Arctic Ecozone+ highlights and key findings summary
Status and trends assessment highlights
- Ecozone+ overview
- Abiotic drivers
- Ecosystem functions and processes
- Ecosystem structure
- Ecosystem composition
- Ecosystem Goods and Services
- Human Influences
1. Ecozone+ overview
- Land area. 3,148,000 km2.
- Area of lakes, ponds, and rivers. 80,000 km2.
- Length of coastline. 179,950 km (3/4 of Canada’s coastline).
- Three major regions: Arctic Cordillera, Northern Arctic, and Southern Arctic. Distinct enough to be ecozones in the Canadian classification system, but are combined here for reporting purposes.
- Rivers draining the ecozone+ flow either to Hudson Bay, Ungava Bay, or directly to the Arctic Ocean.
- Topography and soils. Southern Arctic: mainly discontinuous glacial deposits underlain by granitic bedrock; Northern Arctic: west is lowland plains with outcrops of sedimentary bedrock and cover of glacial moraine and marine deposits, while east is dominated by granite bedrock with very deep permafrost; Arctic Cordillera: rugged mountains, nunataks, valleys and fiords; 75% ice or bare rock; remainder is mainly colluvial and morainal debris.
- Permafrost is continuous, may be several hundred metres thick, and has temperatures colder than -5°C.
- Inuit form the majority of residents. The ecozone+ encompasses most of four regions established through Canadian comprehensive land claim agreements: 1) Inuvialuit Settlement Region (parts of Yukon and NWT); 2) Nunavut; 3) Nunavik (part of Quebec); and, 4) Nunatsiavut (part of Newfoundland and Labrador).
- Co-management regimes for wildlife and habitat through boards or councils with input from Aboriginal regional and local governance bodies, as well as federal and territorial governments, are central to all aspects of ecological management, monitoring, and research.
Figure 1. Regions of the Arctic Ecozone+: the Arctic Cordillera, Northern Arctic, and Southern Arctic.
Long description for Figure 1
This map shows the three major regions of the Arctic Ecozone+: the Arctic Cordillera, Northern Arctic, and Southern Arctic. The Arctic Cordillera is located on the eastern edge of the ecozone+, extending in a thin band down the east coast of Ellesmere Island, the northeast coast of Baffin Island, and onto the northern tip of Labrador and adjacent area of Quebec. The Northern Arctic encompasses most of the remaining parts of the Canadian Arctic Archipelago, a small part of eastern mainland Nunavut, and the northern tip of Quebec. The Southern Arctic encompasses the remainder of the ecozone+ on mainland Nunavut, in the the Northwest Territories, and a band across northern Quebec.
2. Abiotic drivers
- Climate change has particularly affected the Arctic, with warming at about twice the rate of the global average. This high latitude amplification of climate change is projected to continue, augmented by feedback mechanisms. Example: temperatures rise when less heat is reflected from land and sea surfaces because there is less ice and snow.
- Seasonal climate trends from 1950 to 2007 show broad patterns of change with considerable regional variation. Some parameters show greater change or greater variability in the past 20 years. Trends averaged across the ecozone+:
- Temperature: increased in spring and fall. Many individual stations with increasing trends and across all seasons. No cooling trend at any station in any season.
- Precipitation: increased in all seasons, especially winter. Greatest relative increases of all ecozones+ in Canada.
- Climate oscillations strongly influence Arctic climate trends and variability, especially the Pacific Decadal and Arctic oscillations, but these cannot account for the pattern of recent pan-Arctic warming.
High Arctic tundra and muskoxen
3. Ecosystem functions and processes
- Rapid shrinking of all aspects of the cryosphere has been a dominant trend in Arctic ecosystems that began over 30 years ago and is particularly evident over the past decade. Changes in ice and snow are linked with ecosystem disturbance and other ecosystem processes such as hydrology and primary productivity.
