PARENT SESSION
Oral Session # 75: Biodiversity II.
Presiding: K Kirkman
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 100.

Species diversity: from global decreases to local increases.

Sax, Dov^*,1, Gaines, Steven¹, ¹ University of California, Santa Barbara, CA

ABSTRACT- Current patterns of global change may strongly affect patterns of biodiversity at global, regional and local scales. At global scales habitat destruction and the introduction of exotic species are contributing to declines in species diversity. At regional and local scales evidence for declines in diversity are mixed, and recent work suggests that diversity may commonly be increasing. Here we examine evidence that indicates how species diversity is changing across spatial scales for plants, birds and freshwater fishes. This evidence suggests that global decreases in diversity are commonly contrasted by increases in diversity at regional and local scales. This evidence also shows that the magnitude of increases in diversity may be highly predictable for particular taxonomic groups on islands and within continental regions.

Key words: exotic species, biodiversity, aliens, species richness