The U.S. National Park Service (NPS) is faced with direct questions about the condition of Park natural resources. The watershed approach to long-term monitoring of natural, and remote areas within the National Parks has provided important data for detecting both spacial and temporal changes in environmental conditions. These data collections allow the partitioning of cause and effect relationships of ecological change within a given watershed. They also serve to meet both reference and early warning objectives. Success in advancing a number of'acid precipitation' goals has demonstrated the usefulness of these integrated watershed data for inter-ecosystem comparison and for analogy between watersheds. The watershed program owing to the NPS experience is proposed as a model for focusing the National Park Service's inventory and monitoring program inititiative. This approach provides to park researchers and resources managers the needed tools for dealing with today's complex local, regional and global natural resources issues.
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Within the NPS concern about the need for natural resources information was officially articulated in 1987. The statement begins, 'It is the policy of the National Park Service to assemble baseline inventory data describing the natural resources under its stewardship, and to monitor those resources forever -to detect or predict changes that may require intervention, and to provide reference points to which comparisons with other, more altered parts of the home of mankind may be made' (NPS, 1987). Paralleling this resurgence of NPS interest in monitoring, the research community has reaffirmed the scientific necessity for long-term, systematic environmental monitoring to provide a context within which to formulate and test meaningful hypotheses regarding ecological processes and impacts (Likens, 1983; IGBP, 1988).