemented by ecosystem research, provides the most useful findings for policy-relevant assessments of status and trends. The lack of this type of information in many areas has hindered development of this assessment.Important data sets collected through broadscale monitoring programs for the ecozone+ are mainly at the non-biological level: climate, hydrology, and permafrost monitoring. In addition, data on some species groups, notably some caribou populations, small mammals, and waterfowl, provide good trend information. A combination of remote sensing and short-term research projects, often extending into the past through the use of proxy records, provides some data on landscape-level changes. A priority often identified for the region is improvement of the use of Traditional Knowledge along with results from science-based studies.
22. Rapid change and thresholdsGrowing understanding of rapid and unexpected changes, interactions, and thresholds, especially in relation to climate change, points to a need for policy that responds and adapts quickly to signals of environmental change in order to avert major and irreversible biodiversity losses.There are signals of rapid ecosystem change in the Taiga Plains, related to climate change. Loss of frozen peatlands is occurring in some areas; increasing permafrost temperatures at several sites is an early warning that other areas will cross the phase-change threshold leading to permafrost degradation, altering terrestrial and aquatic ecosystems. Other large-scale changes observed in recent years include increases in primary productivity, mainly in the north of the ecozone+, and alteration of vegetation communities in the treeline zone.

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3.4 Theme: Habitat, Wildlife, and Ecosystem Processes
Themes and TopicsKey Findings: NationalKey findings: Taiga Plains Ecozone+
16. Agricultural landscapes as habitatThe potential capacity of agricultural landscapes to support wildlife in Canada has declined over the past 20 years, largely due to the intensification of agriculture and the loss of natural and semi-natural land cover.Not relevant
17. Species of special economic, cultural, or ecological interestMany species of amphibians, fish, birds, and large mammals are of special economic, cultural, or ecological interest to Canadians. Some of these are declining in number and distribution, some are stable, and others are healthy or recovering.The Taiga Plains ecozone+ is important nationally for boreal woodland caribou, who are dependent upon intact blocks of mature boreal forest. Trends are unknown for half of the populations; populations in the more fragmented, southern part of the ecozone+ are decreasing, although one population is reported as being stable. Bluenose-West barren-ground caribou have declined precipitously in recent years. Several waterfowl species that breed in the ecozone+ are declining; causes are not clear. The Taiga Plains is home to most of the global populations of two iconic species that were nearly driven to extinction in the early 20th century and are still considered at risk: the whooping crane and the wood bison.
18. Primary productivityPrimary productivity has increased on more than 20% of the vegetated land area of Canada over the past 20 years, as well as in some freshwater systems. The magnitude and timing of primary productivity are changing throughout the marine system.Overall, primary productivity increased on 22.7% and decreased on 1.5% of the land area of the Taiga Plains from 1985 to 2006. Increased primary productivity was mainly in the north part of the ecozone+, where studies show increased growth of shrubs along with some impairment of growth of lichens and of some white spruce. The large fires characteristic of the ecozone+ influence primary productivity but do not account for the overall increase.
19. Natural disturbancesThe dynamics of natural disturbance regimes, such as fire and native insect outbreaks, are changing and this is reshaping the landscape. The direction and degree of change vary.Natural disturbances in the Taiga Plains show signs of change related to climate. On a decadal basis, the area of forest burned increased from the 1960s then declined again in the most recent decade, though data are incomplete for this latter decade. There are indications of a trend to more fires earlier in the season, a pattern consistent with the observed temperature trends. The main forest insect pest, spruce budworm, is endemic in the southern part of the ecozone+ and there are indications that it may be moving northward. Both the forest tent caterpillar and the mountain pine beetle, relatively new to the ecozone+, show signs of becoming more abundant and expanding northward.
Wildlife disease and parasites
(ecozone+-specific key finding)
-Wildlife disease is of importance to the Taiga Plains ecozone+ for ecological, economic, and human health reasons. Bovine tuberculosis and brucellosis affect a high percentage of wood bison and present risks to human health and to economic activities. There is emerging evidence and growing concern that some wildlife diseases and parasites (including anthrax, ungulate parasites, and viruses and funguses affecting frogs) may be increasing in prevalence and/or range, or may do so in the future, in response to warmer weather and changes in wildlife species distribution.
20. Food websFundamental changes in relationships among species have been observed in marine, freshwater, and terrestrial environments. The loss or reduction of important components of food webs has greatly altered some ecosystems.There is little information on changes in food webs in the Taiga Plains. Abundance of many mammals in the Taiga Plains is cyclic, driven or influenced by food web effects as well as drivers like climate. Changes in small mammal cycles have been reported in other northern regions, and a recent dampening of snowshoe hare and lynx cycles is noted in the NWT. Northern tundra caribou wintering in the Taiga Plains have declined in abundance which may reflect a low period on a population cycle. Declining boreal caribou populations in the south of the ecozone+ may be affected by changes in predator-prey dynamics related to habitat alteration.

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3.5 Theme: Science/Policy Interface
Themes and TopicsKey Findings: NationalKey findings: Taiga Plains Ecozone+
21. Biodiversity monitoring, research, information management, and reportingLong-term, standardized, spatially complete, and readily accessible monitoring information, complemented by ecosystem research, provides the most useful findings for policy-relevant assessments of status and trends. The lack of this type of information in many areas has hindered development of this assessment.Important data sets collected through broadscale monitoring programs for the ecozone+ are mainly at the non-biological level: climate, hydrology, and permafrost monitoring. In addition, data on some species groups, notably some caribou populations, small mammals, and waterfowl, provide good trend information. A combination of remote sensing and short-term research projects, often extending into the past through the use of proxy records, provides some data on landscape-level changes. A priority often identified for the region is improvement of the use of Traditional Knowledge along with results from science-based studies.
22. Rapid change and thresholdsGrowing understanding of rapid and unexpected changes, interactions, and thresholds, especially in relation to climate change, points to a need for policy that responds and adapts quickly to signals of environmental change in order to avert major and irreversible biodiversity losses.There are signals of rapid ecosystem change in the Taiga Plains, related to climate change. Loss of frozen peatlands is occurring in some areas; increasing permafrost temperatures at several sites is an early warning that other areas will cross the phase-change threshold leading to permafrost degradation, altering terrestrial and aquatic ecosystems. Other large-scale changes observed in recent years include increases in primary productivity, mainly in the north of the ecozone+, and alteration of vegetation communities in the treeline zone.

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Theme: Biomes

Key finding 1
Forests

Theme Biomes

National key finding
At a national level, the extent of forests has changed little since 1990; at a regional level, loss of forest extent is significant in some places. The structure of some Canadian forests, including species composition, age classes, and size of intact patches of forest, has changed over longer time frames.

Ecozone+ key finding: Boreal forest is the dominant ecosystem type in the Taiga Plains. Fragmentation from roads and other linear development, resulting in loss of large intact blocks of forest, is most evident in northeastern BC. Climate-related changes in the treeline zone at the north of the ecozone+ include increased shrub growth, a small net increase in tree cover resulting from increased conifer cover at the northern part of the treeline zone balanced with reduction in coniferous forest in the south of the zone (1985-2006), and reduced growth rates, likely due to drought stress, of the majority of white spruce trees since the 1930s.

Spatial characteristics

The Taiga Plains ecozone+, with its large variations in latitude, elevation, and climate, varies in density of forest cover and degree of forest fragmentation. It is an area of frequent large wildfires and thus the vegetation is often a mosaic of uneven-aged forest at different stages of regeneration.Reference 13 Predominantly coniferous forest covers the valleys of the Mackenzie River and its tributaries, all the way to the Mackenzie Delta, although the lowlands of the Liard Valley tend toward mixed woods. Slightly higher elevations, such as the Cameron Hills, and regenerating burns are shrub-covered, while the highest elevations, primarily the eastern slopes of the Mackenzie Mountains, are characterized by tundra vegetation.

Much of this ecozone+ exhibits a proportion of forest greater than 50%. Lower forest densities are found immediately south of Great Slave Lake in the northern portion of Wood Buffalo National Park, the uplands near Norman Wells, in a large area west of Lac la Martre that burned in the mid-1990s, and in portions of the lower reaches of the Mackenzie Valley.Reference 13

Characteristics of Canadian forested regions were examined using remote sensing data.Reference 13 The habitat requirements for many species are strongly influenced by the spatial characteristics of land cover types. These spatial characteristics can include the proportion of particular land cover types in an area and the amount of fragmentation and connectivity of particular land cover types. The presence of edges, implying a certain degree of fragmentation, is important for many species, while others, notably woodland caribou, are adversely affected by fragmentation.

Two methods were used to examine forest spatial characteristics and provide a baseline for future trend analyses, both calculated from the Earth Observation for Sustainable Development dataset of pixels at 30 m spacing within 1 km2 cells (from the year 2000):

  1. forest density (proportion of land area that is forested): results are shown in Figure 5; and,
  2. edge density (the length of all edges between forested and non-forest pixels in each 1 km2 cell): The forest edge density in the Taiga Plains is higher than in many more southerly forests, with a typical value of 250 m/km2, increasing to 500-600 m/km2 in tundra areas flanking the eastern foothills of the Mackenzie Mountains.
Figure 5. Map showing forest density, Taiga Plains, 2000

Proportion of 30 m2 pixels that are forested in each 1 km2 unit is shown. The northern white section is an artefact of the methodology – it corresponds with the boundary of the Taiga Plains ecozone under the 1995 classification. Density is not the number of trees, but the appearance of land cover from space. Lower proportion of forest may represent stands of black spruce or jackpine or regenerating forest with sparse canopy cover, while the higher forest proportion areas may represent mature white spruce stands with a lower density of trees but a dense canopy cover.

Map
Source: Ahern et al., 2011Reference 13
Long description for Figure 5

This map shows forest density in the Taiga Plains ecozone+. The map is derived from remote sensing imagery; each 1 km2 unit on the map is coded to reflect the proportion of pixels in the image that are forested, and the proportion of forest is derived from canopy cover. Most of the ecozone+ is a complex mosaic of forest density, except the southwest section of the ecozone+, which generally has high forest density.  The Mackenzie Delta region, areas to the west of Great Bear Lake and South of Great Slave Lake, and a large area in the centre of the ecozone+ have low (<30%) forest density.  Areas with lower proportion of forest may represent stands dominated by black spruce or jackpine, while mature white spruce with fewer trees will have dense canopy cover and will be depicted as high density forests.  A white space at the north edge of the ecozone+ is an artefact of different ecozone boundaries when the map was produced under the 1995 ecozone classification.

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Intact forest blocks

Figure 6 shows areas of intact forest blocks in the Taiga Plains ecozone+. Note that northeastern BC, which has the lowest density of intact forest blocks, is a region with high forest density (Figure 5). This indicates that the lack of extensive areas of intact forest is due to fragmentation of the forest, rather than to large-scale land conversion or the presence of other natural land cover types.

Figure 6. Intact forest blocks, Taiga Plains ecozone+

Green shows contiguous blocks of forest undisturbed by anthropogenic features. Minimum block size is 10,000 ha. The northern white section is an artefact of the methodology – it corresponds with the boundary of the Taiga Plains Ecozone under the 1995 classification.

map
Source: based on data compiled by Lee et al., 2006Reference 25
Long description for Figure 6

This map depicts the distribution of intact forest blocks in the Taiga Plains ecozone+. To be considered intact, forest blocks must be a minimum of 10,000 ha in area and be undisturbed by anthropogenic features. The majority of the ecozone+ is covered by intact forest blocks, with the exception of the Peace Region in the northeast corner of BC. This region has a high density of forest, as indicated in Figure 4, but the low density of intact blocks indicates that forest fragmentation is prevalent, as land conversion is greatest in this area of the ecozone+.

The treeline zone

The following text box, which provides a broader perspective on treeline change, is excerpted from Canadian biodiversity: ecosystem status and trends 2010.Reference 3

Changes in the treeline zone

The term “treeline” is deceptive – there is not a sharp line where trees end, but rather a zone of transition from increasingly sparse trees to tundra. Treeline zones in Canada are both latitudinal, across the north of the country, and altitudinal, on the slopes of hills and mountains. The emerging picture is one of change, but not a uniform expansion of the treeline. In northern Quebec, trees in the forest-tundra zone have grown faster and taller since the 1970sReference 26 but distribution of trees has not changed greatly.Reference 27 In Labrador, treelines have expanded northward and up slopes over the past 50 years along the coast, but not inland.Reference 28 In the mountains of northwestern Canada, tree growth and density have changed more than the position of alpine treelines.Reference 29

A study on the treeline in western Canada found only a small net increase in tree cover, but major changes in vegetation within the treeline zone. Tree cover increased in the northern half of the zone, but this was mainly offset by decreases in the southern half, especially west of the Mackenzie Delta – likely related to drier conditions due to higher temperatures.Reference 30 The biggest changes were an increase in shrubs and, in the northwest of the treeline zone, a replacement of lichen cover and bare land with small, non-woody plants (herbs).

Figure 7. Vegetation changes in the treeline zone of Western Canada, between 1985 and 2006

Mean change across the zone over 22 years based on analysis of early spring and summer satellite images.

Graph
Source: data from Olthof and Pouliot, 2010Reference 31
Long description for Figure 7

This graph shows the average change in cover of bare ground, lichen, conifer, herb and shrub vegetation categories at the treeline zone over a period of 22 years. The inset map depicts the area analysed in the study, which extends along the treeline zone from the northern part of the Yukon across the Northwest Territories and into the southeastern Nunavut/northern Manitoba. Over the 22 year period, tree cover changed very little (<1%), but herb and shrub cover increased by 12.5% and 15%, respectively. Cover of bare ground decreased by about 9% and lichen cover decreased by approximately 3.5%. The data is based on analysis of early spring and summer satellite images.

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Global perspective

Since 1900, treeline has advanced at 52% of the 166 sites examined around the world and has receded at only 1% of the sites.Reference 32

Several studies have shown strong correlations between summer temperatures and variation in vegetation patterns at the northern edge of the treeline zone in the Taiga Plains, indicating that increasing temperatures are likely to alter shrub abundance, vegetation structure, and species composition.Reference 33, Reference 34 There are indications that this change is underway. Lantz et al., 2010Reference 35 in a study along a transect from the Beaufort coast to the region of Fort McPherson in the south, found that green alder (a tall shrub) at sites at the northern edge of the forest-tundra transition zone showed patterns of recruitment markedly different from green alder at sites to the south. There was a higher proportion of younger shrubs in the northern transition zone, indicating recent colonization of the sites by green alder. The study also showed that green alder growth and reproduction were significantly greater on burned sites, with tall shrubs dominating burned sites in all vegetation zones. The combined effects of increased fire and warmer growing seasons are likely to result in continued northern movement of tall shrubs.

As in other regions of northwestern North America, white spruce stands in or near the treeline zone of the Taiga Plains show signs of decreased growth as the climate warms – perhaps due to the crossing of a physiological threshold for summer temperature and/or drought stress in the warmer summers.Reference 36-Reference 38 An analysis of annual growth, based on tree ring width, of 654 white spruce trees from 9 sites in the Mackenzie DeltaReference 30 showed that there was a high degree of similarity in growth rates among all trees up from 1600 to about 1930, when growth rates diverged. From about 1930 to the end of the study in 2003, growth rates for about 25% of the trees increased (this group is called positive responders), while growth rates for the remaining 75% of the trees (negative responders) declined (Figure 8). White spruce growth rates were compared with climate records from Inuvik (starting in 1927) and with Northern Hemisphere growing season temperatures (records starting in 1856). Annual growth of positive responders was strongly correlated with June temperatures in Inuvik and with North American growing season temperatures, while the low annual growth rates of negative responders were inversely related to temperatures from the current and, especially, the previous summer. This apparent slowing of growth in warmer summers was somewhat mitigated in years with higher April precipitation – an indication that both temperature stress and drought stress may be affecting white spruce in the region.

Figure 8. Growth of white spruce in the Mackenzie Delta, reconstructed from tree rings, 1600-2003, plotted with Northern Hemisphere growing season temperature anomalies, 1856-2003

The black line that starts in 1856 is the trend in temperature anomalies. The two groups of white spruce are the lines starting in 1600: the red line represents the average annual growth “negative responders” (trees showing an inverse relation between growth and summer temperatures after 1930) and the blue line represents the annual growth of “positive responders” (trees showing a positive correlation between growth and summer temperatures). The correlation coefficients show the strength of the relationships between the growth rates of the two groups of trees from 1600 to 1899 (r=0.91) and from 1900 to 2003 (r=0.11).

Graph
Source: adapted from Pisaric et al., 2007Reference 30. Reproduced with permission of John Wiley & Sons, Inc.
Long description for Figure 8

This line graph tracks the growth of white spruce in the Mackenzie Delta, reconstructed by tree rings spanning 1600-2003. Starting in 1856, the graph also plots the Northern Hemisphere growing season temperature anomalies. From 1600 to the early 20th century, white spruce is relatively stable with respect to annual tree ring growth. In the early 20th century, tree ring growth starts to show greater variation: while some trees (25%) showed increased growth in response to a significant increase in summer temperatures in the second half of the 20th century, the majority of trees (75%) had an inverse relationship to increased summer temperatures.

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Key finding 3
Wetlands

Theme Biomes

National key finding
High loss of wetlands has occurred in southern Canada; loss and degradation continue due to a wide range of stressors. Some wetlands have been or are being restored.

Ecozone+ key finding: Wetlands are diverse and widespread in the ecozone+ and are vulnerable to anthropogenic threats including climate change. Periodic spring flooding along the Mackenzie River Basin, which maintains the diversity of delta lakes, has been shown to be more related to climate variables than to the influence of the upstream W.A.C. Bennett dam. There are, however, indications that spring flooding may be less frequent. Delta lakes are affected by the longer ice-free season but also by increased erosion from permafrost slumping, which causes abrupt changes in water quality.

Wetland types include extensive river deltas, floodplain lakes and ponds, meandering river channels bordered by wetlands, thermokarst lakes, peatlands, and marshes. The wetlands of the Taiga Plains provide habitat for hundreds of thousands of migrating and nesting water birds, as well as supporting a diversity of fish and providing habitat for mammals including moose, caribou, muskrats, and beavers. Wetlands are traditional hunting and fishing locations and important culturally to the residents of the Taiga Plains. This section focuses on aspects of wetlands undergoing change or vulnerable to change from anthropogenic threats.

As with the boreal forest in general, large blocks of undisturbed wetlands are important in maintaining wetlands biodiversity. Some species are not tolerant of disturbance and fragmented habitat – the extreme example for the ecozone+ being the whooping crane, a water bird that was driven almost to extinction from habitat loss. Disturbance and habitat alteration in nesting grounds may also be linked to reductions in species of waterfowl breeding in the Taiga Plains (see key finding on Species of special interest on page 54).

Ramsar sites

There are two Ramsar sites (wetlands designated as being of international significance) in the Taiga Plains ecozone+:

  1. Hay-Zama Lakes, in Alberta. This 486 km2 complex of lakes and wetlands, a staging area for migrating waterfowl, is protected as an Alberta park. Oil and gas exploitation, however, predated the creation of the park and is permitted to continue until reserves are depleted.Reference 39 It is a traditional harvesting area for the Dene Tha’.
     
  2. Whooping Crane Summer Range, in NWT and Alberta, within Wood Buffalo National Park. This 16,895 km2 area is the only remaining natural nesting area of the whooping crane; it contains thousands of water bodies including lakes, bogs, marshes, shallow ponds and streams.Reference 20

Ecozone+ wetlands and ponds are formed and maintained by low evapo-tranpiration rates and permafrost conditions as well as by the physical depressions left by glaciations, and thus are vulnerable to environmental shifts. While there are indications of changes in ponds in the Taiga Plains due to warming and thawing permafrost (discussed below), no widespread reduction in pond area has been observed in the ecozone+. Rising temperatures causing increased evapo-transpiration and changing permafrost have led to a regional trend of shrinking ponds in Alaskan boreal forestsReference 40 and there has been some reduction of total pond area in the Old Crow Flats in northern Yukon (Taiga Cordillera ecozone+).Reference 41 As wetlands dry out and fire frequency increases due to global warming, wetland plant species composition could change dramatically because of deep burning into the organic layers.Reference 42

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Deltas and river-associated lakes and wetlands

The extensive Mackenzie River Delta (13,000 km2),Reference 43 with its 45,000 lakes, is partly in the forest and shrub zones of the Taiga Plains ecozone+ and partly across the tundra of the Arctic ecozone+. It is a productive aquatic ecosystem, unusually so for its latitude.Reference 44 Its high productivity is considered to be related to both the longer ice-free season of floodplain lakes (compared with nearby lakes) and their replenishment from the nutrient-rich river sediments.Reference 44 Many of the lakes of the Mackenzie Delta and throughout the continuous permafrost zone are thermokarst wetlands, formed in depressions on top of permafrost.

There are also two major freshwater deltas in the ecozone+: the Slave (the mouth of the Slave River, flowing into Great Slave Lake), and Mills Lake (a widening of the Mackenzie River at the mouth of the Horn River, near Fort Providence). The Slave River Delta, covering an area of 554 km2,Reference 45 is a stopover in spring and fall for birds on all four major continental flyways.Reference 45, Reference 46 Mills Lake (381 km2), is a major staging area for waterfowl during spring and fall migrations, a refuge for moulting diving ducks in summerReference 45 and a grazing area for wood bison.Reference 47

Flood regime

Periodic flooding associated with spring discharge and ice events creates and maintains the diversity of habitat provided by the lakes and wetlands of the Slave and Mackenzie river deltas.Reference 48Reference 49Reference 50Reference 51 A study of lakes and ponds in the Slave River Delta (2003 to 2005) indicated that the degree and frequency of river flooding is the dominant factor controlling water chemistry and plant and diatom plankton communities and biomass in each body of water.Reference 52

The Slave River is influenced by flow regulation from the W.A.C. Bennett dam and associated reservoir (see Lakes and rivers key finding). A study that reconstructed the frequency of spring break-up flood periods over 80 yearsReference 48 showed that floods have tended to be cyclical, alternating through periods of about a decade each of high and low flooding (Figure 9). Spring floods appear to be more related to climate-driven conditions in the upper reaches of the Mackenzie River Basin than to water regulation by the W.A.C. Bennett dam (which started in 1968). Periods of low flooding preceded flow regulation and periods of high flooding followed the onset of flow regulation. The authors predicted that floods will become less frequent with lowered snow pack and thus less headwater runoff resulting from climate change. There are indications that this trend to reduced spring flooding may have begun in this and other parts of the watershed.Reference 48

Figure 9. Flood events in the Slave River Delta, 1925-2005

Flood events are reconstructed from proxy data, as indicated (columns a through c) and from measured discharge (column d). Shaded boxes show periods of high flood frequency inferred from each proxy and the horizontal boxes outlined in dashed lines indicate the main periods of high flooding.

Graph
Source: Brock et al., 2010Reference 48. Used with permission of Canadian Water Resources Journal
Long description for Figure 9

This panelled graph presents three key geochemical and biological parameters that are related to flood frequency, measured in a sediment core in the Slave River Delta, 1925-2005. Discharge data on the Slave River is shown from 1960 to 2005, and was influenced by the completion of the W.A.C. Bennett dam in BC in 1968. Panel a) shows the carbon-to-nitrogen (C/N) ratios measured in the sediment core from 1925-2005; floodwater is associated with high C/N ratios and the high levels measured in the early and late 1970s and around 1995 correspond with high levels of discharge measured in the Slave River. Similarly, the diatom-based flood index, which assesses the relative abundance of diatoms know to be flood indicator species, corresponds roughly to high discharge periods; lower discharge periods have a substantially different index value. Panel c) shows data on the number of seeds of an aquatic plant (Sagittaria cuneata) that corresponds to a period of very low discharges in the 1950s. The sediment core data (C/N ratio and diatom index) suggests that a flooding event occurred in the early 1940s.

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Permafrost degradation

Changes in spring melt and break up are also leading to changes in water quality due to increased erosion from permafrost slumping.Reference 46, Reference 53

Melting and slumping permafrost erodes and alters the physical configuration of wetlands as well as the water quality and shoreline and lake bottom characteristics.Reference 19 An analysis of aerial photographs at 23 study sites in the Mackenzie DeltaReference 54 showed an increase in thaw-slump activity from 1950 through 2004 (Figure 10). Retrogressive thaw slumping is a slope failure caused by thawing of ground ice and slumping of thawed soil, forming headwalls.Reference 55

Figure 10. Increase in retrogressive thaw slumps, Mackenzie Delta, 1973-2004 compared with 1950-1973
  • Average annual rates of slump growth (based on changes in area of disturbance from thaw slumping)
  • Average annual rates of headwall retreat

Error bars are +/- SE.

Graph
Source: Lantz and Kokelj, 2008Reference 54. Reproduced with permission of John Wiley & Sons, Inc.
Long description for Figure 10

These two bar graphs present data documenting an increase in retrogressive thaw slumps in the Mackenzie Delta during two time periods: 1950-1973 and 1973-2004. Increased retrogressive thaw slumping, measured by increases in slump area and slump headwall retreat, indicates increasing thawing of permafrost. Graph A shows a significant increase in slump growth (m2/year) in the 1973-2004 time period compared to 1950-1973. Slump headwall retreat (m/year) in graph B is on average twice that of the preceding time period, at just over 1 m/year between 1973 and 2004.

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Impacts of changes in the deltas on biodiversity

Permafrost degradation was the main environmental factor explaining differences in water quality in a study of 73 lakes, about half of which were affected by retrogressive thaw slumping, in the Mackenzie Delta (both in the tundra region, Arctic Ecozone+, and in the region along the boundary with the Taiga Plains Ecozone+).Reference 53 The effect was mainly on water clarity and the concentration of ions, rather than on total organic carbon. The affected aspects of water quality are strong determinants of lake biotic communities. The authors concluded that the abrupt changes in lake chemistry brought about by thaw slumping can be expected to lead to abrupt shifts in aquatic food webs.

The wide ranges in extent of and in periods of connectivity between Slave and Mackenzie delta lakes and rivers are important in creating a diversity of habitats, which are then able to support many different communities of species of invertebrates, water birds, fish, and mammals.Reference 46, Reference 50 Changes in river flow (reduced flooding) combined with the rise in sea level associated with climate change may result in fewer types of wetlands, with a lowering of habitat diversity in the Mackenzie Delta.Reference 50

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Key finding 4
Lakes and rivers

Theme Biomes

National key finding
Trends over the past 40 years influencing biodiversity in lakes and rivers include seasonal changes in magnitude of stream flows, increases in river and lake temperatures, decreases in lake levels, and habitat loss and fragmentation.

Ecozone+ key finding: The most widespread hydrological change is a trend to increased minimum and winter flows, both in the Mackenzie River as a whole (including tributaries upstream of the Taiga Plains) and in several smaller rivers monitored within the ecozone+. While upstream tributaries to the Mackenzie River are generally exhibiting trends to earlier peak flows, there is no clear trend in timing at most sites on smaller watercourses within the ecozone+. There are indications of a trend to increased streamflow variability within the ecozone+, with implications for riparian habitat.

The Taiga Plains Ecozone+ drains to the Arctic Ocean through the Mackenzie River catchment area. As Canada’s largest river basin (draining 20% of the nation’s area),Reference 56 the Mackenzie River drains a total area of 1,787,000 km2. The Mackenzie River Basin (Figure 11 ) includes a number of other important river systems, including the Athabasca, Peace, Liard, Slave, Arctic Red, and Peel rivers.Reference 57, Reference 58 The extensive Mackenzie River Delta is partly within the Taiga Plains Ecozone+ and partly within the Arctic Ecozone+. The Mackenzie basin has three major lakes: Lake Athabasca (along the Taiga Shield/Boreal Shield ecozones+ boundary), Great Slave Lake (partially within the Taiga Plains Ecozone+ and partially within the Taiga Shield Ecozone+), and Great Bear Lake, which is fully within the Taiga Plains Ecozone+. There are two major freshwater deltas: the Peace-Athabasca (flowing into Lake Athabasca, in the Boreal Shield Ecozone+) and the Slave (flowing into Great Slave Lake, within this ecozone+). Within the Taiga Plains Ecozone+ the Horn River also forms a delta at its confluence with the Mackenzie River. Lakes and wetlands of the Mackenzie and Slave deltas are discussed in the Wetlands key finding, above. Changes related to lake and river ice are discussed in the Ice across biomes key finding, below.

Figure 11. Sub-basins of the Mackenzie River Basin

Sub-basins: 1. Athabasca; 2. Peace; 3. Liard; 4. Peel; 5. Great Slave; 6. Mackenzie-Great Bear

Map
Source: Mackenzie River Basin Board, 2004Reference 59. Reproduced with the permission of the Mackenzie River Basin Board.
Long description for Figure 11

This map shows the six sub-basins of the Mackenzie River basin: the majority of the Taiga Plains ecozone+ falls within the four more northern sub-basins: the Liard, Peel, Great Slave, and Mackenzie-Great Bear. The remainder falls within the two southern sub-basins: the Athabasca and Peace.

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Trends in hydrology for the Mackenzie River

The total annual discharge from the Mackenzie River did not change from 1968 to 1999, despite significantly increased air temperatures in the river basin over this period.Reference 60 However, changes in timing and seasonal distribution of river discharge have occurred, with the strongest single effect of climate change being the trend to earlier peak flows at different locations throughout the basin, correlated with increasing spring temperatures.Reference 19 Trends towards an earlier onset of spring freshet were detected in analyses of the Mackenzie River and its main tributariesReference 61-Reference 63 and were shown to be correlated with increases in air temperatureReference 62 and with climate oscillations.Reference 61 Figure 12 shows this trend for the Liard River, measured at Upper Crossing, Yukon, upstream of the Taiga Plains Ecozone+.

Figure 12. Trend to earlier spring freshet date in the Liard River at Upper Crossing, upstream of the Taiga Plains Ecozone+, 1961-2005
Graph
Source: Burn, 2008.Reference 61 Reprinted with permission from Elsevier
Long description for Figure 12

This line graph presents the spring freshet date from 1961-2005 in the Liard River at Upper crossing, a water quality monitoring station upstream of the Taiga Plains Ecozone+. Trend lines from 35, 40 and 45 years of data are similar and indicate a consistent trend towards  an earlier spring freshet date, though the observed values for freshet data are variable from year to year.

