SS3.04 Biogeochemistry of DOC/DON in a Watershed Context
Date: Wednesday, June 12, 2002
Time: 4:15:00 PM
Location: Carson B
 
WiegnerTN, Stroud Water Research Center, Avondale, USA, twiegner@stroudcenter.org
Seitzinger, S, P, IMCS, Rutgers University, New Brunswick, USA, sybil@imcs.rutgers.edu
 
CHEMICAL COMPOSITION AND BIOAVAILABILITY OF DISSOLVED ORGANIC CARBON AND NITROGEN FROM PRISTINE AND POLLUTED FRESHWATER WETLANDS
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Dissolved organic matter (DOM) is metabolically important in rivers. It provides energy and nutrients to bacteria as C and N. Freshwater wetlands are an important source of dissolved organic carbon (DOC) to rivers; however, their importance as a dissolved organic nitrogen (DON) source is not well known. In addition, it is not yet understood how the quantity and quality of the DOC and DON exported from these wetlands is affected by upland anthropogenic activities. The study presented here examines the chemical composition and bioavailability of DOC and DON from pristine and polluted freshwater wetlands during three seasons. The DOC and DON concentrations, chemical characteristics (aromaticity and molecular weight), and bioavailability in the wetland waters were affected by anthropogenic activities and season. Overall, the percent of wetland DOC and DON utilized by river microbes ranged from 9-32% and 0-65%, respectively. These results suggest that freshwater wetlands may be an important source of labile DOC and DON to rivers and that anthropogenic activities, as well as, season can affect both the quantity and quality of DOM exported from these wetlands.