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Technical Thematic Report No. 11. - Western Interior Basin Ecozone+ Evidence for key findings summary

Theme: Habitat, Wildlife, and Ecosystem Processes

Key finding 16
Agricultural landscapes as habitat

Theme: Habitat, wildlife, and ecosystem processes

National key finding
The 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.

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The Province of BC zones agricultural land as part of the Agricultural Land Reserve (ALR). These lands are designated with agriculture as the primary use; other uses are controlled. Footnote 142 There is pressure to remove land from the ALR for other uses such as urban development.

Most of the agricultural lands (81%) in the WIBE are in the northeast region of the ecozone+ (Figure 44). Footnote 143 Between 1986 and 2006, the agricultural land base in the WIBE expanded from 4,810 to 5,690 km2, approximately 10% of the ecozone+. At lower elevations, grazing, forage production, and orchards were common; grazing in woodlands was associated with middle elevations.

Figure 44: Percentage of land defined as agricultural in the Western Interior Basin Ecozone+, 2006.

map

Long Description for Figure 44

This map shows the percentage of agriculture in 10% categories from 0-10% to 90-100%. The highest percentages are in the South Thompson River around Kamloops and in the southeastern part of the ecozone+. The lowest percentages are in the southern ecozone+, particularly in the west.

Source: Javorek and Grant, 2011 Footnote 143

Unimproved Pasture, which included pasture lands that have not been cultivated or managed such as native pasture, rangeland, and grazeable bush, was the most common agricultural land cover in the WIBE and increased from 64% to 67% from 1986 to 2006 (Figure 45). Footnote 143In contrast, Improved Pasture declined from 9% to 5% (Figure 45). Footnote 143 Cropland, which included all agricultural land except for All Other Land, Unimproved Pasture, Improved Pasture, and Summerfallow, expanded by 6% to make up 15% of agricultural land (Figure 45). Footnote 143 The category Fruit Trees, an important cover type in the WIBE, contained trees such as apple, peach, plum, cherry, apricot, pear, and other tree fruits or nuts, as well as grapes (vineyards). Fruit Trees declined from 2.4% to 1.6% between 1986 and 2006 (Figure 45). Footnote 143

Figure 45: Total agricultural area and the amount of land per cover type (bar chart) and the relative percentage of cover types for the Western Interior Basin Ecozone+ in 1986, 1996, and 2006.
To convert hectares to km2, divide by 100.
Source: Javorek and Grant, 2011 Footnote 143

graph

Long Description for Figure 45

This graphic presents a stacked bar graph showing the following information:

Data for figure 45
 1986 - Agricultural land (ha)1996 - Agricultural land (ha)2006 - Agricultural land (ha)
Oilseeds474195849
Pulses142162404
Soybeans000
Berries83165163
Improved Pasture42,15142,12930,699
All Other Land84,26793,23268,850
Summerfallow5,9653,0702,199
Unimproved Pasture306,207312,398381,413
Cereals5,3008,3187,284
Corn2,3871,7862,297
Tame Hay20,84354,63564,114
Other Crops370748662
Fruit Trees11,5049,6429,322
Vegetables814804712
Winter Cereals1,338916786

Wildlife habitat capacity on agricultural land

A total of 323 terrestrial vertebrates (232 birds, 72 mammals, 10 reptiles, 9 amphibians) are associated with agricultural lands in the WIBE. The All Other Land cover type was the most species rich with 85% of these species using it for both breeding and feeding habitat. The most common agricultural land cover type, Unimproved Pasture, fulfilled breeding and feeding requirements of 25% of these species and provided a single habitat requirement (breeding or feeding) for 44% of these species. Only 12% of these species were able to use Cropland for both breeding and feeding habitat, whereas 25% were able to obtain a single habitat requirement from Cropland. Footnote 143

Wildlife habitat capacity was calculated for each species using a model that incorporated breeding and feeding requirements in terms of cover type and habitat value to the species.143 The "status" of habitat capacity on agricultural land in Canada for 1986, 1996, and 2006 was determined by generating ten categories (Very Low:<20, 20–30, Low: 30–40, 40–50, Moderate: 50–60, 60–70, High: 70–80, 80–90 and Very High: 90–100, >100) based on the national distribution of habitat capacity scores from all reporting Soil Landscapes of Canada polygons. Footnote 143Average wildlife habitat capacity on agricultural land in the WIBE declined from high capacity in 1986 to moderate capacity in 2006 (Figure 46). Over this time period, habitat capacity decreased on 35%, increased on 7%, and remained stable on 58% of agricultural lands (Figure 47).

Figure 46: The share of agricultural land in each habitat capacity category (left axis; stacked bars) and the average habitat capacity (right axis, symbols) for the Western Interior Basin Ecozone+ in 1986, 1996, and 2006.
Letters indicate a statistically significant difference.
Source: Javorek and Grant, 2011 Footnote 143

graph

Long Description for Figure 46

This stacked percentage bar graph shows the following information:

Data for figure 46
 1986 - Share of agricultural land
per habitat
capacity category
1996 - Share of agricultural land
per habitat
capacity category
2006 - Share of agricultural land
per habitat
capacity category
<200.000.000.00
20-300.000.450.00
30-400.000.000.46
40-500.933.132.70
50-6032.1319.8969.42
60-7028.5347.5822.92
70-8027.9117.203.61
80-907.9210.260.49
90-1002.301.490.16
>1000.280.000.16
Habitat capacity Categories
Very high90 to 100
High70 to 90
Moderate50 to 70
Low30 to 50
Very low< 20 to 30

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Figure 47: Changes in wildlife habitat capacity on agricultural lands in the Western Interior Basin Ecozone+, 1986–2006.
Source: Javorek and Grant, 2011 Footnote 143

Changes in wildlife habitat

Long Description for Figure 47

This is a map of habitat capacity, which decreased significantly on 35% of agricultural lands, increased on 7%, and remained stable on 58%. These changes were distributed throughout the ecozone+.

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Soil erosion

Due to the dry climate, the risk of soil erosion by water is generally low in the WIBE except on tilled complex slopes where tillage erosion is important (Figure 48). Footnote 144

Figure 48: Soil erosion risk classes of agricultural land in the Western Interior Basin Ecozone+, 2006.
Source: McConkey et al., 2011 Footnote 144

Soil erosion risk classes

Long Description for Figure 48

This map showed that the risk of soil erosion by water was generally low in the WIBE except on tilled complex slopes where tillage erosion is important. Most agricultural areas in the WIBE were very low risk,< 6 tonnes soil lost/ha/yr. There were areas of low risk, 6–11 t/ha/yr, in the southern Okanagan and just south of the South Thompson River. There was a section of moderate risk, 11–22 t/ha/yr, near the Similkameen River.

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Additional information related to agricultural landscapes can be found in the Grasslands section on page 19 and the Species of special economic, cultural, or ecological interest section on page 66.

Microbiotic soil crust

The grazing of introduced livestock has altered the structure of the Bunchgrass and Ponderosa Pine zones of the WIBE from dominance by native bunchgrasses to increasing cover of native shrubs such as big sage (Artemesia tridentata) as well as non-native species. Footnote 145Natural grasslands in semi-arid environments, including those in the WIBE, often have lichen-dominated microbiotic soil crusts that provide important ecological functions including soil formation and soil surface stabilization, nutrient cycling, seed germination, food and shelter, and moisture retention. Footnote 146 These have been extensively damaged in the WIBE by livestock trampling. Footnote 147 Loss of the soil crust results in a decrease in water retention. For example, five days after rain, soils covered by microbiotic crust in antelope-brush shrub-steppe habitats of South Okanagan retained an average of 31% of the moisture that was present in the soil on day 1, while bare soils retained only 9.5%. Footnote 148 This is particularly important for healthy plant development in semi-arid environments.