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Analyses of hydrometric data at the river basin scale demonstrate a widespread trend to increased minimum and winter flows: in the Liard, 1960-1999,Reference 62 and in the Mackenzie, Liard, Athabasca, Peace, Slave, and Peel rivers, 1960-2000.Reference 63 The increased winter flows in the Liard River (1960-1999) have been attributed in part to the Pacific Decadal Oscillation.Reference 62 Increased winter flows have also been linked to thawing of permafrost from climate change.Reference 19

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Trends in hydrology within the ecozone+

Indicators of hydrological alteration

This section is based on Canada-wide analyses performed by Monk and Baird, 2011Reference 15 for the 2010 Ecosystem Status and Trends Report. Gauging sites that form the Reference Hydrological Basin Network (RHBN) that provides Canada’s contribution to the World Meteorological Organization monitoring program for climate changeReference 64 were examined for trends across a range of hydrological characteristics. Variables were calculated for 172 hydrometric sites across Canada for each hydrological year (1970 to 2005). The variables calculated are “indicators of hydrological alteration” which quantify aspects of streamflow of ecological significance.Reference 65 There was high variability in the results across the country. A main conclusion drawn by the authors was that the shortage of long-term continuous hydrometric records in Canada (particularly in the northern ecozones+) severely limits our ability to monitor current trends and project future trends in hydrological regimes. Many sites have been discontinued and the majority of sites in the national database have fewer than 18 years of data.

Eleven gauging sites with suitable data for this analysis were available for the Taiga Plains Ecozone+. Statistically significant trends in indicators of hydrological alteration at these sites are summarized in Figure 13 . Trends in monthly flows varied, with significant increasing trends during winter months at several sites. Six sites showed statistically significant increases in various measures of minimum runoff (which occurs during winter); five sites had significant increases in baseflow (the seven-day minimum flow divided by the mean annual flow). There were few significant changes in peak flows or in timing of maximum and minimum flows.

The increases in baseflow indicate that a greater component of streamflow is being supplied through groundwater at several of the sites; this is likely to be related to the increased degradation of permafrost throughout the region. One of the most profound projected consequences of permafrost thaw is a transition from surface-water-dominated rivers to groundwater-dominated rivers.Reference 66 Changes in water quality accompany an increase in baseflow, including increases in major ions from the more mineral-rich groundwater – though the overall impacts on nutrient levels and many other water characteristics remain uncertain.Reference 66

Nine sites had significant increasing trends in the number of hydrologic reversals (changes in the direction of the trend in streamflow), suggesting increased variability in runoff (Figure 13). This trend was also seen in many of the sites in neighbouring ecozones+. Ecological impacts of increased variability include: stranding of species in isolated habitat patches (falling levels); entrapment on islands and floodplains (rising levels); and drought and desiccation stress to stream-edge organisms,Reference 65, Reference 67 with the net effect of changes in riparian communities.

Figure 13. Number of sites displaying significant increasing and decreasing trends in indicators of hydrological alteration for the Taiga Plains Ecozone+

Trends shown are significant at the p<0.1 level. Parameters listed on the vertical axis refer to river discharge except: date min/max (decreasing date means earlier and increasing date means later for minimum and maximum annual discharge), low/high pulse # (number of discharge pulses), fall/rise rate (rate of change in discharge), and reversals (number of reversals)

Graph
Source: Monk and Baird, 2011Reference 15
Long description for Figure 13

This bar graph shows the number of sites displaying significant (p<0.1) increasing or decreasing trends in indicators of hydrological change in the Taiga Plains Ecozone+. Bars to the left of the centre line indicate sites with a decrease in that indicator and bars to the right indicate the number of sites with a significant increase. Most indicators show a trend of increase at more sites, including higher river discharge from November to April, and increased river discharge minimums, later maximum discharge and a higher number of reversals. Most parameters showed significant decrease in two sites or less, though low pulse duration and the rise rate of river discharge decreased in multiple sites.

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Trends through the seasons at two hydrometric sites

This section is based on Canada-wide analyses performed by Cannon et al., 2011Reference 14 for the 2010 Ecosystem Status and Trends Report. Trends in hydrology over the course of the seasons (at five-day intervals) and the relationship to trends in climate were examined for Canada’s ecozones+. Analyses were based on climate and hydrology data from Environment Canada’s monitoring networks from 1961-2003 (thus using different subsets of the same data as the above analysis of indicators of hydrological alteration).

Only two sites in the Taiga Plains Ecozone+ had data records that met the study requirements for the period 1961-2003: 1) Hay River, where it drains northeast into Great Slave Lake in the NWT; and, 2) Muskwa River near Fort Nelson in BC, a main tributary of the Fort Nelson River, which in turn drains to the Liard River. With only two points for analysis, the results cannot be interpreted to apply to the entire ecozone+, but instead highlight the hydrologic and climatic changes at these two locations.

Both Hay River and Muskwa River are streams driven by snowmelt processes, but they differ in their annual discharge patterns. Hay River has a distinctively sharp streamflow peak during freshet, whereas the Muskwa River exhibits a broad summer freshet with higher flows lasting for several months. The shifts in climate variables for these rivers were similar, but the hydrologic responses differed due differences in snowmelt processes between the two streams.

Hay River

At the Hay River site, temperature increases were seen over the entire year except during the fall. Summer temperatures remained relatively unchanged, whereas winter and spring temperatures showed increases of up to 3°C, comparing the periods 1961-1982 and 1983-2003. The highest monthly precipitation occurred in July, when a 30% increase occurred between the two periods. Precipitation decreased before and increased marginally after the summer peak, except during December. The hydrograph (Figure 14) shows that the spring freshet occurs between April and May. The magnitude of this peak flow did not change much (comparing averages over 1961-1982 and 1983-2003). The timing of the peak, however, shifted to slightly earlier. The higher summer and fall flows were likely the result of greater precipitation. Winter flows increased between the two time periods, attributed to warmer winters enhancing snowmelt. Monk and Baird, 2011Reference 15 considered permafrost degradation to be a probable cause of the increase in winter discharge observed at the majority of Taiga Plain sites.

Figure 14. Changes in streamflow over the seasons, Hay River, comparing 1961-1982 and 1983-2003.

Measurements are from hydrometric station 07OB001.

Insert text here
Source: Cannon et al., 2011Reference 14
Long description for Figure 14

A line graph comparing streamflow in the Hay River shows that streamflow in the fall and winter was higher in 1983-2003 than 1961-1982. The spring freshet occuring in April shows the same discharge rate in both time periods; increase discharge in the later period starts in mid-summer.

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Muskwa River

Between the periods 1961-1982 and 1983-2003, the only streamflow shift at Muskwa River was an additional 20-25 m3/s of discharge occurring from November to the end of March (Figure 15). This was likely related to the much warmer average winter air temperature in the second time period. Precipitation decreased at this site in winter and increased in the remaining seasons, especially during the July streamflow peak. There was, however, no clear relationship between these observed precipitation changes and the changes in streamflow.

Figure 15. Changes in streamflow over the seasons, Muskwa River, comparing 1961-1982 and 1983-2003

Measurements are from hydrometric station 10CD001.

Graph
Source: Cannon et al., 2011Reference 14
Long description for Figure 15

A line graph comparing streamflow in the Muskwa River shows little difference in streamflow between 1983-2003 and 1961-1982. Winter streamflow was higher in the more recent time period (1983-2003), from December to March. Streamflow in the Muskwa River peaks in June and July, but is high from April through September.

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Key finding 7
Ice across biomes

Theme Biomes

National key finding
Declining extent and thickness of sea ice, warming and thawing of permafrost, accelerating loss of glacier mass, and shortening of lake-ice seasons are detected across Canada’s biomes. Impacts, apparent now in some areas and likely to spread, include effects on species and food webs.

Ecozone+ key finding: Changes in permafrost, well documented for this ecozone+, include: increased temperatures of permafrost, changes in active layer depth, reduction of the continuous permafrost zone, and thawing of discontinuous permafrost in some areas. This has resulted in landscape changes, including loss of frozen peat plateaus. River ice within the Mackenzie Basin shows trends to earlier break-up; datasets are poor for both river and lake ice within the ecozone+.

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Permafrost

The forested peatlands that characterize much of the Taiga Plains are underlain by varying degrees of permafrost (Figure 16) and are vulnerable to climate warming.Reference 68 Both loss and warming of permafrost are occurring. One result has been a shrinking of the zone of continuous permafrost. A study that repeated, in 1988 to 1989, a 1964 permafrost survey along the Mackenzie Highway from Hay River south to Alberta showed that the northern fringe of discontinuous permafrost had migrated northward by about 120 km in 26 years.Reference 69

Figure 16. Permafrost zones of the Taiga Plains.
Map
Source: Smith, 201112 based on Heginbottom et al., 1995Reference 70
Long description for Figure 16

This map shows the distribution of permafrost zones in the Taiga Plains Ecozone+. The southern part of the ecozone+ in BC, Alberta and southern NWT is classified as sporadic permafrost. The middle of the ecozone, from north of Great Slave late to the top of Great Bear Lake is covered by extensive discontinuous permafrost. The northernmost portion is largely continuous permafrost, with the exception of the Mackenzie River Delta, which has extensive discontinuous permafrost.

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A permafrost monitoring network in the Mackenzie Valley provides records of permafrost temperature in the upper 20 to 30 m. This monitoring network is supplemented with results from research on permafrost and on changes in frozen peatlands. Trends, from south to north are:

  • Frozen peatlands are decreasing in parts of the southern Mackenzie Valley, with an average loss of frozen peatland area of 22% at four study sites over the latter half of the 20th century.Reference 71
  • Permafrost temperatures monitored at other sites in the south-central part of the valley, however, show little change (Fort Simpson and Northern Alberta in Figure 17). At these sites, permafrost is likely being preserved by an insulating layer of peat.Reference 72, Reference 73
  • Permafrost temperatures are increasing in the central Mackenzie Valley (shown for Norman Wells and Wrigley in Figure 17), where permafrost is both thicker (up to 50 m deep) and colder.Reference 74, Reference 75
  • Similar rates of permafrost temperature increase, 0.1 to 0.2°C per decade at a depth of 15 m, have occurred since the 1960s in the colder permafrost (-2 to -3°C) at spruce-forested sites in the Mackenzie Delta in the north of the ecozone+.Reference 76, Reference 77
Figure 17. Ground temperatures in the central Mackenzie Valley, 1984-2007

Measurements are at depths near 10 m. Note that the frequency of measurements was reduced in the mid-1990s at the two most southern sites.

Graph
Source: adapted from Smith et al., 2010Reference 78
Long description for Figure 17

This line graph depicts the following information:

Ground temperatures in the central Mackenzie Valley, 1984-2007.
Fort Simpson (10m)

Date
Fort Simpson (10m)

Temperature °C
Northern Alberta (10m)

Date
Northern Alberta (10m)

Temperature °C
Wrigley (12m)

Date
Wrigley (12m)

Temperature °C
Norman Wells (10m)

Date
Norman Wells (10m)

Temperature °C
17/07/1985-0.1519/06/1987-0.1516/07/1985-0.8421/09/1984-1.55
13/01/1986-0.1618/01/1988-0.2315/01/1986-0.8326/01/1985-1.61
15/07/1986-0.1507/07/1988-0.1717/07/1986-0.9015/07/1985-1.57
20/01/1987-0.1720/01/1989-0.2516/01/1987-0.8514/01/1986-1.61
09/07/1987-0.1615/07/1989-0.2212/07/1987-0.8518/07/1986-1.54
20/01/1988-0.1723/03/1990-0.1618/01/1988-0.9508/02/1987-1.58
06/07/1988-0.1631/07/1990-0.2108/07/1988-0.8413/07/1987-1.53
24/01/1989-0.1715/01/1991-0.2124/01/1989-0.8612/01/1988-1.57
29/06/1989-0.1515/07/1991-0.2015/07/1989-0.8709/07/1988-1.51
30/07/1990-0.1515/01/1992-0.2015/01/1990-0.8702/02/1989-1.51
30/01/1991-0.1515/07/1992-0.1715/07/1990-0.8822/08/1989-1.46
29/07/1991-0.1515/01/1993-0.1728/01/1991-0.8420/02/1990-1.42
30/07/1992-0.1615/07/1993-0.1630/07/1991-0.8214/06/1990-1.36
06/09/1994-0.1615/01/1994-0.1927/01/1992-0.8222/01/1991-1.35
17/09/1995-0.1505/09/1994-0.1615/07/1992-0.8631/07/1991-1.31
13/09/1996-0.1415/01/1995-0.1725/01/1993-0.8205/02/1992-1.31
25/09/1997-0.1416/09/1995-0.1528/07/1993-0.8217/06/1992-1.27
05/10/1998-0.1412/09/1996-0.1626/01/1994-0.8102/02/1993-1.30
05/10/1999-0.1323/09/1997-0.1615/07/1994-0.8326/07/1993-1.27
03/10/2000-0.1305/10/1998-0.1515/01/1995-0.8225/01/1994-1.26
27/09/2001-0.1304/10/1999-0.1915/07/1995-0.8230/03/1995-1.25
24/09/2002-0.1302/10/2000-0.1916/01/1996-0.7824/06/1995-1.24
28/09/2003-0.1226/09/2001-0.1916/07/1996-0.7816/01/1996-1.23
28/09/2005-0.1223/09/2002-0.1916/01/1997-0.7827/06/1996-1.24
24/09/2006-0.1227/09/2003-0.1916/07/1997-0.7816/01/1997-1.23
27/09/2007-0.13--16/01/1998-0.7816/06/1997-1.23
----16/07/1998-0.7816/01/1998-1.27
----16/01/1999-0.7616/07/1998-1.23
----16/07/1999-0.7516/01/1999-1.23
----16/01/2000-0.7503/07/1999-1.22
----16/09/2000-0.6903/03/2000-1.21
----16/01/2001-0.7716/07/2000-1.18
----25/06/2001-0.7716/01/2001-1.19
----16/01/2002-0.7516/07/2001-1.16
----16/07/2002-0.7416/01/2002-1.23
----16/01/2003-0.7516/07/2002-1.16
----16/07/2003-0.6616/01/2003-1.12
----16/01/2004-0.6316/07/2003-1.12
----16/07/2004-0.6716/01/2004-1.16
----26/09/2005-0.7216/07/2004-1.19
----16/01/2006-0.7124/09/2005-1.19
----16/07/2006-0.6716/01/2006-1.16
----01/01/2007-0.6616/07/2006-1.16
----01/07/2007-0.6301/01/2007-1.14
------01/07/2007-1.12

At sites further north (Wrigley and Norman Wells), ground temperatures have gradually increased over recent decades: an increase of 0.1°C per decade at Wrigley  and a 0.3°C increase per decade at the Norman Wells site.

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While these changes are consistent with trends in air temperature over the past few decades, changes in snow coverReference 79, Reference 80 and in wildfiresReference 81 are also affecting rates and locations of warming and thawing of permafrost. Fires may trigger a long-term process of permafrost decay,Reference 82 though in sphagnum-moss-dominated peatlands fires are infrequentReference 73 and in other peatlands fires rarely burn deeply enough to have lasting effects on permafrost.83 The distribution of peatlands, fire, and extent of snow cover are interrelated, leading to locally diverse permafrost dynamics.Reference 84

Degradation of permafrost leads to major impacts on landscapes with, for example, loss of frozen peat plateaus. A study of peatlands in the southern Taiga Shield concluded that peat plateaus in what is currently the discontinuous permafrost zone are unlikely to be sustained under a warming climate and that the landscape-level effects of this loss need further investigation.Reference 85

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River and lake ice

Across Canada, lake ice break-up times show consistent trends to earlier dates, while freeze-up dates show fewer trends.Reference 86 Little data, however are available for lake sites within the Taiga Plains Ecozone+. In an analysis that used records from both in situ measurements and remote sensing observations, large lakes in Canada showed an overall trend toward earlier break-up of ice and later freeze-up over the period 1970 to 2004.Reference 87 Three sites in the Taiga Plains Ecozone+ were included in this analysis. Freeze-up was significantly later at two of the sites. There were no significant trends in ice break-up.

Seventeen river sites within the Mackenzie River Basin showed evidence of ice break-up occurring earlier over the period from 1970 to 2002, at a rate of approximately one day earlier per decade in the upstream basin.Reference 88 This analysis was based on hydrological events that correspond with ice break-up.

Spring thaw was measured in situ at sites in the Mackenzie River at Fort Simpson until the late 1980s when the monitoring program was discontinued (Figure 18 A). The mean thaw date moved forward by about a month from 1932 to 1988, with the date of thaw accounting for about 60% of the variability. As the spring thaw date is strongly related to April temperatures, and as April temperatures have continued to increase (Figure 18 B), it is probable that this trend has continued since 1988.Reference 19 The same degree of change has not occurred in the fall, with fall temperatures at Fort Simpson showing no significant trends.Reference 19

Figure 18. (A) Estimated Mackenzie River melt date, 1932 to 1988; and (B) five-year running average of April air temperatures, 1900 to 2005, Fort Simpson
Graph
Source: Mackenzie River Basin Board, 2010,Reference 19 based on Environment Canada data
Long description for Figure 18

These scatter plots show the estimated Mackenzie River melt date between 1932 and 1988 and five- year running average of April temperatures in Fort Simpson between 1900 and 2005. The Mackenzie River melt date (graph A) shows a significant trend towards earlier melt dates by almost a month. The five-year running average in April temperatures shows a significant increase in the last century, increasing from -4°C to approximately -1°C (graph B).

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Theme: Human/Ecosystem Interactions

Key finding 8
Protected areas

Theme Human/ecosystem interactions

National key finding
Both the extent and representativeness of the protected areas network have increased in recent years. In many places, the area protected is well above the United Nations 10% target. It is below the target in highly developed areas and the oceans.

Ecozone+ key finding: In 2009, 5.6% of the ecozone+ had a high level of protection, by far the largest protected area being Wood Buffalo National Park, established in 1922. There was little change in protected areas from 1922 to the early 2000s when several, mainly quite small, protected areas were established. Candidate protected areas have been identified for the Mackenzie Valley in response to the proposed pipeline development. The aim is to maintain ecological integrity by permanently protecting areas of relatively undisturbed and important wildlife habitat which would be managed as a network to provide as much connectivity between them as possible.

Protected areas in northern Canada are planned and managed to safeguard culturally important areas and maintain biodiversity and ecological processes.Reference 89 In the Taiga Plains Ecozone+, there was little change in protected area coverage from 1922 to the early 2000s. Settlement of some land claims in the ecozone+ and growing awareness of the need for protected areas in the face of oil and gas development led to protected areas studies and plans in the Northwest Territories (NWT) part of the ecozone+,Reference 90, Reference 91 with new protected areas being established starting in the early 2000s. Protected areas in BC and Alberta portions of the ecozone+, with the exception of Wood Buffalo National Park, are small. An example is Hay River Protected Area, a 23 km2 BC park (shown in the northeast corner of BC in Figure 19) that protects black spruce muskeg and wetlands of cultural significance to First Nations in the Fort Nelson region.

The approach in protected area planning in northern Canada in recent years is to focus on ecological integrity, designing protected areas to meet the needs of sensitive species and to maintain ecological processes.Reference 89 Along the Mackenzie Valley, this involves connecting wildlife corridors to establish a network of protected areas.Reference 91 This is partly accomplished with buffer zones, areas managed to serve as transition zones between core protected areas and lands or waters subject to development.Reference 92, Reference 93

Status

Overall, in 2009, 5.6% of the ecozone+ was protected through 28 protected areas of IUCN categories I-III, by far the largest protected area being Wood Buffalo National Park, established in 1922 (Figure 19 and Figure 20). The second largest is Caribou Mountains Wildland Park, an Alberta wilderness area established in 2001 adjacent to Wood Buffalo Park. IUCN categories I-III include nature reserves, national wildlife areas, wilderness areas, and other parks and reserves managed for conservation of ecosystems and natural and cultural features.Reference 94 In addition, 22 km2 of the ecozone+ (<0.01%) was protected through three category V and VI protected areas, categories that focus on sustainable use by established cultural tradition within the protected area.Reference 94 Eighteen protected areas not classified by IUCN category protect a further 1.4% of the ecozone+. The most recent of these were Sahyoue and Edacho protected areas, established in 2009.

Figure 19. Map of protected areas in the Taiga Plains Ecozone+
Map
Source: Environment Canada, 2009;Reference 95 data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009Reference 96
Long description for Figure 19

This map shows the locations of protected areas in the Taiga Plains Ecozone+.  The large protected area in the southeast corner of the ecozone+ is Wood Buffalo National Park, which extends outside of the ecozone+ into Alberta. Other large protected areas include Edéhzíe and Saoyue and Edacho in the central part of the ecozone+ and the Gwich'in Land Use Plan Conservation Heritage/Conservation Zone in the north.  A number of smaller conservation areas are scattered through the southwest corner of the ecozone+.

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Figure 20. Growth of protected areas, Taiga Plains Ecozone+, 1922-2009

Data provided by federal, territorial and provincial jurisdictions, updated to May 2009. Only legally protected areas are included. IUCN (International Union for Conservation of Nature) categories of protected areas are based on primary management objectives (see text for more information). Names and establishment dates of the larger protected areas are shown. Note: the yellow “unclassified" category represents protected areas for which the IUCN category was not provided.

Graph
Source: Environment Canada, 2009;Reference 95 data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009Reference 96
Long description for Figure 20

This bar graph shows the following information:

Growth of protected areas, Taiga Plains Ecozone+, 1922-2009.
Year Protection EstablishedCumulative area protected (km2)
IUCN Categories I-III
Unclassified
1922-197223,9370
1973-197423,9400
197523,9410
1976-198223,9420
1983-198523,9480
1986-199324,1810
1994-199524,4530
1996-199824,5720
1999-200025,4060
2001-200232,1830
2003-200432,1832,763
2005-200833,5582,763
200933,5588,263

The graph makes note of the creation of national parks which are responsible for most of the increases from 1922 to 2009. Wood Buffalo National Park was established in 1922, Caribou Mountains Wildland in 2001, Travailant Lake and Mackenzie/Tree River in 2003, Edéhzhíe in 2005 and Sahyoue and Edacho in 2009.

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Cultural and wildlife values are represented in the protected areas in the Taiga Plains that are proposed through the NWT Protected Areas Strategy. Areas were identified under a five-year plan for the Mackenzie Valley to accelerate selection of areas in the face of the proposed Mackenzie Gas Pipeline.Reference 90 Protected areas are also proposed to address specific biodiversity conservation concerns. For example, the conservation zone by Great Bear Lake (Edaį́į́la) that is included in the proposed Sahtu Land Use Plan is intended to protect parts of the summer, fall, and winter ranges for the Bluenose-East Caribou Herd,Reference 97 while Edéhzhíe is intended to protect important migratory bird habitat.Reference 91

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Key finding 9
Stewardship

Theme Human/ecosystem interactions

National key finding
Stewardship activity in Canada is increasing, both in number and types of initiatives and in participation rates. The overall effectiveness of these activities in conserving and improving biodiversity and ecosystem health has not been fully assessed.

Ecozone+ key finding: Stewardship in the ecozone+ is associated with aboriginal cultural and spiritual values, incorporated into land-use planning through, for example, community conservation plans. Public-private sector partnerships and national and international initiatives also contribute to stewardship of ecosystems.

Planning, co-management, and Traditional Knowledge

Stewardship in the Taiga Plains involves aboriginal people who are committed to stewardship through their cultural and spiritual values. These values are reflected in land-use planning which involves community-based development of conservation plans. Land-use planning in the Mackenzie Valley involves four settled land claims (Inuvialuit, Gwich’in, Sahtu, and Tlicho) as well as the Deh Cho Interim Measures Agreement. The Mackenzie Valley Resource Management Act (MVRMA) applies to the Gwich’in, the Sahtu Dene, and the Métis, but does not apply to the Inuvialuit Settlement Region. The MVRMA sets the framework for land-use planning through regional and valley-wide land and water boards.

An important feature of stewardship in the Taiga Plains Ecozone+ is the incorporation of Aboriginal Traditional Knowledge (ATK) into co-management and regulatory boards (for example, Gwich’in Renewable Resources Board, 2012Reference 98), into environmental assessments (for example, Mackenzie River Basin Board, 2010Reference 19), and into research and monitoring (for example, Eamer, 2006Reference 99 and Woo et al., 2007Reference 100). Much effort has gone into developing ways to incorporate ATK into decision making in the Taiga Plains (for example, Mackenzie Valley Environmental Impact Review Board, 2005Reference 101). An assessment of effectiveness of the use of ATK by the Mackenzie Valley Environmental Impact Review Board concluded that, while substantial and sincere efforts had been made in incorporating ATK into their practices, the board was limited in its capacity to fully incorporate it by the need to deal with complex regulatory issues.Reference 102

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Public-private sector partnerships

Stewardship initiatives are also undertaken through public-private sector partnerships. Ducks Unlimited, an international non-profit organization, recognizing the importance of the western boreal forest to waterfowl, started a stewardship program in the late 1990s aimed at wetland conservation.Reference 103 The program includes collection of baseline information on waterfowl habitat, including surveys of waterfowl, habitat mapping, and water quality analyses, as well as research to fill knowledge gaps. The information acquired is used in helping to set conservation priorities, through land-use management and practices and through development of protected areas, with the aim of establishing interconnected areas of wetlands. The project includes, where relevant, working with industry to develop industrial practices that conserve waterfowl habitat.Reference 103

There are four Ducks Unlimited boreal forest wetlands initiatives in the Taiga Plains, developed through partnerships with the forest industry (in British Columbia), government agencies, First Nations and Inuvialuit management boards and renewable resource councils, universities, and private foundations. Taiga Plains projects (Figure 21) are:

  • Fort Nelson: 35,000 km2; partners include the forest industry and the BC Ministry of Forestry;
  • Sahtu: 32,000 km2; reports completed 2003; partners include Government of NWT and the Sahtu Renewable Resources Board;
  • Middle Mackenzie: 52,000 km2; partners include Gwich’in and Sahtu renewable resource boards and the Government of the NWT; and
  • Lower Mackenzie: 34,000 km2: partners include renewable resource boards and committees for the Inuvialuit and Gwich’in, as well as the Government of the NWT.
Figure 21. Locations of four western boreal forest wetlands projects led by Ducks Unlimited
Map
Source: Ducks Unlimited Canada, 2012Reference 104
Long description for Figure 21

This map shows the locations of four Ducks Unlimited Canada boreal forest wetlands projects located in the Taiga Plains Ecozone+.  The Lower Mackenzie and Upper Mackenzie wetland sites are located in the Mackenzie Delta in northwest of the ecozone+. The Sahtu wetland project is located west of Great Bear Lake, and the Fort Nelson project is located in the southwest corner of the ecozone+, in British Columbia.

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National and international initiatives contributing to stewardship in the Taiga Plains

At the national and international scale, several relevant management and habitat plans exist, especially for birds. They are used as means to identify areas for nomination as protected areas, including Ramsar sites (see the key finding on Wetlands). Wiken et al., 2006Reference 105 estimated that approximately 6% of the 166,487 km2 of wetlands in the Taiga Plains (using the 1995 ecozone classificationReference 5) are protected through National Parks. The North American Waterfowl Management Plan, signed in 1986 and 1993 by the governments of Canada, the United States, and Mexico in response to the loss of wetlands and declines in waterfowl, was updated in 2004 and in 2007Reference 106 to include interim land withdrawals for protected areas in the Mackenzie Valley.

Other responses to declines in birds include voluntary partnerships such as Partners in FlightReference 107 and the North American Bird Conservation InitiativeReference 108 have been started and have drafted management plans to assign conservation priorities and list actions (for example, Partners in Flight physiographic region plans, North American Landbird Conservation Plan, and Framework for Landbird Conservation in Canada). These initiatives have no binding provisions but can be useful in identifying and setting priorities for areas for conservation.

Under the Species At Risk Act, critical habitat has to be defined for Endangered or Threatened Wildlife which, in the Taiga Plains includes boreal woodland caribou. In 2012, critical habitat for boreal caribou was identified in the Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal population, in Canada.Reference 109

Key finding 10
Invasive non-native species

Theme Human/ecosystem interactions

National key finding
Invasive non-native species are a significant stressor on ecosystem functions, processes, and structure in terrestrial, freshwater, and marine environments. This impact is increasing as numbers of invasive non-native species continue to rise and their distributions continue to expand.

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Ecozone+ key finding: There is some incursion of non-native plant species, especially along roadways, in the Taiga Plains, with only a few species being moderately invasive. An invasive non-native forest insect, the larch sawfly, has spread to the ecozone+, with regionally significant outbreaks in the 1990s. Increasing access, development, and climate change are liable to increase the rate of introduction and spread of non-native species in terrestrial and aquatic environments.

Currently invasive non-native species are not a significant threat to biodiversity in the ecozone+. However, this situation could change with the introduction and spread of non-native species from increased development and climate change.Reference 110 Road travel is one of the most important pathways of introduction of non-native species to the ecozone+.Reference 111 Non-native species generally take hold after ecosystems have been disrupted, creating niches that the new species can exploit. Both the means of transport and the disruption to ecosystems are generally needed for invasive species to become established in terrestrial mainland ecosystems. In isolated habitats, such as lakes and islands, a transport mechanism alone may be sufficient. Roads remain uncommon in most parts of the ecozone+, but are likely to increase with proposed development, increasing the risk to the biota of the ecozone+ from invasive non-native species.Reference 111

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Plants

About 10% of plant species in the NWT are not native to the region, a proportion comparable with other northern and western jurisdictions, and only a few of these are moderately invasive.Reference 110 By 2010, 116 non-native plant species had been identified in the NWT, mostly near communities or along linear disturbances, such as roads and cut-lines. Yellow and white sweet clover (Melilotus officinalis and M. alba), which have spread along rivers in Alaska and the Yukon,Reference 112 are found north as far as Inuvik but, at least in the NWT, appear not to have spread beyond communities and roadways.

