As National Parks become isolated islands of conservation surrounded by managed and developed landscapes, Congress has recognized the need for "a program of inventory and monitoring of National Park System resources" (National Parks Omnibus Act, 1988). One specific aim is "to monitor key aspects of resources and processes at regular intervals" (2001 NPS Management Policies). This goal has also been described as assessing 'ecosystem status' 'ecosystem integrity' or 'ecosystem health', even though these terms have not been precisely defined. Determining how to monitor these intuitive terms is one of the most challenging aspects of designing a monitoring program. We recognize the general relationships among ecosystem components (Diagram 1, middle, right). 
The abiotic environment affects vegetation structure directly through disturbance (e.g., fires, windthrow) and through biogeochemical cycles (e.g., carbon and nitrogen cycles) and demographic (e.g., establishment, mortality, growth) processes by determining available resources. Plants respond to the abiotic environment through evolutionary adaptation. Vegetation can, in turn, affect the abiotic environment by determining the amount and type of substrate available for decomposition and by physically altering microclimates. In addition, animal members of the ecosystem alter (e.g., herbivory, disease) and respond (e.g., habitat requirements) to the abiotic environment and vegetation composition and structure.
Although we understand the basic relationships among ecosystem components, we still have many questions regarding how best to monitor systems as a whole. Structure and composition of vegetation integrate the abiotic environment and are fairly straightforward to describe, but we cannot measure and account for every component. If we miss a change by monitoring structure, might we notice it monitoring process? Which is the early indicator, structure or process? Are biogeochemical processes so stable that only a major change in vegetation will affect function? Or is vegetation structure static for some time after function begins to shift? Vegetation, after all, is composed of physical entities that may persist even though resources have changed. Are demographic processes more sensitive to change than biogeochemical processes? Which is easier to monitor, structure or function? Which is the most important to protect?
This project is a pilot study to begin to characterize the relationship between vegetation and ecosystem processes. The study asks whether the change in vegetation structure and composition caused by campgrounds and elk exclosures (areas where elk are fenced out, Photo1.) results in a measurable change in biogeochemical function using methods that might be feasible to use in a long-term ecological monitoring program. The study involved two campgrounds and two elk exclosures spread over a wide range of environmental conditions in Olympic National Park. Process measurements included soil CO2, litter fall, decomposition, nitrogen mineralization, and leaching, and were collected over two growing seasons and the winter between (Photo 2).
