ANALYSIS OF WETLAND TOTAL PHOSPHORUS RETENTION AND WATERSHED STRUCTURE

The relationship between total phosphorus retention, landscape positio n of wetlands, and surrounding land-use patterns was explored with the goal of identifying easily determined landscape parameters as indicat ors of a wetland's role in water quality maintenance. Sediment cores w ere collected from 14 wetland sites chosen to represent a range of wet land types, wetland position, and surrounding land-use patterns in a s mall coastal Virginia watershed. Sediment accumulation rates and total phosphorus retention rates were analyzed using Cs-137 dating and acid extraction techniques. Both sediment accumulation rates and total pho sphorus retention rates were found to be comparable to previously repo rted values for similar wetland types. The landscape analysis did not support the hypothesis that total phosphorus retention would vary with landscape setting and/or wetland type. The wetlands sampled may repre sent landscape parameters too similar to detect any significant differ ences. Alternatively, the findings may indicate that in small coastal watersheds, most wetlands perform total phosphorus retention functions to the same level. The management implications of this latter conclus ion may be that headwater wetlands are particularly important for wate r quality functions.