In BC, the Fort Nelson Invasive Plant Management Area has the lowest incidence of invasive plant species in the province. Non-native species have been identified and categorized by current status or whether they are at risk of entering the region. There are 12 species or groups of closely related species in northeast BC classified as highly competitive with an ability to spread rapidly. These include hawkweeds (Hieracium spp.), hound’s tongue (Cynoglossum officinale), and knapweeds (Centaurea spp.).Reference 113

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Forest pests

A few non-native forest insect pests have been introduced to the Taiga Plains, including the larch sawfly (Pristiphora erichsonil), a European species. First reported in western Canada in the 1930s, larch sawfly spread north to the Fort Nelson area in 1952.Reference 114 It continued its northward spread, attacking tamarack (larch) stands in the southern NWT part of the Taiga Plains since the late 1960s.Reference 115 An outbreak of larch sawfly that damaged tamarack appeared in the South Slave in the mid-1990s and quickly moved westward and northward. The outbreak only lasted one year in the Hay River area but persisted in the Norman Wells area for about seven to eight years, but at lower defoliation levels.Reference 115 An outbreak occurred in northwestern Alberta in 1996 to 1999, defoliating large tracts of tamarack.Reference 114

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Aquatic species

The community structure of a water-body influences the chances of a non-native species establishing itself.Reference 116 The aquatic ecology of the Taiga Plains may be especially vulnerable to invasive species as it has relatively few species. Increasing water temperatures are shifting distributions of some fish species northwards in eastern North America: for example, the smallmouth bass (Micropterus dolomieu), a predatory species that has been shown to change species assemblages and thus alter food webs.Reference 117 Warmer waters in the Taiga Plains will also likely provide conditions that non-native species introduced from south of the ecozone+ will thrive in and will alter distributions of aquatic species, with consequences for food webs.

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Key finding 11
Contaminants

Theme Human/ecosystem interactions

National key finding
Concentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.

Ecozone+ key finding: Some legacy contaminants are declining in fish in the ecozone+ but the trends are not clear or consistent with, for example, DDTs increasing in recent years in Mackenzie River burbot. Brominated flame retardants in fish increased sharply up to the mid-2000s and then dropped, based on limited sampling. Mercury levels are naturally high in the Mackenzie Basin and have increased in fish, including in the Mackenzie River and Great Slave Lake within the ecozone+. Changes in aquatic ecology related to climate change may be either accentuating or masking trends in some contaminants.

Contaminants are substances that are introduced into the environment through human activity. Some, like mercury, are naturally occurring but may be augmented through human activity to levels that could harm ecosystems and humans. Contaminants can harm species and ecosystems and impair ecosystem services. They can directly affect animals when present in their diets, for example by impairing reproduction. Contaminants can also become a health risk for humans who rely on animals that accumulate contaminants for food – particularly for aboriginal people with diets heavily reliant on marine mammals and fish.Reference 118 This key finding only covers contaminants that persist in the environment and accumulate in the tissues of plants and animals.

Persistent organic pollutants enter the atmosphere through evaporation or industrial emissions and return to the surface of the Earth after travelling great distances. These contaminants are then deposited through rain or attached to small dust particles, falling on snow, ice, rocks, and vegetation. As the snow melts, it carries the particles and pollutants into aquatic ecosystems.

“Legacy contaminants” are those that have been banned or restricted but are still widespread in the environment. Several persistent organic pollutants, including the pesticide DDT and the industrial chemicals PCBs and HCHs, are considered legacy contaminants.

“Emerging contaminants” are newer chemicals, or substances that have been in use for some time and have recently been detected in the environment – usually emerging contaminants are still in use or only partially regulated. Despite being banned or restricted, some of these substances persist at levels that may impair animal health in some populations of long-lived top predators.Reference 3 Brominated flame retardants, for example PBDEs, are one class of emerging contaminants that have been detected in the environment, even in remote locations, at increasing levels since the mid-1980s. Concentrations of some brominated flame retardants show signs of stabilizing or declining in the last few years in response to new regulation and reductions in their use.118 Other emerging contaminants include some pesticides and herbicides in current use.

Mercury is another contaminant that can accumulate in wildlife. Much of the mercury in marine and freshwater systems is from industrial sources such as coal burning – and mercury releases are increasing in parts of the world.Reference 119 Mercury levels in animals are highly variable and trends are mixed.Reference 118

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Mercury in the Mackenzie River Basin

Mercury in the Mackenzie River Basin has been a focus of study in recent years partly due to increasing concentrations of mercury detected in marine mammals in the Beaufort Sea, as well as detection of relatively high levels of mercury in fish in the northern part of the basin.Reference 120 Sources of mercury to the Mackenzie River were estimated by Carrie et al., 2012Reference 120 as:

  • weathering of sulfide minerals in the mountains in the western part of the river basin (about 78% of the total mercury flux);
  • erosion of coal deposits (about 10%);
  • atmospheric deposition (about 6%); and,
  • mercury bound up in organic matter (about 5%).

All mercury is not equally available to biota, however, and, while relatively small fractions, mercury deposited from the atmosphere and mercury bound up in organic matter may move into the food chain more readily than mercury from other sources.Reference 120 Mercury is magnified through the food chain and levels in predatory fish in many lakes in the basin sometimes exceed Health Canada’s guidelines.Reference 59

Discharge of the Mackenzie River has been increasing over the past 35 years, which will have directly increased the amount of mercury discharged to the Beaufort Sea by a small fraction.Reference 121, Reference 122 As well, the higher water levels erode banks, contributing to higher sediment and mercury loads. An increase in forest fires, one of the predicted impacts from global warming, will likely increase mercury runoff to the Mackenzie River because most of the mercury from atmospheric deposition accumulates in the organic matter in the upper layer of soil which is exposed to erosion following fire.Reference 122

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Trends in mercury and persistent organic pollutants in the Taiga Plains

Mercury increased in lake trout and burbot from both east and west areas of Great Slave Lake from 1992 to 2008 (Figure 22). Legacy contaminants are generally declining in Great Slave Lake fish (represented by HCH levels in Figure 22), though there were no clear trends for PCB concentrations from 1992 to 2007. Changes in lake ecology and fish trophic structure in Great Slave Lake may be either accentuating or masking trends in contaminants. For example, organic contaminants accumulate more in fatty tissues and the lake trout fat levels have decreased in recent years. This reduction in fat levels may be related to changes in the relative numbers of different species in the lake or to other changes in lake ecology.Reference 123

Figure 22. Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008

The East Arm of Great Slave Lake is in the Taiga Shield Ecozone+. The West Basin of the lake is in the Taiga Plains Ecozone+; samples were collected in the Hay River area.

Graphs
Source: based on data from Evans, 2009Reference 123
Long description for Figure 22

These three scatter plots show the following information:

Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. Hg (mercury) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
1993----
1994----
1995-117.50--
1996--82.00-
1997----
1998----
1999108.32143.44108.4883.87
2000-259.90134.82116.30
2001195.90152.84182.13122.04
2002156.60131.46157.40118.07
2003----
2004166.30152.40178.50171.40
2005179.80191.50114.60-
2006206.50160.80158.30-
2007207.00194.45240.40-
2008269.00189.09252.90189.00
Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. ∑PCB (polychlorinated biphenyls) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
199313.8525.0974.52138.44
1994----
1995-20.86--
1996--96.43-
1997----
1998----
199927.5714.41118.2780.37
2000-16.68167.50127.50
200111.0125.63180.45125.90
20023.007.3683.43112.25
2003----
200417.3329.42101.06173.79
200515.2349.8671.69-
200617.3017.6464.05-
20077.4625.63--
2008----
Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. ∑HCH (hexachlor°Cyclohexane) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
19932.022.626.5410.76
1994----
1995-0.96--
1996--7.07-
1997----
1998----
19993.000.755.063.04
2000-0.856.118.12
20011.641.525.847.37
20020.480.582.686.49
2003----
20040.721.181.342.61
20050.210.482.57-
20060.180.261.56-
20070.180.37--
2008----

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Burbot, which tend to accumulate organic contaminants in their large, fatty livers, have been sampled at Fort Good Hope in the Mackenzie River since the 1980s. Burbot livers are a food favoured by First Nations and Inuvialuit in the ecozone+.

Since the 1980s, mercury concentrations have almost doubled in burbot muscle (Figure 23) and have increased somewhat more in livers (not shown). There were no significant correlations between fish age or length and mercury concentrations, so the trends are not related to differences among the samples. Mean concentration over the whole time period was 343 ng/g in muscle and the maximum sample mean was 420 ng/g in 2007, approaching but not exceeding the recommended maximum for mercury in fish for commercial sale of 500 ng/g (more commonly expressed as 0.5 parts per million). Mercury levels in liver were much lower, averaging 86 ng/g. While the legacy contaminant HCH decreased over the sampling period (not shown), DDTs continued to rise, contrary to the general trend in Canada’s North. There was no clear trend for PCBs. PBDEs (brominated flame retardants) increased significantly over the 20-year period, declining in the most recent two years of sampling.

Figure 23. Contaminants in burbot, Mackenzie River at Fort Good Hope

Sample information: muscle tissue for mercury (males); liver tissue for organ°Chlorines (sexes combined, lipid weight); liver for PBDE, sexes combined, wet weight. PBDE congeners analysed for: 47, 99, 100, 153, and 154.

Graphs
Source: based on data from Stern, 2009Reference 124
Long description for Figure 23

These two line graphs show following information:

These two line graphs show following information:Contaminants in burbot, Mackenzie River at Fort Good Hope. Concentration (ng/g)
Yeartotal mercury,
burbot muscle
sum of PCBs,
burbot liver
total DDT,
burbot liver
sum of main PBDE congeners,
burbot liver
1985222---
1986----
1987----
1988-206.0557.340.40
1989----
1990----
1991----
1992----
1993231---
1994-168.861.55-
1995265---
1996----
1997----
1998----
1999286148.8553.581.48
2000345137.552.981.34
2001342138.1927.52-
2002297162.6795.621.57
2003336113.9957.272.60
2004413257.46168.22-
2005301103.4769.121.73
2006389151.22112.75.18
2007420129.2143.952.03
2008410283.38102.710.94
2009----
2010----

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A study of Mackenzie River burbot habitat in the Fort Good Hope vicinityReference 125 concluded that the increasing trends in mercury in burbot may be related to increased productivity in the aquatic environment due to climate change, with contaminants moving more readily into the food web under conditions of higher productivity. This conclusion is supported by the work of Sanei et al., 2012Reference 126 who looked at long-term trends in mercury in sediments in Mackenzie Delta lakes. Their results suggest that increasing phytoplankton productivity can lead to increases in mercury content in lake sediments – meaning that increases in mercury in biota may not be solely a result of increases in atmospheric deposition of mercury.

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Key finding 14
Climate change

Theme Human/ecosystem interactions

National key finding
Rising temperatures across Canada, along with changes in other climatic variables over the past 50 years, have had both direct and indirect impacts on biodiversity in terrestrial, freshwater, and marine systems.

Ecozone+ key finding: The Taiga Plains Ecozone+ has experienced some of the greatest increases in temperature of any Canadian region since 1950 – with the annual mean temperature increasing over 2°C and winter temperatures rising about 5°C at all stations since 1950. This warming has translated into some clear ecosystem trends, such as changes to permafrost landscapes and increases in terrestrial primary productivity. There are indications of other emerging, climate-related trends, such as the northward movement of some forest insect pests.

Trends since 1950

Annual mean temperature has increased about 1.4°C since 1950 over the country as a whole, though the amount of temperature increase differs among ecozones+.Reference 9 The strongest warming has occurred in the west and the northwest of Canada, with an increase in annual mean temperature of over 2°C for the Taiga Plains Ecozone+. When looked at by seasons, the increase occurred only in winter and spring. This warming trend has been accompanied by changes in snow and a lengthening of the growing season.

Results for the Taiga Plains Ecozone+ are summarized in Table 4. The analyses are based on 6 stations for temperature, 10 stations for precipitation, and 4 stations for snow variables. Station distribution is biased (see Figure 24), with more stations in the south; this means that ecozone+ averages should be interpreted with the understanding that they are more representative of what is occurring in the southern part of the ecozone+.

Table 4. Overview of Taiga Plains Ecozone+ climate trends, 1950-2007
Climate VariableTrends 1950-2007
Temperature
  • Significant increases in winter and spring for the ecozone+ as a whole (Figure 25). No significant trends in summer and fall overall, and at only one station in the summer.
  • Strong warming trend especially for the winter season (along with the Boreal Cordillera Ecozone+, the highest in Canada) – with an average increase of 5.2°C (Figure 24).
  • An increase in the length of the growing season by 9 days for the ecozone+ as a whole, but no significant change in the timing of the start or end of growing season.
Precipitation
  • No significant change in precipitation in any season across the ecozone+ as a whole, and few significant changes at individual stations.
Snow cover
  • A significant mean decrease of 11.4 days in snow cover duration (13% of the 1961-1990 average) in the spring half of the snow season (early melt), with no change in snow cover duration during the snow cover onset period, based on data from 4 stations.
  • A significant mean decrease in annual maximum snow depth of 23.6 cm (38% of the 1961-1990 average), based on data from 4 stations.
  • No significant trend in the fraction of annual precipitation falling as snow.

Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors

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Figure 24. Trends in seasonal temperatures at six climate stations, 1950-2007

Trends are based on temperature anomalies, measured as the difference from the base period (1961 to 1990) mean. Triangles are, coloured intense red when the trend is significant at the 5% level. Magnitude of the change (°C) is shown for all significant trends. There are no decreasing trends. Seasons are, spring: March-May; summer: June-August; fall: September-November; winter: December-February.

Maps
Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors
Long description for Figure 24

This set of four maps depicts change in mean annual temperature in each season (°C) between in cities and towns in the Taiga Plains Ecozone+, between 1950 and 2007.  Across the ecozone+, the trend is for a mean increase in temperature in all cities; there were no locations that experienced a trend towards decreasing temperature.  Winter and spring temperatures increased significantly in Normal Wells (+4.58°C; +2.12 °C), Fort Simpson (+4.50°C; +2.33 °C), Hay River (+5.17°C; +2.44 °C), Fort Nelson (+4.57°C; +2.20 °C) and Fort Smith(+5.63°C; +3.26 °C).  Inuvik also experienced an increase of 5.5°C in winter temperatures.

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Figure 25. Average winter temperature trend, 1950-2007

Temperature anomalies, measured as the difference from the base period (1961-1990) mean, are plotted. The data indicate a significant (p < 0.05) increase of 5.2°C from 1950-2007. This analysis is based on data from 6 stations (shown in Figure 24).

Graph
Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors
Long description for Figure 25

This line graph shows the following information:

Average winter temperature trend, 1950-2007.
YearMean Winter Temperature Anomaly (°C)
1950-2.51
1951-1.42
1952-2.97
19531.56
1954-0.78
19550.06
1956-2.86
1957-0.10
1958-0.68
1959-0.81
19601.84
19611.22
1962-2.25
19630.18
19641.90
1965-4.48
1966-3.79
1967-0.83
19680.33
1969-3.74
19702.30
1971-2.81
1972-3.73
19730.58
1974-1.42
1975-1.02
1976-1.67
19773.20
19781.54
1979-1.81
19803.16
19813.33
1982-2.34
1983-0.71
19840.34
1985-0.79
19863.50
19875.95
19882.70
19892.91
1990-1.76
19910.37
19921.08
19932.74
1994-1.68
19952.99
1996-0.35
19971.86
19983.02
19992.55
20003.74
20013.54
20021.75
20034.03
20041.67
20051.33
20066.21
20074.31

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Influence of climate oscillations

Large-scale oscillations of the atmospheric system in the Pacific Ocean influence the precipitation and temperature patterns of the Taiga Plains Ecozone+, especially cold-season temperatures.Reference 8 These oscillations include El Niño/Southern Oscillation (ENSO) events that occur on average every two to seven years and the Pacific Decadal Oscillation (PDO), characterized by abrupt shifts between contrasting phases every 20 to 30 years.Reference 8 The shift to positive PDO and more frequent ENSO events in the mid-1970s appears to have led to contrasting changes across the continent, resulting in greater winter and spring warming in the west than in the east, trends that are particularly strong in this ecozone+.Reference 9

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Climate trends and impacts based on local observations and Aboriginal Traditional Knowledge

In this ecozone+ and more generally in the Mackenzie Basin, documented Aboriginal Traditional Knowledge and local observations speak to a range of trends in climate and related ecological impacts. This knowledge is specific to areas and timeframes so is best interpreted within the context of the knowledge holder (see the references provided). It is beyond the scope of this report to synthesize available information. Some examples of documented observations and interpretations are presented in Table 5.

Table 5. Selected Aboriginal Traditional Knowledge related to climate change and ecosystem impacts.
Examples of observations of climate trendsExamples of observations on ecological impacts, as reported in the Mackenzie River Basin state of the aquatic ecosystem report 2003Reference 59
  • Thinner ice leads to danger to people travelling and hunting, and to migrating caribou and other wildlife.Reference 138-Reference 140
  • Water levels have decreased over a period of one to two decades and small lakes and streams have disappearedReference 139-Reference 142 leading to reduced habitat for fish, waterfowl, and muskrat, which have declined in some areas,Reference 141 interfering with fishing, because traditional fishing sites are too shallow to set netsReference 143 and interfering with travel when important boating routes become too shallow to navigate.Reference 141
  • Changes in vegetation and less berry production; increases in forest fires resulting in loss of wildlife habitat and loss of trapping areas; new species appearing (such as cougars) that were never in the area before.Reference 138, Reference 139, Reference 142

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Climate change impacts

Changes in indicators such as air temperature and permafrost are well documented for the Taiga Plains and show clear trends consistent with climate change. Effects on ecosystems are not as apparent, partly because they are not as well documented.Reference 19 There are indications of ecosystem trends that are primarily climate related, discussed under many of the key findings in this report. Examples:

  • Vegetation community changes in the treeline zone and altered growth rates of white spruce (Forests key finding).
  • Increases in terrestrial primary productivity especially in the north of the Taiga Plains (Primary productivity key finding).
  • Early indications of a trend to reduced frequency of periodic spring flooding in delta wetlands and lakes (Wetlands key finding).
  • Widespread trend to increased streamflow in winter. Some indications of earlier peak flows (upstream in the Mackenzie River Basin) and of increased streamflow variability (Lakes and rivers key finding).
  • Loss of frozen peatlands (Ice across biomes key finding) and increased slumping from thawing ground ice in delta lakes, affecting water quality (Wetlands key finding).
  • Northward spread of some forest insect pests, likely related to warmer temperatures (Natural disturbances key finding).

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Key finding 15
Ecosystem services

Theme Human/ecosystem interactions

National key finding
Canada is well endowed with a natural environment that provides ecosystem services upon which our quality of life depends. In some areas where stressors have impaired ecosystem function, the cost of maintaining ecosystem services is high and deterioration in quantity, quality, and access to ecosystem services is evident.

Ecozone+ key finding: Provisioning services of the ecozone+ include harvest of fish, wildlife, and plants, of cultural, spiritual, nutritional, and economic importance. Reliance on these provisioning services is high and not declining, especially in rural communities. Quality of these services generally remains high, with the exception of declines in barren-ground caribou, leading to harvest restrictions and reduced harvest success in some communities.

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Putting a value to ecosystem services: the boreal forest

Typically, ecosystem goods and services are described through economic analyses to estimate the value of natural capital. However, there are clearly other goods and services that cannot be expressed in economic terms. For example, the Taiga Plains Ecozone+ provides services as a migratory corridor and as the breeding grounds for many boreal forest birds. Cultural services are particularly difficult to assign value to.

The Pembina Institute identified and valued the natural capital of Canada’s boreal forests, including in the analysis the value of forests, agriculture, mineral and energy resources, fish and wildlife, wetlands, peatlands, lakes, and rivers.Reference 144 The analyses focused on ecosystem services such as atmospheric stabilization; climate stabilization; disturbance avoidance; water stabilization; water supply; erosion control and sediment retention; soil formation; nutrient cycling; waste treatment; pollination; biological control such as bird predation of insect pests; habitat; raw materials; genetic resources; and recreation and cultural use. The value of the boreal forest’s ecosystem services ($93.2 billion) is at least 2.5 times greater than the market values of forestry, mining, oil and gas, and hydroelectricity combined ($37.8 billion). The market values do not include either societal or environmental costs separately valued at $11.1 billion. This analysis was not undertaken at the ecozone+ scale.

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Provisioning services

Harvest of fish, wildlife, and plants

Harvesting fish, birds, mammals, and plant species in the Taiga Plains has long supported the needs and culture of aboriginal people. Across the NWT, about 37 to 45% of NWT residents went hunting or fishing in 2002, a statistic that has changed little since the first survey in 1983.Reference 145 The number of aboriginal subsistence hunters in the Taiga Plains is about 5,800; there are no trend data for hunting activity for this group of residents. The number of resident hunters (non-aboriginal hunters) declined by about 3% per year from 1990 to 2004 and stabilized at about 1,200-1,300 hunters annually in recent years.Reference 145

Since hunting and fishing are a way of life for many Taiga Plains residents, earlier river ice break-upReference 131 is a concern. Freeze-up timing tends to be less predictable now than it was in the pastReference 137 and the ice is thinner. Changes in freeze-up patterns are raising concerns about hunter and fisher safety, especially in Gwich’in and Inuvialuit communities, where frozen lakes and rivers provide transportation routes and are used for much of the year for traditional activities such as ice fishing.Reference 131

Between 20 and 30% of households in the NWT portion of the Taiga Plains rely heavily on the provisioning services provided by local fish and game (Figure 26). The percentage would be considerably higher for Taiga Plains households outside of Inuvik, as, for all of the NWT, about 50% of households in small communities reported obtaining most or all meat and fish from local harvest in 2009, in contrast with 16% of households in medium sized communities, which includes Inuvik.Reference 145

Figure 26. Percent of households in the Taiga Plains and Taiga Cordillera (NWT) reporting that most or all of their meat and fish was harvested from the NWT, 1994-2009

Note that this primarily represents households in the Taiga Plains, as there is only one small community (Wrigley) in the NWT part of the Taiga Cordillera Ecozone+.

Graph
Source: data from Environment and Natural Resources, 2011Reference 145
Long description for Figure 26

This bar graph shows the following information:

Percent of households in the Taiga Plains and Taiga Cordillera (NWT) reporting that all or most of their meat and fish was harvested from the NWT, 1994-2009.
YearPercent of households
199421.5
199927.5
200424
200922.5

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Mammals

Mammal species harvested in the middle to northern part of the ecozone+ are shown in Figure 27. The three land claims settlement areas for which data are shown do not fully coincide with the ecozone+ (for example, the small muskox harvest would be mainly outside of the ecozone+), but the data provide a good indication of mammal species important to humans through much of the ecozone+. The mammal harvest is a mix of harvest for meat and for fur. The dominant mammal harvested for meat is the barren-ground caribou.

There is limited information on trends in caribou harvest – some is available through harvest studies established under land claims legislation.Reference 146 Information on the western Northwest Territories herds (Cape Bathurst, Bluenose-West, and Bluenose-East) is available through the Gwich’in Harvest StudyReference 147 and Inuvialuit Harvest StudyReference 148 for community caribou harvests from 1988 to 1997. Information for 1998 to 2005 is available through the Sahtu Harvest Study.Reference 149, Reference 150 As an example of harvest trends drawn from these studies, harvest from the Bluenose-West Herd in the Sahtu decreased from 1,022 in 1999 to 270 caribou in 2005.Reference 151 The Bluenose-West Herd is subject to harvest restrictions due to a decrease in population (see the section on caribou in the key finding on Species of special interest, on page 59).

Figure 27. Summary of annual harvest levels of major mammal species in the Gwich’in and Sahtu settlement areas and the Inuvialuit Settlement Region

Note: four of the six communities included in the Inuvialuit Settlement Region lie outside the Taiga Plains Ecozone+

Graph
Source: Joint Secretariat, 2003 as presented in SENES Consultants Ltd., 2005Reference 152
Long description for Figure 27

This bar graph shows the number of animals harvested annually in the Gwich’in and Sahtu settlement areas and Inuvialuit settlement area (ISR), divided into panels displaying data for large and small mammals.  Barren ground caribou was the most harvested large mammal in all three areas, with harvest numbers in the thousands.  Moose were harvested at low numbers in all three areas, but by far the most in the Sahtu area at around 200 animals.  Muskox was only harvested in the ISR, and woodland caribou only in the Sahtu area.  In the ISR, muskrat was harvested in large numbers (10,000), with fox and hare species also being important.  In the Gwich’in area, muskrat were harvested at a moderate level (>2000), with hare species and marten being the next most abundant harvests.  Hare species were the most harvested animal in the Sahtu area, followed by marten and smaller numbers of muskrat and beaver.

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Waterfowl

The numbers of waterfowl harvested for sport and subsistence in the NWT are relatively low, but ducks and geese are important in the traditional diet.Reference 152 In the Gwich’in region, the top three waterfowl species for subsistence harvest are scoters, mallard, and snow geese.Reference 147

Fish

Fisheries in the Taiga Plains include household, commercial, and recreational, both in rivers and lakes. Some examples of locally important fisheries in the ecozone+:

  • Eleven species of fish are caught using nets in the household fishery in the Gwich’in Settlement Area in the north of the ecozone+, the most important being inconnu (locally called coney, Stenodus leucichthys), Dolly Varden char (Salvelinus malma malma), burbot (locally called loche, Lota lota), and lake whitefish (locally called crookedback, Coregonus autumnali).Reference 19
  • There are both commercial and sport fisheries for lake trout, pike, and inconnu in Great Slave Lake, managed through a mix of area closures, catch limits and gear restrictions.Reference 19
  • Great Bear Lake, as well as being a source of fish for household fisheries, supports a lodge-based sport fishery for lake trout.Reference 153
Berries and products of the boreal forest

Non-timber forest products such as mushrooms, berries, birch sap syrup, floral greens, medicinal herbs, and forest crafts have a long history of traditional use and trade in the Taiga Plains.Reference 145 Participation rates in plant and berry gathering activities during 2002 in the NWT portion of the Taiga Plains are shown in Figure 28.

Figure 28. Percentage of population 15 years of age and older involved in harvesting berries and plants in 2002, north and south Taiga Plains, NWT
Graph
Source: NWT Bureau of Statistics, 2002Reference 154
Long description for Figure 28

This bar graph shows the following information:

Percentage of population 15 years of age and older involved in harvesting berries and plants in 2002, north and south Taiga Plains, NWT.
-Gathered berriesGathered plants
Taiga Plains North1910
Taiga Plains South2711

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However, when looked at on a household basis, and for communities in the Gwich’in Settlement Area, the use of berries is much higher – with almost all households collecting berries and 82% of households collecting Labrador tea leaves, based on a random survey of Gwich’in households in 2000 (Figure 29). The plant names in Figure 29 are the commonly used English names in the region; Latin and Gwich’in names, respectively, are: cranberry: Vaccinium vitis-idaea, natå'at; blueberry: Vaccinium uliginosum, jàk zheii; yellowberry (cloudberry): Rubus chamaemorus, nakàl; Labrador tea: Ledum palustre and groenlandicum, lidii maskeg/maskig.

Figure 29. Use of berries and Labrador tea by Gwich’in households, Fort McPherson, Inuvik, Aklavik, and Tsiigehtchic, 2000

The bars show the estimated average volume of berries and Labrador tea leaves collected per household, averaged over the four communities. The percentage on top of each bar is the estimated percentage of households across the communities active in collecting the particular plant product during the year 2000.

Graph
Source: data from Government of the Northwest Territories, 2009Reference 155
Long description for Figure 29

The bar graph presents the following information:

Use of berries and Labrador tea by Gwich’in households, Fort MacPherson, Inuvik, Aklavik and Tsiigehtchic, 2000.
-Litres per household% of households
Cranberry4396
Blueberry2895
Yellowberry5599
Labrador tea leaves3782

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Trapping

Wild fur from the NWT is considered among the very best in the world and has a long history. In the 1960s and 1970s several species contributed about equally to the total annual fur harvested in the NWT (marten, lynx, muskrat and beaver). However, marten has accounted for most of the NWT fur value during the past 20 years. Marten are a good indicator for trapping because they are widely distributed, relatively easy to trap, and their consistently high pelt value is an incentive for trappers to target this species. Furbearer abundance and availability, fashion trends, international market demand for fur, and the amount of trapping effort all influence trends in fur sales.Reference 145 The number of people trapping in the NWT has decreased since the early 1980s, but leveled to more stable numbers in recent years.Reference 145 Trapping remains an activity of cultural importance and provides ongoing supplementary income to approximately 500 people in the NWT portion of the Taiga Plains (Figure 30).

Figure 30. Trends in numbers of trappers in NWT Taiga Plains communities compared with other NWT ecozones

Note that the two upper lines represent trapping in the Taiga Plains.

Graph
Source: Environment and Natural Resources, 2011;Reference 145 data from the GNWT Fur Harvest Database, GNWT Department of Industry, Tourism and Investment
Long description for Figure 30

This line graph illustrates that between 2001 and 2008, the number of trappers in the north and south Taiga Plains was much higher than in other NWT ecozones+.  The northern and southern Arctic and Taiga Cordillera ecozones+ have few (< 50) trappers and the Taiga Shield has slightly fewer than the north Taiga Plains, with approximately 150 trappers.   In comparison, the northern Taiga Plains typically had around 200 trappers in this time period, and in the southern Taiga Plains the number of trappers ranged from 350 to 250.

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Commercial timber harvest

The commercial timber harvesting in the NWT portion of the Taiga Plains is a minor industry. The volume of timber cut down during seismic exploration projects is estimated to be at least an order of magnitude greater than the volume cut by commercial timber harvest operations.Reference 145 In the NWT, wood is harvested for saw logs and firewood. Typical commercial harvest operations are small-scale local businesses harvesting from 500 to 10,000 m3 per year. The trend in timber harvesting (across the territory) showed an increase during the 1990s, then decreased in the early 2000s before increasing slightly.Reference 145

By contrast, commercial timber harvest has been an important influence in the southwestern part of the ecozone+. Forest products were significant to the economy of the Fort Nelson region until the recent decrease in demand for building materials in the U.S. led to the closure of the Tackama Mill in Fort Nelson. The Fort Nelson mill was, in the mid-2000s, BC’s largest plywood facility.Reference 156

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Theme: Habitat, Wildlife, and Ecosystem Processes

Key finding 17
Species of special economic, cultural, or ecological interest

Theme Habitat, wildlife, and ecosystem processes

National key finding
Many species of amphibians, fish, birds, and large mammals are of special economic, cultural, or ecological interest to Canadians. Some of these are declining in number and distribution, some are stable, and others are healthy or recovering.

