Habitat and climate heterogeneity maintain beta-diversity of birds among landscapes within ecoregions
Article first published online: 14 AUG 2007
© 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd
Global Ecology and Biogeography
Volume 16, Issue 5, pages 650–656, September 2007
How to Cite
Veech, J. A. and Crist, T. O. (2007), Habitat and climate heterogeneity maintain beta-diversity of birds among landscapes within ecoregions. Global Ecology and Biogeography, 16: 650–656. doi: 10.1111/j.1466-8238.2007.00315.x
- Issue published online: 14 AUG 2007
- Article first published online: 14 AUG 2007
- Bailey ecoregions;
- Breeding Bird Survey;
- distance decay of similarity;
- diversity partitioning;
- environmental heterogeneity;
Aim Habitat and climate heterogeneity may affect patterns of species diversity from the relatively local scale of communities to the broad biogeographical scale of continents. However, the effects of heterogeneity on species diversity have not been studied as widely at intermediate scales although differences among landscapes in local climate and habitat should maintain beta-diversity.
Location Bailey ecoregions in the USA.
Methods Using a geographically extensive dataset on bird distribution and abundance in 35 ecoregions, we tested for the effects of habitat and climate heterogeneity on beta-diversity at two discrete spatial scales: among sample points within landscapes, and among landscapes within ecoregions.
Results Landscape-level beta-diversity typically accounted for 50% or more of gamma-diversity and was significantly and positively related to habitat heterogeneity (elevational range within an ecoregion) and climate heterogeneity (variation in potential evapotranspiration). Contrary to predictions, point-level beta-diversity was negatively related to habitat and climate heterogeneity, perhaps because heterogeneity constrains alpha-diversity at the landscape level. The geographical spatial separation of landscapes within an ecoregion did not significantly affect beta-diversity at either scale.
Main conclusions Our results suggest that habitat selection and adaptation to local climate may be the primary processes structuring bird diversity among landscapes within ecoregions, and that dispersal limitation has a lesser role in influencing beta-diversity among landscapes.