SGER: Biogeochemical Response Mechanisms Controlling Nitrogen Export from Defoliated Forests in the Eastern US

University Of Maryland Center For Environmental Sciences, Cambridge MD

Investigators

Abstract

Abstract 0119581 Eshleman SGER: Biogeochemical response mechanisms controlling nitrogen export from defoliated forests in the Eastern U.S. The excessive leakage of dissolved nitrogen (N) from forests defoliated by insects has water quality ramifications for small acid-sensitive streams as well as for downstream receiving waters such as Chesapeake Bay. Controlled laboratory experiments have shed some light on these mechanisms, but they are of limited applicability to actual forest ecosystems. Few field studies have been conducted, primarily due to the relative unpredictability of defoliation outbreaks. The goal of this Small Grant for Exploratory Research project is to take advantage of the recently-forecasted reoccurrence of extensive gypsy moth defoliation in western Maryland. The investigators will conduct a detailed, process-based study of the biogeochemical mechanisms controlling N leakage from disturbed forests in this area by comparing rates of key biogeochemical processes controlling N leakage in forested plots subjected to gypsy moth defoliation with rates in plots not defoliated. In addition, the investigators intend to compare concentrations of dissolved N species in streams draining defoliated and reference watersheds and use remote sensing imagery to detect, map, and estimate the regional-scale extent and intensity of gypsy moth defoliation during the 2001 growing season.