Introduction

Human activities in forests are increasingly organized within plans that have at their core sustainability and the preservation of biodiversity. These plans lie at the heart of

sustainable forest management, whose practices are designed to maintain and enhance the long-term health of forest ecosystems, while providing ecological, economic, social, and cultural opportunities for the benefit of present and future generations (Canadian Council of Forest Ministers, 1995). Sustainable forest management supplements a concern with economic values with concerns that species diversity, structure, and the present and future functioning and biological productivity of the ecosystem be maintained or improved (Landsberg and Gower, 1996). The growing acceptance of sustainable forest management has been characterized as a paradigm shift of massive proportions within the forest science and forest management communities that is only now reaching maturation (Franklin, 1997).