Conservation of Biodiversity in a World of Use

Article excerpt

Over the last decade biodiversity conservation has become an objective of international conventions, national governments, state agencies, non-governmental organizations, local communities, school clubs, and individuals. Unfortunately, while becoming a common objective, the true meaning of biodiversity conservation has been pulled from its roots in the biological sciences, becoming a political concept with as many meanings as it has advocates. This confusion of meanings can frustrate efforts to mobilize conservation action, because successful conservation relies on clear goals laid out with specific and commonly understood definitions and assumptions.

Of the many confusing concepts associated with biodiversity conservation, few demand greater definition and scrutiny than "conservation through use," sometimes known as "compatible" or "sustainable" use. At face value these terms suggest that certain types or levels of human use are ecologically benign, incurring little or no loss of biodiversity. In fact, it was the promise that such human use would serve as the basis for conservation that brought so many different interest groups to agree on the importance of biodiversity conservation. Advocates of compatible use have suggested that substituting a compatible use for an incompatible one, or helping to perpetuate an existing use deemed as being compatible, is a reasonable strategy for conserving biodiversity. But strong warnings have been issued by conservation biologists such as Freese (1998): "Human intervention in an ecosystem for commercial purposes inevitably alters and generally simplifies, at some scale, ecosystem structure, composition, and function."

We maintain that compatibility between human use and biodiversity conservation cannot be stated in binary terms as a "yes" or "no" condition. All use has consequences. Different kinds and intensities of human use affect various aspects or components of biodiversity to differing degrees. Further, individual or societal decisions about the degree of biodiversity impact that is deemed "compatible" are value dependent and should be recognized as such. In reality, the incidence, the source, and the effects of many changes are often unclear, and that lack of clarity impedes action on both political and practical levels.

Because the interaction between biodiversity and human use results in such complex impacts and variable degrees of conservation, we believe that some means of measuring the success of biodiversity conservation efforts is desperately needed. In that spirit, we have proposed a heuristic framework for measuring the consequences of human use for biodiversity. This framework builds from a matrix presented by Noss (1990) and draws from a very specific definition of biodiversity.

Biodiversity refers to the natural variety and variability among living organisms, the ecological complexes in which they naturally occur, and the ways in which they interact with each other and with the physical environment. Biodiversity has three different components: genetic, population/ species, and community/ecosystem. Each of these components has compositional, structural, and functional attributes. Composition refers to the identity and variety of elements in each of the biodiversity components. Structure refers to the physical organization or pattern of the elements. Function refers to ecological or evolutionary processes acting among the elements.

We suggest that the effects of human use or alteration on biodiversity can be assessed with our framework by determining how different types and intensities of resource use affect both the components of biodiversity and their attributes as defined above. In order to test the application of the framework, we examined conservation efforts at two sites where The Nature Conservancy has been working: the Roanoke River in North Carolina and the Pantanal in Brazil. We then additionally tested the framework against illustrative examples of human resource use from the literature. …