Assessing environmental change in undisturbed watersheds of US National Parks and Reserves

Long-term biogeochemical monitoring coupled with ecosystem research provides essential information for land conservation. Knowledge from longterm study of natural resources within preserved areas, such as the U.S. National Parks, is key to understanding ecosystem processes and the effects of human activity on them. In 1980, the U.S. National Park Service, embarked on a program of integrated watershed-ecosystem studies. These long-term watershed studies are expanding our knowledge about the response of natural systems to stress; the sources of stress; aquatic and terrestrial biogeochemical cycles, especially nitrogen (N) and sulfur (S); and, surface water chemistry, biology, and hydrology.