- Permafrost has warmed and the active layer has increased in thickness--with major implications, including: changes in vegetation, alteration of carbon balance, changes in wetlands, nutrient cycling, and habitat features such as tussock tundra and sites suitable for denning mammals. Greater changes in the past two decades have occurred in permafrost in the Arctic than in taiga and boreal ecozones because there is less insulation from vegetation and snow.
- WestPermafrost temperatures increased since the early 1990s (Tuktoyaktuk Peninsula, Mackenzie Delta tundra uplands, Herschel Island)
- Central-southernGeneral increase in thaw depth (Baker Lake)
- High ArcticPermafrost temperatures increased since mid-1990s with more rapid increase from 2005 to 2011, related to warm winters (Alert)
- EastPermafrost warmed since mid-1990s, following a cooling period in early 1990s; active layer depth increased (Iqaluit, Northern Quebec sites)
Melting pingo wedge ice near Tuktoyaktuk
Melting pingo wedge ice near Tuktoyaktuk. Photo: Emma Pike, Wikimedia
- Snow has decreased, both in duration of snow cover and in maximum depth of the snowpack--despite an increase in snowfall. This is related to warmer temperatures. Around the circumpolar Arctic, snow cover in June has declined precipitously, especially since 2000, marking a major, broad-scale ecological change. Ecological consequences of reduced duration of snow cover include reduced albedo that increases climate warming and changes to other ecosystem processes, notably permafrost, streamflow, and timing and extent of primary production. Changes in snowpack affect vegetation and animals.
- Snow cover durationshorter on average by 9 days in fall and 8.5 days in spring from 1950 to 2007
- Snow depth (maximum) – reduced by an average of 13 cm, with high variability from site to site (and with very few monitoring sites)
- Sea ice. A major shift in the state of Arctic ecosystems has been the reduction in extent of sea ice in the past 30 years, with accelerated melting and loss of multi-year ice in the last few years. Terrestrial, as well as marine, ecosystems are affected, including changes in coastal climate conditions and features, and loss of critical habitat for animals that spend parts of their lifecycles on or at the edge of sea ice.
- Extent of sea ice in September (annual minimum) severely declined since first satellite measurement in 1979. The 2012 extent, the lowest on record, was 48% below the 1979-2000 average.
- Loss of multi-year ice: percentage of ice aged four or more years decreased from 26% in 1988 to 7% in 2012.
- Glaciers. Over half of the 300,000 km2 of glaciers and ice caps (excluding the Greenland Ice Sheet) draining to the Arctic Ocean are in the Canadian Arctic Archipelago. The rate of loss of this land ice, from melting and ice-berg calving, has increased since the late 1980s. Meltwater from Canadian Arctic glaciers contributed an estimated 0.71 mm per year to global sea level rise from 2003 to 2009 (29% of observed sea level rise in this period). As ice masses melt, land available for development of tundra ecosystems will increase.
- Arctic Island glaciershave been losing mass since the late 19th century, with the trend slowing for a period in mid-20th century, and with accelerated loss in the past 25 years (four glaciers on Queen Elizabeth Island). Longest of these records (Agassiz Ice Field) shows the recent melt rate was the highest in at least 4,200 years. Small ice caps on Baffin Island have declined or disappeared.
- River and lake ice timing and duration. Trend information is indirect, as long-term, ground-based monitoring is lacking. Evidence from lake sediments suggests annual ice duration has decreased since about 1850 with greater change in recent decades. A study based on remote sensing of lake ice concluded that the ice-free period increased across Canada, but change was more pronounced in the Arctic. Increased ice-free season is linked to warmer water and alterations in water mixing regimes and distribution of nutrients and oxygen. These are linked to observed increases in lake productivity and to changes in algal communities.