Loss of soil crust also encourages the spread of invasive alien plant species by providing suitable beds for germination of their seeds and the WIBE is more affected by invasive alien plants than any other part of BC. Footnote 145 The result is a major loss of rangeland productivity for livestock and degradation of the native grassland plant communities. Footnote 93 Footnote 104 See also the Invasive terrestrial plants section on page 46.

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.

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Sagebrush-dominated ecosystems are rare in Canada and, as the northern extension of the sagebrush-dominated Great Basin Desert of the US, Footnote 8the WIBE contains assemblages of plants and animals that occur nowhere else in Canada. Footnote 26The species richness is high throughout much of this ecozone+ (Figure 49), including a large number of species and ecosystems of conservation concern.

Figure 49: Distribution of species richness of vascular plants, vertebrates, butterflies and dragonflies in the Western Interior Basin Ecozone+, 2008.
Source: Austin and Eriksson, 2009 Footnote 49

map

Long Description for Figure 49

This is a map of the number of species in large grids in the WIBE. The greatest species richness, greater than 500, is in the south and around Kelowna.

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Species of conservation concern

NatureServe is a conservation organization that identifies animals and plants in North America according to global conservation concern. Footnote 149 The BC Conservation Data Centre performs the same function for BC. Footnote 150 The WIBE has 7 species of animals and 48 species of plants of global conservation concern and 131 species of animals and 305 species of plants of provincial conservation concern (Table 8 and Table 9); some of these rankings are for subspecies. A species' ranking changes between geographic levels because a species may be secure throughout its entire range (global or G-rank) but of conservation concern in the portion of its range that occurs in BC (provincial or S-rank). At both levels, species are classified as critically imperilled, imperilled, vulnerable, apparently secure, and secure. In addition, S-ranks for birds include the qualifiers of breeding, non-breeding, and migrant populations.

Many of the Great Basin Desert-associated plants and animals of the WIBE are at the northern limit of their range. Therefore, many species in the WIBE are ranked for conservation concern at the provincial level but not at the global level. These peripheral populations have special importance for biological conservation and the long-term persistence of these species. Peripheral populations may have unique genetic or behavioural attributes relative to the core population. These attributes can provide the species with resilience to changing environmental conditions as well as providing a source of individuals for reintroductions and translocations. Footnote 151 Footnote 152

Table 8. Number of animal species and subspecies assessed for global conservation concern (G-rank,
left number) and provincial conservation concern (S-rank, right number) in the Thompson and Okanagan regions. Footnote 153
Conservation Status RankAmphibiansBreeding BirdsGastropods and bivalvesInsectsMammalsRay-finned fishReptiles and turtlesTotals
Extinct or Extirpated0; 00; 00; 00; 10; 00; 00; 10; 2
Historical0; 00; 00; 10; 01; 10; 00; 01; 2
Critically Imperilled0; 10; 90; 10; 100; 60; 00; 10; 28
Imperilled0; 10; 91; 20; 60; 70; 70; 31; 35
Vulnerable0; 31; 183; 60; 180; 91; 60; 45; 64
Total species and
subspecies of
conservation concern
0; 51; 364; 100; 351; 231; 130; 97; 131
Apparently secure or
secure
7; 243; 86; 035; 025; 318; 612; 3146; 22
Not ranked or unrankable0; 00; 00; 00; 00; 00; 00; 00; 0
Total number of species
assessed
7441035261912153

These data include subspecies separately when they are ranked separately.
If there is uncertainty about a species' conservation status, it may be ranked with a range, such as S2S3.
In these cases, species were included in the totals for the first ranking of the range (S2 in the example).
Data for birds indicate provincial ranking for breeding populations.
The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together
approximate the WIBE.
Source: BC Ministry of Environment, 2011

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Table 9. Number of plant species assessed for global conservation concern (G-rank, left number) and provincial conservation concern (S-rank, right number) in the Thompson and Okanagan regions. Footnote 153
Conservation Status RankVascularNon-vascularTotals
Extinct or Extirpated0; 00; 00; 0;
Historical0; 70; 00; 7
Critically Imperilled0; 1011; 151; 116
Imperilled8; 1195; 2413; 143
Vulnerable15; 2619; 1334; 39
Total species of conservation
concern
23; 25325; 5248; 305
Apparently secure or secure226; 122; 0248; 1
Not ranked or unrankable5; 05; 010; 0
Total number of species assessed25452306

If there is uncertainty about a species' conservation status, it may be ranked with a range, such as S2S3.
In these cases, species were included in the totals for the first ranking of the range (S2 in the example).
The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together
approximate the WIBE.
Source: BC Ministry of Environment, 2011

At the national level, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses species to determine if they are at risk of extinction or extirpation. Species designated by COSEWIC as being at risk may qualify for legal protection and recovery efforts under the Species at Risk Act. Footnote 154 In the WIBE, 93 animal species, subspecies, or populations have been assessed or are candidates for assessment by COSEWIC, and 54 of these are under Species at Risk Act protection (Table 10). Of plant species occurring in the WIBE, 28 have been assessed or are candidates for assessment by COSEWIC and 20 are under Species at Risk Act protection (Table 11).

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Table 10. Number of animal species, subspecies, and populations assessed by the Committee on the Status of Endangered Species in Canada (COSEWIC) Footnote 153, Footnote 155 in the Thompson and Okanagan regions.
COSEWIC StatusAmphibiansBreeding BirdsGastropods
and bivalves
InsectsMammalsRay-finned fishReptiles and
turtles
Totals
Extinct or Extirpated------11
Endangered281416224
Threatened16-222215
Special Concern27-285529
Not at Risk29--22217
Candidate for
Assessment
-2-1-1-4
Data Deficient----21-3
Number assessed by
COSEWIC
7321915171293
Number protected by
the Species at Risk Act
51816106854

These data include subspecies and populations separately when they are ranked separately.
The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together approximate the WIBE.
Source: BC Ministry of Environment, 2011

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Table 11. Number of plant species assessed by the Committee on the Status of Endangered Species in Canada (COSEWIC) Footnote 153 Footnote 155in the Thompson and Okanagan regions.
Conservation Status RankVascularNon-vascularTotals
Extinct or Extirpated---
Endangered11213
Threatened415
Special Concern213
Not at Risk4 4
Candidate for Assessment112
Data Deficient1-1
Number assessed by COSEWIC23528
Number protected by the Species at
Risk Act
16420

The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together
approximate the WIBE.
Source: BC Ministry of Environment, 2011

Ecosystems of conservation concern

NatureServe and the BC Conservation Data Centre also identify and rank the conservation concern of ecological communities, or ecosystems, in North America and BC, respectively. The identification of ecological communities in BC is ongoing. Footnote 150 The WIBE has 54 ecosystems of global conservation concern and 185 ecosystems of provincial conservation concern (Table 12). More information about individual ecosystems can be found in the Forests section on page 13, the Grasslands section on page 19, the Wetlands section on page 25, the Lakes and rivers section on page 28, and in the Ecosystem conversion section on page 40.

