Research Opportunities & Collaboration in the Appalachians (ROCA)
Aerial photo of two of the ROCA sampling sites (click to open a larger view).
With funding from A. W. Mellon Foundation, AL scientists have been working with scientists from colleges in the Appalachian College Association (ACA) on a collaborative research and educational project. The focus of the project was on watersheds in the Appalachian Mountains, particularly on the hydrobiogeochemical changes that occur when forested lands are harvested, mined and reclaimed. In the coal-rich, Appalachian Mountain region, deforestation, surface mining, and land reclamation from previous mining activities represent the dominant land use changes that are occurring. The study was aimed at understanding and quantifying the important ecosystem responses to these land management activities in the region, including changes in vegetation, nutrients, and soil properties. AL and ACA scientists have employed the “small watershed technique” to compare export rates of water, dissolved solids, and suspended solids from a group of small, gauged watersheds that have been subjected to different land management practices. The research was conducted in three watersheds (TNEF, TMAT, and EBNR) on the western slope of Dans Mountain, approximately 10 km from the AL facility in western Maryland.
Montana flume used in gaging at reclaimed mine site.
Annual water and nitrogen (N) budgets for forested TNEF were estimated using stream water and wet deposition data collected during the years 1999-2004. Measurements of biogeochemical variables typically used to examine N saturation in forests were also made during this period, including: foliar N concentrations; N resorption; carbon and nitrogen concentrations in the forest floor, mineral soil and vegetation; net rates of N mineralization and nitrification; and dissolved N concentrations in soil solution. We observed several symptoms of N saturation. TNEF was a strong, but highly variable, source of N (dominated by nitrate, NO 3 -) to the stream in all years, with a mean annual export of 9.46 kg N ha -1 yr -1 and a range of 4.4 kg N ha -1 yr -1 to 18.4 kg N ha -1 yr -1. These extremely high rates of N export are notable because they are some of the highest export rates ever reported for non-manipulated temperate forests in the U.S. Although TNEF is a young aggrading forest, the watershed exhibits symptoms of N saturation commonly observed in more mature forests, suggesting that other factors, such as land use and disturbance history, nutrient limitations, and climatic variations need to be carefully considered in understanding the responses of forest ecosystems to atmospheric N deposition.
For additional information, visit the AL's ROCA website.
Related Publications:
- Thesis titled "A comparative hydrologic analysis of surface mined and forested watersheds in western Maryland." to fulfill requirements of University of Maryland MEES Program by Timothy N. Negley (2002).
- Thesis titled "Aboveground production and nitrogen availability at a rehabilitated ecosystem : the role of soil moisture and microtopography." to fulfill requirements of University of Maryland MEES Program by Molly M. Ramsey (2002).
- Thesis titled "Multi-factor controls on denitrification in natural and reclaimed mine wetlands." to fulfill requirements of University of Maryland MEES Program by Madhura Kulkarni.
- Thesis titled "Comparison of base cations in streams and soils in two small Western Maryland Watersheds." to fulfill requirements of University of Maryland MEES program by Cynthia Giffen.
- Eshleman KN. 2004. Hydrological consequences of land use change: a review of the state-of-science. In Ecosystems and Land Use Change, Defries R, Asner G, Houghton S (eds.). Geophysical Monograph Series 153, American Geophysical Union: Washington, DC; 13-29.
- Negley TL, Eshleman KN. 2006. Comparison of stormflow responses of surface-mined and forested watersheds in the Appalachian Mountains, USA. Hydrol. Proc. (16): 3467-3483. (nutshell page)
Project PI's:
Dr. Lou Pitelka
Dr. Keith Eshleman
Dr. Mark Castro
 Forested watershed site |
 ACA collaborators and students participate in workshop at AL. |
 Preparation of vegetation samples in the lab. |