Preprint of : Vanclay , J . K . , 1992 . Species richness and productive forest management . In : F . R . Miller and K . L

There are many reasons to preserve the biological diversity of the earth, and perhaps the most compelling is the insurance that it provides for the uncertain times ahead. The responsibility for maintaining this biodiversity falls particularly heavily on the custodians of the tropical forests, where species richness is highest. How can these forests provide for the immediate needs of local inhabitants, whilst maintaining their rich diversity for all in the longer term? A "hands-off" approach is neither practical nor necessary, and a few simple guidelines provide reasonable protection for most species. Strict nature reserves provide a small but important part of the solution. They should be large, contiguous and compact, and should be set within a matrix of production forest. Remaining fragments of old-growth forest may be critical for some specialist species and should be protected. However, reserve networks should not be restricted to old-growth forest, but should represent all vegetation types. In many cases, degraded lands may be the only option for representing some types, and they should be protected and rehabilitated. Nature reserves are only part of the solution, and must be supplemented by production forests, managed in a sympathetic way. Timber may be harvested in many ways, but for most tropical forests, polycyclic selection logging may provide the best compromise between production and maintenance of diversity. Selection logging should strive for minimal canopy opening and minimal soil disturbance. Some veteran trees should be retained to provide hollows and nesting sites for fauna. Buffer strips should be maintained along streams, and should be supplemented to form interconnecting corridors between undisturbed forest. Roads should be narrow, well engineered and well drained to minimize erosion and silting. Agroforestry can also help maintain biodiversity. Windbreaks and hedgerows should be wide, linking forested areas to create wildlife corridors, and should include a large range of plant species. Maintenance of biodiversity requires participation and good husbandry from all land custodians, not just forestry. Agriculture and urban developments are often the dominant land use, so can contribute much toward the maintenance of wildlife habitat.