Table 12. Number of ecosystems (ecological communities) assessed for global conservation concern (G-rank, left number) and provincial conservation concern (S-rank, right number) in the Thompson and Okanagan regions. Footnote 153
Conservation status rankAlpineForest and woodlandGrassland, herbaceous, and shrubWetland and riparianTotals
Extinct or Extirpated0; 00; 00; 00; 00; 0
Historical0; 00; 00; 00; 00; 0
Critically Imperilled0; 01; 61; 53; 115; 22
Imperilled1; 06; 316; 135; 1818; 62
Vulnerable0; 07; 672; 322; 3131; 101
Total ecosystems of
conservation concern
1; 014; 1049; 2130; 6054; 185
Apparently secure or secure2; 16; 828; 410; 726; 94
Not ranked or unrankable45; 47167; 130; 2227; 0269; 70
Total number of ecosystems assessed481874767349

Some ecosystems are identified in more than one group (e.g., the Betula occidentalis/Rosa spp.
(water birch/roses) ecosystem is classified first in the riparian group and second in the shrub group).
For this analysis, each ecosystem was placed with its primary group.
The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together approximate the WIBE.
Source: BC Ministry of Environment, 2011

Species of special interest

Birds

From 1973 to 2006, the abundance of landbirds in the WIBE declined significantly (p<0.05) in all habitats except shrub/successional habitats, where they increased (Figure 50). Footnote 156 Declines in bird populations have been attributed to the cumulative impacts of ecosystem conversion to agricultural lands, overgrazing by livestock, forest harvest, insect outbreaks that affect bird habitats, habitat fragmentation, urban development, altered fire regimes, and invasion of non-native plants. Footnote 157 Footnote 158 Footnote 159 Footnote 160

Figure 50: Annual indices of population change in bird assemblages for five habitat categories. The index is an estimate of the average number of individual birds that would be counted on a randomly selected route by an average observer in a given year.
The index is an estimate of the average number of individual birds that would be counted on a randomly
selected route by an average observer in a given year.
Source: Downes et al. 2011 Footnote 156

graph

Long Description for Figure 50

This figure has five line graphs of abundance indices. They show the following information:

Data for figure 50
YearShrub/successionalGrasslandOther open
habitat
Urban and
Suburban
Forest
197343.540.2119.2136.3201.7
197447.138.793.1192.5220.6
197550.255.4107.8177.3233.1
197662.655.6127.1138.3230.1
197746.648.4106.5125.6195.9
197850.154.5133.5160.1198.9
197954.247.2143.2130.7227.5
198058.747.6115.1169.6229.0
198157.147.1103.3138.2203.6
198263.734.599.5118.2154.7
198348.139.777.2119.9204.6
198460.843.690.7132.8240.0
198556.935.794.4140.8183.1
198655.338.195.6122.5258.6
198763.847.3113.0166.0268.6
198860.837.1106.1147.3261.0
198958.247.685.2125.4226.9
199065.642.5100.9135.3225.9
199177.941.283.5128.0226.6
199260.749.2104.6136.4223.1
199364.439.791.1110.2207.0
199460.234.597.9116.8229.8
199557.031.493.3125.6218.4
199655.332.177.3120.5207.0
199755.026.185.4138.0186.4
199859.133.178.2119.1180.4
199955.130.683.5115.1162.7
200054.427.176.5116.0185.4
200157.428.573.1106.8202.8
200256.424.763.598.0170.2
200359.221.762.2108.6177.8
200460.126.469.5109.5177.1
200555.030.063.6106.1152.8
200666.636.566.0108.5166.4

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Burrowing owls

Burrowing owls are ground-dwelling birds that use burrows created by ground squirrels, prairie dogs, and badgers for nesting and roosting. They are losing habitat as shortgrass prairies are converted to agricultural crop production. Footnote 161 Moreover, the use of pesticides has reduced the availability of food for the owls. Footnote 162From 1990 to 2000, the number of owls declined by 90% Footnote 162 and the species was designated as Endangered in 1995. Footnote 162 The wild BC population has been augmented through a captive breeding program since 1992. Footnote 163

Sage thrashers

Sage thrashers (Oreoscoptes montanus) are one of Canada's rarest bird species. They are found in mature sagebrush habitats, which are under threat from conversion to intensive agriculture, housing, and golf courses. Footnote 164 In the southern Okanagan and Similkameen valleys, habitat loss has reduced the number of breeding adults to fewer than 30 individuals. Footnote 164 Sage thrashers were designated as Endangered in 1992. Footnote 153

Williamson's sapsuckers

Williamson's sapsuckers (Sphyrapicus thyroideus) are losing their habitat, old-growth western larch (Larix occidentalis), to timber harvest and land clearing. Footnote 165 The 2005 population was estimated to be 430 breeding adults with 85% of these individuals in the southern Okanagan (the Okanagan–Greenwood population). Footnote 165 They were designated as Endangered in 2005. Footnote 153

Ungulates

First Nations and recreational hunters harvest many of the ungulate species in the WIBE. Most ungulate populations in the WIBE were stable or increasing from 2008 to 2011 with the exceptions of caribou (Rangifer tarandus) and mountain goats (Oreamnos americanus) (Table 13). Footnote 166

Table 13. The status and trends (2008–2011) of ungulate populations in the Western Interior Basin Ecozone+. Footnote 166
SpeciesThompson region: Estimated population and trendOkanagan region: Estimated population and trend
Mule deer (Odocoileus hemionus)35,000–55,000;
Increasing
28,000–42,000; Increasing
White-tailed deer (Odocoileus virginianus)5,000–8,000; Increasing31,000–44,000; Increasing
Black-tailed deer (Odocoileus hemionus columbianus)1,000–2,000; IncreasingNone
Moose (Alces alces)8,000-12,000; Increasing2,000-3,000; Stable
Elk (Cervus canadensis)300-400;
Stable/Increasing
1,000-1,500; Increasing
Caribou200–300; Declining5–15; Stable
Bighorn sheep Table Footnote a2,000-2,500; Increasing1,000-1,200; Stable/Increasing
Mountain goat1,400-2,000; Declining200-300; Stable

Source: BC Ministry of Forests, Lands and Natural Resource Operations, 2011

Table Footnote

Footnote 1

Thompson region includes both California and Rocky Mountain bighorn sheep; the Okanagan region has only California bighorn sheep.
Population trends: Declining is >20% decline; Stable is<20% change; Increasing is >20% increase.
The Thompson and Okanagan regions are BC Ministry of Environment boundaries that together approximate the WIBE.

Return to Footnoteareferrer

Bighorn sheep (Ovis canadensis californiana and O. c. canadensis) are iconic ungulates for the ecozone+. In BC, the range of California bighorn sheep is largely restricted to the WIBE. Bighorn sheep are habitat specialists, inhabiting steep, open terrain. Overharvested historically, populations of California bighorn sheep were increasing until 1999 when pneumonia killed 70% of the southern Okanagan population (Figure 51). Footnote 22, Footnote 167 More information can be found in the ESTR technical thematic report Wildlife pathogens and disease in Canada. Footnote 168

Figure 51: California Bighorn Sheep population in the Western Interior Basin Ecozone+, 1900–2008.
Source: data from Demarchi et al., 2000; Footnote 167 BC Ministry of Forests, Lands and Natural Resource Operations, 2011; Footnote 166and BC Ministry of Forests, Lands and Natural Resource Operations, unpublished data

graph

Long Description for Figure 51

This line figure shows the following information:

Data for figure 51
1900 - Number of sheep1950 - Number of sheep1970 - Number of sheep1975 - Number of sheep1983 - Number of sheep1993 - Number of sheep1996 - Number of sheep2002 - Number of sheep2004 - Number of sheep2008 - Number of sheep
1350150016501850225030004500283828383460
Carnivores

The North American range of large carnivores retracted as Europeans settled the landscape and persecuted predators (Figure 52). Footnote 169 For example, badgers and wolverine (Gulo gulo) were persecuted, trapped, and, until the 1950s, poisoned by bait intended for wolves. Footnote 170

Grey wolves (Canis lupus) were intentionally killed and possibly extirpated in the WIBE by 1968. Footnote 171 However, wolves have recolonized the Thompson region at a density of 2.8–3.1 per 1,000 km2. Footnote 172 Wolves have also returned to the southern Okanagan, Footnote 173 although their densities are unknown. Wolf populations have also been increasing in the Kootenays, Footnote 174 east of the WIBE.

