Is a forest with 1 000 species better, and managed better, than a forest with 500 species? This issue of Unasylva looks at issues related to forest biological diversity and its conservation and sustainable use. One of the key messages is that numbers are not the only issue.
In the first article, J. Burley clarifies some of the central concepts and issues related to forest biological diversity. He introduces the three levels of biological diversity - genetic, species and ecosystem - and discusses key issues such as value and use, assessment, and public and political attention to the subject.
J. McNeely focuses on forest biodiversity and the role of people at the ecosystem level. Human impacts can be negative (e.g. deforestation, overhunting), but McNeely emphasizes that people are part of many forest ecosystems, and that forests must be managed to balance diverse objectives - to meet needs for timber, fuelwood and non-wood products, to safeguard aesthetic and recreational values and to provide global environmental benefits, including biodiversity conservation.
With intensive forest management practices focused mainly on wood production, forest biodiversity in Poland, as in other countries of Central and Eastern Europe, has decreased in recent centuries even while forest cover has been increasing. In the past decade, however, the conservation of biodiversity has been emphasized in Polish forest policy and practice as one of the central concerns of sustainable forest management. K. Rykowski presents the main principles of Poland's approach to conservation, focusing primarily on production forests. He emphasizes that protected areas are inadequate, on their own, to ensure the conservation of trees and other forest-related species.
To conserve forest biodiversity, new policy and practices are also needed in managed forests in the Brazilian Amazon. M. Kanashiro and co-authors describe the work of the Dendrogene Project, which focuses on providing skills and tools to forest users so that knowledge-based management systems and policies can be applied in practice.
R. Nasi and co-authors examine implications of forest fire for biodiversity. Fire can destroy plant and animal communities, influence species functioning and deprive forest fauna of habitat and food. Yet it is a natural force necessary to maintain the health of certain fire-adapted ecosystems.
Co-management protocols developed in East Africa primarily apply to forests and woodlands managed for local goods and services. Can they also be applied to forests that have global and national value for conserving biodiversity? Using examples from a project on reducing biodiversity loss in Kenya, Uganda and the United Republic of Tanzania, W.A. Rodgers, R. Nabanyumya, E. Mupada and L. Persha stress that communities need to derive tangible benefits as an incentive to conserve.
From a local perspective, there is generally little difficulty in identifying the main threats to forest biodiversity in tropical countries (predominantly habitat loss, encroachment, unregulated exploitation and environmental degradation); thus D. Sheil argues that biodiversity conservation needs to be concerned less with research and monitoring than with good on-the-ground practice. Resources must be allocated effectively if conservation is to be successful, focusing on fundamental priorities such as preventing conversion of protected areas to other land uses and protecting high-profile taxa.
In the next article, C. Palmberg-Lerche shares some thoughts on forest biological diversity conservation, including the need for close links among conservation activities at various levels. She notes the need for dynamic programmes that harmonize conservation and sustainable use of forests and forest genetic resources within a mosaic of land use options, and that include a strong element of active gene management. She stresses that human intervention in nature is not necessarily negative.
Forest plantations are often considered to be limited in biological diversity - perhaps because they are compared with natural forests rather than with the degraded ecosystems that they often replace. In our last article, M.L. Wilkie describes how plantations established centuries ago to stabilize sand dunes in Denmark have become, with time and careful management, species-rich ecosystems.
An important topic not covered here is the equitable sharing of the benefits of biodiversity, which is one of the three main goals of the Convention on Biological Diversity (CBD). This subject was addressed in Unasylva 206 (2001), as was the CBD's work programme on forests. The activities of the CBD and FAO in this field are complementary. A box at the end of the current issue refers readers to Web sites for information on FAO's programmes related to forest biological diversity.
As this issue shows, there is no optimal level of biodiversity. There are many reasons why one ecosystem may have more diversity than another - not all of them related to human intervention. Moreover, conservation should not aim at preserving a chimaeric status quo. Changes in biodiversity occur through time in all communities and ecosystems. Conservation management can only be successful in the long term if it uses the intrinsic dynamics of ecosystems and species to conserve their diversity and evolutionary capacity. Productive and protective purposes can be rendered compatible with conservation through sound planning and intersectoral coordination of activities at the local and national levels.