PARENT SESSION
Poster Session #5: Soil Ecology.
Monday, August 6, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall
The relationship between three tropical tree species and their surrounding soil microbial communities .
Chatterjee, Keya1, Lawrence, Deborah1, Mills, Aaron1, 1
ABSTRACT- Through differences in the quality and quantity of litter, nutrient uptake, root turnover, and water use efficiency, individual tree species have different effects on the organic matter, nutrient availability and moisture in the soils surrounding them. In controlled settings, greenhouse studies have shown a correlation between plant species and soil microbial communities. It follows that different tree species in a natural setting would also be associated with differently functioning microbial communities. In order to test this hypothesis, community level physiological profiling (CLPP) was used to investigate the variation in the soil microbial communities within a 1m radius of three tropical tree species (Pentaclethera macrobolos, Casearia arboria, and Socratea exormita). Nine soil samples taken at 15cm depth were pooled from each tree and nine trees of each species were sampled within a 1-ha plot. Biolog GN2 plates were inoculated with a 10-4 dilution. The species that were investigated could not be differentiated by PCA alone, although spatial variation seemed to be a confounding factor. The mean number of substrates used did not vary significantly from species to species (mean=10.1). This implies that either the differences in function could not be detected by this method, or that the soil microbial communities surrounding these different tree species are controlled by other factors such as soil type, litter mass or tree density.
KEY WORDS: microbial community, tropical forests, tree species, Biolog