- Based on one remote sensing study, lake ice-free season increased by 1.75 days per year in six Arctic lakes, 1985-2004, with both earlier break-up and later freeze-up
- River flow monitoring is sparse in the Arctic Ecozone+ and status and trends are not known for most of the smaller rivers. Trends for large Canadian rivers draining to the Arctic Ocean and surrounding seas and straits are better known, but observed changes are driven mainly by conditions in southern ecozones+. Large river discharge trends vary among analyses, being dependent on the subset of stations and the time period looked at. Long-term trends are also related to decadal-scale climate oscillations. Analyses of hydrometric data also reveal recent (since about 1990) shifts in seasonal timing of streamflow, as well as increases in variability.
- Annual river flowsdecreased from 1960s to about 2000, especially for rivers discharging to Hudson Bay and Labrador Sea--but no overall flow change in rivers directly entering the Arctic Ocean (3 analyses varying in time period and sites included).
- Annual river flowsincreased since 1989, detected in analyses that include data into the first decade of the 2000s; includes a reversal of earlier declines in discharge to Hudson Bay and Labrador Sea.
- Wetland, pond, and lake area trends varied and there is no systematic monitoring. Recent short-term trends were detected through remote sensing. Ecosystem changes have occurred at the landscape scale, altering amounts and quality of freshwater and wetland ecosystems and affecting tundra carbon balance.
- Pond and lake extentincreased in some Southern Arctic areas from melting permafrost and greater precipitation (including over 3% gain, 2000-2009, in the Mackenzie Delta)
- Pond and lake extentdecreased, including ponds drying up, in drier Northern Arctic and Arctic Cordilleran areas from warmer summers and earlier ice melt. Some Ellesmere Island ponds that had been permanent water bodies for millennia dried up in 2005 and 2006.
- Extreme weather events--especially heavy snow in critical periods in spring or fall, and rain-on-snow events that create ice layers in the snow--have been documented to cause population crashes in several animal groups, including Peary caribou, muskoxen and small mammals, especially in the High Arctic.
- Fire is not currently a major disturbance in tundra ecosystems but there is evidence that it may become more widespread with warmer summers.
- Permafrost disturbance, in the form of slope failures and thermokarst ponding due to high temperatures melting permafrost, is increasingly observed in areas with ice-rich permafrost in fine sediment. Slumping of land due to permafrost thawing strips areas of vegetation cover and reduces productivity of nearby surface waters. In the Southern Arctic slumping can expose stores of frozen organic matter, turning tundra sites from carbon sinks to sources.
- Retrogressive thaw slumps (slope failures) increased in Mackenzie Delta region since 1970s. Increases also recorded on Ellesmere and Melville islands.
- Community and population dynamics are strongly influenced by climatic variables and oscillations, especially in the High Arctic. Food chains are short and a few animals dominate. Ecosystems are nutrient limited. Cyclic population fluctuations of small mammals often drive populations of predators. Populations of other grazers are indirectly linked to small mammal cycles through changes in vegetation or because they are alternate prey species. Caribou, the main large tundra grazer, fluctuate in numbers over periods of decades and their foraging ranges expand and contract, affecting vegetation over broad areas.
- Small mammals(lemmings, voles, and shrews) showed no clear long-term trends in abundance, though trend detection was made difficult by cyclic and year-to-year variation in abundance and generally short monitoring records (19 NWT-Nunavut Small Mammal Survey sites, various periods 1990-2012)
Tundra vole. Photo: Wikimedia
- Wildlife disease. The main wildlife disease of concern is brucellosis in caribou, infecting 20 to 50% of barren-ground caribou (2011 estimate), which may be an increase in prevalence since the 1960s. Brucellosis is considered to be responsible at least in part for the recent decline of the Southampton Island caribou herd. The disease is not in the woodland caribou of northern Quebec (George and Leaf River herds).
- Wildlife host-parasite systems are susceptible to climate change as free-living parasite life stages are temperature and moisture sensitive. Temperatures have warmed enough for a lungworm that parasitizes muskoxen to expand its range and develop to the infective stage in one season instead of two, but it is not clear to what extent these changes have occurred.
indication of ecosystem change
The protozoan ungulate parasite Besnoitia tarandi recently emerged as a disease-causing agent in caribou in northern Quebec and Labrador (hunter observations; veterinary studies) and may be a cause of increased lesions reported for caribou in 2005 discussions with hunters in the Western Arctic.