Ecozone+ key finding: The Taiga Plains Ecozone+ is important nationally for boreal woodland caribou, who are dependent upon intact blocks of mature boreal forest. Trends are unknown for half of the populations in the Taiga Plains Ecozone+; populations in the more fragmented, southern part of the ecozone+ are decreasing, although one population is reported as being stable. Bluenose-West barren-ground caribou have declined precipitously in recent years. Several waterfowl species that breed in the ecozone+ are declining; causes are not clear. The Taiga Plains is home to most of the global populations of two iconic species that were nearly driven to extinction in the early 20th century and are still considered at risk: the whooping crane and the wood bison.

This section presents accounts of status, trends, and conservation issues for selected species in the Taiga Plains Ecozone+. Two iconic species that had been driven close to extinction by human settlement and exploitation, the wood bison and the whooping crane, have seen population increases due in large part to conservation measures taken in the ecozone+, but restricted ranges and other concerns mean that ongoing efforts are required to maintain healthy, viable populations. The Taiga Plains Ecozone+ provides important habitat for caribou and grizzly bears, species valued by humans living within and outside of the ecozone+, and, with its numerous boreal forest wetlands, is important both as breeding habitat and as staging habitat during migration for waterfowl.

In the accounts below, COSEWIC refers to the Committee on the Status of Endangered Wildlife in Canada, a committee of experts that assesses wildlife species and designates which are in danger of disappearing from Canada. SARA refers to the Species at Risk Act.

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Wood bison

The conservation ranking for wood bison (Bison bison athabascae) has improved due to intense efforts to re-build populations. COSEWIC initially assessed wood bison as Endangered in 1978, then down-listed the species to Threatened in 1988. This status was reaffirmed in 2000. Wood bison are protected under the Species at Risk Act.Reference 157

During historic times, wood bison, Canada’s largest terrestrial mammal and a northern subspecies of the American bison, ranged over most of the boreal region of North America west of the Precambrian Shield. Historical estimates are reported as about 150,000Reference 157 or over 168,000.Reference 158 Abundance declined in the 19th century due to the invention and spread of firearms and the consequent overharvest of wood bison.Reference 159 The population was about 300 animals in 1893, confined to a small area in the southeastern Taiga Plains, when the first protective legislation was enacted to control hunting.Reference 160 Wood bison numbers reached an all-time low of about 250 animals in 1896.Reference 158 The remaining habitat was protected as Wood Buffalo National Park in 1922. A national recovery program was established in 1957. Eighty to ninety percent of the total wood bison population is in the Taiga Plains Ecozone+ and the adjacent section of Wood Buffalo National Park (Table 6).

Disease (brucellosis and tuberculosis, as well as outbreaks of anthrax – see also key finding on Wildlife diseases on page 79), cross-breeding with plains bison, and habitat loss through development (agriculture, forestry, and oil and gas) are the main threats faced by wood bison.Reference 157 From 1925 to 1928, 6,673 plains bison were shipped from Buffalo National Park, near Wainwright, Alberta, to Wood Buffalo National Park. These plains bison were from a herd that was being culled due to infection with tuberculosis, but the young animals introduced to Wood Buffalo National Park were thought to be disease-free. The relocated plains bison hybridized with the endemic wood bison and introduced tuberculosis to the herd. The source of brucellosis is less clear.Reference 161

Conservation efforts include measures to keep disease-free populations from making contact with diseased animals. The NWT’s Bison Control Area (Figure 31), established in 1987, is surveyed annually and kept free of bison to protect the Mackenzie herd from disease.Reference 162 In 2011 and 2012 infected bison have spread to the west of Wood Buffalo National Park, leading to intensified management efforts in this part of Alberta. The aim is to keep the disease-free Hay-Zama herd from contact with diseased animals and to control the risk of tuberculosis and brucellosis spreading to cattle.Reference 163 Maintaining bison-free zones has a cost in terms of habitat loss. About 50% of the historical range of wood bison is unavailable for recovery because of the need to control the spread of wildlife disease.Reference 164 Ranges of wood bison populations in or near the Taiga Plains Ecozone+ are shown on Figure 31 and status and trends are outlined in Table 6.

Figure 31. Wood bison populations in the Taiga Plains Ecozone+ and vicinity
Map
Source: Environment and Natural Resources, 2013Reference 165
Long description for Figure 31

This map shows the locations of free-ranging wood bison populations in the southern part of the Taiga Plains Ecozone+.  There are several populations located in and around Wood Buffalo National Park which are classified as free-ranging and diseased.  The Mackenzie population ranges on the west side of Great Slave Lake.  The Nahanni population and two other free ranging populations further south and east (in AB and BC) also fall within the boundaries of the Taiga Plains Ecozone.

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Table 6. Wood bison populations in the Taiga Plains: status and trends.
PopulationStatus and trends
Wood Buffalo National ParkThe total population was about 12,000 in the 1960s, declining to 2,100 in 1999. In 1974/75, 3,000 bison perished due to flooding in the Peace-Athabasca Delta. The population has increased in recent years and was estimated at 5,000 in 2009.Reference 160, Reference 166 The herd expanded to the west in 2011 and 2012.Reference 163

Infected with bovine tuberculosis and brucellosis (introduced through importation of infected plains bison in the late 1920s)Reference 160 and subject to several severe anthrax outbreaks since 1962.Reference 167
Slave River LowlandsConsidered part of the Wood Buffalo National Park population. Also infected with bovine tuberculosis and brucellosisReference 162 and subject to anthrax outbreaks.Reference 167

Declined from between 1,300 and 2,500 bison in the 1960s to about 500 by the 1980s, remaining stable for the next 20 years, then increasing to about 1,700 by the year 2009.Reference 162, Reference 166
NahanniEstablished 1980 with release of 28 bison.Reference 162

Between 1989 and 1998, 71 more bison were released and, by March 2004, there were an estimated 400 bison.Reference 162 A survey in 2011 showed that the population numbers have remained stable at about 400.Reference 166
Hay-Zama LakesEstablished 1984 with introduction of 29 bison; population grew to about 500 by 2007.Reference 39 A 2012 survey counted 587 bison, within the management goal of 400 to 600.Reference 163

Permit hunt started in 2008, in part to keep the herd from expanding and coming in contact with infected animals from the Wood Buffalo National Park population.Reference 168 All animals tested through the harvest have been determined to be disease-free.Reference 163
MackenzieThe largest healthy herd in northern Canada.Reference 162, Reference 166

Established 1963 by releasing 18 bison near Fort Providence. The herd expanded its territory and increased to 2,400 animals by 1989, followed by a decline to 1,600 bison in 2008. An anthrax outbreak in August, 2012 killed 440 bison, reducing the herd to fewer than 1,000 animals.Reference 166

Sources of mortality include anthrax outbreaks in 1993Reference 169 and 2012Reference 166 and loss of bison through thin spring ice in 1989.Reference 162

Whooping crane

COSEWIC designated the whooping crane (Grus Americana) as Endangered in Canada in 1978 and the species is protected under SARA.Reference 170 The whooping crane, never a common species, was reduced to an estimated 1,400 birds in 1860, with most of these remaining birds disappearing over the next 40 years due to encroachment of settlement on all but the northernmost of its breeding grounds. Wintering habitat also contracted during this time. The all-time low for the population was 14 known adults.Reference 171 The breeding range, which had extended across much of the central and northern prairies of North America, was reduced to a single site in Wood Buffalo National Park.

The only remaining self-sustaining wild population in the world breeds in Wood Buffalo National Park within the Taiga Plains Ecozone+ and migrates to the Aransas National Wildlife Refuge along the Gulf of Mexico, in Texas.Reference 171 Two additional non-self-sustaining populations have been established in the United States. One, with reintroduction starting in 2001, migrates between the Wisconsin and Florida.

The Canadian whooping crane wild population has increased from 18 in 1938 to 283 in the winter of 2010/11.Reference 172 Current threats include limited genetic diversity of the species and loss and degradation of migration stopover habitat and coastal wintering habitat, as well as threat of chemical spills in Texas.Reference 173

Whooping cranes breed in isolated wetlands with soft substrates, substantial amounts of open water (creating long sight lines for spotting predators), and suitable vegetation for nesting materials. They have, over the years, expanded their breeding range locally, and it is considered that there is ample suitable habitat in the vicinity of their current range in the Taiga Plains Ecozone+.Reference 171 Population growth is likely to be controlled more by limitation of suitable habitat on the wintering grounds in TexasReference 171, Reference 173 Predation on the breeding range may, however, influence the rate of population growth. The 10-year cycle for predators, especially wolves, in Wood Buffalo National Park was considered by Boyce and Miller, 1985Reference 174 to account for the slight periodicity in population abundance, with slowed growth and slight dips approximately every 10 years (Figure 32). A national recovery strategyReference 175 and an international recovery planReference 173 are in place to coordinate monitoring, research, and conservation measures for the whooping crane.

Figure 32. Growth of the Aransas-Wood Buffalo whooping crane population, 1938-2010

Total population, based on winter counts.

Graph
Source: based on data from COSEWIC, 2010;Reference 171 2010 and 2011 data from Whooping Crane Conservation Society, 2011Reference 172
Long description for Figure 32

This line graph shows the following information:

Growth of the Aransas-Wood Buffalo whooping crane population, 1938-2010.
YearTotal countsYearTotal counts
193818197669
193922197772
194026197875
194116197976
194219198078
194321198173
194418198273
194522198375
194625198486
194731198597
1948301986110
1949341987134
1950311988138
1951251989146
1952211990146
1953241991132
1954211992136
1955281993143
1956241994133
1957261995158
1958321996159
1959331997182
1960361998183
1961391999188
1962322000180
1963332001176
1964422002185
1965442003194
1966432004217
1967482005220
1968502006237
1969562007266
1970572008270
1971592009263
1972512010283
197349--
197449--
197557--

 

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Caribou

Migratory barren-ground caribou (Rangifer tarandus groenlandicus) winter in the Taiga Plains Ecozone+ and non-migratory woodland caribou (Rangifer tarandus caribou) range through much of the ecozone+ year-round.

Barren-ground caribou

This section, based on the report on Northern caribou population trends in Canada,Reference 97 a technical thematic report prepared for the 2010 Ecosystem Status and Trends Report, presents population trend information for the two barren-ground caribou herds: the Bluenose-East and the Bluenose-West. Both herds calve in the Southern Arctic (Arctic Ecozone+) and winter in the Southern Arctic and the Taiga Plains ecozones+.

Bluenose-East Herd

The Bluenose-East Herd was not officially recognized as a distinct herd until 1999.Reference 176 A photographic post-calving survey was undertaken in 2000, providing an estimate of 104,000 ± 22,100 (95% CI) (Figure 33). This was followed by a decline to an estimated 70,100 ± 8,100 in 2005 and 66,800 ± 5,200 in 2006. This translates into a 10% exponential rate of decline from 2000 to 2006. However, by 2010, the post-calving herd estimate was 98,600 caribou ± 7,100. There are gaps in the information as demographic rates were not monitored and information on distribution based on collared caribou has not been analyzed.

Figure 33. Bluenose-East Caribou Herd population estimates

Estimates are for caribou one year and older. Surveys were conducted in July.

Graph
Source: Gunn et al., 2011Reference 97
Long description for Figure 33

This bar graph presents the following information:

Bluenose-East Caribou Herd population estimates.
Year2000200520062010
Population estimate, post-calving photo survey104,00070,08166,75498,646
95% confidence intervals22,1008,1205,1827,125

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Trends in vital rates are uncertain as monitoring has been infrequent until recently. Spring calf:cow ratios ranged between 25 and 52 calves: 100 cows and showed no trend between 2001 and 2009 (R. Popko, unpublished data in Adamczewski et al., 2009).Reference 177

Bluenose-West Herd

Although the Bluenose-West Herd was not officially recognized as a distinct herd until 1999,Reference 176 population estimates were derived for 1986, 1987, and 1992 based on locations of radio-collars during post-calving surveys of the Bluenose Herd. The herd peaked at 112,400 ± 25,600 (95% CI) in 1992 and then declined to 76,400 ± 14,300 in 2000, and 20,800 ± 2,040 in 2005 (Figure 34). The 2005 estimate was confirmed by an estimate of 18,050 ± 530 caribou in 2006. Since then, the trend appears to have leveled out, with a preliminary estimate for a July 2009 survey of 17,900 ± 1,300 caribou.Reference 178

Figure 34. Bluenose-West Caribou Herd population estimates

Population estimates are for caribou one year and older. Data obtained during phot°Census surveys of the “Bluenose” herd prior to 2000 were re-analyzed to estimate Bluenose-West population trends. These estimates should not be considered as reliable as the later estimates.Reference 179

Graph
Source: Gunn et al., 2011Reference 97
Long description for Figure 34

This figure shows the following information:

Bluenose-West Caribou Herd population estimates.
YearPopulation estimate,
re-analysis of "Bluenose" photo survey
95% confidence intervalsPopulation estimate, post-calving photo survey95% confidence intervals
198688,3696,899--
1987106,8874,655--
1992112,36025,566--
2000--76,37614,347
2005--20,8002,040
2006--18,050527
2009--17,8971,310

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Based on recommendations of the Wildlife Management Advisory Council (NWT), the Gwich'in Renewable Resources Board, and the Sahtu Renewable Resources Board, co-management boards in the herd’s range, all non-aboriginal hunting of the Bluenose-West Herd ceased in 2006. The co-management boards made further recommendations to restrict aboriginal harvesting of the Bluenose-West Herd by establishing a total allowable harvest and the requirement for a tag to harvest, measures that were implemented in 2007.Reference 97

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Woodland caribou, boreal population

This section is based on the 2011 scientific assessment and 2012 recovery strategy for the woodland caribou (Rangifer tarandus caribou), boreal population.Reference 109, Reference 180Note that this information has been updated since the release of the ESTR national thematic report, Woodland caribou, boreal population, trends in Canada.Reference 181

Woodland caribou are distributed throughout the boreal region of Canada.Reference 182 There are two genetically distinct varieties, or ecotypes, of woodland caribou: 1) forest-dwelling woodland caribou, which are non-migratory and live in relatively small groups year-round in the boreal forest; and 2) forest tundra woodland caribou, which are migratory and live in large herds and winter in the boreal forest. The forest-dwelling ecotype of woodland caribou is made up of ten geographically distinct populations – the boreal population (referred to as “boreal caribou”), which is found through most of the Taiga Plains Ecozone+, is the most widespread. In 2002, COSEWIC assessed the boreal caribou as ThreatenedReference 183 and boreal caribou were added to Schedule 1 of the federal Species at Risk Act.Reference 184

The range of the woodland caribou, including the boreal population, has retracted significantly from historical distributions. The southern limit of distribution has progressively receded in a northerly direction since the early 1900s, a trend that continues to the present day.Reference 109, Reference 183, Reference 185-Reference 187

Taiga Plains Ecozone+ status and trends

Boreal caribou primarily inhabit Canada’s boreal, rather than taiga, ecozones+, with the exception of the Taiga Plains Ecozone+, which provides some of the largest tracts of habitat for these at-risk caribou. This is due to the prevalence of mature or old growth coniferous forests and peatlands, the preferred habitat of boreal caribou.Reference 188 Studies have shown that treed fen and bog peatlands are crucial to the survival of boreal caribou in northern Alberta. This finding would apply to the entire zone of sporadic permafrost that reaches into northern BC and southern NWT (Figure 16).Reference 189 Fifteen boreal caribou local populationsReference * (or components thereof) occur in the Taiga Plains Ecozone+. Of these, 33.3% (n=5) are in decline, 6.7% (n=1) are increasing, and the status of the remaining 60% (n=9) is unknown (Figure 35).

Figure 35. Estimated population status of boreal caribou local populations in the Taiga Plains Ecozone+
Map
Source: Callaghan et al., 2011Reference 181
Long description for Figure 35

This map shows the status and location of boreal caribou populations in the Taiga Plains Ecozone+. Only three populations in the Gwich’in area in the northern tip of the ecozone+ are classified as increasing.  The Inuvialuit and Sahtu populations, whose ranges cover a large part of the northern part of the ecozone+ are of unknown status, as are the North Slave, Maxhamish, Calendar, Steen River/Yates populations.  The Deh Cho (N/SW), South Slave/SE Deh Cho, Snake Sahtahneh, Bistcho, Chinchaga and Caribou Mountains populations are classified as in decline, and located in the southern half of the ecozone+.

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Causes of declines

Broad-scale range recession and population declines of boreal caribou in most areas are associated with human settlement and industrial resource extraction due to the loss, degradation, and fragmentation of their coniferous-forest habitat.Reference 187, Reference 190-Reference 192 Proximate causes of decline associated with landscape-level habitat change include increased predation,Reference 109, Reference 193, Reference 193-Reference 197 increased access by hunters,Reference 190, Reference 194 and linear disturbance.Reference 198, Reference 199 Weather and climate change may affect several aspects of boreal caribou ecology by combining with other threats in complex ways that magnify the principle causes of decline.

In the Taiga Plains Ecozone+ boreal caribou populations known to be in decline have relatively small ranges in the southern part of the ecozone+ (Figure 35).

Table 7 presents an analysis of the proportion of disturbance, both from fire and from anthropogenic sources (defined in the caption), on the ranges of each of the populations completely or partially in the Taiga Plains Ecozone+. This analysis indicates that 57 to 87% of the range of each population that is known to be declining is classified as “disturbance”, with the populations in BC and Alberta having the highest degree of anthropogenic disturbance (see also Figure 6 in the Forest biome key finding). Fire is the main cause of disturbance for the populations in the NWT. Boreal caribou can shift their range use to avoid burned areas provided sufficient old-growth forest remains. Although fire may have short term adverse effects, large fires prepare the conditions for future large, even-aged stands of mature forest that are vital to boreal caribou. In a healthy ecosystem, as one large tract of habitat is disturbed by fire, another is reaching maturity.

Table 7. Boreal caribou population range disturbance.
Population StatusLocal population or
unit of analysis
Local Population Range Disturbance

Fire %
Local Population Range Disturbance

Anthropogenic %
Local Population Range Disturbance

Total % of Disturbance
not availableNWT24831
not availableBC Maxhamish0.55758
not availableBC Calendar85861
declineAB/Bistcho 206171
declineBC Snake Sahtaneh68687
not availableBC Parker15758
not availableBC Prophet17777
stableAB/Yates 432161
declineAB/BC Chinchaga87476
declineAB Caribou Mountains442357

Population status is taken from Figure 35 . Note that the ranges of some of the populations extend into neighbouring ecozones+

“Fire %” is the percent of the range area burned within the past 40 years (since 2010). Fire data from the Canadian Large Fire Database, augmented by additional coverage for the Northwest Territories and Parks Canada, that contained wildfires >2 km2 were also used.

“Anthropogenic %” is the percent of the range area affected by anthropogenic disturbance, based on mapping conducting by the Landscape Science and Technology Division of Environment Canada in collaboration with Global Forest Watch Canada (GFWC). All visible linear and polygonal anthropogenic disturbances were digitized from Landsat images. Linear disturbances included roads, railroads, seismic lines, pipelines, power transmission lines, airstrips, dams and other/unknown; polygonal features included  settlement areas, mines agricultural areas, cutblocks, oil and gas activities , well pads and other/unknown. All features in the database were buffered by 500 m to create a “zone of influence”, and merged to create a non-overlapping coverage of all anthropogenic disturbances.

Source: Environment Canada, 2011Reference 180 and 2012Reference 190

Waterfowl

This section draws from Trends in breeding waterfowl in Canada,Reference 200 a technical thematic report prepared for the 2010 Ecosystem Status and Trends Report. Analyses of trends by ecozone+ in the waterfowl report included data up to 2006 and have not been updated.

Waterfowl population composition and abundance in the Taiga Plains Ecozone+ is surveyed by the joint Canadian Wildlife Service and US Fish and Wildlife Service waterfowl breeding survey that was established in 1955.Reference 201 Long-tailed duck (Clangula hyemalis), scoters (combined white-winged scoter (Melanitta fusca), surf scoter (M. perspicillata) and black scoter (M. nigra), scaup (combined lesser scaup (Aythya affinis) and greater scaup (A. marila)), northern pintail (Anas acuta), mallard (A. platyrhynchos), and American wigeon (A. Americana) show declining population trends (Table 8, Figure 36, and Figure 37). These populations overlap during breeding, whereas most have different wintering areas,Reference 202 suggesting that the reasons for their declines may be associated with this ecozone+. Waterfowl are patchily distributed across the ecozone+ and trends are also variable from location to location, as shown for scaup in Figure 38.Reference 203

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Table 8. Abundance trends for selected waterfowl species in the Taiga Plains Ecozone+, 1970s-2000s
SpeciesNesting habitatTrend (%/yr)PNote 1 of Table 8Annual Abundance Index
(in 1,000s)

1970s
Annual Abundance Index
(in 1,000s)

1980s
Annual Abundance Index
(in 1,000s)

1990s
Annual Abundance Index
(in 1,000s)

2000s
Annual Abundance Index
(in 1,000s)

% change
BuffleheadCavity0.104-96.396.285.697.41.2
Long-tailed duckGround-4.164*Note 2 of Table 842.630.612.511.6-72.8
Scoter (white-winged, surf, and black)Ground-4.089*Note 2 of Table 8250.3233.186.487.9-64.9
Scaup (lesser and greater)Ground-3.273*Note 2 of Table 8951.8744.5427.6384.3-59.6
Northern pintailGround-2.722*Note 2 of Table 894.569.337.644.7-52.7
MallardGround-2.155*Note 2 of Table 8232.9237.2168.8131.6-43.5
American wigeonGround-2.024*Note 2 of Table 8194.1185.5119.7121.7-37.3
Green-winged tealGround0.665-141.7249163.5201.442.2
Canada goose-0.472-54.768.163.365.419.5

Notes of Table 8

Note 1 of Table 8

P is the statistical significance

Return to note 1 referrer of table 8

Note 2 of Table 8

indicates P<0.05;

Return to note 2 referrer of table 8

Note: no value indicates not significant

Source: Fast et al., 2011Reference 200

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Figure 36. Taiga Plain Ecozone+ population trends for (A) scaup and scoter; (B) Canada goose, long-tailed duck, and bufflehead, 1970-2006
Graphs
Source: Fast et al., 2011Reference 200
Long description for Figure 36

These two line graphs show the following information:

Taiga Plains Ecozone+ population trends for (A) scaup and scoter; (B) Canada goose, long-tailed duck, and bufflehead, 1970-2006. (Number of breeding pairs)
YearScaupScoterBuffleheadCanada GooseLong-tailed duck
1970726,057256,50473,32677,93635,679
1971835,040190,989111,80691,06652,621
19721,959,096338,748116,32381,1276,560
1973951,786240,68566,61041,74727,112
1974769,027207,389104,62226,58331,177
19751,044,060194,66999,25366,64111,167
1976507,857103,98889,12739,30434,404
1977915,746172,81196,82938,01962,284
1978892,921446,38585,34745,93962,588
1979915,991351,226119,44538,707102,224
1980863,425168,676105,51937,43534,806
1981787,820243,83861,77960,01214,843
1982667,246177,30348,37836,12345,061
1983874,096355,42296,77849,0653,722
1984946,801170,466133,89526,39562,279
1985618,909245,41770,04990,4161,861
1986665,211160,367108,09079,3961,861
1987819,018351,538111,207103,28544,655
1988624,056136,901124,020109,06421,390
1989578,222320,824101,95190,24575,370
1990458,48949,51471,97181,04611,343
1991405,65879,49873,10374,8636,481
1992487,854143,73750,01590,51411,553
1993458,569134,18684,63372,9713,975
1994448,34951,987101,81349,01914,820
1995418,12938,638112,69582,49229,749
1996311,55477,26560,13247,6616,023
1997333,949166,36996,89634,27323,987
1998371,31138,26599,42942,52112,387
1999582,25784,178104,97957,8414,678
2000406,11669,76070,13721,0728,506
2001376,72676,705112,56971,07214,849
2002432,82652,36796,698111,0705,560
2003387,882124,928101,34765,7447,311
2004523,568149,839110,51545,16135,201
2005306,55267,35897,77780,0345,569
2006256,35974,48892,66963,3334,057

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Figure 37. Taiga Plains Ecozone+ population trends for American wigeon, green-winged teal, mallard and northern pintail, 1970-2006
Graph
Source: Fast et al., 2011Reference 200
Long description for Figure 37

This line graph shows the following information:

Taiga Plains Ecozone+ population trends for American widgeon, green winged teal, mallard and northern pintail, 1970-2006.
YearAmerican wigeonGreen-winged tealMallardNorthern pintail
1970147,747180,683225,29731,511
1971234,724131,167277,50025,100
1972198,356214,436406,820218,244
1973225,238173,903222,891115,451
1974109,48572,291143,20430,529
1975266,091179,581323,449193,438
1976109,83436,50192,92778,673
1977261,646193,556245,906160,162
1978220,363121,398212,18850,364
1979167,700113,038178,93341,509
1980316,872193,649244,02270,765
1981209,794156,943199,38373,165
1982141,701204,309129,93135,989
1983109,894332,044309,70395,549
1984234,438135,102109,59873,733
1985159,122204,644246,49679,380
198698,339277,501481,01158,323
1987168,597347,039191,42086,871
1988237,209313,850247,06160,698
1989179,314324,752212,89348,318
1990112,753187,134123,82227,000
1991107,03591,16088,53843,392
1992131,035176,007127,59265,779
1993123,511193,853220,56576,650
199449,106193,31170,09514,864
1995119,951167,687120,47212,378
199654,879109,41192,4768,668
1997180,88280,884247,14826,922
1998112,270214,231193,67235,227
1999205,881221,064403,83765,036
2000109,349307,124204,48357,982
2001124,252215,439139,24757,045
2002109,876206,216206,68458,332
2003186,525253,167134,57534,119
2004193,771207,964135,15953,285
200551,99265,67754,91412,416
200676,172154,47846,30140,003

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Figure 38. Geographic distribution of breeding scaup and of trends in scaup, 1976 to 2003

The densities shown in map A are averages over the study period. The map of change in scaup abundance (B) compares count data from the years 1976 to 1980 with data from 1999 to 2003. These maps are based on the survey results that are summarized in Figure 36, Figure 37, and Table 8.

Graphs
Source: adapted from Fournier and Hines 2005Reference 203
Long description for Figure 38

These two maps show the trends in the geographic distribution of scaup between 1976 and 2006: map A shows the total average number of birds/km2, and map  B shows the change in birds/km2.  The northern part of the Taiga Plains Ecozone+ in general has higher densities of scaup, with at least 2-4 birds in most places and 4-8 in many places.  An area on the north side of Great Slave Lake also has high densities of birds.  In most of the rest of the ecozone+, scaup densities are < 4 birds/km2.  Between 1976 and 2003, bird densities change substantially in two areas of the ecozone+: substantial areas in the north part of the ecozone+, and areas north and west of Great Slave Lake have experience declines of up to 17 birds/km2.

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Despite their abundance, total populations of greater and lesser scaup have been declining since the mid-1980s, with most of the decline being for those breeding in the western boreal forests (Figure 39). Population growth rate for lesser scaup may be most sensitive to adult female survival during the breeding and non-breeding seasons, and, to a lesser extent, to nesting success, duckling survival, and juvenile survival.Reference 204 This suggests that changes to breeding habitat may greatly influence population growth.

Figure 39. Declines in scaup in the boreal forest compared with trends in tundra and prairie-parkland, 1955 1997

Greater and lesser scaup total breeding population estimates are combined.

Graph
Source: Afton and Anderson, 2001Reference 205
Long description for Figure 39

This line graph shows trends in scaup in the boreal forest compared with trends in tundra and prairie parkland, 1955-1997.  Tundra populations of scaup remained relatively stable over this time period, in contrast with prairie-parkland and boreal forest, which both show declines.  The scaup population in the boreal forest are variable, but usually between 3 and 5 million birds until the early 1990s, when populations dip below 3 million.  Prairie-parkland numbers are lower overall but less variable than boreal forest populations, and generally fall between 1 and 2 million birds. Tundra populations remained stable over this period at less than 1 million birds.

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The reasons for the declines of these waterfowl populations are not well understood, as very few waterfowl studies have been conducted in the Taiga Plains. Climate change may play an important role, especially for late-nesting long-tailed ducks, scoters, and scaup.Reference 206, Reference 207 As photoperiod is likely the main breeding cue for these species, mismatches in timing may be occurring between their relatively fixed late nesting dates (but see Anteau and Afton, 2009Reference 208) and invertebrate phenology, which is driven by temperature and has likely changed recently due to climate warming.Reference 209 The mismatch hypothesis between breeding birds and changing food supply, although not yet tested in the taiga regions, has been demonstrated elsewhere (for example Thomas et al., 2001Reference 210). The mismatch hypothesis however, is one of many that may explain declines in scaup populations (see review in Austin et al., 2000Reference 211).

Causes of the declines observed for northern pintail, mallard and American wigeon remain unclear. These species fluctuate greatly between years, and some have declined in other regions as well. Canada goose and green-winged teal populations show no statistically significant trends.