Grizzly bears (Ursus arctos) were extirpated in most of the ecozone+ (Figure 53). Footnote 175Grizzlies are directly affected by disturbance and fragmentation associated with roads and off-road access. Footnote 176 Other large carnivores in the WIBE include lynx (Lynx canadensis), cougars (Puma concolor), and black bears (Ursus americanus).

Figure 52: Reduction in the ranges of large carnivores in North America.
Source: Hummel and Ray, 2008 Footnote 169

map

Long Description for Figure 52

These three maps show the current and historical distribution of three carnivores, which have been reduced to half their previous range. Grey wolves used to cover nearly all of North America and are now primarily restricted to Canada and Alaska. Grizzly bears were distributed throughout western North America and are now in northwestern North America and Alaska. Wolverines were reduced from Canada and northern USA to primarily north central and northwestern Canada.

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Figure 53: Grizzly bear range in BC, 2004.
Source: Grizzly bear range in the Western Interior Basin Ecozone+, 2004. Footnote 177 This information is provided by the Province of BC under the Open Government License for Government of BC Information v.BC1.0.

map

Long Description for Figure 53

This map shows that grizzly bears were extirpated from most of the WIBE. Threatened populations persist along the western part of the ecozone+ and a small section has a viable population in the northeast.

Fish
Coho

Although the species is not listed provincially as a species at risk, the Interior Fraser River population of coho salmon (Oncorhynchus kisutch) has been ranked as Endangered by COSEWIC since 2002. Footnote 178 The population declined by 60% between 1990 and 2000 (Figure 54) because of habitat changes and overexploitation. Footnote 178

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Figure 54: Estimated total abundance from fishery exploitation rates, escapements, and marine fishery catches of Interior Fraser Coho salmon for the Fraser, Lower Thompson, North Thompson, and South Thompson rivers, 1975–2001.
Data for the Fraser Canyon and Upper Fraser available since 1998.
Source: data from COSEWIC, 2002 Footnote 178 updated from Irvine et al., 2001 Footnote 179

graph

Long Description for Figure 54

This line graph shows the following information:

Data for figure 54
YearSouth Thompson - Estimated total abundanceNorth Thompson - Estimated total abundanceLower Thompson - Estimated total abundance
19751835469754-
19761226864713-
197726572133975-
197825028122364-
197931918149670-
19802198932996-
19811289564524-
198218308132382-
198319392109816-
19844818321769217205
1985532041413495973
1986481863041136511
1987455641185949153
19888480224515013843
198948496864559763
1990326779754217021
1991128964521712619
19926412511891725905
1993150457766769916
19947915177029217
19958261512724509
199610667746454509
19973418112957037
1998532198102828
1999337998015502
2000391972824616
2001142352841810568
Kokanee

Kokanee are sockeye salmon that live and reproduce in lakes. In the WIBE, kokanee were historically harvested by First Nations Footnote 180 and used to support recreational fishing. Okanagan Lake kokanee have two genetically distinct stocks, stream spawners and shore spawners. Footnote 181 Footnote 182 Both stocks declined from over 450,000 spawners each in the early 1970s to fewer than 50,000 shore spawners and fewer than 10,000 stream spawners in the mid- to late 1990s. As a result, the recreational fishery was closed. Footnote 45 In 2011, population estimates were 276,000 shore spawners and 17,700 stream spawners. Footnote 183 Declines have been attributed to decreasing lake productivity due to nutrient reduction initiatives, degraded shoreline habitat due to development, forestry, and recreational activities, drops in lake water levels for flood control, and competition for food with mysis shrimp. Footnote 184 See the Habitat alteration and loss, Nutrient loading to lakes and Invasive aquatic species sections on pages 32, 53, and 48, respectively.

Sockeye

Returns of Okanagan sockeye salmon have fluctuated greatly, from over 200,000 fish in 1967 to fewer than 5,000 in each of 1963, 1994, 1995, and 1998. Precipitous declines in Okanagan sockeye returns in the early to mid-1960s coincided with the construction of five dams on the Columbia River. Footnote 185 Presently, there are nine dams on the Columbia River and as well as the Zosel Dam at the outlet of Osoyoos Lake that block upstream migration of sockeye salmon. In 2009, the McIntyre Dam was modified to allow sockeye to pass. Footnote 58 In 2004, the Okanagan Nation Alliance began an experimental reintroduction program by releasing sockeye fry into Okanagan River upstream of Skaha Lake. Footnote 111, Footnote 186

Steelhead

Steelhead are sea-run rainbow trout that return to freshwater to spawn. Thompson River steelhead have been declining (Figure 55) primarily because of bycatch during commercial salmon fishing. Footnote 187

Figure 55: Thompson River Basin steelhead spawner abundance estimates, 1984–2008.
Source: BC Ministry of Environment, unpublished data

graph

Long Description for Figure 55

This line graph shows the following information:

Data for figure 55
YearSteelhead spawner abundance estimates
19841115
19853514
19862326
19871675
19881500
19891671
19901200
19911200
1992900
19932955
19942660
19952591
19961019
19973000
19981470
19992419
2000835
20011880
20021672
20031344
20041165
20052000
20061800
2007870
20081000
Sturgeon

White sturgeon (Acipenser transmontanus), the largest freshwater fish in Canada, is ranked as imperilled in BC and Endangered by COSEWIC. Footnote 153 , Footnote 188 One of the six BC populations, the Middle Fraser population, lives in the WIBE where a catch-and-release recreational fishery is permitted. Footnote 189 The Middle Fraser population was estimated at 3,800 adult fish (fish that measured >50 cm from the tip of the nose to the fork in the tail) in 2003; population trends are unknown. Footnote 190 White sturgeon are slow growing and slow maturing, so they are particularly vulnerable to overharvesting, habitat degradation and loss, and a developing aquaculture industry. Footnote 190

Plants

The WIBE contains numerous rare and distinctive plants such as alkaline wing-nerved moss (Pterygoneurum kozlovii), Columbian carpet moss (Bryoerythrophyllum columbianum), dwarf woolly-heads (Psilocarphus brevissimus var. brevissimus), Grand Coulee owl-clovers (Orthocarpus barbatus), Lemmon's holly ferns (Polystichum lemmonii), Lyall's mariposa lilies (Calochortus lyallii), Mexican mosquito ferns (Azolla mexicana), mountain holly ferns (Polystichum lonchitis), nugget moss (Microbryum vlassovii), rusty cord-moss (Entosthodon rubiginosus), scarlet ammannias (Ammannia robusta), short-rayed asters (Symphyotrichum frondosum), slender collomias (Collomia tenella), small-flowered lipocarphas, stoloniferous pussytoes (Antennaria flagellaris), and toothcups (Rotala ramosior). Most of these species are provincially and federally listed and more information can be found with their associated recovery plans and strategies.

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.