- Phenology. The start and the length of the growing season are largely determined by snow cover. The trends from 1950 to 2007 were towards earlier snowmelt and longer snow-free seasons (see point on snow above). Broader ecological consequences of earlier and longer growing seasons are expected to include changes in insect pollination and seed production, but there is little information on these consequences for the Canadian Arctic.
Thirty-year trend for tundra plants to earlier flowering and earlier leafing-out, corresponding with warming and earlier snowmelt over the same period (2013 synthesis of International Tundra Experiment (ITEX) results, based on plant plots, circumpolar scale including Canadian sites).
- Nutrient cycling. Because tundra ecosystems are nutrient limited due to low rates of productivity, decomposition and mineralization, changes in nutrient cycling can have major consequences to tundra vegetation. Research in northern Alaska indicated that increased nutrient uptake has been important in the widespread conversion of tundra areas to shrub that has occurred there in recent decades. Soil microbial communities, important in nutrient cycling, changed in composition in some experimentally warmed plots, especially in wet sedge tundra (based on research around the circumpolar Arctic).
Research on the effects on climate change on nutrient cycling in tundra has shown that availability of inorganic and organic nitrogen can increase in experimentally warmed plots (analysis of studies around the circumpolar Arctic, including Canadian sites)
indication of ecosystem change
Experimental warming of Canadian High Arctic tundra plots led to changes in mycorrhizal fungi communities associated with birch and willow shrub roots. These fungi-root associations are important in nutrient uptake. Broader ecological consequences are not known.
- Carbon storage and release. Tundra ecosystems have been carbon sinks for tens of thousands of years due to low decomposition rates and permafrost processes. Warming brings potential for a change from carbon sink to carbon source, but there are few studies on carbon flux in Canadian tundra. In addition, examination of circumpolar studies indicated a greater potential for increasing loss of carbon from Low Arctic ecosystems than from High Arctic ecosystems. Canadian Arctic tundra ecosystems contain about 76 Gt of soil organic carbon in the upper metre (2008 estimate). This is carbon that might react to near-term climate change. Release of carbon is a positive feedback, increasing atmospheric greenhouse gas concentrations and contributing to climate change.
indication of ecosystem change
Circumpolar studies using experimental warming of tundra plots (including those on Ellesmere Island) indicated that wet tundra systems may remain carbon sinks when warmed but dry tundra systems may become carbon sources.
Arctic tundra wetlands
Arctic tundra wetlands. Photo: G. Burba, iStock
- Pollination. There has been little study on pollination relationships in the Canadian Arctic and little is known about current status and trends related to climate change. While many tundra plants are self-pollinated or pollinated by the wind, insect pollination is important for setting seeds and maintaining genetic diversity. Flies, bumblebees and butterflies are important pollinators.
- Primary production in lakes and ponds increased in the 20th century, based on analysis of sediment cores. The best explanation for this change in freshwater algae is climate warming leading to longer ice-free seasons and associated changes in lake ecosystems. Changes are most pronounced in the High Arctic.
A pronounced 20th century increase in freshwater primary production in six Baffin Island lakes appears to be synchronized with the record of recent climate trends (based on analysis of sediment core that extend back in time over 5,000 years).
- Primary production on land. Several measures of primary productivity show marked and widespread increases.
Photosynthetic capacity of plant coverincreased throughout the Arctic Ecozone+ from 1985 to 2006, based on the Normalized-Difference Vegetation Index (NDVI), which is calculated from space-based (satellite) observations. Areas with particularly strong trends included the Labrador Peninsula, the area northwest of Hudson Bay, and southern Ungava Peninsula. (Based on a study done for this report.)