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Fish

Three fishes in the Taiga Plains Ecozone+ are considered at risk in the Northwest Territories: the shortjaw cisco (Coregonus zenithicus) is classified “at risk” and the bull trout (Salvelinus confluentus), and inconnu (Stenodus leucichthys; Upper Mackenzie River and Great Slave Lake stocks only) are classified as “may be at risk”.Reference 212

In 1987, COSEWIC designated the shortjaw cisco as Threatened based on the reduced population and level of habitat exploitation across Canada. The rating was confirmed during a status review in 2003.Reference 213 In the NWT, the shortjaw cisco inhabits Great Slave Lake, which is at the northern edge of its known range; there are also unconfirmed reports of the species in Great Bear Lake.Reference 212 Population status and trends in the ecozone+ are poorly known.Reference 213

The presence of bull trout was confirmed in the early 2000s in the Sahtu region of the Taiga Plains, extending its previously known distribution northward by 4° latitude.Reference 214 Bull trout, which are likely quite widely distributed in high gradient streams and rivers of the south-central Mackenzie River Valley, have been shown to be highly sensitive to a variety of individual and cumulative anthropogenic impacts; many populations south of the ecozone+ have been extirpated or may be threatened.Reference 214

In the upper Mackenzie and Great Slave Lake, inconnu populations appear to have been decimated by net fisheries close to their spawning rivers.Reference 215 Elders recount that their demise began when the flourishing fur trade in the 1940s and 1950s demanded large amounts of feed for dog teams.Reference 216 The decline continued with commercial fishing and loss through bycatch by the lake whitefish fishery in Great Slave Lake. Conservation measures, now in place for many years, have yielded only a slow recovery.Reference 215

Baseline information on fish stocks is summarized in the Mackenzie Basin report on the state of the aquatic environmentReference 59 and through the NWT Environmental Audit and the Cumulative Impacts Monitoring Program.Reference 217 The status for most fish stocks, where data are available, is considered to be stable or increasing. In Great Bear Lake, the lake trout population declined between the early 1970s and the mid 1980s. Quotas were assigned in 1987. Since then, the lake trout harvest has been much lower than the maximum sustainable yield (Figure 40). Arctic grayling stocks in the upper Mackenzie River Basin were adversely affected by a warm-water-induced outbreak of waterborne pathogens in 1989, but stocks appear to have recovered to their former levels, based on information related to sports fisheries, for example, on the Kakisa River (southwest of Great Slave Lake).Reference 217

Figure 40. Harvest of lake trout in Great Bear Lake, 1972-1990
Graph
Source: Mackenzie River Basin Board, 2004;Reference 59 data from Department of Fisheries and Oceans, Hay River.
Long description for Figure 40

This line graph shows that the lake trout harvest in Great Bear Lake declined substantially between 1975 and 1990.  Between 1975 and 1987, harvest was far above the maximum recommended harvest of 9,000 fish: about 19,000 fish were harvested in 1975, which felt to about 13,500 in 1985.  After 1987, harvest fell rapidly, with <4,000 trout harvested in 1990.

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Key finding 18
Primary productivity

Theme Habitat, wildlife, and ecosystem processes

National key finding
Primary productivity has increased on more than 20% of the vegetated land area of Canada over the past 20 years, as well as in some freshwater systems. The magnitude and timing of primary productivity are changing throughout the marine system.

Ecozone+ key finding: Overall, primary productivity increased on 22.7% and decreased on 1.5% of the land area of the Taiga Plains from 1985 to 2006. Increased primary productivity was mainly in the north part of the ecozone+, where studies show increased growth of shrubs, along with some impairment of growth of lichens and of some white spruce. The large fires characteristic of the ecozone+ influence primary productivity but do not account for the overall increase.

This section is based on analyses and interpretations in Monitoring biodiversity remotely: a selection of trends measured from satellite observations of Canada.Reference 13 Additional material has been added on the relationship with forest fires, forage quality, and on aquatic productivity.

The Normalized Difference Vegetation Index (NDVI) measures vegetation vigour due to chlorophyll activity, or “greenness”. Changes in NDVI over the period 1985 to 2006 were examined by Ahern et al., 2011Reference 13 for each ecozone+, based on the findings of Pouliot et al., 2009Reference 218 Results are shown in Figure 41. Overall, 22.7% of the Taiga Plains Ecozone+ showed a statistically significant (95% confidence limits) positive change and 1.5% showed a significant negative change in NDVI.

Figure 41. Trend in Normalized Difference Vegetation Index, Taiga Plains Ecozone+ 1985-2006
Map
Source: Ahern et al., 2011Reference 13
Long description for Figure 41

This map shows trends in Normalized Difference Vegetation Index (NDVI) between 1985 and 2006.  In the Taiga Plains Ecozone+, 22.7% of the land area has increased significantly in NDVI values, which reflects an increase in primary productivity, while only 1.5% of the ecozone+ had lower NDVI values.  The areas of increasing NDVI are concentrated in the northern part of the ecozone+, and the isolated areas of decrease are mostly in an area to the west of Great Slave Lake.

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In the northern Taiga Plains, the extensive area of strong NDVI increase visible in the map corresponds to a large area of conifer forest north of Great Bear Lake to the east of the Mackenzie Valley. A similar but smaller patch lies in the lower Mackenzie Valley. Further south, areas of increasing NDVI are more isolated. The area of decreasing NDVI west of Great Slave Lake does not correspond to any recent burns. The region has a high water table and areas previously vegetated with forest and tall shrubland have been flooded during years of high precipitation.Reference 216

Pouliot et al., 2009Reference 218 also examined the influence of climate and land cover change on the observed NDVI trends in eight regions of Canada. Climate influence was examined by analyzing, on a grid basis, correlations between monthly temperature and precipitation data (Mitchell 2005 in Pouliot et al., 2009Reference 218) and annual peak NDVI. This analysis suggested that NDVI in the Taiga Plains is strongly influenced by climate, more so than in any other region in Canada. As in other northern regions, NDVI was negatively correlated with precipitation and positively correlated with temperature.Reference 218

Olthof et al., 2008Reference 219 examined NDVI trends in a portion of the Taiga Plains Ecozone+ (as well as tundra areas to the north) using the same dataset used by Ahern, 2011Reference 13 and Pouliot, 2009Reference 218 along with higher resolution Landsat data. They found that lichen-dominated communities had consistently lower NDVI trends than vascular-plant-dominated communities, though all showed increasing trends. This is consistent with ground studiesReference 220-Reference 224 and was attributed to increasing vigour and biomass of vascular plants and some impairment of lichen growth due to drying.Reference 219 White spruce in this northern region also show signs of decreased growth rates, likely related to drought stress (see the Forest biome key finding and Figure 8).

In the boreal forest, using satellite-based measurements to index primary productivity is complicated by the effects of forest fires. Productivity is decreased for about a decade following a forest fireReference 225 and then post-fire succession vegetation or age of the trees can also complicate interpreting remote sensing measured trends in plant productivity.Reference 226, Reference 227 Ahern, 2011Reference 13 analyzed the changes in NDVI in relation to fire history across Canada: NDVI trends were negative in areas recently affected by fire (1994 to 2004), positive in areas affected by fires from 1980 to 1990 (where regeneration would have dominated), and generally positive or close to zero in areas affected by fire prior to 1980 (1960 to 1980). The authors concluded that, in the northern portion of Canada’s forested zone, many of the observed changes may be a result of the natural cycle of fire and succession, however, trends in wildfire alone cannot account for the scale and the distribution of the change in NDVI observed over the 22-year period.

Trends of increasing plant productivity as indexed by satellite-based measures (NDVI) may not translate into an increase in forage quality for herbivorous insects or mammalian herbivores. One interacting factor, for example, is that the amount of solar radiation (or cloud cover) and temperature also affect the levels of compounds such as tannins in plants, which affects forage quality.Reference 228 Thus the conditions that promote greater primary productivity may also lower the quality of some of the vegetation as food for herbivores.

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Key finding 19
Natural disturbances

Theme Habitat, wildlife, and ecosystem processes

National key finding
The dynamics of natural disturbance regimes, such as fire and native insect outbreaks, are changing and this is reshaping the landscape. The direction and degree of change vary.

Ecozone+ key finding: Natural disturbances in the Taiga Plains show signs of change related to climate. On a decadal basis, the area of forest burned increased from the 1960s then declined again in the most recent decade, though data are incomplete for this latter decade. There are indications of a trend to more fires earlier in the season, a pattern consistent with the observed temperature trends. The main forest insect pest, spruce budworm, is endemic in the southern part of the ecozone+ and there are indications that it may be moving northward. Both the forest tent caterpillar and the mountain pine beetle, relatively new to the ecozone+, show signs of becoming more abundant and expanding northward.

Fire

The interest in monitoring trends in forest fires has increased recently because of the relationship between a warming climate, fires, and the implications for carbon cycling and storage. People in the communities take note of increases in fire frequency in relation to warmer temperatures. However, it is unclear whether the reported frequency or landscape patterns of fire are different from in the past. For example, 90 fires were reported in the Fort McPherson area in 2003, a hot, dry summer,Reference 129 but it is difficult to interpret this in terms of long-term trends because the number of fires and the area burnt annually is highly variable – a few years can be expected to have exceptionally high rates. The Taiga Plains experienced large fires in the 1940s, a warm and dry decade, as documented, for example, in the Fort Smith area.Reference 229 In a Fort Providence study of fire history over the 19th and 20th centuries, the highest proportion of forest stands began their growth following the extensive fires in the 1940s.Reference 230 Few trees survived fire beyond 200 years. In addition to the 1940s, the 1860s, 1880s, and 1920s were decades in which large areas were burned.

Patterns of human involvement with fire have changed with changes in settlement, cultural and economic practices: both patterns of accidental or deliberate fire ignition and those of fire suppression. For example, in the past, aboriginal people in the central and southern part of the ecozone+ used burning as a management tool to improve conditions for important food sources such as moose, wood bison, hare, beaver, grouse, and berries that thrive in early successional habitats.Reference 216, Reference 230, Reference 231 This resulted in a landscape that included grasslands that have since reverted to forest.Reference 232

Fire behaviour in the boreal forest is partly related to the age of the tree stands.Reference 233 After a rapid increase over the first few decades, flammability decreases and remains at a lower level in the mature forest, rising again as the stand deteriorates. Short fire intervals promote regrowth of deciduous trees over conifers. Intense fires in young conifer stands clear areas that can then become deciduous stands, via seeds that can travel long distances by wind. Variation in the depth of burn results in great differences in seedling density. A warmer, drier climate with increased fire frequency will result in more severe, deeper fires that burn soil organic matter and kill more below-ground plant parts than light surface fires.Reference 233

The discussion below summarizes recent trends in fire extent, duration and timing. It is based on Trends in large fires in Canada, 1959-2007,Reference 13 a technical thematic report prepared for the 2010 Ecosystem Status and Trends Report. Data used in analyses for the report were current to 2007 and have not been updated.

Some of the largest fires in the country occur in the Taiga Plains Ecozone+.Reference 234, Reference 235 This is due to a combination of factors, including the dry, continental climate;Reference 236 the remote location with little suppression effort;Reference 234 and, a dominance of boreal fuel types with relatively high average fuel loads that lead to higher consumption rates.Reference 237, 2Reference 238 These factors result in relatively severe fires that burn over large areas.

Area burned

On average an area of 2,858 km2 burns each year, with great variability from year to year (Figure 42). In many years the annual area burned (by fires over 2 km2) is less than 100 km2, while in other years it can be very high – 17,354 km2 burned in 1995. Some low values early in the period of record may be due to limited monitoring in this northern ecozone+, but this trend continues into recent decades, validating the occurrence of very low fire years (see, for example, 1991, 1997 and 2002 in Figure 42). In comparison with other ecozones+, the average annual area burned is high (0.71% of the forested ecozone+ area, second only to the Taiga Shield), despite the frequency of very low fire years.Reference 10

Figure 42. Annual area burned by large fires in the Taiga Plains Ecozone+, 1959-2007.

Note: this fire trend is based on large fires (fires over 2 km2 in size, rather than the total area burned).

Graph
Source: Krezek-Hanes et al., 2011Reference 10
Long description for Figure 42

This bar graph shows the following information:

Annual area burned by large fires in the Taiga Plains Ecozone+, 1959-2007.
YearArea burned (km2)
1959705
1960112
19611,849
1962200
196351
196454
1965308
19661,124
1967289
19681,852
19694,605
19701,111
19714,358
19722,076
19731,907
1974178
19754,210
19762,944
1977631
1978106
197912,142
198011,144
198113,722
19823,900
1983894
19841,006
1985159
19863,080
19873,574
1988611
19892,049
19901,015
1991128
199221
19937,693
199413,605
199517,354
19961,429
199798
19983,330
19993,737
2000552
200166
200216
20032,269
20044,273
20051,850
2006592
20071,088

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The long-term trend in area burned is similar to trends at the national level. Area burned is shown by decade since the 1960s in Figure 43 and the fires are mapped in Figure 44. Area burned increased from the 1960s until the 1990s and then fell sharply in the 2000s. As noted above, the low numbers at the beginning of the record may be attributed to data collection techniques that improved starting in the 1970s.Reference 236Although the numbers for the 2000s should be considered with caution since they do not include a full decade, the recent decline may be related to changes in large atmospheric oscillations.Reference 10

Figure 43. Trend in total area burned per decade for the Taiga Plains Ecozone+

The value for the 2000s decade was pro-rated over 10 years based on the average from 2000-2007

Graph
Source: Krezek-Hanes et al., 2011Reference 10
Long description for Figure 43

This bar graph shows the following information:

Trend in total area burned per decade in the Taiga Plains Ecozone+.
DecadeArea burned (km2)
1960s10,443
1970s29,663
1980s40,138
1990s48,410
2000s13,383

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Figure 44. Map of distribution of large fires in the Taiga Plains Ecozone+, 1980s-2000s

Fires shown for the 2000s include through 2007 only.

Map
Source: Krezek-Hanes et al., 2011Reference 10
Long description for Figure 44

This map shows the distribution of large fires in the Taiga Plains Ecozone+, colour coded by decade.  In the 1980s, there were several large areas burned in the southern half of the ecozone+, but also distributed through the north.  The 1990s saw extensive areas burned in the middle of the ecozone+ and in the far northwest.  There was substantially less area burned in the 2000s, and these areas were concentrated in the south of the ecozone+.

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Duration and timing of fires

The average duration of active large fire occurrence is 81 days (about 4 months), which has not changed significantly. This is different from the fire season duration, which is calculated based on fire weather indices and is longer, at approximately 173 days.Reference 239 The fire season is the period of time that the weather is conducive for fires to occur. The numbers documented here are based on the actual occurrence of large fires. Based on this analysis, fires most commonly occur in June through to August, but can occur as early as April and as late as September (Figure 45).

The average duration of the period of fire occurrence has not changed over time but the distribution of fires within the fire season has undergone some subtle changes over the last four decades. The proportion of fires that occur in April has shifted from zero in the 1960s to 1.2% in the 1990s. The proportion of fires that occur in May has been steadily increasing, a statistically significant change (R2=0.93, p=0.035). All fires that were reported in April were human caused; those in May were equally distributed between being caused by humans or lightning. Early-season fires may also occur in dry years when fires from the previous season have smoldered in deep layers of peat throughout the winter, re-emerging as surface fires in the spring.Reference 216 More data are needed to determine if these small changes are the start of a lengthening of the fire season or are artifacts of the large fire database limitations.

Figure 45. Percent of all large fires that occur in each month of the fire season, by decade, 1960s-1990s

Note: this fire trend is based on the number of large fires over 2 km2 in size.

Graphs
Source: Krezek-Hanes et al., 2011Reference 10
Long description for Figure 45

This clustered bar chart shows the following information:

Percent of all large fires that occur in each month of the fire season by decade, 1960s-1990s.
DecadeApril
(percent)
May
(percent)
June
(percent)
July
(percent)
August
(percent)
September
(percent)
Average Duration
(days)
1960s02374115370
1970s06274420294
1980s17225118081
1990s19294611282

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There were no changes in how fires were distributed among the latter months of the fire season, with late-season fires being predominantly caused by lightning, the cause of 83% of Taiga Plains Ecozone+ large fires (Figure 46 a). The proportion of fires caused by lightning in comparison to those caused by humans increased from the 1960s to the 1990s (Figure 46 a). The total area burned as a result of lightning ignitions also increased over the 40 year period (Figure 46 b). This increase in area burned by lightning is most likely due to warmer temperatures during the fire season in the 1990s.Reference 239, Reference 240

Figure 46. Trends in a) proportion of large fires by cause and b) total area burned by lightning and through humans ignitions, by decade, 1960s-1990s

Large fires are defined as over 2 km2.

Graphs
Source: Krezek-Hanes et al., 2011Reference 10
Long description for Figure 46

These two bar graphs show the following information:

Trends in a) proportion of large fires by cause and b) total area burned by lightning and through human ignition, by decade 1960s-1990s.
DecadeTotal human (Percentage)Total lightning (Percentage)Area human (km2)Area lightning (km2)
60s63866,987.883,455.59
70s352272,199.292,7463.55
80s13313217.843,9920.39
90s222321,282.615,4691.92

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Insect outbreaks

Trends in large-scale native insect outbreaks are correlated with weather conditions and forest fires, both of which influence the likelihood of insect outbreaks. Insect outbreaks can repeatedly defoliate trees, causing failure of the trees to reproduce (produce cones) and causing reduction in growth and vigour. Additionally, multi-species infestations may further damage trees already weakened by an initial attack. Significant insect pests in the ecozone+ are spruce budworm (Choristoneura fumiferana), larch sawfly (Pristiphora erichsonii), and forest tent caterpillar (Malacosoma disstria).

Spruce budworm, by far the most serious pest in the Taiga Plains Ecozone+, is a small moth known for severe and extensive outbreaks causing heavy defoliation in fir and spruce trees, particularly in the boreal forest.Reference 241 The outbreaks can last 5 to 15 years and populations can reach extremely high densities.Reference 242 Outbreaks of the spruce budworm are closely tied to climate, although the specific weather factors favouring outbreaks are not well understood.Reference 243 Outbreaks are initiated by tight synchrony between the larvae forming feeding sites and the tree’s developing buds. Spring frosts can affect the buds and cause budworm collapsesReference 244 and frosts probably limit the northern distribution of the budworm.

In the NWT, a recent outbreak was severe. At its peak (2002), the budworm moderately or severely defoliated approximately 24,000 km2 of white spruce.Reference 243 Although this outbreak collapsed throughout most of the NWT between 2003 and 2005, it has persisted in and moved progressively further north in the Sahtu (Norman Wells) region.Reference 46, Reference 115 

Spruce budworm outbreaks in the Fort Nelson area are concentrated in mature white spruce stands and aspen/spruce mixed stands.Reference 241 Based on analysis of tree rings, outbreaks in this part of the ecozone+ occur on average every 26 years, with five to six outbreaks in the 20th century. The most recent outbreak extended from about 1987 to 2003.Reference 245, Reference 246

Forest tent caterpillar is a hardwood defoliator, in particular attacking trembling aspen. Otvos et al., 2010Reference 247 analyzed the six outbreaks that have occurred since the start of detailed record keeping in 1944 in British Columbia. They found that outbreaks have become larger in extent and longer in duration. Forty-six percent of aspen defoliation in the province (resulting from all six outbreaks combined) occurred in the boreal white and black spruce biogeoclimatic zone. The outbreak in the 1990s was concentrated around Fort Nelson.Reference 246

The NWT experienced its first outbreak of forest tent caterpillar in the mid-1990s in the Liard Valley in the southwest corner of the NWT part of the ecozone+.Reference 248 The outbreak lasted two to three years, peaking in 1996.Reference 248 As forest tent caterpillar eggs are susceptible to mortality during winter cold spells,Reference 249 the strong trend to warmer winters experienced in the Taiga Plains over the past 50 years has likely contributed to the increase in tent caterpillar outbreaks in the ecozone+.

Mountain pine beetle reached the Fort Nelson Forest District in 2010, spreading along the Kechika River corridor.Reference 250 There are extensive pine plateaus in this region potentially at risk if the infestation increases in intensity and extent.Reference 246

Mountain pine beetle is present in the Alberta part of the Taiga Plains Ecozone+, and reached a few kilometers into the Northwest Territories in the summer of 2012.Reference 251 Infestation levels in the northern part of Alberta are low relative to the most affected area in the centre of the province.Reference 252 However, surveys of the ratio of new infestations to infestations from the previous year in Alberta, conducted in the summer of 2010, showed that the beetle is spreading in the north.Reference 252 A survey of winter mortality conducted the following spring (2011) concluded that there was a high survival rate of beetles, leading to forecasts of further increases in beetle infestation.Reference 253 Beetles were first detected in the west-central part of Alberta in 2006, rapidly becoming abundant and spreading east.Reference 252 There have been localized outbreaks of mountain pine beetle in Alberta in the past, including small pockets of infestations in the north since 2001.Reference 254

The mountain pine beetle’s preferred host is mature, even-aged pine standsReference 250 – thus forest management practices, including fire suppression, have an impact on the spread of this insect pest. Climate is also an important factor: temperatures of -40°C are required to cause sufficient winter mortality to result in declines.Reference 254 While the mountain pine beetle is likely at the far northern limit of its range in the Taiga Plains under current climatic conditions, there is potential for more serious eruptions and further expansion of its range under future climate change.Reference 255

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Key finding specific to ecozone+
Wildlife disease and parasites

Theme Habitat, wildlife, and ecosystem processes

Ecozone+ key finding: Wildlife disease is of importance to the Taiga Plains Ecozone+ for ecological, economic, and human health reasons. Bovine tuberculosis and brucellosis affect a high percentage of wood bison and present risks to human health and to economic activities. There is emerging evidence and growing concern that some wildlife diseases and parasites (including anthrax, ungulate parasites, and viruses and funguses affecting frogs) may be increasing in prevalence and/or range, or may do so in the future, in response to warmer weather and changes in wildlife species distribution.

The status of wildlife health in the Taiga Plains is mostly undescribed although the knowledge base is starting to improve through community-based monitoring, at least for wildlife species important to people. For example, the status of caribou health in parts of the ecozone+ was monitored through hunters working with biologists and veterinarians from 2003 to 2008. Hunters and Elders were interviewed to document their local ecological knowledge of wildlife health and local hunters were trained as monitors to collect tissue samples and measurements to assess body condition and monitor health of harvested caribou (n=69) and moose (n=19). In 2007 the program was extended to include participation in the annual caribou hunt held by one community.Reference 256

Changes can be expected in disease and parasites in the ecozone+ from two climate-change-related factors:

  1. Temperature dependency of parasites and pathogens for some diseases. For example, moose tick outbreaks in Alberta are known to coincide with warmer temperatures in spring and with earlier snow loss.Reference 257
  2. Expansion of the range of endemic species or the colonization of regions of the ecozone+ by non-native species. An example is the spread of muskoxen into the northeast Taiga Plains starting in the 1990s from northeast of Great Bear Lake where the muskoxen were known to be infected with a lungworm. In this example, there was a concern that the muskoxen could pass the infection to Dall sheep. However, studies showed that infection across species did not occur under experimental conditions.Reference 258

This section draws from Wildlife pathogens and diseases in CanadaReference 11 and Northern caribou population trends in Canada,Reference 97 technical thematic reports prepared for the 2010 Ecosystem Status and Trends Report.

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Diseases affecting ungulates

Bovine tuberculosis

Bovine tuberculosis (BTb) is caused by infection with the bacterium Mycobacterium bovis. It readily infects domestic cattle, and in people it causes a disease indistinguishable from human tuberculosis (infection with M. tuberculosis). Infected animals, meat products, and milk are significant health hazards for people, and for public health reasons, BTb was successfully eradicated from Canada’s domestic animal population through a long and costly program of testing all herds and slaughtering entire herds in which any infected animals were detected.

Bison in Wood Buffalo National Park and adjacent areas became infected with BTb in the 1920s (see section on wood bison in the Species of special interest key finding on page 54). Infection has persisted in this herd and surveys between 1997 and 1999 found that approximately 49% of these bison were infected.Reference 259 In the past two decades, other populations of wild bison, apparently free of infection with BTb, have become established in the Taiga PlainsReference 260 (Figure 31). Measures to prevent the spread of BTb to these infection-free herds are not fully effective and the disease has spread west in recent years.Reference 163, Reference 261 Thus, the potential spread of BTb from infected to non-infected wild bison, all of which are assessed as Threatened by the Committee on the Status of Endangered Wildlife in Canada, and also to livestock, is a major conservation and socio-economic issue.

Brucellosis

Brucellosis is the name given to all diseases caused by infection with any of the several different species of the bacterial genus Brucella. The clinical manifestations of brucellosis are many, but the most common are infection and inflammation of the female and male reproductive tracts with resulting abortion and male infertility, and infection of joints and tendon sheaths resulting in progressive lameness. Infection persists, often for the lifetime of the animal. People are similarly susceptible to infection with Brucella sp., and brucellosis in animals with which people have contact is a public health risk.Reference 262-Reference 264

Infection with Brucella sp. is of potential ecological and public health significance in bison in and around Wood Buffalo National Park, where the bison populations infected with bovine tuberculosis are co-infected with bovine brucellosis caused by Brucella abortus.Reference 265 Approximately 30% of bison in Wood Buffalo National Park area are infected.Reference 259

Brucella suis biotype 4 is present in barren-ground caribou in northern Canada:Reference 263 20 to 50% of animals in various herds are infected.Reference 266, Reference 267 However, the ecological impact, if any, on infected populations is not known. Infection of northern people with this bacterium occurs and is associated with consumption of caribou.Reference 263, Reference 264 Whether or not B. suis biotype 4 is a naturally occurring pathogen in North America or a pathogen introduced from Europe in imported reindeer also is not known. There are no records of this infection in woodland caribou.

As noted for bovine tuberculosis, it seems certain that without effective intervention of some form bovine brucellosis will spread to non-infected wild bison herds progressively over time, and that the vast majority of wild bison in Canada then will be infected.Reference 260 This will place bison recovery efforts further at odds with livestock economies and public health interests. Too little is known about the ecology of Brucella in caribou to identify current trends or predict future trajectories.

Anthrax

Anthrax is the name given to all forms of disease caused by infection with the bacterium Bacillus anthracis. It is most typically a disease of wild and domestic ungulates, in which it usually is rapidly fatal. Mammalian predators and scavengers also die regularly during anthrax outbreaks in ungulates. Humans are susceptible to anthrax and disease in people ranges from a self-limiting infection of the skin to fatal disease. Ungulates generally become infected from bacterial spores in soil. Environmental conditions that cause these spores to persist for decades or even centuries in soil and to concentrate on the soil surface, such as high-calcium soil chemistry for spore persistence, and flooding followed by dry periods for spore concentration, appear to be major risk factors in outbreaks of anthrax in wild and domestic ungulates. Animal to animal transmission of the bacterium plays only a minor role. Anthrax probably was introduced to North America by European exploration and settlement.Reference 268-Reference 270

In Canadian wildlife, anthrax has been recognized most often in bison in and around Wood Buffalo National Park. The first recognized outbreak was in 1962 and sporadic outbreaks have occurred ever since, often with inter-outbreak time spans of many years (see the wood bison section of the Species of special interest key finding on page 54). The total number of bison and other species to have died of anthrax is unknown, but a minimum of 1,309 bison in the Taiga Plains died of the disease in outbreaks between 1962 and 1993 and a 2012 outbreak killed 440 bison.Reference 166 The occurrence of outbreaks in wild bison and in livestock appear linked to climatic factors, particularly intense precipitation followed by drought. To date, no predictive models have been published with respect to outbreaks of anthrax in Canada and predicted climate change.

Johne’s disease

The bacterium causing Johne’s disease, known for causing chronic wasting and diarrhea in cattle, has been found in caribou from Greenland and was found at low levels in Bluenose-West caribou in 2008.Reference 271 The bacterium has also been found in wood bison.Reference 272

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Parasites affecting ungulates

Besnoitiosis

Besnoitia is a genus of protozoan parasite which develops pin-head sized cysts in the skin and connective tissues of its herbivore intermediate host and typical coccidial forms in the intestines of its carnivore definitive hosts. No disease due to Besnoitia has been recognized in definitive hosts, but intermediate hosts sometimes develop disease conditions associated with severe infections.Reference 273 In Canada, Besnoitia tarandi infects caribou and probably muskoxen. Infection is very common in barren-ground caribou and has been described in woodland caribou.Reference 274, Reference 275 Although occasional severe manifestations of infection on the skin have been seen, most infections appear to have little or no health consequences for these species.

The status of Besnoitia, assessed from caribou harvested in the fall from 2007 to 2009 from several Canadian herds, was variable, with the Bluenose-West Herd having an infection rate in the range of 30 to 45%.Reference 276

Winter tick

Throughout most of their range in North America, moose suffer periodic events of high mortality in late winter associated with severe infestations with winter tick, Dermacentor albipictis. This tick is native to North America and infests other hosts including woodland caribou and bison. However, severe infestations frequently resulting in death are common only in moose. Winter ticks occur in the southern Taiga Plains ecozone+,Reference 277 and have recently been found further north in the Mackenzie Valley between Tulita and Fort Good Hope.Reference 278, Reference 279

Weather events affect the abundance of the ticks, particularly conditions in April when gravid adult female ticks drop to the ground and may survive to lay eggs, thus affecting the numbers of larvae available to infest moose the following fall. Environmental conditions also affect the resilience of the moose, particularly conditions in late winter and early spring the following year when infested moose must endure the ticks. There are not sufficient historical records to determine if there are trends in winter tick infestations and their effects on moose populations. Hunters along the Mackenzie River in the Northwest Territories have recently observed moose in the spring with severe hair loss typical of winter tick infestation, a phenomenon new to the Traditional Knowledge of First Nations in the region.Reference 280

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Diseases affecting amphibians

Frogs are at the northern limit of their distribution in the Taiga Plains. Pathogens that are affecting amphibians globally have recently been detected in the ecozone+.

  • Ranaviruses, lethal viruses responsible for die-offs of amphibians world-wide wideReference 281 have recently been found in wood frogs in the NWT portion of the Taiga Plains.Reference 282
  • Chytrid fungus, Batrachochytrium dendrobatidis (Bd), which infects the skin of amphibians, has been linked to catastrophic amphibian declines around the world since the 1990s.Reference 283 There is strong evidence linking Bd to the declines of amphibian species in western North America.Reference 284, Reference 285 Bd was found in samples at a single site in the Taiga Plains in a 2007 to 2008 study,Reference 282 but was detected in all three species of amphibians in the survey area (wood frogs, boreal chorus frogs, and western toads).

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Key finding 20
Food webs

Theme Habitat, wildlife, and ecosystem processes

National key finding
Fundamental changes in relationships among species have been observed in marine, freshwater, and terrestrial environments. The loss or reduction of important components of food webs has greatly altered some ecosystems.

