Biogeoclimatic ecosystem classification in British Columbia

Abstract

Biogeoclimatic ecosystem classification is a system of ecological classification widely used in British Columbia. The system has been expanded by the B.C. Forest Service from the pioneering work of V.J. Krajina and his students. The recognized units result from a synthesis of vegetation, climate, and soil data. The approach to classification is hierarchical with three interrelated levels of integration. The multiple-category, local and regional levels involve vegetation and site; a chronological level deals with vegetation dynamics. Taxa of any level and category can be integrated according to their interpretive value for management. Vegetation units are defined and arranged into a floristic hierarchy based on the plant association, using traditional Braun-Blanquet methods modified to suit regional conditions. Where possible, zonal (climatic climax) plant associations are identified, thus defining biogeoclimatic subzones, which are divided into variants and aggregated into zones, regions, and formations. Plant associations are transformed into site associations-environmentally characterized classes of ecosystems with similar biotic potential. Site associations are then subdivided into series and types, using biogeoclimatic and adaphic characteristics as differentiae. Examples of classification at local and regional levels are provided, as are examples of management applications. Biogeoclimatic ecosystem classification is a unique approach that draws on several of the European (including Russian) and North American schools of vegetation and land classification, and has similarities with the Cajander forest type, Barnes land type, Daubenmire habitat type, and Hills site type approaches. The classification provides a powerful integrative and predictive tool, with proven practical value for forest managers.