The effects of phosphorus and carbon additions on anaerobic microbial activity in peat soils of the Florida Everglades

摘要

Human activities have altered the natural biogeochemical cycles of many elements to the extent that they are now treated as pollutants in many ecosystems. The Everglades of South Florida have been negatively impacted by two such elements, phosphorus and mercury. This study tested the hypothesis that increased phosphorus concentration contributes to conditions that lead to increased anaerobic microbial activity and microbial populations that might be linked to mercury methylation in Everglades peat soils. Soil was collected from a pristine Eleocharis marsh in the Shark River Slough area of Everglades National Park. Changes in microbial communities from aerobically-dominated to anaerobically-dominated processes were measured by reductions in redox potential, CO2 and CH4 evolution, enzyme activity, and bacterial density. The results indicate that in Everglades peat soil phosphorus level plays a significant role in shifting microbial communities from aerobically-dominated to anaerobically dominated, processes.