Ecozone+ key finding: There is little information on changes in food webs in the Taiga Plains. Abundance of many mammals in the Taiga Plains is cyclic, driven or influenced by food web effects as well as drivers like climate. Changes in small mammal cycles have been reported in other northern regions, and a recent dampening of snowshoe hare and lynx cycles is noted in the NWT. Northern tundra caribou wintering in the Taiga Plains have declined in abundance which may reflect a low period on a population cycle. Declining boreal caribou populations in the south of the ecozone+ may be affected by changes in predator-prey dynamics related to habitat alteration.

Cycles in population abundance

Cyclic abundance is perhaps the best-known feature of community and population dynamics in the Taiga Plains. The amplitude and frequency of cyclic abundance depend on body mass (smaller species cycle at a higher rate). Large-bodied mammals: moose, muskoxen, boreal caribou, and wood bison, do not appear to exhibit cyclic dynamics.

Migratory tundra (barren-ground) caribou wintering in the northern Taiga Plains likely are cyclic in their abundance, based on what is known about herds elsewhere,Reference 127 with the halving time in their herd size being from 5 to 7 years (see Species of special interest key finding on page 59). The Bluenose-West herd has experienced a sharp decline – a drop in abundance from 1992 to 2004 from over 110,000 to about 18,000 caribou – followed by a leveling off at this lower population. This may be a low point in the cyclic patterns of northern caribou abundance. Management actions have been taken to reduce harvest. Continued monitoring will show if altered conditions in the caribou range (for example, changes in fire ecology or in snow condition on winter range)Reference 97 affect the herd’s ability to rebound from the current phase of low abundance.

Typically, the highs and lows in abundance of cyclic mammals can differ by an order of magnitude and vary in timing and extent even between neighbouring regions.Reference 286 Cycles or fluctuations in mice, voles, lynx, and snowshoe hare are well documented (Figure 47 and Figure 48 and Danell et al., 1998Reference 287). The amplitude of the snowshoe hare and lynx cycles has dampened over time (Figure 48). Fluctuations in abundance among grouse and ptarmigan species have also been noted in this ecozone+.Reference 288 Cycles in prey species are linked to cycles in predators, especially for specialized predators (Figure 48). Prey abundance also influences generalist predators such as foxes and they, in turn, influence the abundance of alternate prey species.Reference 289

Climate variability also has a role in entraining spatial and temporal variability in abundance in the boreal forest.Reference 290 However, how climate interacts with direct and indirect effects on mechanisms causing cycles is both complex and only partially understood. Across North America, the amplitude of hare populations in peak years and forest fires (total burned area) are correlated.Reference 291, Reference 292 Changes in climate and fire activity have the potential to affect both the synchrony and the amplitude of hare cycles across large areas in the ecozone+. Murray, 2003Reference 293 reported that synchrony in hare population cycles across North America have recently declined, although the reasons for the decoupling are uncertain. Similarly in northern Europe, the cyclic abundance for grouse, mice and voles as well as the larch bud moth has diminished or disappeared. These collapses may be linked to changes in climate.Reference 294 With the exception of the dampening of the snowshoe hare and lynx cycle in the NWT (Figure 48), changes and collapses in hare and small mammal cycles have not been observed in the Taiga Plains so far, however longer datasets from continuing monitoring programs will be required to detect changes in synchrony and amplitudes of cycles in all northern ecozones+.

Figure 47. Trends in small mammal abundance in northern, central, and southern areas of the Taiga Plains Ecozone+, 1990-2012

Based on surveys over 5 nights in August, 100 traps per night.

Graph and map
Source: Environment and Natural Resources, 2012.Reference 295 Data coordinated by the NWT Small Mammal Survey, Government of the Northwest Territories. Participating groups: Ducks Unlimited Canada (Cardinal Lake); Sahtu Renewable Resources Board (Tulita); Gwich'in Renewable Resource Board (Inuvik); Protected Areas Strategy Secretariat (Trout Lake); ENR (all other sites).
Long description for Figure 47

This graphic is composed of three line graphs of a small mammal abundance index and a map that indicates the sampling locations in the north, south and central regions of the Taiga Plains Ecozone+. The three line graphs show the following information:

Trends in small mammal abundance in northern, central and southern areas of the Taiga Plains Ecozone+, 1990-2009. Abundance Index (number per 100 trap nights)
YearNorth

Cardinal Lake
North

Inuvik
Center

Norman Wells
Center

Tulita
South

Fort Smith
South

Fort Liard
South

Fort Simpson
South

Trout Lake
1990-1215-16---
1991-134-5---
1992----11-4-
1993--1-13115-
1994--5-15376-
1995--18-353810-
1996--6-15170-
1997--26-13343-
1998--33-205016-
1999--5-7247-
2000--6-5-1-
2001--4-17---
2002--6-21-5-
20032-10-14-2-
20047-9135-0-
2005162931-8-2-
20069922-16-7-
2007121816-21-215
2008-418-----
2009--------
2010--------
2011--------
2012--------

 

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Figure 48. Density of snowshoe hares, 1987-2012, and trapper success for lynx, 1958-2012 in the NWT part of the Taiga Plains Ecozone+
Graph and map
Source: Environment and Natural Resources, 2012Reference 295
Long description for Figure 48

This line graph shows the estimated density of snowshoe hares and trapper success for lynx in the Northwest Territories part of the Taiga Plains Ecozone+.  Hare density is highly variable between years and cycles through highs and lows, with highs in the early 1960s and 70s, the late 1970s, the early 1990s and 2000.  Data on the number of lynx pelts from 1987-2009 is overlaid on the hare data, and shows high numbers of lynx pelts sold at auction in the same years that hare density was high.  However, after 2005, hare density stays high, but the number of lynx pelt sold drops.

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Predator-prey relations: boreal caribou

There may be impacts on boreal caribou in the southern part of the ecozone+ related to changes in predator-prey relations, in turn related to habitat changes from forest harvest practices and habitat fragmentation, possibly combined with higher rates of areas burned. This is based on the conclusion from several studies that the most significant proximate cause of boreal caribou declines in Canada is increased predation driven by landscape changes that favour younger forests and higher densities of alternative prey (moose and deer, in this part of the ecozone+).Reference 181 Boreal caribou are declining in the southern part of the ecozone+ (see the Woodland caribou, boreal population section of the Species of special interest key finding on page 60).

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Aquatic food webs

Food webs are complex and the first indications of significant changes can be through indirect, unpredictable effects. In aquatic ecosystems, food web changes are a suspected cause of increases in some contaminants (or less of a decrease than would be expected, based on declines in legacy contaminants elsewhere). This has been proposed as one explanation for contaminant levels and trends in Great Slave LakeReference 123, Reference 296 (see Contaminants key finding). In the Boreal Cordillera, this effect was demonstrated for lake trout: differences in the food web compared with neighbouring lakes (related in part to fishing pressure) resulted in a higher degree of biomagnification of organochlorines Lake Laberge in the southern Yukon.Reference 297, Reference 298

Other factors that can be expected to alter aquatic food webs (and may be altering them now) include warmer water temperatures, resulting in changes in fish distribution in streams. The extent of thaw slumping (slope failure from thawing of ground ice) is increasing in Mackenzie Delta lakes, and is leading to changes in aspects of water quality that determine biotic communities, with an expected consequence of shifts in aquatic food webs (see Wetlands key finding on page 18).

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Footnote

Footnote *

A boreal caribou local population is a group of boreal caribou occupying a defined area distinguished spatially from areas occupied by other groups of boreal caribou. Local population dynamics are driven primarily by local factors affecting birth and death rates, rather than immigration or emigration among.Reference 109

Return to footnote * referrer

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Theme: Science/Policy Interface

Key finding 21
Biodiversity monitoring, research, information management, and reporting

Theme Science/policy interface

National key finding
Long-term, standardized, spatially complete, and readily accessible monitoring information, complemented by ecosystem research, provides the most useful findings for policy-relevant assessments of status and trends. The lack of this type of information in many areas has hindered development of this assessment.

Ecozone+ key finding: Important data sets collected through broadscale monitoring programs for the ecozone+ are mainly at the non-biological level: climate, hydrology, and permafrost monitoring. In addition, data on some species groups, notably some caribou populations, small mammals, and waterfowl, provide good trend information. A combination of remote sensing and short-term research projects, often extending into the past through the use of proxy records, provides some data on landscape-level changes. A priority often identified for the region is improvement of the use of Traditional Knowledge along with results from science-based studies.

Relatively long-term monitoring programs that are established in the Taiga Plains include small-mammal monitoring to track trends in food webs and population cycles in the boreal forest, and permafrost monitoring along the Mackenzie Valley, providing a latitude transect and a time series of permafrost trends. Most wildlife population data are sporadic, and information is lacking particularly on several boreal caribou herds, landbirds, and predators. Wildlife parasites and disease and forest insect pests show early indications of changes that warrant follow-up through monitoring and research.

Detecting trends over the extensive deltas and forested river valleys and plateaus can only be accomplished by monitoring over large areas. Studies that look at patterns of vegetation and landforms in relation to latitude and climate (for example, Lantz et al., 2010Reference 33) provide the baseline information needed to design effective monitoring at this scale.

Because of this need to monitor changes at broad scales in the ecozone+, and because ground-based monitoring is in short supply, surveys and studies conducted through remote sensing hold potential for improving understanding of status, trends, and ecosystem processes in the Taiga Plains. In some cases, where ground-based monitoring that has been discontinued (for example, monitoring of lake ice phenologyReference 299), satellite-based monitoring can be used to look at short-term trends or to extend existing time series. Results from studies conducted by remote sensing have provided trend data reported on here – including data on primary productivity, fires, and changes in the treeline zone.

Effective ecological monitoring needs ecosystem-based research to direct priorities and to help interpret results. Studies such as the Mackenzie GEWEX (Global Energy and Water Cycle Experiment) Study (MAGS) provide detailed information on the status and trends in the atmospheric and hydrological systems of the Mackenzie River Basin. MAGS involves coordinated research into many atmospheric, land surface, and hydrological issues associated with cold climate systems.Reference 300

A monitoring and research priority frequently identified for the region is the need to develop methods that make use of all types of knowledge more effectively.Reference 100, Reference 102, Reference 142, Reference 301 Both science-based work and Traditional Knowledge studies have their limitations when used to look ahead to consequences of future stressors. Baselines are shifting; Traditional Knowledge roots are deep in the past and often based on knowledge gained under a less changeable environment with different conditions. The same dilemma occurs with science-based studies, though on a more compressed timescale, as older studies often are not applicable any more. This points out the need to understand current baseline conditions and drivers of change, as well as to combine forces through coordinated Traditional Knowledge and science studies.Reference 19

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Key finding 22
Rapid change and thresholds

Theme Science/policy interface

National key finding
Growing understanding of rapid and unexpected changes, interactions, and thresholds, especially in relation to climate change, points to a need for policy that responds and adapts quickly to signals of environmental change in order to avert major and irreversible biodiversity losses.

Ecozone+ key finding: There are signals of rapid ecosystem change in the Taiga Plains, related to climate change. Loss of frozen peatlands is occurring in some areas; increasing permafrost temperatures at several sites is an early warning that other areas will cross the phase-change threshold leading to permafrost degradation, altering terrestrial and aquatic ecosystems. Other large-scale changes observed in recent years include increases in primary productivity, mainly in the north of the ecozone+, and alteration of vegetation communities in the treeline zone.

Early detection of rapid change requires coordination of ecosystem research and monitoring (science-based and local knowledge) to observe and interpret the responses of ecosystems to stresses. Signals from research and monitoring in the Taiga Plains that may indicate rapid change or approaching thresholds:

Loss of frozen peat plateaus – an observed trend in parts of the ecozone+, has led to significant changes in ecosystems in the Taiga Shield Ecozone+ (in northern Quebec), with conversion of lichen-rich black spruce forest to wetlands. Permafrost monitoring in the Mackenzie Valley reveals that permafrost is warming --this in itself does not have ecological impacts – but signifies an approaching period of more extensive permafrost thawing that is known to have widespread ecological consequences.Reference 12, Reference 19 Thawing of permafrost is a phase change – abrupt by definition (Ice across biomes key finding on page 22).

Signs of change in the treeline zone that indicate fundamental alteration of ecosystems: broadscale increase in tall shrubs, decrease in lichen cover. (Forest key finding on page 13).

Annual growth rates of white spruce in relation to spring temperature: About 75% of white spruce in the study area in the north of the ecozone+ experienced an abrupt change in this relationship (with decreased growth rates), indicative of a threshold having been crossed.Reference 30 (Forest key finding on page 13).

Mismatches in timing: an emerging issue to track for the ecozone+, with warmer temperatures in the spring resulting in earlier ice break-up and earlier peaks of plant growth. A mismatch between peak food source abundance and hatch dates may be a cause of declines of scaup in the western boreal forest (Species of special interest key finding on page 54 and discussion above on climate trends since 1950).

Delta flood regime. A possible emerging trend with potential for rapid, extensive ecosystem change is alteration of flood regimes in the Slave and Mackenzie deltas. The thousands of small lakes and wetlands provide a diversity of habitats important to wildlife; wetland productivity and diversity are maintained by periodic replenishment of sediments and nutrients from high spring floods. Reduction of flooding in north-flowing river systems in North America is a predicted consequence of climate change. In the Slave Delta, high flood frequency may be declining (Wetlands key finding on page 18).

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Conclusion: Human Well-Being and Biodiversity

The Taiga Plains Ecozone+, with its forested plateaus and river valleys dotted with thousands of lakes and wetlands, forms a broad, uninterrupted corridor extending from Canada’s boreal forest ecozones+ in the south almost to the Arctic Ocean. It is bordered to the west by the Taiga Cordillera and to the east by the Taiga Shield, both with predominantly patchy, often sparse, forest stands and bare rock. Continuation of the trend of expansion and intensification of settlement, agriculture, and industrial development along the southern zone of Canada’s boreal forest brings with it increases in fragmentation and landuse conversion. Associated forest harvest and fire suppression alter age characteristics and structure of the forest in the more densely settled parts of Canada’s boreal ecozones+. The Taiga Plains may increasingly become nationally important as a refuge and a corridor for boreal forest biota that require large intact tracts of mixed-age and mature coniferous forest.

This is illustrated by the distribution of boreal caribou in Canada (Figure 49). The range of the woodland caribou, including the boreal population, has retracted significantly from historical distributions. The southern limit of distribution has progressively receded in a northerly direction since the early 1900s, a trend that continues now.Reference 183, Reference 185-Reference 187 The Taiga Plains Ecozone+ is also important as a migration corridor and connecting habitat for other species, including predators and migratory birds. Two iconic at-risk species, wood bison and whooping crane, extirpated throughout most of their North American ranges through habitat change, were left with tiny remnant populations in the Taiga Plains. Both have been subjects of decades of recovery actions and the continuation of both species is still dependent upon large blocks of intact, protected habitat within the ecozone+.

Figure 49. Current distribution of boreal caribou and historical (early 1900s) distribution of woodland caribou (Rangifer tarandus caribou) in Canada
Map
Source: Environment Canada, 2012Reference 109
Long description for Figure 49

This map shows the current distribution and historical (early 1900s) range limits of boreal woodland caribou (Rangifer tarandus caribou) across northern Canada.  The current distribution aligns with the boundaries of the Taiga Plains Ecozone+ and then stretches across the northern half of Saskatchewan, and the central parts of Manitoba, Ontario, Quebec and Labrador. The historical southern limits of the species’ range extend substantially further south, down through most of BC and into Montana, along the edge of the prairies and includes most of Ontario, Quebec and eastern Canada.

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The people who live in the Taiga Plains are well aware of the value of their land. Hunting, fishing, berry and plant gathering, and trapping remain important cultural and economic activities for many residents – for example, almost all households in Gwich’in communities collect berries and 20 to 30% of Taiga Plains households in the NWT obtain most or all of their meat and fish from the land. Forest harvest in the south, wilderness tourism, recreation, and guided hunting and fishing are other economic sectors dependent upon healthy ecosystems.

Because of this strong attachment to the land and because the Taiga Plains and the lands and the sea to its north contain oil and gas reserves, this ecozone+ has a rich history of grappling with issues around sustainable development. The ecozone+ is a centre of studies, dialogue, and co-operatively managed work aimed at balancing the goal of conservation of (and respect for) the land (encompassing ecosystems and traditional cultures) with the goal of creating flourishing, sustainable community economies.

Processes and initiatives centred in the Taiga Plains have influenced land claim settlements, co-management processes, and ideas and practices around involving Aboriginal Peoples and Traditional Ecological Knowledge across much of the North. Proposed oil and gas and pipeline developments led to assessments, consultations, and recommendations, from the Berger inquiry of the 1970sReference 302 to the recent Mackenzie Gas Project assessment. Reference 303, Reference 304 Agencies and renewable resource management boards and councils in the ecozone+ have supported major research and monitoring programs and projects on cumulative effects, ecological indicators, baseline information, land-use planning, and methods and promotion of the use of Traditional Ecological Knowledge in environmental monitoring, planning, and management.Reference 59 Examples are the Mackenzie River Basin Impact Study,Reference 305 the West Kitikmeot Slave Study,Reference 306 the NWT Cumulative Impact Monitoring Program,Reference 217 and the Arctic Borderlands Ecological Knowledge Co-op.Reference 99

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References

Reference 1

Environment Canada. 2006. Biodiversity outcomes framework for Canada. Canadian Councils of Resource Ministers. Ottawa, ON. 8 p.

Reference 1

Reference 2

Federal-Provincial-Territorial Biodiversity Working Group. 1995. Canadian biodiversity strategy: Canada's response to the Convention on Biological Diversity. Environment Canada, Biodiversity Convention Office. Hull, QC. 86 p.

Reference 2

Reference 3

Federal, Provincial and Territorial Governments of Canada. 2010. Canadian biodiversity: ecosystem status and trends 2010. Canadian Councils of Resource Ministers. Ottawa, ON. vi + 142 p.

Reference 3

Reference 4

Mackenzie Gas Project. 2010. Environmental impact statement for the Mackenzie Gas Project (download page for 8 volumes plus supplemental material) [online]. Mackenzie Gas Project. (accessed May, 2012).

Reference 4

Reference 5

Ecological Stratification Working Group. 1995. A national ecological framework for Canada. Agriculture and Agri-Food Canada, Research Branch, Centre for Land and Biological Resources Research and Environment Canada, State of the Environment Directorate, Ecozone Analysis Branch. Ottawa, ON/Hull, QC. vii + 125 p.

Reference 5

Reference 6

Rankin, R., Austin, M. and Rice, J. 2011. Ecological classification system for the ecosystem status and trends report. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 1. Canadian Councils of Resource Ministers. Ottawa, ON. ii + 14 p.

Reference 6

Reference 7

Gunn, A., Eamer, J. and Carrière, S. In Prep. 2013. Taiga Plains Ecozone+ status and trends assessment. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Ecozone+ Report. Canadian Councils of Resource Ministers. Ottawa, ON.

Reference 7

Reference 8

Bonsal, B. and Shabbar, A. 2011. Large-scale climate oscillations influencing Canada, 1900-2008. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 4. Canadian Councils of Resource Ministers. Ottawa, ON. iii + 15 p.

Reference 8

Reference 9

Zhang, X., Brown, R., Vincent, L., Skinner, W., Feng, Y. and Mekis, E. 2011. Canadian climate trends, 1950-2007. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 5. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 21 p.

Reference 9

Reference 10

Krezek-Hanes, C.C., Ahern, F., Cantin, A. and Flannigan, M.D. 2011. Trends in large fires in Canada, 1959-2007. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 6. Canadian Councils of Resource Ministers. Ottawa, ON. v + 48 p.

Reference 10

Reference 11

Leighton, F.A. 2011. Wildlife pathogens and diseases in Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 7. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 53 p.

Reference 11

Reference 12

Smith, S. 2011. Trends in permafrost conditions and ecology in Northern Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 9. Canadian Councils of Resource Ministers. Ottawa, ON. iii + 22 p.

Reference 12

Reference 13

Ahern, F., Frisk, J., Latifovic, R. and Pouliot, D. 2011. Monitoring ecosystems remotely: a selection Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 17 of trends measured from satellite observations of Canada. . Canadian Councils of Resource Ministers. Ottawa, ON.

Reference 13

Reference 14

Cannon, A., Lai, T. and Whitfield, P. 2011. Climate-driven trends in Canadian streamflow, 1961-2003. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 19. Canadian Councils of Resource Ministers. Ottawa, ON.

Reference 14

Reference 15

Monk, W.A. and Baird, D.J. 2011. Biodiversity in Canadian lakes and rivers. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 20. Canadian Councils of Resource Ministers. Ottawa, ON.

Reference 15

Reference 16

Ecosystem Classification Group. 2009. Ecological regions of the Northwest Territories: Taiga Plains. Environment and Natural Resources, Government of the Northwest Territories. Yellowknife, NT. 173 p.

Reference 16

Reference 17

Geological Survey of Canada. 1994. Surficial materials of Canada, map 1880A [online]. Natural Resources Canada. (accessed 23 October, 2009).

Reference 17

Reference 18

National Energy Board. 2010. National Energy Board approves Mackenzie Gas Project (news release, December 16 2010) [online]. (accessed May, 2012).

Reference 18

Reference 19

Mackenzie River Basin Board. 2010. Mackenzie River Basin: state of the aquatic ecosystem report. Produced for the Mackenzie River Basin Board by Hatfield Consultants and J.D.Meisner and Associates Ltd. Mackenzie River Basin Board. Fort Smith, NT. 100 p.

Reference 19

Reference 20

Wetlands International. 2007. RAMSAR sites information service [online]. (accessed 17 November, 2009).

Reference 20

Reference 21

Parks Canada. 2012. Canada's existing World Heritage Sites [online]. (accessed 18 January, 2013).

Reference 21

Reference 22

Statistics Canada. 2000. Human activity and the environment 2000. Human Activity and the Environment, Catalogue No. 11-509-XPE. Statistics Canada. Ottawa, ON. 332 p.

Reference 22

Reference 23

Statistics Canada. 2008. Human activity and the environment: annual statistics 2007 and 2008. Human Activity and the Environment, Catalogue No. 16-201-X. Statistics Canada. Ottawa, ON. 159 p.

Reference 23

Reference 24

Statistics Canada. 2006. 2006 Community profiles [online]. (accessed 22 October, 2009).

Reference 24

Reference 25

Lee, P., Gysbers, J.D. and Stanojevic, Z. 2006. Canada's forest landscape fragments: a first approximation (a Global Forest Watch Canada report). Global Forest Watch Canada. Edmonton, AB. 97 p.

Reference 25

Reference 26

Gamache, I. and Payette, S. 2004. Height growth response of tree line black spruce to recent climate warming across the forest-tundra of eastern Canada. Journal of Ecology92:835-845.

Reference 26

Reference 27

Gamache, I. and Payette, S. 2005. Latitudinal response of Subarctic tree lines to recent climate change in eastern Canada. Journal of Biogeography32:849-862.

Reference 27

Reference 28

Payette, S. 2007. Contrasted dynamics of northern Labrador tree lines caused by climate change and migrational lag. Ecology88:770-780.

Reference 28

Reference 29

Danby, R.K. and Hik, D.S. 2007. Evidence of recent treeline dynamics in southwest Yukon from aerial photographs. Arctic60:411-420.

Reference 29

Reference 30

Pisaric, M.F.J., Carey, S.K., Kokelj, S.V. and Youngblut, D. 2007. Anomalous 20th century tree growth, Mackenzie Delta, Northwest Territories, Canada. Geophysical Research Letters34, L05714, 5 p.

Reference 30

Reference 31

Olthof, I. and Pouliot, D. 2010. Treeline vegetation composition and change in Canada's western Subarctic from AVHRR and canopy reflectance modeling. Remote Sensing of Environment114:805-815.

Reference 31

Reference 32

Harsch, M.A., Hulme, P.E., McGlone, M.S. and Duncan, R.P. 2009. Are treelines advancing? A global meta-analysis of treeline response to climate warming. Ecology Letters12:1040-1049.

Reference 32

Reference 33

Lantz, T.C., Gergel, S.E. and Kokelj, S.V. 2010. Spatial heterogeneity in the shrub tundra ecotone in the Mackenzie Delta region, Northwest Territories: implications for Arctic environmental change. Ecosystems13:194-204.

Reference 33

Reference 34

Lantz, T.C., Kokelj, S.V., Gergel, S.E. and Henryz, G.H.R. 2009. Relative impacts of disturbance and temperature: persistent changes in microenvironment and vegetation in retrogressive thaw slumps. Global Change Biology15:1664-1675.

Reference 34

Reference 35

Lantz, T.C., Gergel, S.E. and Henry, G.H.R. 2010. Response of green alder (Alnus viridis subsp. fruticosa) patch dynamics and plant community composition to fire and regional temperature in north-western Canada. Journal of Biogeography37:1597-1610.

Reference 35

Reference 36

D'Arrigo, R.D., Kaufmann, R.K., Davi, N., Jacoby, G.C., Laskowski, C., Myneni, R.B. and Cherubini, P. 2004. Thresholds for warming-induced growth decline at elevational tree line in the Yukon Territory, Canada. Global Biogeochemical Cycles18:1-7.

Reference 36

Reference 37

Wilmking, M., D'Arrigo, R., Jacoby, G.C. and Juday, G.P. 2005. Increased temperature sensitivity and divergent growth trends in circumpolar boreal forests. Geophysical Research Letters32:L15715-.

Reference 37

Reference 38

D'Arrigo, R., Wilson, R., Liepert, B. and Cherubini, P. 2008. On the 'divergence problem' in northern forests: a review of the tree-ring evidence and possible causes. Global and Planetary Change60:289-305.

Reference 38

Reference 39

Alberta Parks. 2007. Hay-Zama Lakes Wildland Park. Government of Alberta. 4 p.

Reference 39

Reference 40

Riordan, B., Verbyla, D. and McGuire, A.D. 2006. Shrinking ponds in subarctic Alaska based on 1950–2002 remotely sensed images. Journal of Geophysical Research111:1-11.

Reference 40

Reference 41

Labrecque, S., Lacelle, D., Duguay, C.R., Lauriol, B. and Hawkings, J. 2009. Contemporary (1951-2001) evolution of lakes in the Old Crow Basin, northern Yukon, Canada: remote sensing, numerical modeling and stable isotope analysis. Arctic62:225-238.

Reference 41

Reference 42

Hogenbirk, J.C. and Wein, R.W. 1991. Fire and drought experiments in northern wetlands: a climate change analogue. Canadian Journal of Botany69:1991-1997.

Reference 42

Reference 43

Burn, C.R. and Kokelj, S.V. 2009. The environment and permafrost of the Mackenzie Delta area. Permafrost and Periglacial Processes20:83-105.

Reference 43

Reference 44

Squires, M.M., Lesack, L.F.W., Hecky, R.E., Guildford, S.J., Ramlal, P. and Higgins, S.N. 2009. Primary production and carbon dioxide metabolic balance of a lake-rich Arctic river floodplain: partitioning of phytoplankton, epipelon, macrophyte, and epiphyton production among lakes on the Mackenzie Delta. Ecosystems12:853-872.

Reference 44

Reference 45

Latour, P.B., Leger, J., Hines, J.E., Mallory, M.L., Mulders, D.L., Gilchrist, H.G., Smith, P.A. and Dickson, D.L. 2008. Key migratory bird terrestrial habitat sites in the Northwest Territories and Nunavut, third edition. Occasional Paper No. 114. Edited by Gaston, A.J. Canadian Wildlife Service, Environment Canada. 18 p.

Reference 45

Reference 46

Government of the Northwest Territories and NWT Biodiversity Team. 2010. Northwest Territories state of the environment - 2010 biodiversity special edition. Environment and Natural Resources, Government of the Northwest Territories. Yellowknife, NT. 36 p.

Reference 46

Reference 47

EBA Engineering Consultants Ltd. and Canadian Wildlife Service. 2006. Ecological assessment of the Edéhzhíe candidate protected area. Canadian Wildlife Service. Yellowknife, NT. 95 + appendices.

Reference 47

Reference 48

Brock, B.E., Martin, M.E., Mongeon, C.L., Sokal, M.A., Wesche, S.D., Armitage, D., Wolfe, B.B., Hall, R.I. and Edwards, T.W.D. 2010. Flood frequency variability during the past 80 years in the Slave River Delta, NWT, as determined from multi-proxy paleolimnological analysis. Canadian Water Resources Journal35:281-300.

Reference 48

Reference 49

Beltaos, S. and Prowse, T. 2009. River-ice hydrology in a shrinking cryosphere. Hydrological Processes23:122-144.

Reference 49

Reference 50

Lesack, L.F.W. and Marsh, P. 2010. River-to-lake connectivities, water renewal, and aquatic habitat diversity in the Mackenzie River Delta. Water Resources Research46:W12504-.

Reference 50

Reference 51

Goulding, H.L., Prowse, T.D. and Beltaos, S. 2009. Spatial and temporal patterns of break-up and ice-jam flooding in the Mackenzie Delta, NWT. Hydrological Processes23:2654-2670.

Reference 51

Reference 52

Sokal, M.A., Hall, R.I. and Wolfe, B.B. 2010. The role of flooding on inter-annual and seasonal variability of lake water chemistry, phytoplankton diatom communities and macrophyte biomass in the Slave River Delta (Northwest Territories, Canada). Ecohydrology3:41-54.

Reference 52

Reference 53

Kokelj, S.V., Zajdlik, B. and Thompson, M.S. 2009. The impacts of thawing permafrost on the chemistry of lakes across the subarctic boreal-tundra transition, Mackenzie Delta region, Canada. Permafrost and Periglacial Processes20:185-199.

Reference 53

Reference 54

Lantz, T.C. and Kokelj, S.V. 2008. Increasing rates of retrogressive thaw slump activity in the Mackenzie Delta region, NWT, Canada. Geophysical Research Letters35, L06502:1-5.

Reference 54

Reference 55

Margesin, R. (ed.). 2009. Permafrost soils. Soil Biology 16. Springer-Verlag. Berlin, Germany. 347 p.

Reference 55

Reference 56

Culp, J.M., Prowse, T.D. and Luiker, E.A. 2005. Mackenzie River Basin. In Rivers of North America. Edited by Benke, A.C. and Cushing, C.E. Elsevier Academic Press. London, UK. Chapter 18. pp. 805-849.

