Presenter(s): Sky Ramirez-Doble
Faculty Mentor(s): Krista McGuire & Stephanie Ostresh
Oral Session 1 O
70% of remaining tropical forests, sites with high biodiversity, primary productivity, and CO2 exchange, are being converted into agricultural or logged areas. Tropical agricultural sites have been found with altered levels of soil carbon, nitrogen, and microbial composition; however, anthropogenic effects on soil and litter microbial functional potential are poorly understood. To help reveal the relationship between an altered soil and litter chemistry and microbial functionality, total soil and litter carbon and nitrogen concentrations were correlated with the presence of key decomposition macromolecules in litter and soil in the three most abundant tree species in El Yunque National Forest: Prestoea montana var. acuminate, Casearia arborea, and Dacryodes excelsa. Through a series of statistical tests, we were able to determine if (1) tree species and land use create distinct physical and chemical zones that alter microbial composition and functional potential, (2) differential carbon and nitrogen availability across land use reflects the dominant tree species present, and (3) high land use areas are correlated to earlier successional species such as Casearia arborea and low land use are correlated with late successional species such as Dacryodes excelsa. My research will provide insight into the anthropogenic effects of tropical agriculture.