Biogeochemical indices of phosphorus retention and release by wetland soils and adjacent stream sediments

Abstract

ABSTRACT Eutrophication is still a water quality problem within many watersheds. The Lake Okeechobee Basin, Florida, USA, like many watersheds is impacted by eutrophication caused by excess phosphorus (P). To meet water quality criteria to reduce this impairment, several levels of information on P dynamics within the Basin are required. The use of biogeochemical indices to help determine P retention/release of different landscape units such as wetlands and streams provides useful information on P dynamics. The objective of our study was to determine P retention/release indices for a range of wetland soils and their adjacent stream sediments. We sampled several wetlands and adjacent streams within Okeechobee's Basin, which represented a range of P impacted systems. Regression analyses suggest that a single incubation of sediment/soil equilibrated at 1000 mg P kg−1 was sufficient (> 96% of the time) to estimate maximum P sorption capacity (Smax). Using this single incubation, sampled wetlands had nearly twi...