360
T.J .B. Boyle
subzone of the biogeoclimatic units. In the coastal forest region there are
two major biogeoclimatic units, the "coastal western hemlock" zone
(CWH), which is divided into ten subzones, and the "coastal Douglas fir"
zone (CDF) . For forest management purposes, "site units" based on
environmental characteristics, such as moisture and nutrient status, are
identified at the local level, and used for developing silvicultural prescriptions, for range management, and for integrating recreation into
multiple-use management (MacKinnon, Meidinger , & Klinka, 1992).
The Biophysical Classification System
A biophysical classification system was developed by the wildlife branch
of British Columbia's Ministry of the Environment , originally for the
purpose of classifying ecosystems for wildlife habitat (Demarchi, 1992). It
is a hierarchical system, with a strong emphasis on physical attributes and
successional, as well as climax, vegetation. At the highest level of the
hierarchy are ecodomains, which are global in context. These are subdivided into ecodivisions, ecoprovinces, of which there are 10 in British
Columbia , ecoregions , and ecosections.
A hierarchical biophysical system has been design by the Canadian
Committee on Ecological Land Classification, as a consistent classification
system for the national level. The system recognizes 15 "ecozones," 45
"ecoprovinces," 177 "ecoregions," and 5428 "ecodistricts." The biophysical characteristics of these hierarchical classes also result in different
landscape types. The ecoregions provide a scale of detail that is both
meaningful and manageable on a national scale, and are now widely used
by Environment Canada for data base and other applications (Turner,
Rubec, & Wiken, 1992). Although developed independently from the
British Columbia system, the two systems were recently harmonized
with the adoption of the British Columbia units by Environment Canada
(D. Demarchi, B-ritish Columbia Environment, and H. Hirvonen, Environment Canada, personal communication) .
The biogeoclimatic and biophysical classification systems were developed independently, and are based on a different set of characteristics .
The BEC system uses primarily climax vegetation types to infer units that
are homogeneous in terms of climate and soil properties. In contrast, the
biophysical system places major emphasis on landforms (Demarchi,
1992). The result is that the ecoregions and ecosections of the biophysical
system are geographically contiguous, whereas the site units of the BEC
system are not necessarily contiguous and have a strong topographical
element (Demarchi, 1991). The two systems have now effectively been
integrated, with ecosection being subdivided by biogeoclimatic units.
This integration of the two systems is widely used for many applications, including ecological reserve system design, a provincial old-growth
strategy , and threatened and endangered species cataloguing, in addition
T.J .B. Boyle
subzone of the biogeoclimatic units. In the coastal forest region there are
two major biogeoclimatic units, the "coastal western hemlock" zone
(CWH), which is divided into ten subzones, and the "coastal Douglas fir"
zone (CDF) . For forest management purposes, "site units" based on
environmental characteristics, such as moisture and nutrient status, are
identified at the local level, and used for developing silvicultural prescriptions, for range management, and for integrating recreation into
multiple-use management (MacKinnon, Meidinger , & Klinka, 1992).
The Biophysical Classification System
A biophysical classification system was developed by the wildlife branch
of British Columbia's Ministry of the Environment , originally for the
purpose of classifying ecosystems for wildlife habitat (Demarchi, 1992). It
is a hierarchical system, with a strong emphasis on physical attributes and
successional, as well as climax, vegetation. At the highest level of the
hierarchy are ecodomains, which are global in context. These are subdivided into ecodivisions, ecoprovinces, of which there are 10 in British
Columbia , ecoregions , and ecosections.
A hierarchical biophysical system has been design by the Canadian
Committee on Ecological Land Classification, as a consistent classification
system for the national level. The system recognizes 15 "ecozones," 45
"ecoprovinces," 177 "ecoregions," and 5428 "ecodistricts." The biophysical characteristics of these hierarchical classes also result in different
landscape types. The ecoregions provide a scale of detail that is both
meaningful and manageable on a national scale, and are now widely used
by Environment Canada for data base and other applications (Turner,
Rubec, & Wiken, 1992). Although developed independently from the
British Columbia system, the two systems were recently harmonized
with the adoption of the British Columbia units by Environment Canada
(D. Demarchi, B-ritish Columbia Environment, and H. Hirvonen, Environment Canada, personal communication) .
The biogeoclimatic and biophysical classification systems were developed independently, and are based on a different set of characteristics .
The BEC system uses primarily climax vegetation types to infer units that
are homogeneous in terms of climate and soil properties. In contrast, the
biophysical system places major emphasis on landforms (Demarchi,
1992). The result is that the ecoregions and ecosections of the biophysical
system are geographically contiguous, whereas the site units of the BEC
system are not necessarily contiguous and have a strong topographical
element (Demarchi, 1991). The two systems have now effectively been
integrated, with ecosection being subdivided by biogeoclimatic units.
This integration of the two systems is widely used for many applications, including ecological reserve system design, a provincial old-growth
strategy , and threatened and endangered species cataloguing, in addition