Themes

Abstract

Societies value diversity, including biological diversity. Endangered species legislation both in the United States and elsewhere in the world has arisen from sets of values that emphasize the importance of protecting the richness of life that has evolved over millions of years. Thus, biological diversity, or biodiversity, is a well-established target for conservation efforts from an ethical or moral standpoint. To ecologists and other conservation scientists, however, biodiversity is a complex and multifaceted concept, and little is known directly about the ecological consequences of diversity per se. For example, how important is biodiversity to the stability and resilience of ecological communities and ecosystems? What aspects of biodiversity (for example, numbers of species, genetic variation, or architectural diversity) are most important to ecological systems? What hierarchical levels of biodiversity (for example, genes, genotypes, species, or community types) are most important to which ecological functions (for example, persistence of populations and communities, flux rates of nutrients, or global environmental change)? Because these questions remain largely unanswered, biological diversity requires much closer evaluation as a scientific target for conservation efforts.