BC is Special
Ecosystem DiversityEcosystems are complex, dynamic and adaptive systems that are continually evolving. When they become simplified through the loss of component parts or processes, they lose their ecological resilience - the ability to withstand and adapt to natural or human-caused disturbances, including climate change. Simplification can be the result of numerous factors, including human activity (such as settlements, natural resource use, and transportation corridors) and the impact of alien invasive species.
For the purposes of this report, terrestrial ecosystems were assessed at a broad provincial scale using the Biogeoclimatic Ecosystem Classification (BEC) system, which was developed specifically for B.C. Biogeoclimatic zones are broad geographic areas sharing similar climate and vegetation. Twelve of B.C's 16 biogeoclimatic zones are forested, three are alpine and one is dominated by grasses.
Major findings on ecosystem diversity:
1. At the broad scale, four biogeoclimatic zones [Coastal Douglas-fir, Interior Douglas-fir, Ponderosa Pine, and Bunchgrass], representing approximately 5% of British Columbia's land base, are of provincial conservation concern (critically imperilled, imperilled or vulnerable).
2. At the fine scale, more than half of the ecological communities described in British Columbia are of provincial conservation concern.
3. British Columbia has a majority of the global range for six of the 16 biogeoclimatic zones that occur in the province [Coastal Douglas-fir, Interior Cedar-Hemlock, Montane Spruce, Mountain Hemlock, Sub-boreal Pine-Spruce, and Sub-boreal Spruce].
4. The Coastal Douglas-fir biogeoclimatic zone is the rarest biogeoclimatic zone in British Columbia and is of great conservation concern.
5. Low-elevation grassland communities are the rarest land cover type in British Columbia and are concentrated in the biogeoclimatic zones of conservation concern [See Major Finding 1].
6. Significant areas of wetlands in British Columbia have been converted or degraded, particularly in the two Major Drainage Areas of greatest conservation concern [those of the Columbia River and Fraser River].
7. Estuaries are of concern in British Columbia because of their rarity and the level of human impacts to them.
Species DiversityA species is a genetically distinct group of organisms that are capable of successfully interbreeding. Each species plays a unique role in nature. Of all the Canadian provinces and territories, B.C. is home to the richest diversity of vascular plants, mosses, mammals, butterflies and breeding birds, and the largest number of species of reptiles, tiger beetles and amphibians found in only one province or territory.
More than 50,000 different species (not including single-celled organisms) exist in B.C., but only about 3,800 of these have been assessed for their conservation status. Some parts of the province (primarily unroaded and unsettled areas) have not been surveyed for species occurrence and some taxonomic groups remain largely unstudied. Some species that have disappeared from other jurisdictions still flourish here. For example, B.C. has the largest population of grizzly bears (estimated at about 17,000) of any province or state apart from Alaska. By contrast, California once had an estimated 10,000 grizzlies and now has none.
Major Findings on Species Diversity:
8. Of the species assessed to date in British Columbia, 43% are of provincial conservation concern, and these are concentrated in the four biogeoclimatic zones of conservation concern [Coastal Douglas-fir, Interior Douglas-fir, Ponderosa Pine, and Bunchgrass].
9. British Columbia is known to have a majority of the global range for 99 species.
Genetic Diversity Genetic diversity is the foundation of biodiversity. Genes are the functional units of heredity and genetic variation, which enable species to adapt to changing environments. B.C. has a disproportionately high level of genetic diversity relative to its species diversity. The province's glacial history, complex topography and varied climate have contributed to theevolution of a wide variety of adaptations to different environments. As a result, many species occur in the province as geographically distinct subspecies, which differ from each other in appearance, environmental tolerances and behaviour.
These differences reflect differences in genetic make-up.
Due to B.C.'s large size and biophysical variability, the province is home to many species that are at the edge of their range. Such populations are often genetically distinct from populations at the core of the species range and potentially may be better able to adapt to environmental stresses such as those caused by climate change.
Major Finding on Genetic Diversity:
10. British Columbia has a high level of genetic diversity within species, which is critical for adaptation and resilience.
Key and Special Elements of Biodiversity Key elements are species and ecosystem components and the processes performed by them that have a fundamental or disproportionate influence on how ecosystems function. Examples include pollination (vital to plant reproduction); connectivity within ecosystems (allowing movement of species); the ability of wetlands to filter, cleanse and replenish water supplies; and the important role of broadleaf trees in ensuring forest health.
Special elements are uncommon components that in some cases are found only in B.C. Examples include seasonal concentrations of species, such as stopover points for migrating birds and rookeries where Steller sea lions gather to breed; special communities, such as temperate rainforests and intact large
mammal predator-prey systems; and noteworthy features, including karst cave systems, hot springs, saline lakes and fishless lakes, all of which are inhabited
by rare and specialized species.
Major Finding on Key and Special Elements:
11. The flow of water in lakes, streams, wetlands and groundwater systems is being seriously impacted in British Columbia by dams, water
diversions, logging, stream crossings and climate change.
12. The natural disturbance processes that shape British Columbia's forests [such as wild fire and insects] are being disrupted by human activities.
13. British Columbia's mainland coast features a number of interconnected key and special elements of biodiversity: intact temperate rainforest, an intact large mammal predator-prey system, glacially influenced streams and salmon-driven nutrient cycling.
14. The majority of British Columbia has intact or relatively intact predator-prey systems, but a major threat to them is motorized access
and associated human activities.
15. British Columbia has many significant seasonal concentrations of species [e.g., migratory birds, spawning salmon] that are vulnerable
to human impacts.
To see Major Findings 16 through 23, please see BC is Threatened