Reference 56

Reference 57

The Atlas of Canada. 2008. Rivers [online]. Natural Resources Canada. (accessed 1 March, 2009).

Reference 57

Reference 58

The Atlas of Canada. 2008. Lakes [online]. Natural Resources Canada. (accessed 1 March, 2009).

Reference 58

Reference 59

Mackenzie River Basin Board. 2004. Mackenzie River Basin state of the aquatic ecosystem report 2003. Mackenzie River Basin Board Secretariat. Fort Smith, NT. 213 p.

Reference 59

Reference 60

Woo, M.K. and Thorne, R. 2003. Streamflow in the Mackenzie Basin, Canada. Arctic56:328-340.

Reference 60

Reference 61

Burn, D.H. 2008. Climatic influences on streamflow timing in the headwaters of the Mackenzie River Basin. Journal of Hydrology352:225-238.

Reference 61

Reference 62

Burn, D.H. and Cunderlik, J.M. 2004. Hydrological trends and variability in the Liard River Basin. Hydrological Sciences Journal49:53-67.

Reference 62

Reference 63

Aziz, O.I.A. and Burn, D.H. 2006. Trends and variability in the hydrological regime of the Mackenzie River Basin. Journal of Hydrology319:282-294.

Reference 63

Reference 64

Environment Canada. 2010. Water survey of Canada [online]. (accessed October, 2009).

Reference 64

Reference 65

Richter, B.D., Baumgartner, J.V., Powell, J. and Braun, D.P. 1996. A method for assessing hydrologic alteration within ecosystems. Conservation Biology10:1163-1174.

Reference 65

Reference 66

Frey, K.E. and McClelland, J.W. 2009. Impacts of permafrost degradation on arctic river biogeochemistry. Hydrological Processes23:169-182.

Reference 66

Reference 67

Poff, N.L., Allan, J.D., Bain, M.B., Karr, J.R., Prestegaard, K.L., Richter, B.D., Sparks, R.E. and Stromberg, J.C. 1997. The natural flow regime. Bioscience47:769-784.

Reference 67

Reference 68

Robinson, S.D. and Moore, T.R. 2000. The influence of permafrost and fire upon carbon accumulation in high boreal peatlands, Northwest Territories, Canada. Arctic, Antarctic, and Alpine Research32:155-166.

Reference 68

Reference 69

Kwong, Y.T.J. and Gan, T.Y. 1994. Northward migration of permafrost along the Mackenzie highway and climatic warming. Climatic Change26:399-419.

Reference 69

Reference 70

Heginbottom, J.A., Dubreuil, M.A. and Harker, P.A.C. 1995. Permafrost, 1995. In The National Atlas of Canada. Edition 5. National Atlas Information Service, Geomatics Canada and Geological Survey of Canada. Ottawa, ON. Map.

Reference 70

Reference 71

Beilman, D.W. and Robinson, S.D. 2003. Peatland permafrost thaw and landform type along a climatic gradient. In Proceedings of the 8th International Conference on Permafrost. Zurich, Switzerland, 21-25 July, 2003. Edited by Phillips, M., Springman, S.M. and Arenson, L.U. Swets & Zeitlinger. Lisse, Netherlands. Vol. 1, pp. 61-65.

Reference 71

Reference 72

Halsey, L.A., Vitt, D.H. and Zoltai, S.C. 1995. Disequilibrium response of permafrost in boreal continental western Canada to climate change. Climatic Change30:57-73.

Reference 72

Reference 73

Kuhry, P. 1994. The role of fire in the development of Sphagnum-dominated peatlands in western boreal Canada. Journal of Ecology82:899-910.

Reference 73

Reference 74

Smith, S.L., Burgess, M.M., Riseborough, D. and Nixon, F.M. 2005. Recent trends from Canadian permafrost thermal monitoring network sites. Permafrost and Periglacial Processes16:19-30.

Reference 74

Reference 75

Romanovsky, V.E., Gruber, S., Instanes, A., Jin, H., Marchenko, S.S., Smith, S.L., Trombotto, D. and Walter, K.M. 2007. Frozen ground. In Global outlook for ice and snow. Edited by Eamer, J. United Nations Environment Programme. Chapter 7. pp. 181-200.

Reference 75

Reference 76

Kanigan, J.C.N. 2007. Variation of mean annual ground temperature in spruce forests of the Mackenzie Delta, Northwest Territories. Thesis (Thesis (M.Sc.)). Carleton University, Geography Department. 131 p.

Reference 76

Reference 77

Kanigan, J.C.N., Burn, C.R. and Kokelj, S.V. 2008. Permafrost response to climate warming south of treeline, Mackenzie Delta, Northwest Territories, Canada. In Proceedings of the 9th International Conference on Permafrost. Fairbanks, AK, 29 June-3 July, 2008. Edited by Kane, D.L. and Hinkel, K.M. Institute of Northern Engineering, University of Alaska Fairbanks. Fairbanks, AK. Vol. 1, pp. 901-906.

Reference 77

Reference 78

Smith, S.L., Romanovsky, V.E., Lewkowicz, A.G., Burn, C.R., Allard, M., Clow, G.D., Yoshikawa, K. and Throop, J. 2010. Thermal state of permafrost in North America: a contribution to the international polar year. Permafrost and Periglacial Processes21:117-135.

Reference 78

Reference 79

Burgess, M.M. and Smith, S.L. 2000. Shallow ground temperatures. In The physical environment of the Mackenzie Valley, Northwest Territories: a baseline for the assessment of environmental change. Edited by Dyke, L.D. and Brooks, G.R. Geological Survey of Canada, Bulletin 547. pp. 89-103.

Reference 79

Reference 80

Goodrich, L.E. 1982. The influence of snow cover on the ground thermal regime. Canadian Geotechnical Journal19:421-432.

Reference 80

Reference 81

Smith, S.L., Burgess, M.M. and Riseborough, D. 2008. Ground temperature and thaw settlement in frozen peatlands along the Norman Wells pipeline corridor, NWT Canada: 22 years of monitoring. In Proceedings of the 9th International Conference on Permafrost. Fairbanks, AK, 29 June-3 July, 2008. Edited by Kane, D.L. and Hinkel, K.M. Institute of Northern Engineering, University of Alaska Fairbanks. Fairbanks, AK. Vol. 2, pp. 1665-1670.

Reference 81

Reference 82

Barrett, K., McGuire, A.D., Hoy, E.E. and Kasischke, E.S. 2011. Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity. Ecological Applications21:2380-2396.

Reference 82

Reference 83

Zoltai, S.C. 1993. Cyclic development of permafrost in the peatlands of northwestern Alberta, Canada. Arctic and Alpine Research25:240-246.

Reference 83

Reference 84

Bauer, I.E. and Vitt, D.H. 2011. Peatland dynamics in a complex landscape: development of a fen-bog complex in the Sporadic Discontinuous Permafrost zone of northern Alberta, Canada. Boreas40:714-726.

Reference 84

Reference 85

Turcotte, B., Morse, B., Bergeron, N.E. and Roy, A.G. 2011. Sediment transport in ice-affected rivers. Journal of Hydrology409:561-577.

Reference 85

Reference 86

Duguay, C.R., Prowse, T.D., Bonsal, B.R., Brown, R.D., Lacroix, M.P. and Menard, P. 2006. Recent trends in Canadian lake ice cover. Hydrological Processes20:781-801.

Reference 86

Reference 87

Latifovic, R. and Pouliot, D. 2007. Analysis of climate change impacts on lake ice phenology in Canada using the historical satellite record. Remote Sensing of Environment106:492-507.

Reference 87

Reference 88

de Rham, L.P., Prowse, T.D. and Bonsal, B.R. 2008. Temporal variations in river-ice break-up over the Mackenzie River Basin, Canada. Journal of Hydrology349:441-454.

Reference 88

Reference 89

Wiersma, Y.F., Beechey, T.J., Oosenbrug, B.M. and Meikle, J.C. 2005. Protected areas in northern Canada: designing for ecological integrity. Phase 1 report. CCEA Occasional Paper No. 16. Canadian Council on Ecological Areas, CCEA Secretariat. Ottawa, ON. xiv + 128 p.

Reference 89

Reference 90

NWT Protected Areas Strategy Secretariat. 2003. Mackenzie Valley five-year action plan (2004-2009): conservation planning for pipeline development. Northwest Territories Protected Areas Strategy. 35 p.

Reference 90

Reference 91

NWT Protected Areas Strategy. 2011. Northwest Territories protected areas strategy [online]. (accessed 27 February, 2012).

Reference 91

Reference 92

Gah, E., Witten, E., Korpach, A., Skelton, J. and Wilson, J.M. 2008. Methods for identifying potential core representative areas for the Northwest Territories protected area strategy: terrestrial coarse filter representation analysis. Manuscript Report No. 179. Department of Environment and Natural Resources, Government of the Northwest Territories. xiii + 88 p.

Reference 92

Reference 93

NWT Protected Areas Strategy Advisoy Committee. 1999. Northwest Territories Protected Areas Strategy: a balanced approach to establishing protected areas in the Northwest Territories. Government of Canada and Government of Northwest Territories. iv + 102 p.

Reference 93

Reference 94

IUCN. 1994. Guidelines for protected area management categories. Commission on National Parks and Protected Areas with the assistance of the World Conservation Monitoring Centre, International Union for Conservation of Nature. Gland, Switzerland and Cambridge, UK. x + 261 p.

Reference 94

Reference 95

Environment Canada. 2009. Unpublished analysis of data by ecozone+ from: Conservation Areas Reporting and Tracking System (CARTS), v.2009.05 [online]. Canadian Council on Ecological Areas. (accessed 5 November, 2009).

Reference 95

Reference 96

CCEA. 2009. Conservation Areas Reporting and Tracking System (CARTS) [In French only], v.2009.05 [online]. Canadian Council on Ecological Areas [In French only]. (accessed 5 November, 2009).

Reference 96

Reference 97

Gunn, A., Russell, D. and Eamer, J. 2011. Northern caribou population trends in Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 10. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 71 p.

Reference 97

Reference 98

Gwich'in Renewable Resources Board. 2012. Gwich'in Renewable Resources Board (accessed May, 2012).

Reference 98

Reference 99

Eamer, J. 2006. Keep it simple and be relevant: the first ten years of the Arctic Borderlands Ecological Knowledge Co-op. In Bridging scales and knowledge systems: concepts and applications in ecosystem assessment. Edited by Reid, W.V., Berkes, F., Wilbanks, T. and Capistrano, D. Island Press. Washington, DC. Chapter 10. pp. 186-204.

Reference 99

Reference 100

Woo, M.K., Modeste, P., Martz, L., Blondin, J., Kochtubajda, B., Tutcho, D., Gyakum, J., Takazo, A., Spence, C., Tutcho, J., Di Cenzo, P., Kenny, G., Stone, J., Neyelle, I., Baptiste, G., Modeste, M., Kenny, B. and Modeste, W. 2007. Science meets traditional knowledge: water and climate in the Sahtu (Great Bear Lake) region, Northwest Territories, Canada. Arctic60:37-46.

Reference 100

Reference 101

Mackenzie Valley Environmental Impact Review Board. 2005. Guidelines for incorporating Traditional Knowledge in environmental impact assessment. Yellowknife, NT. 39 p.

Reference 101

Reference 102

White, G. 2006. Cultures in collision: Traditional knowledge and Euro-Canadian governance processes in northern land-claim boards. Arctic59:401-414.

Reference 102

Reference 103

Slattery, S. 2011. Waterfowl in the boreal forest. In Ducks Unlimited Magazine, Sept/Oct 2011. Ducks Unlimited. pp. 74-80.

Reference 103

Reference 104

Ducks Unlimited Canada. 2012. Conservation projects in Canada's western boreal forest [online]. (accessed 3 March, 2012).

Reference 104

Reference 105

Wiken, E., Moore, H. and Latsch, C. 2006. Peatland and Wetland Protected Areas in Canada. Wildlife Habitat Canada. Ottawa, Canada. 18 p.

Reference 105

Reference 106

North American Waterfowl Management Plan. 2009. North American Waterfowl Management Plan (NAWMP) [online]. http://www.nawmp.ca/eng/real_e.html(accessed 27 August, 2009).

Reference 106

Reference 107

Rich, T.D., Beardmore, C.J., Berlanga, H., Blancher, P.J., Bradstreet, M.S.W., Butcher, G.S., Demarest, D.W., Dunn, E.H., Hunter, W.C., Iñigo-Elias, E.E., Kennedy, J.A., Martell, A.M., Panjabe, A.O., Pashley, D.N., Rosenberg, K.V., Rustay, C.M., Wendt, J.S. and Will, T.C. 2004. Partners in flight North American landbird conservation plan. Cornell Lab of Ornithology. Ithaca, NY. 84 p.

Reference 107

Reference 108

NABCI - International. 2005. Bird conservation regions [online]. North American Bird Conservation Initiative - International. http://www.nabci.net/International/English/bcrmap.html(accessed 1 April, 2007).

Reference 108

Reference 109

Environment Canada. 2012. Recovery strategy for the woodland caribou (Rangifer tarandus caribou), boreal population, in Canada. Species at Risk Act Recover Strategy Series. Environment Canada. Ottawa, ON. xi + 138 p.

Reference 109

Reference 110

Environment and Natural Resources. 2011. Northwest Territories state of the environment report: highlights 2011. Government of the Northwest Territories. Yellowknife, NT. 56 p.

Reference 110

Reference 111

Snyder, E. and M.Anions. 2008. Risk analysis of invasive plants and insects in the Northwest Territories. NatureServe Canada and Northwest Territories Department of Environment and Natural Resources. v + 28 p. + appendices.

Reference 111

Reference 112

Government of Yukon. 2007. Yukon invaders. Environment Yukon. Whitehorse, YT. 8 p.

Reference 112

Reference 113

Northeast Invasive Plant Committee. 2011. 2011 Plan and profile. Northeast Invasive Plant Committee, Peace River Regional District. 38 p.

Reference 113

Reference 114

Natural Resources Canada. 2011. Larch sawfly [online]. https://tidcf.nrcan.gc.ca/insects/factsheet/7907(accessed 3 February, 2012).

Reference 114

Reference 115

Decker, R. 2009. Personal communication. Forest Ecologist, Forest Management Division. Environment and Natural Resources, Government of the Northwest Territories. Hay River, NWT.

Reference 115

Reference 116

Vander Zanden, M.J., Olden, J.D., Thorne, J.H. and Mandrak, N.E. 2004. Predicting occurrences and impacts of smallmouth bass introductions in north temperate lakes. Ecological Applications14:132-148.

Reference 116

Reference 117

Jackson, D.A. and Mandrak, N.E. 2002. Changing fish biodiversity: predicting the loss of cyprinid biodiversity due to global climate change. In Fisheries in a changing climate. Edited by McGinn, N.A. American Fisheries Society Symposium 32. American Fisheries Society. Bethesda, MD. pp. 89-98.

Reference 117

Reference 118

AMAP. AMAP assessment 2009: human health in the Arctic. Arctic Monitoring and Assessment Programme. Oslo, Norway. xvii + 256 p.

Reference 118

Reference 119

Wong, C.S.C., Duzgoren-Aydin, N.S., Aydin, A. and Wong, M.H. 2006. Sources and trends of environmental mercury emissions in Asia. Science of the Total Environment368:649-662.

Reference 119

Reference 120

Carrie, J., Stern, G.A., Sanei, H., Macdonald, R.W. and Wang, F.Y. 2012. Determination of mercury biogeochemical fluxes in the remote Mackenzie River Basin, northwest Canada, using speciation of sulfur and organic carbon. Applied Geochemistry27:815-824.

Reference 120

Reference 121

Peterson, B.J., Holmes, R.M., McClelland, J.W., Vörösmarty, C.J., Lammers, R.B. and Shiklomanov.A.I. 2002. Increasing river discharge to the Arctic Ocean. Science98:2171-2173.

Reference 121

Reference 122

Leitch, D.R., Carrie, J., Lean, D., Macdonald, R.W., Stern, G.A. and Wang, F. 2007. The delivery of mercury to the Beaufort Sea of the Arctic Ocean by the Mackenzie River. Science of the Total Environment373:178-195.

Reference 122

Reference 123

Evans, M.S. 2009. Spatial and long-term trends in the persistent organic contaminants and metal in the lake trout and burbot from the Northwest Territories. In Synopsis of research conducted under the 2008-2009 Northern Contaminants Program. Edited by Smith, S., Stow, J. and Edwards, J. Indian and Northern Affairs Canada. Ottawa, ON. pp. 152-163.

Reference 123

Reference 124

Stern, G.A. 2009. Trace metals and organohalogen contaminants in fish from selected Yukon lakes: a temporal and spatial study. In Synopsis of research conducted under the 2008-2009 Northern Contaminants Program. Edited by Smith, S., Stow, J. and Edwards, J. Indian and Northern Affairs Canada. Ottawa, ON. pp. 172-178.

Reference 124

Reference 125

Carrie, J., Wang, F., Sanei, H., Macdonald, R.W., Outridge, P.M. and Stern, G.A. 2010. Increasing contaminant burdens in an arctic fish, burbot (Lota lota), in a warming climate. Environmental Science & Technology44:316-322.

Reference 125

Reference 126

Sanei, H., Outridge, P.M., Dallimore, A. and Hamilton, P.B. 2012. Mercury-organic matter relationships in pre-pollution sediments of thermokarst lakes from the Mackenzie River Delta, Canada: the role of depositional environment. Biogeochemistry107:149-164.

Reference 126

Reference 127

Gunn, A. 2003. Voles, lemmings and caribou - population cycles revisited? Rangifer Special Issue14:105-112.

Reference 127

Reference 128

Huntington, H.P., Fox, S., Berkes, F. and Krupnik, I. 2005. The changing Arctic: indigenous perspectives. In Arctic Climate Impact Assessment. Edited by Symon, C., Arris, L. and Heal, B. Cambridge University Press. New York, NY. Chapter 3. pp. 61-98.

Reference 128

Reference 129

Gordon, A.B., Andre, M., Kaglik, B., Cockney, S., Allen, M., Tetlichi, R., Buckle, R., Firth, A., Andre, J., Gilbert, M., Iglangasak, B. and Rexford, F. 2008. Arctic Borderlands Ecological Knowledge Co-op community reports 2006-2007. Arctic Borderlands Ecological Knowledge Society. Whitehorse, YT. 56 p.

Reference 129

Reference 130

Northern Yukon Ecological Knowledge Co-op. 1997. Community-based ecological monitoring: a summary of 1996-97 observations & pilot project evaluation [online]. Arctic Borderlands Ecological Knowledge Co-op. (accessed 12 December, 2007).

Reference 130

Reference 131

Hay, M.B., N.Michelutti and J.P.Smol. 2000. Ecological patterns of diatom assemblages from Mackenzie Delta lakes, Northwest Territories, Canada. Canadian Journal of Botany-Revue Canadienne de Botanique78:19-33.

Reference 131

Reference 132

Arctic Borderlands Ecological Knowledge Co-op. 2004. Proceedings of the 9th Annual Gathering Arctic Borderlands Ecological Knowledge Co-op. Inuvik, NT. 23-25 February, 2004. Arctic Borderlands Ecological Knowledge Society. Whitehorse, YT. 46 p.

Reference 132

Reference 133

Arctic Borderlands Ecological Knowledge Co-op. 2001. Proceedings of the sixth annual gathering. Aklavik, NT. 1-3 March, 2001. Arctic Borderlands Ecological Knowledge Society. Whitehorse, YT. 64 p.

Reference 133

Reference 134

Allen, M., Andre, M., Gordon, J., Greenland, D. and Tetlichi, D. 2003. Arctic Borderlands Ecological Knowledge Co-op community reports 2002/03. Arctic Borderlands Ecological Knowledge Co-op. Whitehorse, YT. 33 p.

Reference 134

Reference 135

Assinewe, V. 2003. Climate change as an influence on indigenous peoples' food resources part ii. Indigenous people' contributions to understadning global environment change. United Nations Environment Programme, Convention on Biological Diversity. Ste-Anne-de-Bellevue, Quebec. Conference presentation.

Reference 135

Reference 136

Arctic Borderlands Ecological Knowledge Co-op. 1999. Proceedings of the fourth annual gathering. Inuvik, NT. 1-3 March, 1999. Arctic Borderlands Ecological Knowledge Society. Whitehorse, YT. 20 p.

Reference 136

Reference 137

Eddy, S. 2001. Tuktoyaktuk and Aklavik Tariuq (ocean) community-based monitoring program results from the first indicators workshop. Fisheries and Oceans Canada. Aklavik, Northwest Territories.

Reference 137

Reference 138

Snowshoe, N. 2001. Proceedings of the Circumpolar Climate Change Summit, Whitehorse, Yukon, 19-21 March 2001. the Northern Review24:47-48.

Reference 138

Reference 139

GeoNorth Ltd. 2000. Climate change impacts and adaptation strategies for Canada's northern territories: final workshop report. Natural Resources Canada and Environment Canada. Yellowknife, NT. 69 p.

Reference 139

Reference 140

Bielawski, E. 1994. Lessons from Lutsel K'e. In Mackenzie River Basin Impact Study (MBIS) interim report #2. Edited by Cohen, S.J. Environment Canada. pp. 74-76.

Reference 140

Reference 141

Flett, L., Bill, L., Crozier, J. and Surrendi, D. 1996. A report of wisdom synthesized from the traditional knowledge component studies. Northern River Basins Study Synthesis Report No. 12. Northern Rivers Ecosystem Initiative, Government of Canada, Government of Alberta, and Government of Northwest Territories. Edmonton, AB. 389 p.

Reference 141

Reference 142

Cohen, S.J. (ed.). 1997. Mackenzie Basin Impact Study (MBIS) final report. Environment Canada. Toronto, ON. 372 p.

Reference 142

Reference 143

Freeman, M.M.R. 1997. Broad whitefish traditional knowledge study. Canadian Technical Report of Fisheries and Aquatic Sciences No. 2193. Edited by Tallman, R.F. and Reist, J.D. Central and Arctic Region, Fisheries and Oceans Canada. Winnipeg, MB. 52 p.

Reference 143

Reference 144

Anielski, M. and Wilson, M. 2005. Counting Canada's natural capital: assessing the real value of Canada's boreal ecosystems. The Boreal Initiative and the Pembina Institute. Ottawa, ON and Drayton Valley, AB. 78 p.

Reference 144

Reference 145

Environment and Natural Resources. 2011. State of the Environment Report, Indicator 18. Use of renewable resources. [online]. Government of the Northwest Territories. (accessed May, 2012).

Reference 145

Reference 146

Usher, P.J. and Wenzel, G.W. 1987. Native harvest surveys and statistics: a critique of their construction and use. Arctic42:145-160.

Reference 146

Reference 147

GRRB. 2009. Gwich'in harvest study. Gwich'in Renewable Resource Board. Inuvik, NT. 164 p.

Reference 147

Reference 148

Inuvialuit Renewable Resources Committee. 2003. Inuvialuit harvest study: data and methods report 1988-1997. Inuvialuit Renewable Resources Committee. Inuvik, NT. 209 p.

Reference 148

Reference 149

Bayha, J. and Snortland, J. 2006. Sahtu settlement harvest study data report: 2004 & 2005. Sahtu Renewable Resources Board. Tulita, NT. 63 p.

Reference 149

Reference 150

SRRB. 2004. Harvest study [online]. Sahtu Renewable Resources Board. (accessed 16 November, 2009).

Reference 150

Reference 151

SRRB. 2007. Report on a public hearing held by the Sahtu Renewable Resources Board and reasons for decision on the setting of a total allowable harvest for the Bluenose-West Caribou Herd. Sahtu Renewable Resources Board. Fort Good Hope, NT.

Reference 151

Reference 152

SENES Consultants Ltd. 2005. Terrestrial environment. In NWT environmental audit. Status of the environment report. SENES Consultants Ltd. Yellowknife, NT. Chapter 5. pp. 5.1-5A.12.

Reference 152

Reference 153

Roberge, M.M. and Dunn, J.B. 1988. Assessment and evaluation of the lake trout sport fishery in Great Bear Lake, NWT, 1984-85. Canadian Manuscript Report of Fisheries and Aquatic Sciences No. 2008. Central and Arctic Region, Department of Fisheries and Oceans. Winnipeg, MB. vii + 91 p.

Reference 153

Reference 154

NWT Bureau of Statistics. 2002. NWT regional employment & harvesting survey - summary of results. NWT Bureau of Statistics. Yellowknife, NT. 5 p.

Reference 154

Reference 155

Government of the Northwest Territories. 2009. Moose harvest levels [online]. Department of Environment and Natural Resources, Government of the Northwest Territories. http://www.enr.gov.nt.ca/_live/pages/wpPages/Moose.aspx(accessed 27 August, 2009).

Reference 155

Reference 156

Canfor. 2011. ForestTalk.com: Canfor permanently closes Rustad and Tackama operations. Posted December 5, 2011 [online]. (accessed May, 2012).

Reference 156

Reference 157

Government of Canada. 2011. Wood bison (Species at Risk public registry) [online]. (accessed May, 2012).

Reference 157

Reference 158

Soper, J.D. 2013. History, range and home life of the northern bison. Ecological Monographs11:347-412.

Reference 158

Reference 159

Hornaday, W.T. 1889. The extermination of the American bison. In Report of the National Museum (Smithsonian Institition) for 1886-'87. Government Printing Office. Washington, DC. pp. 367-584.

Reference 159

Reference 160

Parks Canada. 2011. Species at risk: wood bison [online].

Reference 160

Reference 161

Wobeser, G. 2009. Bovine tuberculosis in Canadian wildlife: an updated history. Canadian Veterinary Journal-Revue Veterinaire Canadienne50:1169-1176.

Reference 161

Reference 162

Environment and Natural Resources. 2010. Wood bison management strategy for the Northwest Territories 2010-2020. Government of Northwest Territories. 22 p.

Reference 162

Reference 163

Government of Alberta. 2012. Managing disease risk in Alberta's wood bison with special focus on bison to the west of Wood Buffalo National Park, 2011-2012 progress report. Government of Alberta. ii + 16 p.

Reference 163

Reference 164

Reynolds, H.W. and Gates, C.C. 1991. Managing wood bison: a once endangered species. In Wildlife production: conservation and sustainable development. Edited by Renecker, L.A. and Hudson, R.J. University of Alaska Fairbanks. Fairbanks, AK. pp. 363-371.

Reference 164

Reference 165

Environment and Natural Resources. 2013. Mackenzie bison population [online]. Department of Environment and Natural Resouces, Government of Northwest Territories. (accessed January, 13 A.D.).

Reference 165

Reference 166

Environment and Natural Resources. 2012. Wood bison in the NWT [online]. Government of Northwest Territories. (accessed 20 January, 2013).

Reference 166

Reference 167

Dragon, D.C. and Elkin, B.T. 2012. An overview of early anthrax outbreaks in northern Canada: field reports of the Health of Animals Branch, Agriculture Canada, 1962-1971. Arctic54:32-40.

Reference 167

Reference 168

Government of Alberta. 2010. Bison hunting education booklet. Government of Alberta. i + 20 p.

Reference 168

Reference 169

Gates, C.C., Elkin, B.T. and Dragon, D.C. 1995. Investigation, control and epizootiology of anthrax in geographically isolated, free-roaming bison population in northern Canada. The Canadian Veterinary Journal59:256-264.

Reference 169

Reference 170

Species at Risk Public Registry. 2009. Whooping Crane [online]. Government of Canada. (accessed 27 August, 2009).

Reference 170

Reference 171

COSEWIC. 2010. COSEWIC assessment and status report on the whooping crane Grus americana in Canada. committee on the Status of Endangered Wildlife in Canada. Ottawa. x + 36 p.

Reference 171

Reference 172

Whooping Crane Conservation Association. 2011. Sixth aerial census of 2010-11 [online]. (accessed 14 January, 2013).

Reference 172

Reference 173

Canadian Wildlife Service and United States Fish and Wildlife Service. 2006. International recovery plan for the whooping crane. Recovery of Nationally Endangered Wildlife (RENEW). Albuquerque, NM. 162 p.

Reference 173

Reference 174

Boyce, M.S. and Miller, R.S. 1985. Ten-year periodicity in whooping crane census. Auk102:658-660.

Reference 174

Reference 175

Environment Canada. 2007. Recovery strategy for the whooping crane (Grus americana) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada. Ottawa, ON. vii + 27 p.

Reference 175

Reference 176

Nagy, J.A. 2009. Evidence that the Cape Bathurst, Bluenose-West, and Bluenose-East calving grounds are not theoretical and justification for division of the "Bluenose" Herd into the Cape Bathurst, Bluenose-West, and Bluenose-East herds. Draft Manuscript Report No. 194. Department of Environment and Natural Resources, Government of the Northwest Territories. Yellowknife, NT. 84 p.

Reference 176

Reference 177

Adamczewski, J., Boulanger, B., Croft, B., Cluff, D., Elkin, B., Nishi, J., Kelly, A., D'Hont, A. and Nicolson, C. 2009. Decline in the Bathurst Caribou Herd 2006-2009: a technical evaluation of field data and modeling. Environment and Natural Resources, Government of the Northwest Territories. Yellowknife, NT. Draft (17 December, 2009).

Reference 177

Reference 178

Davison, T. 2009. Personal communication. Preliminary results of caribou surveys for 2009. Environment and Natural Resources, Government of the Northwest Territories. Inuvik, NT.

Reference 178

Reference 179

Adamczewski, J. 2011. Personal communication. Information in review of draft northern caribou report. Environment and Natural Resources, Government of the Northwest Territories. Yellowknife, NT.

Reference 179

Reference 180

Environment Canada. 2011. Scientific assessment to inform the identification of critical habitat for woodland caribou (Rangifer tarandus caribou), boreal population, in Canada: 2011 update. Environment Canada. Ottawa, ON. xiv + 103 p.

Reference 180

Reference 181

Callaghan, C., Virc, S. and Duffe, J. 2011. Woodland caribou, boreal population, trends in Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 11. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 36 p.

