PARENT SESSION
Oral Session # 60: Invasive Species V: Genetics; Chemical Cycling Effects.
Presiding: S Miao
Wednesday, August 6. 1:30 PM to 5:00 PM, SITCC Meeting Room 204.
Microbial community function and composition over a range of geographical locations, plant communities and invasive plant species.
Bray, Sarah1, 1 University of Florida, Gainesvillle, FL, 32611-8526
ABSTRACT- Invasion of natural systems by non-native plant species has been shown to alter nutrient cycling, nutrient regimes and native plant biodiversity. These effects of invasive species may be due to unique qualities of the invader or the dominance of that species in the community. The majority of this information, however, has come from case studies of individual species, limiting our ability to make conclusions about invasive species effects across systems. For a standardized assessment of the effects of invasive species on microbial communities across a geographical range, I examined soil samples of communities heavily impacted by five non-native plant species in Florida and Texas: Sapium sebiferum, Meleleuca quinquenerva, Schinus terebenthifolius, Ardisia crenata, and Ruellia tweediana. Soil samples were taken from both non-invaded and invaded areas for each species. Microbial community function was determined by Biolog and composition was analyzed by extraction of microbial phospholipid fatty acids (PLFA). Carbon substrate utilization patterns from Biolog as analyzed by principle components analysis showed little difference between invaded and non-invaded areas within and across species. While the metabolic abilities of the microbial communities were not altered by plant invasion, the identities of the microbes as determined by PLFA did change. These results suggest that while invasion may alter the species of microbes present in the soil, the function of the community remains intact.
Key words: microbial communities, PLFA, exotic plants, carbon substrate utilization