Session Information
| Session | Poster Session | | Date | Monday (2008-04-07) | | Time | 5:00 PM - 7:00 PM | | Room | Grand Terrace |
Presentation Information
| Presenter | Jennifer Costanza | | Title | Landscape heterogeneity and plant species richness in the Southeastern US | | Affiliation | University of North Carolina-Chapel Hill | | Authors | Jennifer Costanza | | Keywords | Grain and extent, Heterogeneity, Southeastern US, Species richness, Vegetation | | Presentation Type | Poster | Abstract:
Investigating the causes and consequences of species richness patterns at local to global scales has been an important field of research in ecology for decades. It is especially important today to understand the mechanisms that influence species diversity, given threats such as global climate change and habitat loss. Landscape heterogeneity may be an important factor in determining species richness; however, we lack a clear understanding of how the two are related, and at what scales. Therefore, I investigate the relationship between heterogeneity and plant species richness across Virginia, North Carolina and South Carolina. I examine how the relationship varies with the grain size at which habitat heterogeneity is sampled as well as with the geographic extent of sampling. Species richness data come from more than 7000 0.1-ha vegetation plots located across the three-state area, and provide a unique opportunity for integrating fine-scale data across a regional extent. Measures of habitat heterogeneity are derived from the variation in remotely-sensed indices of productivity across grain sizes surrounding plot locations. I vary both the extent of the sampled plot data, from a conservation landscape on the North Carolina Coastal Plain to the entire three-state area, as well as the heterogeneity grain size. I show that for small heterogeneity grain sizes, the heterogeneity-richness relationship is positive, but as grain size increases to encompass multiple land use types, the relationship becomes less positive. In addition, as the spatial extent of the study area increases, the heterogeneity-richness relationship becomes weaker. These results have implications for both ecological theory, and for land managers, who increasingly manage to promote a mosaic of habitat types across a landscape. |
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