Nitrogen cycle effects of forest disturbances, as detected by NASA imagery in the Chesapeake Bay Watershed

Lindsay N. Deel, West Virginia University, lindsay.deel@gmail.com (Presenter)
Brenden E. McNeil, West Virginia University, brenden.mcneil@mail.wvu.edu
Travis R. Cowles, West Virginia University, trcowles1@gmail.com
Angelica Gutierrez-Magness, University of Maryland, angelica.gutierrez@noaa.gov
Keith N. Eshleman, University of Maryland Center for Environmental Science, eshleman@al.umces.edu
Philip A. Townsend, University of Wisconsin, ptownsend@wisc.edu

The wide range of disturbances that affect forests (e.g. forest harvest, defoliation) can have important effects on ecosystem services related to nitrogen cycling (e.g. forest productivity, protection from coastal eutrophication). Protection of these services is especially important within the densely populated, but largely forested Chesapeake Bay Watershed (CBW). This poster summarizes some of our ongoing efforts demonstrating the usefulness of NASA imagery-based metrics of forest disturbance for predicting ecosystem functions and related ecosystem services within the CBW. Using a long time-series of Landsat imagery, we have found a strong relationship between cumulative disturbance and canopy nitrogen at the small watershed scale, suggesting that the current functioning of these forests is affected by the sum total of many previous disturbances. Our related Landsat-based study found that knowledge of the spatial pattern of disturbances within small watersheds can improve predictions of streamwater nitrogen export, especially in years of low-level disturbance. We are currently building on these abovementioned studies by expanding the scale of analysis to the entire Chesapeake Bay Watershed (CBW). The end goal of these ongoing efforts is to more precisely quantify the N load exported from forests of the CBW, which are currently assumed in management models to be a static amount of ~2.2 kg/ha. Based on our previous studies, we expect to find a general overestimation of the assumed contribution of forested watersheds to total N loads to the Bay, except in selected forest types and during periods of severe disturbance (such as gypsy moth outbreaks). By demonstrating the utility of NASA imagery for understanding the extent and estimated impact of disturbed forests on the export of nutrients to the Bay, we hope to provide science that can better direct management resources and policy directives.

Presentation Type:  Poster

Session:  Science in Support of Decision Making   (Wed 10:00 AM)

Associated Project(s): 

• Townsend, Phil: Characterization of forest functional types and their role in mediating ecosystem response to environmental change ...details

Poster Location ID: 136