Tundra biomass (net primary production) for both wet and dry tundra typesincreased over the past 20-plus years on Ellesmere Island. Snow-bed heath biomass increased from 33 g/m2 in 1981 to 87 g/m2 in 2008.(Based on long-term studies at Alexandra Fiord.)
Annual above-ground production of wetland grasses almost doubled from 1990 to 2010 on Bylot Island, due to increases in summer temperature. (Based on long-term studies on Bylot Island.)
Lichens and bearberry on dry tundra
Lichens and bearberry on dry tundra. Photo: urbanraven, iStock
- Human stressors on ecosystem functions and processes. Climate change, due to anthropogenic increases in greenhouse gases, is the major stressor across the ecozone+. Roads and other human disturbances are important locally.
The Arctic is warming at about twice the rate of the global average, with some of the most marked changes in the Canadian Arctic (As reported in Intergovernmental Panel on Climate Change and Arctic Council assessments.)
Atmospheric carbon dioxide started to increase rapidly in the late 19th century, based on ice core samples from Antarctica. Carbon dioxide measured in the atmosphere above Alert, Nunavut steadily increased from about 335 to 390 ppm from 1975 to 2010.
4. Ecosystem structure
- Reduction of the tundra biome. Evidence for the trend towards loss of tundra comes from remote sensing, climate records and ground-based studies. The trend is linked with increasing primary productivity and changes in tundra plant communities. The strongest changes have occurred in northwestern Canada.
indication of ecosystem change
Increase in shrub cover has been confirmed in a range of locations, including Herschel Island, northern Alaska, the Mackenzie Delta, and the region east of Ungava Bay. Greater shrub cover means reduced lichen and a possible change in community structure. Shrub cover also increases ground-level absorption of solar radiation, leading to greater heating of the atmosphere, a positive feedback mechanism of growing importance.
- Shifts in algal and invertebrate species assemblages in lakes and ponds. Evidence for this trend comes from analysis of lake sediment cores and is linked with increases in primary productivity, as well as with changes in the duration of lake ice cover. The trends are widespread across the ecozone+ and are evident in other parts of the circumpolar Arctic where recent warming has occurred.
indication of ecosystem change
Species assemblages in Arctic lakes and pondshave changed, beginning in the mid-19th century. After centuries or millennia of relative stability, diatom communities have changed radically, and there is evidence that the changes are working their way up through higher trophic levels. (Based on studies of lake core sediments at several locations in the Canadian Arctic.)
- Tundra plant communities. Tundra plant communities are showing changes around the circumpolar Arctic that are consistent with responses to warming (based on experimental and plot resampling studies through the International Tundra Experiment). However, trends in localized plant communities are hard to predict because they are subject to local conditions, including soil moisture, topography, permafrost, and precipitation.
For a study of plant communities around the circumpolar Arctic, including Canadian sites, plant plots at 46 ITEX sites were re-sampled between 1980 and 2010. Overall there was an increase in canopy height and in the height of most vascular plants, and an increase in shrubs and plant litter. Experimental warming of tundra plots for one to six years led to increased growth of shrubs and grasses and decreased growth of lichens and mosses (based on 61 ITEX sites, 5 of which are in Canada).
In the same studies, mosses, lichens and bare ground cover decreased.
- Major human stressor on ecosystem structure. Climate change is the major human-induced stressor on ecosystem structure in the Arctic.
- Fragmentation and human disturbance. Overall, the degree of human-induced fragmentation in the Arctic is extremely low. However, fragmentation is a concern at the regional level and likely to become more widespread as human population and industrial development increase. Human infrastructure, such as roads and airstrips, can change the spatial distribution of predator foraging areas, affecting the reproductive success of some prey species and the nesting distribution of raptors. Planning can mitigate these impacts.
Food supplementation from human garbage is likely associated with the expansion of the red fox into the Arctic in the mid-20th century. Red fox out-compete Arctic fox, so the red fox expansion can result in loss of Arctic foxes from ecosystems.
