Biodiversity - editor E.O. Wilson, 1988
Calls attention to the rapidly accelerating loss of plant and animal species to increasing human population pressure and the demands of economic development. Biodiversity creates a systematic framework for analyzing the problem and searching for possible solutions. Online book from National Academic Press.

Biodiversity and Conservation
A Hypertext Book by Peter J. Bryant, School of Biological Sciences, University of California, Irvine. The origin, nature and value of biological diversity, the threats to its continued existence, and approaches to preserving what is left.