The role of particular species in controlling ecosystem processes is central to our perceptions of how biodiversity may influence ecosystem function. Yet, the understanding of links between species and function in tropical ecosystems remains poor, as does the understanding of microbial species-function relationships in any ecosystem. This grant supports experiments that examine the connections between tree species, free-living nitrogen-fixing microbial communities living on and beneath trees, and rates of free-living nitrogen fixation in a lowland tropical rain forest in Costa Rica. Preliminary data show that neighboring trees of different species support distinct rates of free-living nitrogen fixation. Using a suite of complementary genetic techniques, this research will examine the role of microbial community dynamics, and their links to specific canopy trees, in regulating the observed differences in nitrogen fixation rates.
Tropical forests exchange more carbon, water, and energy with the atmosphere than any other biome and thus play a critical role in regulating environmental change on a global scale. As human activities continue to alter the species composition of these forests, the need for understanding the importance of high native biodiversity in tropical systems becomes increasingly urgent. The student responsible for this research has an extensive record of outreach and training, and will continue her work with local high-school students and middle-school girls by integrating her research experiences into student-focused workshops.