Arctic fox by her den
Arctic fox by her den, near Cambridge Bay. Photo: DR Ferry, iStock.com
5. Ecosystem composition
The report does not cover all Arctic terrestrial species; it presents information on species of conservation concern (those considered at risk of extinction) and species of special interest due to their ecological importance and/or importance to humans.
- Sensitivity to change. Relatively low species diversity and generally simple food webs may limit the ability of Arctic ecosystems to resist perturbation and to recover when damaged.
Selected species of conservation concern
- Caribou. The caribou of the islands and mainland of the High Arctic: Peary caribou and the Dolphin and Union population of barren-ground caribou are listed under Canada’s Species at Risk Act (SARA) as being of conservation concern (Endangered and Special Concern, respectively).
Peary caribou have declined from about 44,000 to about 11,000 to 12,000 over the past 50 years. Their overall distribution has also declined, by about 15% between 1980 and 2006, with the apparent disappearance of two geographic populations.
The Dolphin and Union caribou of Victoria Island had been recovering slowly from a sharp decline through the 19th and early 20th centuries. However, hunting pressure and low cow survival suggest likelihood of a decline
Peary caribou. Photo: Paul Loewen, iStock
- Polar bear. In 2013, the Canadian population of polar bears was estimated at approximately 16,200. Although the total size of the global population is unknown, it is likely that well over half of the world’s polar bears live in Canada. They are adapted to hunting seals from sea ice, so rapidly declining sea ice due to climate change poses the most serious threat to the species. Polar bears are listed under SARA as being of conservation concern (Special Concern).
- Primary production on land. Several measures of primary productivity show marked and widespread increases.
Of Canada’s polar bears, as of 2013, 2 sub-populations are considered to be increasing or likely increasing, 6 are stable, and 4 are declining or likely declining. Data are insufficient to provide a trend for 1 sub-population (based on assessment of data available in 2013.)
- Grizzly bear. About a quarter of Canada’s grizzly bear population lives in the Northwest Territories and Nunavut. They are vulnerable to human disturbance and to declines in caribou, an important seasonal food source. Population trends are poorly known. Barren-ground grizzly bears are expanding northward in some areas of the northwestern Arctic. The western population of grizzly bears has been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as of Special Concern, but it is not listed under SARA.
- Wolverine. The western population was assessed by COSEWIC as of Special Concern (2003). A new wolverine assessment will be completed in 2014. Wolverine have low reproductive rates and are vulnerable to food shortages in the winter, when, on the tundra, they feed mainly on caribou.
Wolverine are considered (based on the 2003 COSEWIC assessment) to be at moderate to low densities, with stable populations in the NWT and Nunavut, and sensitive to changes due to harvest. Wolverine have been reduced to unconfirmed sightings in Quebec (since 1978) and Labrador (since 1950s), due to trapping, hunting, and declines in caribou.
Wolverine. Photo: R. Gau, nwtspeciesatrisk.ca
Selected species and species groups of special interest
- Migratory tundra caribou, a category that includes three subspecies (barren-ground, Grant’s, and migratory woodland caribou), along with Peary and Dolphin and Union caribou (presented above as species of conservation concern) are the dominant large herbivore of the Arctic. Wintering ranges of many migratory herds extend south to the taiga. Populations typically rise and fall over decades, although human stressors, especially climate change and expansion of human population and development, may affect recovery of some herds.
Arctic mainland caribou herds increased in numbers in the 1970s and 1980s and have generally declined in the past decade or more, with high variability in the rates of decline.
Beverley herd of barren-ground caribou
Beverley herd of barren-ground caribou, Thelon River, Nunavut, 1978. Photo: Cameron Haye, Wikimedia
- Muskoxen. Canada has about three-quarters of the world’s muskoxen, most of them on the Arctic islands. Muskoxen were reduced to a few isolated herds by 1916, partly through commercial harvest. Populations have rebuilt through introductions and range extensions.