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The Normalized Difference Vegetation Index (NDVI), calculated from remote sensing data, indicates the amount and vigour of green vegetation--an indirect measure of primary productivity. Significance of the trend analyses was assessed at the 95% confidence level using the Mann-Kendall test. Footnote 191 From 1985 to 2006, this index increased for 16,713 km2(30.1%) and decreased for 1,035 km2 (1.3%) of the WIBE (Figure 56). The increases were associated with areas of mixed forest and may indicate regeneration following extensive forest harvesting. The decreases were scattered throughout the ecozone+ in areas that were primarily classified as conifer forest. The reasons for the decreases in the WIBE are not known.Footnote12

Figure 56. Trends in the Normalized Difference Vegetation Index for the Western Interior Basin Ecozone+, 1985-2006.
Source: Ahern et al., 2011 Footnote 12

map

Long Description for Figure 56

This map presents trends in the Normalized Difference Vegetation Index for the Western Interior Basin Ecozone+. From 1985 to 2006, this index increased for 16,713 km2 (30.1%) and decreased for 1,035 km2 (1.3%) of the WIBE. The increases were associated with areas of mixed forest throughout the ecozone+. The decreases were scattered throughout the central part of the ecozone+ in areas that were primarily classified as conifer forest; the reasons for the decreases in the WIBE are not known.

Key finding 19
Natural disturbance

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.

Top of Page

The ecosystems of the WIBE have been shaped by several interacting factors including climate, extensive fires coincident with European settlement, harvesting, fire suppression, and insect attack. Although the nature of disturbance has changed from one largely dominated by fire and insect attack historically to harvesting and insect attack since 1950, the area disturbed annually has not diminished. Footnote 192

Fire

Fire is of fundamental importance to the ecosystems of the WIBE, particularly the Bunchgrass, Ponderosa Pine, and dry portions of the Interior Douglas-fir biogeoclimatic zones. Historic natural disturbances were likely diverse and episodic at multiple spatial and temporal scales. Footnote 192 High seasonal and annual variability in weather coupled with lightning strikes in complex topography likely resulted in a mixed-severity disturbance regime. Footnote 192

Large fires as natural disturbance

From the 1960s to the 1990s, there were fewer fires in south-central BC because of vigorous fire protection by the BC Forest Service (Figure 57). Footnote 193 The suppression of normal fire cycles and the subsequent accumulation of woody fuels create an environment for more intense, stand-replacing wildfires. Footnote 194 Footnote 195 Footnote 196 Footnote 197 Fire suppression increases the length of the fire cycle which allows pine stands to age thereby increasing their susceptibility to mountain pine beetle attack. Footnote 198 Footnote 199 Large-scale outbreaks of native insects are discussed on page 81. Fire suppression also allows forests to encroach into grasslands and ponderosa pine forests, Footnote 197 reducing habitat for species that require open landscapes. Footnote 14 In the South Okanagan and Lower Similkameen valleys, conifer densities increased in unburned landscapes between 1938–1985 and 1985–1996. Footnote 195

On average, only 54 km2 (0.1%) of the forested areas burn each year. For 2000–2007, the average area burned by large fires increased to over 156 km2 (Figure 58), Footnote 200 possibly due to changing climate, Footnote 201increased fuel loads due to long-term suppression, Footnote 202, Footnote 203 and a positive interaction between forest fires and the mountain pine beetle epidemic. Footnote 204

Figure 57: Total area burned per decade by large fires (>2 km2 in size) (top) and the distribution of large fires (bottom) in the Western Interior Basin Ecozone+, 1960s–2000s
The value for the 2000s decade was pro-rated over 10 years based on the average from 2000–2007.
Source: Krezek-Hanes et al., 2011 Footnote 200

map

Long Description for Figure 57

The top figure is a bar chart showing the following information:

Data for figure 57
1960s - Area burned (km2)1970s - Area burned (km2)1980s - Area burned (km2)1990s - Area burned (km2)2000s - Area burned (km2)
344.05400.87190.84463.87156.2

The lower figure is a map of area burned by large fires. These fires were spread throughout the WIBE. The large fires in the 2000s were located in the northeast, southwest, and around Kelowna.

Top of Page

Figure 58: Annual area burned by large fires in the Western Interior Basin Ecozone+, 1959-2007.
Source: Krezek-Hanes et al., 2011 Footnote 200

graph

Long Description for Figure 58

This bar chart shows the following information:

Data for figure 58
YearArea burned (km2)
19590
1960171
196124
196231
19630
19640
196510
19660
196739
19680
196968
1970148
1971113
19729
197392
197424
19756
19760
19770
19780
19799
19802
19810
19822
19830
198422
1985109
19867
198740
19882
19897
19907
19919
19929
19930
199448
1995148
199672
199717
1998147
19998
200040
200158
200240
2003791
2004122
200533
2006160
20076

Large-scale outbreaks of native insects

Large-scale outbreaks of native insects play a major role in the functioning of ecosystems. Footnote 205 By 1994, about two dozen insect pests, primarily moth and beetle species, had degraded commercially valuable forests and horticultural operations in the WIBE. Footnote 206 In addition, the change in forest cover from tree death and salvage harvesting can increase the flood risk and threaten fisheries and aquatic ecosystems. Footnote 207

The predominant insect pests in the WIBE are mountain pine beetles (Dendroctonus ponderosae) and western spruce budworms (Choristoneura occidentalis), which together accounted for >90% of the insect damage in this ecozone+ in 2009. Footnote 208 Other insects that damage forests in the WIBE are western balsam bark beetles (Dryocetes confusus), spruce beetles (Dendroctonus rufipennis), Douglas-fir tussock moths (Orgyia pseudotsugata), and aspen leaf miners (Phyllocnistis populiella).

Mountain pine beetle

The extent of mountain pine beetles increased between 1999 and 2009 in BC (Figure 59). Specifically, the area affected by mountain pine beetle in the WIBE increased from 500 km2 in 2003 to a peak of 8,100 km2 in 2008 (Figure 60).

Figure 59: Area infested by mountain pine beetle in BC, 1999 and 2009.
Source: data from BC Ministry of Forests, Lands and Natural Resource Operations, 2011 Footnote 209

map

Long Description for Figure 59

These maps show cumulative percentage of areas of killed pines in 1999 and 2009 throughout BC. In 1999, most of the mountain pine beetle infestation was in the central part of the province, with some outbreaks in the WIBE. This expanded throughout the province substantially in 2009, as well as increased infestations in the WIBE.

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Figure 60: Area of forest affected by mountain pine beetle in the Western Interior Basin Ecozone+ and all of BC, 1975–2009.
"Low" includes both "Trace" and "Light" areas.
Source: Analysis based on data from the BC Ministry of Forests and Range, 2010 Footnote 208 and the National
Forestry Database, 2010 Footnote 210

graph

Long Description for Figure 60

This stacked bar chart shows the following information:

YearWestern Interior Basin - Low
Area affected (km2)
Western Interior Basin - Moderate
Area affected (km2)
Western Interior Basin - Severe
Area affected (km2)
BC total
1975000300
1976000440
1977000600
1978000780
1979000690
19800001,540
19810001,600
19820002,900
19830004,620
19840004,620
19850003,000
1986000940
1987000660
1988000630
1989000530
1990000414
1991000496
1992000448
1993000491
199400032
1995000400
1996000560
1997000-
1998000-
1999191137371,646
200011981142,840
2001145102627,855
20021771355619,686
20032431868640,668
20041,32857139570,219
20053,0391,373072687,361
20063,0442,1641,50892,434
20073,8912,5211,584100,519
20085,4302,12161378,420
20093,8171,49936689,534
Western spruce budworm

Western spruce budworms favour dry, low-elevation Douglas-fir zones and therefore the majority of their BC range is in the WIBE (Figure 61). Annual defoliation by spruce budworm in the WIBE increased to peak of 3,800 km2 in 2007 (Figure 62). Most of the defoliation was considered low or moderate. Footnote 208

Figure 61: Areas of the Western Interior Basin Ecozone+ defoliated by western spruce budworm in 2008.
Source: data from BC Ministry of Forests and Range, 2010 Footnote 208

map

Long Description for Figure 61

This map shows low, moderate, and severe areas in the WIBE defoliated by western spruce budworm in 2008. Most of the areas with low defoliation were scattered throughout the ecozone+. Moderate areas occurred along the north central border and southwestern parts of the ecozone+. There were no areas of severe defoliation.

