PARENT SESSION
Oral Session #11: Biodiversity and Ecosystem Function. Presiding: A. Downing.
Monday, August 6, 2001. 1:00 PM to 4:45 PM. Madison Ballroom C.
Cross-scale determinants of the Savannah River Site mammalian community, South Carolina.
Bock, Jodi1,2, Allen, Craig1,2, 1 2
ABSTRACT- Landscapes and ecosystems continue to be degraded, increasing the importance of understanding the relationship between the distribution of functional groups and ecosystem resilience. The theory of 'cross-scale resilience' predicts that the functional groupings of the Savannah River Site (SRS) mammalian community will be diverse within and dispersed across scales, such as landcover. Our objectives were to determine the validity of this theory by investigating whether mammalian functional groups (feeding guilds) were either randomly distributed, segregated by habitat, or influenced predominantly by landscape indices, such as patch size, perimeter, shape, and context. Context was defined as landcover richness within two scales: maximum dispersal distance of small and meso-mammals. Pearson correlation analyses were performed to determine relationships between functional grouping richness, landscape indices, species abundance and richness. Results suggest that patch dimensions do not determine functional group distributions or abundance for SRS as a whole. However, there are interactions between patch indices and species abundance within swamp and planted pine landcovers, indicating habitat segregation and diversity between landcovers. The difference in mean values of richness was significant among landcovers, with sandhill being statistically different than swamp, and swamp being different than planted pine (P<0.05). Also, patch context did have a positive correlation with species and functional richness for both small and meso-mammals dispersal distances.
KEY WORDS: Savannah River Site, scale, landscape indices, mammals