Muskox had been nearly extirpated in Canada, through commercial harvest, by the early 20th century. Since then numbers have built up through natural recovery and range expansion, aided by hunting bans and some reintroductions. Most (85%) of the estimated Canadian muskox population of 114,300 (three-quarters of the world’s muskox population) are on Arctic islands.
- Large carnivores of North America, including wolves, grizzly bears and wolverines, have lost much of the southern parts of their ranges to expansion of human populations. As a consequence, northern ranges are increasingly important. Wolf populations are not monitored regularly and overall trends are not known. They can reproduce rapidly, making them resilient to disturbance. Their numbers tend to rise and fall in accordance with fluctuations in chief prey populations – including caribou, muskoxen and Arctic hares.
- Birds. The Arctic Ecozone+ is of global significance for the many bird species that breed wholly or chiefly in Arctic regions. Arctic-breeding migratory birds can be affected in other parts of their ranges as well, and trends may often be related to conditions on wintering or staging grounds.
Some waterfowl populations show mixed trends – such as common eiders, which appear to be declining in some parts of the ecozone+ and remaining relatively stable in other places. Some distinct species trends:
King eiders: the western population declined from about 900,000 in 1960 to between 200,000 and 260,000 in the early 1990s; remain at about this level (based on the most recent survey during migration, 2003). The eastern population is also declining, although this decline may be related to a shift in distribution linked to human disturbance (based on data from Greenland).
Greater snow geese: increased dramatically from a few thousand in the 1930s to an estimated million birds in 2012. The increase is related to changes in agricultural practices in the U.S. wintering grounds and has led to overgrazing on staging and breeding areas in Canada. Lesser snow geese also show population growth. (Based on annual counts on the wintering grounds.)
The eastern population of tundra swans, which nests from Alaska to Baffin Island, has remained stable at around 90,000 to 100,000 birds from 1982 to 2012. (Based on annual counts on the wintering grounds.)
Arctic-breeding shorebirds are declining globally by 1.9% per year, with the rate of decline increasing for several species. The causes of these widespread declines are not clear. Sixty percent of North American shorebirds breed in the Arctic, many primarily in Canada.
There are relatively few landbird species in the Arctic and few data on their population trends. Arctic-breeding landbirds known to be declining, based on counts on wintering grounds, include: hoary redpoll, American tree sparrow and Harris’s sparrow, and snowy owl
American tree sparrow
American tree sparrow. Photo: P. Chouinard, iStock
- Major range shifts of species native to Canada. Arctic residents have reported changes in animal behaviour and distribution, and these observations have been documented in several studies. Among the observations are the presence of new insect and bird species and the northward movement of existing Arctic and boreal species, such as ravens, cougars and grizzly bears.
Moose have been expanding their range northwards in recent decades in much of the Arctic. Moose provide another prey source for predators, such as wolves, as well as an alternate food source for subsistence economies. They can also indirectly affect other ungulates – for example, if the availability of moose keeps the wolf population high through the summer on caribou wintering grounds, the caribou will face increased predation when they return.
- Human stressors on ecosystem composition. Climate change is a human-induced stressor for some species. Human settlements and infrastructure affect ecosystem composition through habitat change, disturbance, and harvest. Contaminants and pollution, from local sources and from long-range atmospheric transport, affect both terrestrial and aquatic ecosystems. Increased transportation and development in the Arctic is likely to increase the level of and impacts from human stressors.
Barrels abandoned on the tundra
Barrels abandoned on the tundra, Nunavut. Photo: Ryerson Clark, iStock
6. Ecosystem Goods and Services
- Living space. Modern Inuit and Inuvialuit use huge tracts of land as they travel to neighbouring communities to visit and conduct business and to remote camp sites to hunt, fish, and trap. Ice and snow form an important part of this living space. River, lake, and sea ice provides access to the land for hunting and fishing and for transport during much of the year.
In the Arctic, permafrost supports building structures, often on land that would be unusable if it were not frozen. Climate-change-induced reduction in extent of permafrost and increase in depth of annual thawing are current risk factors and future threats. Loss and reduction of ice cover negatively affects travel on land and over rivers, lakes and along coastal areas.
