PARENT SESSION
Oral Session #58: Theoretical Ecology.
Presiding: M. Neubert
Wednesday, August 7. 8:00 AM to 11:30 AM. Grand Ballroom East, Radisson.

The distribution-abundance relationship and its effect on species diversity within and among communities.

Veech, Joseph^*,1, ¹ Miami University, Oxford, Ohio

ABSTRACT- The distribution-abundance relationship describes an ecological pattern in which locally abundant species tend to be more widespread than less abundant species. Ecologists have primarily studied the mechanisms presumed to cause the pattern with less attention given to identifying the consequences of the pattern. One major consequence may be the way in which patterns of distribution and abundance relate to the diversity of species within and among communities (alpha and beta diversity). I collected more than 50 datasets on the abundance and distribution of arthropod species. For each dataset, I estimated the average alpha diversity of sampled sites using species richness and the Shannon index. I calculated beta diversity using an additive partition of total diversity. That is, beta diversity was obtained as the difference between the total pooled diversity of the sampling sites and the average alpha diversity. For each dataset, I also quantified the strength of the distribution-abundance relationship using the slope of a linear regression of the two variables. I found that the average amount of diversity within a community was relatively large when there was a strong relationship (steep slope) between the distribution and abundance of the species inhabiting the communities. This result suggests that the mechanisms that produce the positive relationship between the distribution and abundance of species also maintain high local diversity (alpha) relative to the diversity not found in any one community (beta).

KEY WORDS: species diversity, distribution-abundance relationship, arthropod