Present address: Center for Conservation and Sustainable Development, Missouisi Botanical Garden, PO Box 299, St. Louis, MO 63166-299, USA.
Phylogenetic structure illuminates the mechanistic role of environmental heterogeneity in community organization
Article first published online: 5 SEP 2011
© 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society
Journal of Animal Ecology
Volume 81, Issue 2, pages 455–462, March 2012
How to Cite
Stevens, R. D., Gavilanez, M. M., Tello, J. S. and Ray, D. A. (2012), Phylogenetic structure illuminates the mechanistic role of environmental heterogeneity in community organization. Journal of Animal Ecology, 81: 455–462. doi: 10.1111/j.1365-2656.2011.01900.x
- Issue published online: 10 FEB 2012
- Article first published online: 5 SEP 2011
- Received 25 January 2011; accepted 29 July 2011 Handling Editor: Daniel Stouffer
- diversity begets diversity;
- environmental heterogeneity;
- interspecific competition;
- phylogenetic diversity;
- rodent community;
- spatial analysis
1. Diversity begets diversity. Numerous published positive correlations between environmental heterogeneity and species diversity indicate ubiquity of this phenomenon. Nonetheless, most assessments of this relationship are phenomenological and provide little insight into the mechanism whereby such positive association results.
2. Two unresolved issues could better illuminate the mechanistic basis to diversity begets diversity. First, as environmental heterogeneity increases, both productivity and the species richness that contributes to that productivity often increase in a correlated fashion thus obscuring the primary driver. Second, it is unclear how species are added to communities as diversity increases and whether additions are trait based.
3. We examined these issues based on 31 rodent communities in the central Mojave Desert. At each site, we estimated rodent species richness and characterized environmental heterogeneity from the perspectives of standing primary productivity and number of seed resources. We further examined the phylogenetic structure of communities by estimating the mean phylogenetic distance (MPD) among species and by comparing empirical phylogenetic distances to those based on random assembly from a regional species pool.
4. The relationship between rodent species diversity and environmental heterogeneity was positive and significant. Moreover, diversity of resources accounted for more unique variation than did total productivity, suggesting that variety and not total amount of resource was the driver of increased rodent diversity. Relationships between environmental heterogeneity and phylogenetic distance were negative and significant; species were significantly phylogenetically over-dispersed in communities of low environmental heterogeneity and became more clumped as environmental heterogeneity increased.
5. Results suggest that species diversity increases with environmental heterogeneity because a wider variety of resources allow greater species packing within communities.