- Food. Harvest of country foods is not just a matter of calories and nutrients, but a central feature of Inuit and Inuvialuit cultural identity. Caribou are particularly important. For example, the annual combined harvest for the Northwest Territories and Nunavut is about 1.6 million kg of caribou – or, based on beef replacement value, about $35 million for meat alone. In addition, there is the value of hides, commercial harvesting, and the cultural value to Arctic peoples and communities.
Studies from the early 1970s to recent years show that Inuit and Inuvialuit across the ecozone+ continue to rely heavily on traditional (or country) foods. Participation rates for fishing were about 70% in all regions, and about 50 to 60% for hunting caribou, moose or sheep, based on a comprehensive study conducted in 2001.
Fishing in the Burnside River
Fishing in the Burnside River, Nunavut. Photo: C. Farish, iStock.
7. Human Influences
- Stressors and cumulative impacts. The dominant human-linked stressor on Arctic systems is climate change and, based on climate model projections, that will continue to be true for the foreseeable future. Other widespread stressors include contaminants from long-range atmospheric transport. At the local or regional level, stressors include habitat fragmentation and disturbance, overharvest, and localized contamination. These stressors interact, often in complex and unpredictable ways.
Jericho Diamond Mine pit
Jericho Diamond Mine pit, Nunavut (operated 2006-2008). Photo: Tom Churchill, Wikimedia
- Main threats to caribou. Stressors from human activities can interact with and exacerbate natural stressors, such as predation, parasites, and disease. This interaction can be particularly problematic during low periods in the caribou herds’ population cycles when the herds are most vulnerable.
The human population of the Arctic and neighbouring taiga ecozones+ almost doubled between 1971 and 2006. The increased population, combined with new hunting technologies that make hunting more efficient, are likely to lead to increased harvest pressure.
Increased development – mineral and hydrocarbon exploration and development, power lines, shipping, road construction, etc. – places pressures on caribou, particularly the migratory herds.
Climate change will affect the movements and distribution of the herds, as well as the ability of hunters to get on the land. The particular impacts will vary from herd to herd, depending on their traditional ranges and movement patterns and on how the stressors from climate change interact with other stressors, both natural and anthropogenic.
- Stewardship and conservation. A major human stressor for the Arctic is climate change. This stressor cannot be overcome through stewardship and conservation measures within the Arctic. It is a global problem, and the most significant measure that can be taken to conserve Arctic ecosystems is to reduce greenhouse gas emissions worldwide.
Canada’s annual greenhouse gas emissions rose from below 600 megatonnes CO2 equivalent in 1990 to 746 megatonnes in 2007, then declined to 702 megatonnes in 2011. The Copenhagen target is 612 megatonnes by 2020 (17% below emissions for 2005).
- Protected areas. As plant and animal ranges shift and ecosystem function and processes are affected by climate change and by increasing development pressures, it becomes even more important to focus on conservation of important lands and waters, such as breeding areas for migratory birds and caribou.
The total area protected in the Arctic Ecozone+ increased from less than 50,000 km2 in the 1950s to close to 300 km2 by 2009. Overall, 11.3% of land is protected, with the highest proportion (24%) in the Arctic Archipelago and the lowest in the Northern Arctic (6.7%). (Based on analysis of Conservation Areas Reporting and Tracking System data current to May, 2009)
- Environmental governance. Resource management boards, established pursuant to land claims settlements, have become the dominant forces in management of land and natural resources in the Canadian Arctic. The networks of resource management boards, councils, and local hunters’ and trappers’ associations function as bottom-up, co-operative systems that are mandated to make use of science and Aboriginal traditional knowledge in making decisions about management of the land and natural resources of the Arctic.
Co-management meeting about the Yukon North Slope
Co-management meeting about the Yukon North Slope, Aklavik, NWT, Dec. 2007. Photo: Wildlife Management Advisory Council (North Slope).
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