Shenandoah National Park is one of only 48 “Class I” air areas managed by the National Park Service under the Clean Air Act (CAA). “Class I” areas provide special protection for air quality, sensitive ecosystems and clean, clear views.  Additional authority to consider and protect air quality related values (AQRVs) in Class I parks is provided by the NPS Organic Act and the Wilderness Act.   NPS Management policies state that the “Service will acquire the information needed to effectively participate in decision-making that affects park air quality.”  Toward this goal, SHEN and its research partners are actively engaged in air-quality monitoring and research about air pollution’s effects on human health, streams, aquatic life, vegetation, and wildlife.  The park operates an air quality station that has made measurements of precipitation chemistry (National Atmospheric Deposition Program—NADP, NTN, MDN) since 1981, of fine particles and visibility (Interagency Monitoring of Protected Visual Environments—IMPROVE) since 1982, and of ground-level ozone since 1983.  Meteorological measurements at the same Big Meadows location began as early as 1935.

The Shenandoah Watershed Study (SWAS), a cooperative agreement between the University of Virginia and Shenandoah National Park (SHEN), was established in 1979 to provide increased understanding of hydrologic and biogeochemical changes that occur in response to acidic deposition and other ecosystem stressors.  The underlying scientific objective of the SWAS program is to improve understanding of hydro-biogeochemical processes that govern ecosystem conditions in the mountain watersheds of SHEN, but the partnership is a tool that has provided decades of positive feedback loops between air and water quality monitoring, research, and land management.

We will present a snapshot of projects that have used the long term connections built between monitoring, research, and management in this positive feedback loop.  Examples include: consideration of a liming project to mitigate the effects of acid rain, determination of the impact of wild fire on stream mercury and carbon concentrations, evaluation of the impact of watershed defoliation on stream nitrate concentrations, assessment of the long-term trends in episodic acidification to inform fish monitoring trends, and looking forward, predicting the impacts of a more extreme climate.  The Organic Act of 1916, created the National Park Service  to “conserve the scenery and natural and historic objects and the wild life therein”, and cooperative conservation is the key to park protection.