Contribution of fluvial wetlands to nitrogen retention in urbanizing coastal watersheds in New England across multiple scales

Start Date: 2014-03-01 End Date: 2016-02-29
Principal Investigators: Anne Lightbody, Linda Kalnejais, Wil Wollheim

Abstract: Surface water quality in rapidly urbanizing coastal watersheds in New England is at risk due to excess anthropogenic nutrient inputs. We propose to use an innovative combination of hydrologic flow tracing, in-situ enrichment experiments, stable isotopes of water, and remote sensing data to determine the importance of floodplain and in-stream wetlands to nitrogen transformations, storage, and release across different seasons in the Lamprey (NH) and Ipswich (MA) watersheds. Experimental work will focus on two detailed field reaches, where we will determine the location and residence times of lentic compartments as a function of inundation and season, and quantify different biogeochemical mechanisms for nutrient removal and release as a function of season. Resulting estimates of net seasonal uptake rates will be extended to coastal watersheds throughout Massachusetts and New Hampshire and will be suitable for incorporation into existing reach-scale models of the system. This combination of approaches will greatly improve our ability to predict how these quantities may change in the future in response to changes in wetlands abundance, nitrogen inputs, and precipitation frequency.