Ecosystem Diversity

Terrestrial Ecozones of Canada

Nationally, ecosystems in Canada are divided into provincial-scale marine and terrestrial ecozones. These are roughly equivalent to the “biomes” taught in introductory ecology courses: Sonoran desert, tall grass and short grass prairies, boreal forest, and so on. The Columbia Basin is entirely within the Montane Cordillera ecozone. Some federal statistics - such as those on the state of the environment and the state of forests - are compiled by ecozone.
Two ecological classification systems are in wide use in B.C. today. The Biogeoclimatic Zone system, developed initially to serve forestry, defines zones, subzones and variants based on the biological communities that can develop within the constraints of climate and geography (Meidinger, 1997). It is two-dimensional, although the natural zonation in plant communities that occurs with elevational differences in temperature and moisture gives a three-dimensional aspect to it. Biogeoclimatic zones are divided into subzones, and these are divided into variants. A zone, subzone or variant may occur wherever physiography, soils and climate are suitable, and there are disjunct occurrences of each.

Ecoprovinces and Ecoregions of British Columbia

By contrast, the ecoregion classification system is hierarchical: Broad Ecozones (roughly equivalent to biomes), defined areas of geography on a continental scale, are subdivided into Ecoprovinces, each of which is further divided into Ecoregions, and hence into Ecosections (Demarchi, 1996). Each subdivision in this system is unique; it does not occur anywhere else.
These two classification systems - biogeoclimatic zones and ecoregions - have been integrated for certain planning purposes, especially those involving ecosystem management in forest development plans. The result is a bioecoclimatic (BEC)map of B.C.

The following table shows the Southern Interior Mountains Ecoprovince and some of its Ecoregions.

	Southern Interior Mountains Ecoprovince
	Columbia Highlands Ecoregion
	Selkirk-Bitterroot Foothills Ecoregion
	Southern Rocky Mountain Trench Ecoregion
	Western Continental Ranges Ecoregion

 

Forest Region and Districts

Some ecological information, such as forest inventory data and rare and endangered species tracked by the Conservation Data Centre, are compiled by Forest Region and Forest District.

 

A more complete forest region and district map of British Columbia, and for the CDC tracking list of endangered species, is at: http://wlapwww.gov.bc.ca/wld/

 

How much is protected?

Beginning about 1991, under the Protected Areas Strategy (PAS) the provincial government began a program of protecting representative ecosystems of the province. Pre- and post-PAS protected areas established up to 1997 in southeast British Columbia are shown in the map at right, adapted from one available on the Ministry of Environment, Lands and Parks website.

How much of each ecoregion is protected? The following map shows the proportion of each ecoregion protected as of 1997:

 

 

 

The Ministry's website also provides detailed statistics on the amount of protected area by ecoregion.

 

Further Reading

Harding, Lee, 1994. Overview of ecosystem diversity. Chapter 18 in Biodiversity in British Columbia: our changing environment. Environment Canada.
Demarchi, D., 1996. An introduction to the ecoregions of British Columbia.
Meidinger, D., 1997. Biogeoclimatic Units of British Columbia.