LESSONS FROM THE PAST - FORESTS AND BIODIVERSITY

The biodiversity of forested regions today is the result of complex historical interactions among physical, biological, and social forces over time, often heavily influenced by cycles of various sorts. Fire, agriculture technology, and trade have been particularly powerful human influences on forests. Virtually all of our planet's forests have been affected by the cultural patterns of human use, and the resulting landscape is an ever-changing mosaic of unmanaged and managed patches of habitat, which vary in size, shape, and arrangement. Because chance factors, human influence and small climatic variation can cause very substantial changes in vegetation, the biodiversity for any given landscape will vary substantially over any significant time period - and no one variant is necessarily more 'natural' than the others. This implies that biodiversity conservation efforts may need to give greater attention to ecosystem processes than to ecosystem products. A review of historical evidence shows that past civilizations have tended to over-exploit their forests, and that such abuse of important resources has been a significant factor in the decline of the over-exploiting society. It appears that the best way to maintain biodiversity in forest ecosystems in the late 20th Century is through a combination of strictly protected areas (carefully selected on the basis of clearly defined criteria), multiple-use areas managed by local people, natural forests extensively managed for sustainable yield of logs and other products and services, and forest plantations intensively managed for the wood products needed by society. This diversity of approaches and uses will provide humanity with the widest range of options, the greatest diversity of opportunities, for adapting to the cyclical changes which are certain to continue.