Nutrient Uptake and Retention Patterns in Two Streams with Contrasting Watershed Landuse

Abstract

ABSTRACT We estimated the uptake lengths (Sw) of NO3-N and PO4-P using the nutrient enrichment method to assess their transport dynamics in Panther Creek (forested stream) and Ledbetter Creek (agricultural stream). The agricultural stream had higher ambient NO3-N than the forested stream, while PO4-P was higher in the forested stream than agricultural stream. Although we expected shorter Sw estimates in the forested stream based on the ambient nutrient concentrations and higher metabolism, the agricultural stream (Ledbetter) had shorter Sw (372 m for N and 327 and 242 m for P) than estimates from Panther Creek (753 and 870 m for N; 827 m for P). Nutrient uptake patterns in these streams may reflect the combined effects of biological activities and hydrologic characteristics. Ledbetter Creek contained several large pools and backwater areas that allowed longer residence and contact time for amended nutrients than Panther Creek. It was also assumed that Ledbetter had a potential for higher abiotic phosphoru...