Figure 62: Area of forest defoliated by western spruce budworm in the Western Interior Basin Ecozone+ and all of BC, 1999–2009.
"Low" includes both "Trace" and "Light" areas.
Source: analysis based on data from the BC Ministry of Forests and Range, 2010 Footnote 208

graph

Long Description for Figure 62

This stacked bar chart shows the following information:

YearWestern Interior Basin - Low
Area affected (km2)
Western Interior Basin - Moderate
Area affected (km2)
Western Interior Basin - Severe
Area affected (km2)
BC Total
199960012
200014150147
2001231801,236
20021,6685774,874
20038625065,222
200475613636,237
200585918914,640
20061,8291,497327,769
20073,190598138,473
20083,2584507,822
20092,590829187,661
Western balsam bark beetle

Western balsam bark beetles attack true firs in the genus Abies, which grow at mid- to high elevations. Figure 63 shows the area of forest affected annually by western balsam bark beetle from 1999 to 2009 in the WIBE and in BC overall. Most forest affected by balsam bark beetles is in the cooler Montane Cordillera Ecozone+ to the north and east of the WIBE. This insect tends to affect the same stands year after year with chronic, low-level, scattered attacks. Footnote 211

Top of Page

Figure 63: Area of forest affected by the western balsam bark beetle in the Western Interior Basin Ecozone+ and all of BC, 1999–2009.
"Low" includes both "Trace" and "Light" areas.
Source: analysis based on data from the BC Ministry of Forests and Range, 2010 Footnote 208

graph

Long Description for Figure 63

This stacked bar chart shows the following information:

YearWestern Interior Basin - Low
Area affected (km2)
Western Interior Basin - Moderate
Area affected (km2)
Western Interior Basin - Severe
Area affected (km2)
BC Total
199983606,074
20001081205,588
200114614110,727
20021194309,905
200313823013,903
200423426120,176
20056214118,463
20067424011,942
20076738015,647
2008576105,321
20096334017,277
Spruce beetle

Spruce beetles (or spruce bark beetles) account for a relatively small proportion of insect damage in the WIBE, but areas affected by spruce beetles in the WIBE are not consistent with provincial trends. In BC, spruce beetle peaked in 2003 and then declined; in the WIBE, the area affected has continued to increase (Figure 64). The WIBE's proportion of the total area damaged in BC increased from 0.1% in 1999 to 47% in 2009. Footnote 211

Figure 64: Area of forest by the spruce beetle in the Western Interior Basin Ecozone+ and all of BC, 1999–2009.
"Low" includes both "Trace" and "Light" areas.
Source: analysis based on data from the BC Ministry of Forests and Range, 2010 Footnote 208

graph

Long Description for Figure 64

This stacked bar chart shows the following information:

YearWestern Interior Basin - Low
Area affected (km2)
Western Interior Basin - Moderate
Area affected (km2)
Western Interior Basin - Severe
Area affected (km2)
BC Total
1999214506
20001221,060
200111831,060
200213502,690
2003181013,159
200492591,048
200520193556
200623444837
2007225216368
200845336279
2009227614308

Key finding 20
Food webs

Theme: Habitat, wildlife, and ecosystem processes Food webs

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.

Top of Page

Non-native invasive species disrupt food webs by consuming, destroying, or otherwise removing food sources for native species. Introduced to Okanagan Lake in 1966, non-native mysis shrimp facilitated declines of kokanee and rainbow trout by consuming cladoceran zooplankton, a shared food resource. Footnote 45 Due to their diurnal migration pattern, mysis shrimp are rarely preyed upon by fish, so they effectively have no predators in the lake. More information can be found about mysis shrimp in the Invasive aquatic species section on page 48 and about Kokanee on page 76.

Predator-prey dynamics can be disrupted when the abundances of multiple prey species change. That is, less common prey species ("alternate prey") such as mountain goats can decline when there are shifts in the abundance of a primary prey species, such as deer. In the mid-1990s, poor winters resulted in mule deer populations that were half their previous size. Cougars may have preyed upon mountain goats as an alternate food source, which reduced the mountain goat population. Footnote 212 Since cougars and mule deer have returned to their previous population sizes, mountain goats have gradually been increasing again although recovery has been slow due to their relatively late reproductive maturity. Footnote 213

Top of Page


Content Footnote

Footnote 12

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

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Footnote 22

Demarchi, R.A. 2000. Bighorn sheep (Ovis canadensis) in accounts and measures for managing identified wildlife: accounts version 2004. British Columbia Ministry of Water, Land and Air Protection. Victoria, BC. 19 p.

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Footnote 45

Rae, R. and Andrusak, H. 2006. Ten-year summary of the Okanagan Lake action plan 1996-2005. BC Ministry of Environment. Penticton, BC. 41 p.

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Footnote 49

Austin, M.A. and Eriksson, A. 2009. The biodiversity atlas of British Columbia. Biodiversity BC. 135 p.

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Footnote 58

Alex, K. 2010. Providing fish passage at McIntyre Dam. Bilateral Okanagan Basin Technical Working Group Meeting. 24 February, 2010. Penticton, BC. Meeting presentation.

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Footnote 111

Rae, R. 2005. The state of fish and fish habitat in the Okanagan and Similkameen basins. Canadian Okanagan Basin Technical Working Group. Westbank, BC. 125 p.

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Footnote 142

Provincial Agricultural Land Commission. 2009. Business plan 2009/10. Provincial Agricultural Land Commisison. Burnaby, BC. 21 p.

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Footnote 143

Javorek, S.K. and Grant, M.C. 2011. Trends in wildlife habitat capacity on agricultural land in Canada, 1986-2006. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 14. Canadian Councils of Resource Ministers. Ottawa, ON. vi + 46 p.

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Footnote 144

McConkey, B.G., Lobb, D.A., Li, S., Black, J.M.W. and Krug, P.M. 2011. Soil erosion on cropland: introduction and trends for Canada. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 16. Canadian Councils of Resource Ministers. Ottawa, ON. iv + 22 p.

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Footnote 145

Pitt, M. and Hooper, T.D. 1994. Threats to biodiversity of grasslands in British Columbia. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 20. pp. 279-292.

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Footnote 146

Marsh, J., Nouvet, S., Sanborn, P. and Coxson, D. 2006. Composition and function of biological soil crust communities along topographic gradients in grasslands of central interior British Columbia (Chilcotin) and southwestern Yukon (Kluane). Botany 84:717-736.

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Footnote 147

Krannitz, P.G. 2008. Response of antelope bitterbrush shrubsteppe to variation in livestock grazing. Western North American Naturalist 68:138-152.

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Footnote 148

Atwood, L. and Krannitz, P. 2000. Effect of the microbiotic crust of the antelope-brush (Purshia tridentata) shrub-steppe on soil moisture. In Proceedings of a Conference on the Biology and Management of Species and Habitats at Risk, Kamloops, BC.February 15-19, 1999. Edited by Darling, L.M. B.C. Ministry of Enviroment, Lands and Parks and University College of the Cariboo. Victoria, BC. Vol. 2, pp. 809-812.

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Footnote 149

NatureServe. 2012. About us [online]. NatureServe.
(accessed 23 March, 2012).