Reference 181

Reference 182

Banfield, A.W.F. 1961. A revision of the reindeer and caribou, genus Rangifer. National Museum of Canada Bulletin No. 177. Queen's Printer. Ottawa, ON. 137 p.

Reference 182

Reference 183

COSEWIC. 2002. COSEWIC assessment and update status report on the woodland caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, ON. xi + 98 p.

Reference 183

Reference 184

Government of Canada. 2013. Woodland caribou boreal population (Species at Risk public registry) [online]. (accessed January, 2013).

Reference 184

Reference 185

Kelsall, J.P. 1984. COSEWIC status report on the woodland caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, ON. 103 p.

Reference 185

Reference 186

Schaefer, J.A. and Mahoney, S.P. 2003. Spatial and temporal scaling of population density and animal movement: a power law approach. Écoscience10:496-501.

Reference 186

Reference 187

Vors, L.S., Schaefer, J.A., Pond, B.A., Rodgers, A.R. and Patterson, B.R. 2007. Woodland caribou extirpation and anthropogenic landscape disturbance in Ontario. Journal of Wildlife Management71:1249-1256.

Reference 187

Reference 188

Rettie, W.J. and Messier, F. 2000. Hierarchical habitat selection by woodland caribou: its relationship to limiting factors. Ecography23:466-478.

Reference 188

Reference 189

Anderson, R.B. 1999. Peatland habitat use and selection by woodland caribou (Rangifer tarandus caribou) in northern Alberta. Thesis (M.Sc.). University of Alberta. Edmonton, AB. 49 p.

Reference 189

Reference 190

Bergerud, A.T. 1974. Decline of caribou in North America following settlement. Journal of Wildlife Management38:757-770.

Reference 190

Reference 191

Mallory, F.F. and Hillis, T.L. 1998. Demographic characteristics of circumpolar caribou populations: ecotypes, ecological constraints, releases and population dynamics. Rangifer10:49-60.

Reference 191

Reference 192

Schaefer, J.A. 2003. Long-term range recession and the persistence of caribou in the Taiga. Conservation Biology17:1435-1439.

Reference 192

Reference 193

Bergerud, A.T. 1967. Management of Labrador caribou. Journal of Wildlife Management31:621-642.

Reference 193

Reference 194

Edmonds, E.J. 1988. Population status, distribution and movements of woodland caribou in west central Alberta. Canadian Journal of Zoology66:817-826.

Reference 194

Reference 195

Seip, D.R. 1992. Factors limiting woodland caribou populations and their interrelationships with wolves and moose in southeastern British Columbia. Canadian Journal of Zoology70:1494-1503.

Reference 195

Reference 196

McLoughlin, P.D., Dzus, E., Wynes, B. and Boutin, S. 2003. Declines in populations of woodland caribou. Journal of Wildlife Management67:755-761.

Reference 196

Reference 197

Vors, L.S. and Boyce, M.S. 2009. Global declines of caribou and reindeer. Global Change Biology15:2626-2633.

Reference 197

Reference 198

Dyer, S.J., O'Neill, J.P., Wasel, S.M. and Boutin, S. 2001. Avoidance of industrial development by woodland caribou. Journal of Wildlife Management65:531-542.

Reference 198

Reference 199

Dyer, S.J., O'Neill, J.P., Wasel, S.M. and Boutin, S. 2002. Quantifying barrier effects of roads and seismic lines on movements of female woodland caribou in Northeastern Alberta. Canadian Journal of Zoology80:839-845.

Reference 199

Reference 200

Fast, M., Collins, B. and Gendron, M. 2011. Trends in breeding waterfowl in Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 8. Canadian Councils of Resource Ministers. Ottawa, ON. v + 37 p.

Reference 200

Reference 201

Smith, G.W. 1995. A critical review of the aerial and ground surveys of breeding waterfowl in North America. Biological Science Report No. 5. National Biological Service. Washington, DC. 252 p.

Reference 201

Reference 202

Bellrose, F.C. 1980. Ducks, geese and swans of North America. Stackpole Books. Harrisburg, PA. 540 p.

Reference 202

Reference 203

Fournier, B.J. and Hines, J.E. 2005. Geographic distribution and changes in population densities of waterfowl in the Northwest Territories, Canada, 1976-2003. Canadian Wildlife Service Technical Report No. 433. Environment Canada. Ottawa, ON. 33 p.

Reference 203

Reference 204

Koons, D.N., Rotella, J.J., Willey, D.W., Taper, M., Clark, R.G., Slattery, S., Brook, R.W., Corcoran, R.M. and Loworn, J.R. 2006. Lesser scaup population dynamics: what can be learned from available data? Avian Conservation and Ecology1:1-6.

Reference 204

Reference 205

Afton, A.D. and Anderson, M.G. 2001. Declining scaup populations: a retrospective analysis of long-term population and harvest survey data. Journal of Wildlife Management65:781-796.

Reference 205

Reference 206

Devink, J.M., Clark, R.G., Slattery, S.M. and Trauger, D.L. 2008. Are late-spring boreal lesser scaup (Aythya affinis) in poor body condition? Auk125:291-298.

Reference 206

Reference 207

Drever, M.C., Clark, R.G., Derksen, C., Slattery, S.M., Toose, P. and Nudds, T.D. 2012. Population vulnerability to climate change linked to timing of breeding in boreal ducks. Global Change Biology18:480-492.

Reference 207

Reference 208

Anteau, M.J. and Afton, A.D. 2009. Lipid reserves of lesser scaup (Aythya affinis) migrating across a large landscape are consistent with the spring condition hypothesis. Auk126:873-883.

Reference 208

Reference 209

Corcoran, R.M., Loworn, J.R. and Heglund, P.J. 2009. Long-term change in limnology and invertebrates in Alaskan boreal wetlands. Hydrobiologia620:77-89.

Reference 209

Reference 210

Thomas, D.W., Blondel, J., Perret, P., Lambrechts, M.M. and Speakman, J.R. 2001. Energetic and fitness costs of mismatching resource supply and demand in seasonally breeding birds. Science291:2598-2600.

Reference 210

Reference 211

Austin, J.E., Afton, A.D., Anderson, M.G., Clark, R.G., Custer, C.M., Lawrence, J.S., Pollard, J.B. and Ringelman, J.K. 2000. Declining scaup populations: issues, hypotheses, and research needs. Wildlife Society Bulletin28:254-263.

Reference 211

Reference 212

Environment and Natural Resources. 2010. Species at risk in the Northwest Territories. Government of the Northwest Territories. Yellowknife. 64 p.

Reference 212

Reference 213

Todd, T.N. 2003. Update COSEWIC status report on the shortjaw cisco Coregonus zenithicus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, ON. 19 p.

Reference 213

Reference 214

Reist, J.D., Low, G., Johnson, J.D. and McDowell, D. 2002. Range extension of bull trout, Salvelinus confluentus, to the central Northwest Territories, with notes on identification and distribution of Dolly Varden, Salvelinus malma, in the western Canadian Arctic. Arctic55:70-76.

Reference 214

Reference 215

Fisheries and Oceans Canada. 2010. Proceedings of the regional advisory process on the Buffalo River Inconnu (Stenodus Ieucichthys) population, Great Slave Lake, Northwest Territories. March 30-31, 2010, Yellowknife, NT. Canadian Science Advisory Secretariat Proceedings Series 2011/005. Central and Arctic Region, Fisheries and Oceans Canada. Winnipeg, MB. vi = 11 p.

Reference 215

Reference 216

Chowns, T.J. 2012. Personal communication. Written submission in review of the draft report.

Reference 216

Reference 217

Indian and Northern Affairs Canada. 2009. A preliminary state of knowledge report of valued components for the NWT Cumulative Impact Monitoring Program (NWT CIMP) and audit - final draft - updated November 2009 (original version February 1, 2002). Indian and Northern Affairs Canada. 133 p.

Reference 217

Reference 218

Pouliot, D., Latifovic, R. and Olthof, I. 2009. Trends in vegetation NDVI from 1 km Advanced Very High Resolution Radiometer (AVHRR) data over Canada for the period 1985-2006. International Journal of Remote Sensing30:149-168.

Reference 218

Reference 219

Olthof, I., Pouliot, D., Latifovic, R. and Chen, W.J. 2008. Recent (1986-2006) vegetation-specific NDVI trends in northern Canada from satellite data. Arctic61:381-394.

Reference 219

Reference 220

Sturm, M., Racine, C. and Tape, K. 2001. Climate change: increasing shrub abundance in the Arctic. Nature411:546-547.

Reference 220

Reference 221

Tape, K., Sturm, M. and Racine, C. 2006. The evidence for shrub expansion in northern Alaska and the Pan-arctic. Global Change Biology12:686-702.

Reference 221

Reference 222

Arft, A.M., Walker, M.D., Turner, P.L., Gurevitch, J., Alatalo, J.M., Molau, U., Nordenhäll, U., Stenström, A., Stenström, M., Bret-Harte, M.S., Dale, M., Diemer, M., Gugerli, F. and Henry, G.H.R. 1999. Responses of tundra plants to experimental warming: meta-analysis of the International Tundra Experiment. Ecological Monographs69:491-511.

Reference 222

Reference 223

Hollister, R.D., Webber, P.J. and Tweedie, C.E. 2005. The response of Alaskan Arctic tundra to experimental warming: differences between short- and long-term responses. Global Change Biology11:525-536.

Reference 223

Reference 224

Walker, M.D., Wahren, C.H., Hollister, R.D., Henry, G.H.R., Ahlquist, L.E., Alatalo, J.M., Bret-Harte, M.S., Calef, M.P., Callaghan, T.V., Carroll, A.B., Epstein, H.E., Jónsdóttir, I.S., Klein, J.A., Magnússom, B., Molau, U., Oberbauer, S.F., Rewa, S.P., Robinson, C.H., Shaver, G.R., Suding, K.N., Thompson, C.C., Tolvanen, A., Totland, O., Turner, P.L., Tweedie, C.E., Webber, P.J. and Wookey, P.A. 2006. Plant community responses to experimental warming across the tundra biome. Proceedings of the National Academy of Sciences103:1342-1346.

Reference 224

Reference 225

Hicke, J.A., Asner, G.P., Kasischke, E.S., French, N.H.F., Randerson, J.T., Collatz, G.J., Stocks, B.J., Tucker, C.J., Los, S.O. and Field, C.B. 2003. Postfire response of North American boreal forest net primary productivity analyzed with satellite observations. Global Change Biology9:1145-1157.

Reference 225

Reference 226

McMillan, A.M.S., G.C.Winston and M.L.Goulden. 2008. Age-dependent response of boreal forest to temperature and rainfall variability. Global Change Biology14:1904-1916.

Reference 226

Reference 227

Program for Regional and International Shorebird Monitoring (PRISM) Boreal Committee. 2004. Boreal shorebirds: an assessment of conservation status and potential for population monitoring. Program for Regional and International Shorebird Monitoring (PRISM) Boreal Committee. 41 p.

Reference 227

Reference 228

Weladji, R.B., Klein, D.R., Holand, O. and Mysterud, A. 2002. Comparative response of Rangifer tarandus and other northern ungulates to climatic variability. Rangifer22:29-46.

Reference 228

Reference 229

Simard, H.M.B. 2001. A fire history study - toward a community protection plan for Fort Smith, NT. Thesis (Thesis (M.Sc.)). University of Alberta. Edmonton, AB.

Reference 229

Reference 230

Chowns, T. 2002. Fort Providence fire history study. Resources, Wildlife and Economic Development, Government of the Northwest Territories. Unpublished report.

Reference 230

Reference 231

Holman, H.L. 1944. Report on forest fire protection in the Mackenzie District NWT. National Archives of Canada, Record Group 39, Vol. 464, File 50050.

Reference 231

Reference 232

Lewis, H.T. and Ferguson, T.A. 1988. Yards, corridors, and mosaics: how to burn a boreal forest. Human Ecology16:57-77.

Reference 232

Reference 233

Van Wagner, C.E. 1983. Fire behaviour in northern conifer forests and shrublands. In The Role of Fire in Northern Circumpolar Ecosystems. Edited by Wein, R.W. and MacLean, D.A. John Wiley & Sons Ltd. New York, NY. Chapter 4. pp. 65-80.

Reference 233

Reference 234

Parisien, M.A., Peters, V.S., Wang, Y., Little, J.M., Bosch, E.M. and Stocks, B.J. 2006. Spatial patterns of forest fires in Canada, 1980-1999. International Journal of Wildland Fire15:361-374.

Reference 234

Reference 235

Burton, P.J., Parisien, M.-A., Hicke, J.A., Hall, R.J. and Freeburn, J.T. 2008. Large fires as agents of ecological diversity in the North American boreal forest. International Journal of Wildland Fire17:754-767.

Reference 235

Reference 236

Stocks, B.J., Mason, J.A., Todd, J.B., Bosch, E.M., Wotton, B.M., Amiro, B.D., Flannigan, M.D., Hirsch, K.G., Logan, K.A., Martell, D.L. and Skinner, W.R. 2003. Large forest fires in Canada, 1959-1997. Journal of Geophysical Research108:8149-8161.

Reference 236

Reference 237

Amiro, B.D., Cantin, A., Flannigan, M.D. and de Groot, W.J. 2009. Future emissions from Canadian boreal forest fires. Canadian Journal of Forest Research/Revue canadienne de recherche forestière39:383-395.

Reference 237

Reference 238

Amiro, B.D., Todd, J.B., Wotton, B.M., Logan, K.A., Flannigan, M.D., Stocks, B.J., Mason, J.A., Martell, D.L. and Hirsch, K.G. 2001. Direct carbon emissions from Canadian forest fires, 1959-1999. Canadian Journal of Forest Research/Revue canadienne de recherche forestière31:512-525.

Reference 238

Reference 239

Podur, J., Martell, D.L. and Knight, K. 2002. Statistical quality control analysis of forest fire activity in Canada. Canadian Journal of Forest Research/Revue canadienne de recherche forestière 32:195-205.

Reference 239

Reference 240

Gillett, N.P., Weaver, A.J., Zwiers, F.W. and Flannigan, M.D. 2004. Detecting the effect of climate change on Canadian forest fires. Geophysical Research Letters 31:L18211-.

Reference 240

Reference 241

Alfaro, R.I., Taylor, S., Brown, R.G. and Clowater, J.S. 2001. Susceptibility of northern British Columbia forests to spruce budworm defoliation. Forest Ecology and Management145:181-190.

Reference 241

Reference 242

Fleming, R.A. and Candau, J.N. 1998. Influences of climatic change on some ecological processes of an insect outbreak system in Canada's boreal forests and the implications for biodiversity. Environmental Monitoring and Assessment49:235-249.

Reference 242

Reference 243

Canadian Forest Service. 2012. Spruce budworm [online]. Natural Resources Canada. (accessed 3 September, 2012).

Reference 243

Reference 244

Volney, W.J. and Fleming, A.R.A. 2000. Climate change and impacts of boreal forest insects. Agriculture, Ecosystems and Environment82:283-294.

Reference 244

Reference 245

Burleigh, J.S., Alfaro, R.I., Borden, J.H. and Taylor, S. 2002. Historical and spatial characteristics of spruce budworm Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae) outbreaks in northeastern British Columbia. Forest Ecology and Management168:301-309.

Reference 245

Reference 246

Ritchie, C. 2009. Personal communication. Ministry of Forests, Lands and Natural Resource Operations, Government of British Columbia. Prince George, BC.

Reference 246

Reference 247

Otvos, I.S., Omendja, K., Foord, S., Conder, N., Borecky, N. and Nevill, R. 2010. Preliminary hazard rating for forest tent caterpillar in British Columbia. Forestry Chronicle86:636-648.

Reference 247

Reference 248

Brandt, J.P. 1997. Forest health monitoring in west-central Canada in 1996. Information Report No. NOR-X-351. Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre. Edmonton, AB. 39 p.

Reference 248

Reference 249

Cooke, B.J. and Roland, J. 2003. The effect of winter temperature on forest tent caterpillar (Lepidoptera: Lasiocampidae) egg survival and population dynamics in northern climates. Environmental Entomology32:299-311.

Reference 249

Reference 250

BC Ministry of Forests, Lands and Natural Resource Operations. 2012. Fort Nelson District Mountain Pine Beetle Working Group [online]. British Columbia Ministry of Forests, Lands and Natural Resource Operations. (accessed 3 September, 2012).

Reference 250

Reference 251

Government of Northwest Territories. 2013. Personal communication. Mountain pine beetle in the NWT. Forest Management Division, Environment and Natural Resources, Government of the Northwest Territories.

Reference 251

Reference 252

Forest Health Program. 2011. Forest health in Alberta, 2010 annual report. Government of Alberta. Edmonton, AB. iv + 48 p.

Reference 252

Reference 253

Alberta Sustainable Resource Development. 2011. Beetle bulletin, July 2011 [online]. Government of Alberta. (accessed 9 March, 2012).

Reference 253

Reference 254

Alberta Sustainable Resource Development. 2009. Beetle facts [online]. Government of Alberta. (accessed 9 March, 2012).

Reference 254

Reference 255

Bleiker, K.P., Carroll, A.L. and Smith, G.D. 2010. Mountain pine beetle range expansion: assessing the threat to Canada's boreal forest by evaluating the endemic niche. Natural Resources Canada, Canadian Forest Service. Victoria, BC. 17 p.

Reference 255

Reference 256

Brook, R.K., Kutz, S.J., Veitch, A., Popko, R., Elkin, B. and Guthrie, G. 2009. Fostering community-based wildlife health monitoring and research in the Canadian North. Ecohealth6:266-278.

Reference 256

Reference 257

Pybus, M. 1999. Moose and ticks in Alberta: a dieoff in 1998/99. Occasional Paper No. 20. Fisheries and Wildlife Management Division, Alberta Environment. Edmonton, AB. 17 p.

Reference 257

Reference 258

Kutz, S.E., A.Garde, A.Veitch, J.Nagy, F.Ghandi and L.Polley. 2004. Muskox lungworm (Umingmakstrongylus pallikuukensis) does not establish in experimentally exposed thinhorn sheep (Ovis dalli). Journal of Wildlife Diseases40:197-204.

Reference 258

Reference 259

Joly, D.O. and Messier, F. 2004. Factors affecting apparent prevalence of tuberculosis and brucellosis in wood bison. Journal of Animal Ecology73:623-631.

Reference 259

Reference 260

Gates, C.C., Mitchell, J., Wierzchowski, J. and Giles, L. 2001. A landscape evaluation of bison movements and distribution in northern Canada. Axys Environmental Consulting Ltd. Calgary, AB. 113 p.

Reference 260

Reference 261

Nishi, J.S., Shury, T. and Elkin, B.T. 2006. Wildlife reservoirs for bovine tuberculosis (Mycobacterium bovis) in Canada: strategies for management and research. Veterinary Microbiology 112:325-338.

Reference 261

Reference 262

Thorne, E.T. 2001. Brucellosis. In Infectious diseases of wild mammals. Edition 3. Edited by Williams, E.S. and Barker, I.K. Iowa State University Press. Ames, IA. Chapter 22. pp. 372-395.

Reference 262

Reference 263

Forbes, L.B. 1991. Isolates of Brucella suis biovar 4 from animals and humans in Canada, 1982-1990. The Canadian Veterinary Journal32:686-688.

Reference 263

Reference 264

Chan, J., Baxter, C. and Wenman, W.M. 1989. Brucellosis in an Inuit child, probably related to caribou meat consumption. Scandinavian Journal of Infectious Diseases21:337-338.

Reference 264

Reference 265

Tessaro, S.V. 1986. The existing and potential importance of brucellosis and tuberculosis in Canadian wildlife: a review. Canadian Veterinary Journal27:119-124.

Reference 265

Reference 266

Koller-Jones, M. 14 August, 2006. Personal communication. Canadian Food Inspection Agency.

Reference 266

Reference 267

Leighton, F.A. Brucellosis in arctic caribou. Unpublished data.

Reference 267

Reference 268

Dragon, D.C. and Rennie, R.P. 1995. The ecology of anthrax spores: tough but not invincible. Canadian Veterinary Journal36:295-301.

Reference 268

Reference 269

Hugh-Jones, M.E. and de Vos, J. 2002. Anthrax and wildlife. Scientific and Technical Review (World Organization for Animal Health- OIE)21:359-383.

Reference 269

Reference 270

Dragon, D.C., Elkin, B.T., Nishi, J.S. and Ellsworth, T.R. 1999. A review of anthrax in Canada and implications for research on the disease in northern bison. Journal of Applied Microbiology87:208-213.

Reference 270

Reference 271

Orsel, K., Kutz, S., Barkema, H. and De Buck, J. 2008. Presence of M. avium spp. paratuberculosis in free-ranging caribou. 5th annual meeting of the CircumArctic Rangifer Monitoring and Assessment Network. Vancouver, BC. Poster presentation.

Reference 271

Reference 272

Sibley, J.A., Woodbury, M.R., Appleyard, G.D. and Elkin, B. 2007. Mycobacterium avium subspecies paratuberculosis in bison (Bison bison) from northern Canada. Journal of Wildlife Diseases43:775-779.

Reference 272

Reference 273

Leighton, F.A. and Gajadhar, A.A. 2001. Besnoitia spp. and besnoitiosis. In Parasitic diseases of wild mammals. Edition 2. Edited by Samuel, W.M., Pybus, M.J. and Kocan, A.A. Iowa State University Press. Ames, IA. pp. 468-478.

Reference 273

Reference 274

Wobeser, G. 1976. Besnoitiosis in a woodland caribou. Journal of Wildlife Diseases12:566-571.

Reference 274

Reference 275

Ayroud, M., Leighton, F.A. and Tessaro, S.V. 1995. The morphology and pathology of Besnoitia sp. in reindeer (Rangifer tarandus tarandus). Journal of Wildlife Diseases31:319-326.

Reference 275

Reference 276

Ducrocq, J., Lair, S. and Kutz, S. 2009. Prevalence and intensity of Besnoitia tarandi in caribou herds: preliminary results. Fifth annual meeting of the CircumArctic Rangifer Monitoring and Assessment Network. Vancouver, BC. Poster presentation.

Reference 276

Reference 277

Samuel, W.M. 2004. White as a ghost: winter ticks and moose. Federation of Alberta Naturalists. Edmonton, AB. 100 p.

Reference 277

Reference 278

Kutz, S.J., Jenkins, E.J., Veitch, A.M., Ducrocq, J., Polley, L., Elkin, B. and Lair, S. 2009. The Arctic as a model for anticipating, preventing, and mitigating climate change impacts on host-parasite interactions. Veterinary Parasitology163:217-228.

Reference 278

Reference 279

Kashivakura, C.K. 2013. Detecting Dermacentor albipictus, the winter tick, at the northern extent of its range: hunter-based monitoring and serological assay development. University of Calgary. Thesis (M.Sc., under defense).

Reference 279

Reference 280

Elkin, B.T. 2009. Personal communication. Environment and Natural Resources, Government of the Northwest Territories.

Reference 280

Reference 281

Collins, J.P., Brunner, J.L., Miera, M.V., Parris, M.J., Schock, D.M. and Storfer, A. 2003. Ecology and evolution of infectious diseases. In Amphibian conservation. Edited by Semlitsch, R. Smithsonian Press. Washington, DC. pp. 139-151.

Reference 281

Reference 282

Schock, D.M., Ruthig, G.R., Collins, J.P., Kutz, S.J., Carrière, S., Gau, R.J., Veitch, A.M., Larter, N.C., Tate, D.P., Guthrie, G., Allaire, D.G. and Popko, R.A. 2010. Amphibian chytrid fungus and ranaviruses in the Northwest Territories, Canada. Diseases of Aquatic Organisms92:231-240.

Reference 282

Reference 283

Skerratt, L.F., Berger, L., Speare, R., Cashins, S., McDonald, K.R., Phillott, A.D., Hines, H.B. and Kenyon, N. 2007. Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. Ecohealth4:125-134.

Reference 283

Reference 284

Briggs, C.J., Vredenburg, V.T., Knapp, R.A. and Rachowicz, L.J. 2005. Investigating the population-level effects of chytridiomycosis: an emerging infectious disease of amphibians. Ecology86:3149-3159.

Reference 284

Reference 285

Schlaepfer, M.A., Sredl, M.J., Rosen, P.C. and Ryan, M.J. 2007. High prevalence of Batrachochytrium dendrobatidis in wild populations of lowland leopard frogs Rana yavapaiensis in Arizona. Ecohealth4:421-427.

Reference 285

Reference 286

Erb, J., Stenseth, N.C. and Boyce, M.S. 2001. Spatial variation in mink and muskrat interactions in Canada. Oikos93:365-375.

Reference 286

Reference 287

Danell, K., T.Willebrand and L.Baskin. 1998. Mammalian herbivores in the boreal forests: their numerical fluctuations and use by man. Conservation Ecology2:9.

Reference 287

Reference 288

Environment and Natural Resources. 2009. Northwest Territories Small Mammal Survey.Government of Northwest Territories. Unpublished data.

Reference 288

Reference 289

Brook, R.W., Duncan, D.C., Hines, J.E., Carrière, S. and Clark, R.G. 2005. Effects of small mammal cycles on productivity of boreal ducks. Wildlife Biology11:3-11.

Reference 289

Reference 290

Sinclair, A.R.E., Goslline, J.M., Holdsworth, G., Krebs, C.J., Boutin, S., Smith, J.N.M., Boonstra, R. and Dale, M. 1993. Can the solar cycle and climate synchronize the snowshoe hare cycle in Canada? Evidence from tree rings and ice cores. American Naturalist141:173-198.

Reference 290

Reference 291

Ferron, J. and St-Laurent, M.-H. 2008. Forest-fire regime: the missing link to understand snowshoe hare population fluctuations? In Lagomorph Biology: Evolution, Ecology, and Conservation. Edited by Alves, P.C., Ferrand, N. and Hacklander, K. Springer-Verlag Berlin Heidelberg. pp. 141-152.

Reference 291

Reference 292

Bryant, J.P., Clausen, T.P., Swihart, R.K., Landhäusser, S.M., Stevens, M.T., Hawkins, C.D.B., Carrière, S., Kirilenko, A.P., Veitch, A.M., Popko, R.A., Cleland, D.T., Williams, J.H., Jakubas, W.J., Carlson, M.R., Bodony, K.L., Cebrian, M., Paragi, T.F., Picone, P.M., Moore, J.E., Packee, E.C. and Malone, T. 2009. Fire drives transcontinental variation in tree birch defense against browsing by snowshoe hares. American Naturalist174:13-23.

Reference 292

Reference 293

Murray, D.L. 2003. Snowshoe hare and other hares. In Wild mammals of North America. Edited by Feldhamer, G.A., Thompson, B.C. and Chapman, J.A. Johns Hopkins University Press. Baltimore, MD. pp. 147-175.

Reference 293

Reference 294

Ims, R.A., Henden, J.A. and Killengreen, S.T. 2008. Collapsing population cycles. Trends in Ecology & Evolution23:79-86.

Reference 294

Reference 295

Environment and Natural Resources. 2012. Small mammal abundance indices in the NWT -- 1990-2012 [online]. Northwest Territories State of the Environment Report. Government of the Northwest Territories. (accessed 13 February, 2013).

Reference 295

Reference 296

Evans, M.S., Muir, D., Lockhart, W.L., Stern, G., Ryan, M. and Roach, P. 2005. Persistent organic pollutants and metals in the freshwater biota of the Canadian Subarctic and Arctic: an overview. Science of the Total Environment351:94-147.

Reference 296

Reference 297

Ryan, M.J., Stern, G.A., Diamond, M., Croft, M.V., Roach, P. and Kidd, K. 2005. Temporal trends of organochlorine contaminants in burbot and lake trout from three selected Yukon lakes. Science of the Total Environment351:501-522.

Reference 297

Reference 298

Kidd, K.A., Schindler, D.W., Muir, D.C.G., Lockhart, W.L. and Hesslein, R.H. 1995. High concentrations of toxaphene in fishes from a Subarctic lake. Science269:240-242.

Reference 298

Reference 299

Howell, S.E.L., Brown, L.C., Kang, K.K. and Duguay, C.R. 2009. Variability in ice phenology on Great Bear Lake and Great Slave Lake, Northwest Territories, Canada, from SeaWinds/QuikSCAT: 2000-2006. Remote Sensing of Environment113:816-834.

Reference 299

Reference 300

Rouse, W.R., Blyth, E.M., Crawford, R.W., Gyakum, J.R., Janowicz, J.R., Kochtubajda, B., Leighton, H.G., Marsh, P., Martz, L., Pietroniro, A., Ritchie, H., Schertzer, W.M., Soulis, E.D., Stewart, R.E., Strong, G.S. and Woo, M.K. 2003. Energy and water cycles in a high-latitude, north-flowing river system - summary of results from the Mackenzie GEWEX Study - Phase I. Bulletin of the American Meteorological Society84:73-87.

Reference 300

Reference 301

Clarkson, P. and Andre, D. 2002. Communities, their knowledge and participation. Cumulative effects assessment management framework and Mackenzie Valley cumulative impacts monitoring program. Role of traditional knowledge, elders and the communities: Task 9/6. Gwich'in Renewable Resource Board and Gwich'in Tribal Council. Inuvik, NWT. 37 + appendices p.

Reference 301

Reference 302

Berger, T.R. 1977. Northern frontier, northern homeland: the report of the Mackenzie Valley Pipeline Inquiry. Ministry of Supply and Services Canada. Ottawa, ON. 203 p.

Reference 302

Reference 303

National Energy Board. 2010. Mackenzie Gas Project - reasons for decision. Volume 1: respecting all voices: our journey to a decision. National Energy Board. 78 p.

Reference 303

Reference 304

National Energy Board. 2010. Mackenzie Gas Project - reasons for decision. Volume 2: technical considerations: implementing the decision. National Energy Board. 310 p.

Reference 304

Reference 305

Cohen, S.J. 1996. Integrated regional assessment of global climatic change: lessons from the Mackenzie Basin Impact Study (MBIS). Global and Planetary Change11:179-185.

Reference 305

Reference 306

West Kitikmeot Slave Study Society. 2001. West Kitikmeot Slave study final report. West Kitikmeot Slave Study Society. Yellowknife, NT. xxvi + 62 p.

Reference 306

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