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Footnote 150

BC Conservation Data Centre. 2012. BC Conservation Data Centre home [online]. British Columbia Conservation Data Centre.
(accessed 23 March, 2012).

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Footnote 151

Fraser, D.F. 2000. Species at the edge: the case for listing of "peripheral" species. In Proceedings of a Conference on the Biology and Management of Species and Habitats at Risk, Kamloops, Feb 15-19, 1999. Kamloops, BC. 15 February, 1999-19 February, 1999. Edited by Darling, M. British Columbia Ministry of Environment, Lands and Parks and University College of the Cariboo. Victoria, BC. pp. 49-54.

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Footnote 152

Bunnell, F.L. and Squires, K.A. 2004. Plagued by a plethora of peripherals: refining guidelines for peripheral taxa. In Proceedings of the Species at Risk 2004 Pathways to Recovery Conference. Victoria, BC, 2-6 March, 2004. Edited by Hooper, T.D. Pathways to Recovery Conference Organizing Committee. Victoria, BC.

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Footnote 153

BC Ministry of Environment. 2010. BC species and ecosystems explorer [online]. British Columbia Ministry of Environment. (accessed 9 July, 2010).

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Footnote 154

COSEWIC. 2009. COSEWIC and the Species at Risk Act [online]. Committee on the Status of Endangered Wildlife in Canada. (accessed 2 January, 2013).

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Footnote 155

COSEWIC. 2010. COSEWIC Committee on the Status of Endangered Wildlife in Canada [online].Government of Canada. (accessed 7 July, 2010).

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Footnote 156

Downes, C., Blancher, P. and Collins, B. 2011. Landbird trends in Canada, 1968-2006. Canadian Biodiversity: Ecosystem Status and Trends 2010, Technical Thematic Report No. 12. Canadian Councils of Resource Ministers. Ottawa, ON. x + 94 p.

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Footnote 157

Ritter, S. 2000. Idaho bird conservation plan. Version 1.0. Idaho Partners in Flight. Hamilton, MT. 167 p.

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Footnote 158

Partners in Flight British Columbia and Yukon. 2003. Canada's Great Basin Landbird Conservation Plan. Version 1.0. Partners in Flight British Columbia and Yukon. Delta, BC. 100 p.

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Footnote 159

Lance, A.N. and Phinney, M. 2001. Bird responses to partial retention timber harvesting in central interior British Columbia. Forest Ecology and Management 142:267-280.

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Footnote 160

Croteau, E., S.Lougheed, P.Krannitz, N.Mahony, B.Walker and P.Boag. 2007. Genetic population structure of the sagebrush brewer's sparrow, Spizella breweri breweri, in a fragmented landscape at the northern range periphery. Conservation Genetics 8:1453-1463.

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Footnote 161

McDonald, D., N.M.Korfanta and S.J.Lantz. 2004. The burrowing owl (Athene cunicularia): A technical conservation assessment. 76 p.

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Footnote 162

COSEPAC. 2006. Évaluation et Rapport de situation du COSEPAC sur la Chevêche des terriers (Athene cunicularia) au Canada . Comité sur la situation des espèces en péril au Canada. Ottawa, ON. vii + 31 p.

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Footnote 163

Burrowing Owl Recovery Implementation Group. 2008. Action plan for the burrowing owl (Athene cunicularia hypugaea) in British Columbia. British Columbia Ministry of Environment. Victoria, BC. 21 p.

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Footnote 164

COSEPAC. 2000. Évaluation et Rapport de situation du COSEPAC sur le Moqueur des armoises (Oreoscoptes montanus) au Canada. Comité sur la situation des espèces en péril au Canada. Ottawa, ON. ix+30 p.

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Footnote 165

COSEPAC. 2005. Évaluation et Rapport de situation du COSEPAC sur le Pic de Williamson (Sphyrapicus thyroideus) au Canada. Comité sur la situation des espèces en péril au Canada. Ottawa, ON. vii+50 p.

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Footnote 166

BC Ministry of Forests, Lands and Natural Resource Operations. 2011. BC ungulate species regional population estimates and status [online]. British Columbia Ministry of Forests, Lands and Natural Resource Operations.

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Footnote 167

Demarchi, R.A., C.L.Hartwig and D.A.Demarchi. 2000. Status of the California bighorn sheep in British Columbia. Wildlife Bulletin No. B-98. British Columbia Ministry of Environment. Victoria, BC. 67 p.

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Footnote 168

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.

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Footnote 169

Hummel, M. and Ray, J.C. 2008. Caribou and the north: a shared future. Dundurn Press. Timmins, ON. 287 p.

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Footnote 170

Hatler, D.F., Nagorsen, D.W. and Beal, A.M. 2008. Volume 5: the carnivores of British Columbia. Royal BC Museum Handbook: The Mammals of British Columbia. Royal BC Museum. Victoria, BC. 407 p.

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Footnote 171

Tompa, F.S. 1983. Status and management of wolves in British Columbia. In Wolves in Canada and Alaska: their status, biology, and management. Edited by Carbyn, L.N. Canadian Wildlife Service Report 45. Ottawa, ON. pp. 20-29.

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Footnote 172

Ministry of Forests Lands and Natural Resource Operations. 2012. Draft management plan for the grey wolf (Canis lupus) in British Columbia. 60 p.

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Footnote 173

Harris, B. 2013. Wolf sightings and reports 2004-2011. Unpublished data.

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Footnote 174

Mowat, G. 2007. Large carnivore population review for the Kootenay region. British Columbia Ministry of Environment, Kootenay Region. Nelson, BC. 32 p.

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Footnote 175

BC Ministry of Environment. 2010. Grizzly bear hunting: frequently asked questions [online].British Columbia Ministry of Environment.

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Footnote 176

Ross, P.I. 2002. Updated COSEWIC status report on the grizzly bear (Ursus arctos) in Canada, in COSEWIC assessment and update status report on the grizzly bear (Ursus arctos) in Canada. Comité sur la situation des espèces en péril au Canada. Ottawa, ON. 91 p.

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Footnote 177

BC Ministry of Environment. 2013. Grizzly bear population units [online]. (accessed 14 March, 2013).

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Footnote 178

COSEPAC. 2002. Évaluation et Rapport de situation du COSEPAC sur le saumon coho (Oncorhynchus kisutch) (population du Fraser intérieur) au Canada. Comité sur la situation des espèces en péril au Canada. Ottawa, ON. viii + 39 p.

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Footnote 179

Irvine, J.R., Parken, C.K., Chen, D.G., Candy, J., Ming, T., Supernault, J., Shaw, W. and Bailey, R.E. 2001. 2001 Stock status assessment of coho salmon from the interior Fraser River. Research Document No. 2001/083. Fisheries and Oceans Canada, Canadian Science Advisory Secretariat. Ottawa, ON. 67 p.

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Footnote 180

Hewes, G.W. 1998. Fishing. In Handbook of North American Indians: volume 12: plateau. Edited by Walker D.E. Smithsonian Institute. Washington, DC. pp. 620-640.

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Footnote 181

Pollard, S. 2000. Review and conclusions of assessments to genetically discriminate between stream and beach spawning kokanee in Okanagan Lake. In Okanagan Lake Action Plan Year 4 (1999) Report. Fisheries Project Report No. RD 83. Edited by Andrusak, H., Sebastian, D., McGregor, I., Matthews, S., Smith, D., Ashley, K., Pollard, S., Scholten, G., Stockner, J., Ward, P., Kirk, R., Lasenby, D., Webster, J., Whall, J., Wilson, A.G. and Yassien, H. British Columbia Ministry of Agriculture, Food and Fisheries. Victoria, BC. pp. 248-258.

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Footnote 182

Withler, R. 2005. Microsatellite analysis of stream and beach spawning kokanee. In Okanagan Lake action plan, year 9 (2004) report. Edited by Andrusak, H., Matthews, S., McGregor, I., Ashley, K., Rae, R., Wilson, A., Webster, J., Andrusak, G., Vidmanic, L., Stockner, J., Sebastian, D., Scholten, G., Woodruff, P., Jantz, B., Bennett, D., Wright, H., Withler, R. and Harris, S. BC Ministry of Environment. Victoria, BC. pp. 327-334.

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Footnote 183

Askey, P. 2011. BC Ministry of Forests, Lands and Natural Resource Operations. Unpublished data.

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Footnote 184

Shepherd, B.G. 2000. A case history: The kokanee stocks of Okanagan Lake. In Proceedings of a Conference on the Biology and Management of Species and Habitats at Risk, Kamloops, Feb 15-19, 1999. Edited by Darling, L.M. British Columbia Ministry of Environment, Lands and Parks. Victoria, BC. Vol. 2, pp. 609-616.

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Footnote 185

Hyatt, K. and Rankin, P. 1999. A habitat based evaluation of Okanagan sockeye salmon escapement objectives. Canadian Stock Assessment Secretariat Research Document No. 99/191. Fisheries and Oceans Canada. Ottawa, ON. 59 p.

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Footnote 186

Okanagan National Alliance. 2010. Okanagan sockeye reintroduction program [online]. (accessed 23 March, 2012).

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Footnote 187

Slaney, T.L., Hyatt, K.D., Northcote, T.G. and Fielden, R.J. 1996. Status of anadromous salmon and trout in British Columbia and Yukon. Fisheries 21:20-35.

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Footnote 188

COSEWIC. 2003. COSEWIC assessment and update status report on the white sturgeon Acipenser transmontanus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa, ON. vii + 51 p.

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Footnote 189

BC Ministry of Forests, Lands and Natural Resource Operations. 2011. 2011-2013 Freshwater fishing regulations synopsis [online]. British Columbia Ministry of Forests, Land and Natural Resource Operations.(accessed 23 March, 2012).

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Ptolemy, J. and Vennesland, R. Update COSEWIC status report on the white sturgeon Acipenser transmontanus in Canada, in COSEWIC assessment and update status report on the white sturgeon, Acipenser transmontanus, in Canada. Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Ottawa, ON. 51 p.

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Footnote 191

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 Sensing 30:149-168.

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Footnote 192

Klenner, W., Walton, R., Arsenault, A. and Kremsater, L. 2008. Dry forests in the southern interior of British Columbia: historic disturbances and implications for restoration and management. Forest Ecology and Management 256:1711-1722.

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Footnote 193

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 Research 108:8149-8161.

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Footnote 194

BC Ministry of Forests and Range. 1995. Biodiversity guidebook. Forest Practices Code Guidebook [online]. BC Ministry of Forests and Range, Government of British Columbia. (accessed 3 March, 2011).

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Footnote 195

Turner, J.S. and Krannitz, P.G. 2001. Conifer density increases in semi-desert habitats of British Columbia in the absence of fire. Northwest Science 75:176-182.

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Footnote 196

Turner, N.J. 1999. "Time to burn": traditional use of fire to enhance resource production by aboriginal peoples in British Columbia. In Indians, fire and the land in the Pacific Northwest. Edited by Boyd, R. Oregon State University Press. Corvallis, OR. pp. 185-218.

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Footnote 197

Gayton, D.V. 1996. Fire-maintained ecosystems and the effects of forest ingrowth. British Columbia Ministry of Forests. Nelson, BC. 4 p.

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Footnote 198

Taylor, S.W. and Carroll, A.L. 2004. Disturbance, forest age, and mountain pine beetle outbreak dynamics in BC: a historical perspective. In Mountain pine beetle symposium: challenges and solutions.October 30-31, 2003, Kelowna, British Columbia. Edited by Shore, T.L., Brooks, J.E. and Stone, J.E. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre. Victoria, BC. pp. 41-51.

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Footnote 199

Li, C., Barclay, H.J., Hawkes, B.C. and Taylor, S.W. 2005. Lodgepole pine forest age class dynamics and susceptibility to mountain pine beetle attack. Ecological Complexity 2:232-239.

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Footnote 200

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.

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Footnote 201

Volney, W.J.A. and Hirsch, K.G. 2005. Disturbing forest disturbances. The Forestry Chronicle 81:662-668.

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Footnote 202

Allen, E. 2001. Forest health assessment in Canada. Ecosystem Health 7:27-34.

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Footnote 203

Parker, T.J., Clancy, K.M. and Mathlasen, R.L. 2006. Interactions among fire, insects and pathogens in coniferous forests of the interior western United States and Canada. Agricultural and Forest Entomology 8:167-189.

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Footnote 204

Jenkins, M.J., Hebertson, E., Page, W. and Jorgensen, C.A. 2008. Bark beetles, fuels, fires and implications for forest management in the intermountain west. Forest Ecology and Management 254:16-34.

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Footnote 205

McCullough, D.G., Werner, R.A. and Neumann, D. 1998. Fire and insects in northern and boreal forest ecosystems of North America. Annual Review of Entomology 43:107-127.

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Footnote 206

Harding, L.E. 1994. Threats to diversity of forest ecosystems in British Columbia. In Biodiversity in British Columbia: our changing environment. Edited by Harding, L.E. and McCullum, E. Environment Canada. Delta, BC. Chapter 19. pp. 245-278.

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Footnote 207

Schnorbus, M., Bennett, K. and Werner, A. 2010. Quantifying the water resource impacts of mountain pine beetle and associated salvage harvest operations across a range of watershed scales: hydrologic modelling of the Fraser River Basin. Information Report: BC-X-423. Natural Resources Canada, Canadian Forestry Service, Pacific Forestry Centre. Victoria, BC. 64 p.

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Footnote 208

BC Ministry of Forests and Range. 2010. Forest health - 2008 aerial overview survey [online]. British Columbia Ministry of Forests and Range. (accessed 25 January, 2010). Survey data spatial files.

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Footnote 209

BC Ministry of Forests, Lands and Natural Resource Operations. 2011. Observed percentage of pine volume killed in 2009 (red and grey attack) [online]. British Columbia Ministry of Forests and Range. (accessed 9 February, 2012).

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Footnote 210

National Forestry Database. 2010. Forest insects - quick facts. Areas within which moderate to severe defoliation occurs including area of beetle-killed trees by insects and province/territory, 1975-2009: mountain pine beetle [online]. Canadian Council of Forest Ministers. (accessed May, 2010).

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Footnote 211

Westfall, J. and Ebata, T. 2008. 2008 summary of forest health conditions in British Columbia. BC Ministry of Forests and Range. Victoria, BC. 85 p.

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Footnote 212

Côté, S.D. and Festa-Bianchet, M. 2003. Mountain goat. In Wild mammals of North America: biology, management, and conservation. Edited by Feldhamer, G.A., Thompson, B. and Chapman, J. The John Hopkins University Press. Baltimore, MD. pp. 1061-1075.

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Footnote 213

Mountain Goat Management Team. 2010. Management plan for the mountain goat (Oreamnos americanus) in British Columbia. Prepared for the BC Ministry of Environment. Victoria, BC. 87 p.

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Footnote 214

Vaughan, H., Brydges, T., Fenech, A. and Lumb, A. 2001. Monitoring long-term ecological changes through the Ecological Monitoring and Assessment Network: science-based and policy relevant. Environmental Monitoring and Assessment 67:3-28.

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Introduction