Evaluation of anthropogenic atmospheric inputs on US national park ecosystems

It is estimated that more than half the threats to national park resources originate outside park boundaries, and most threats are attributable to degradation of air and water quality. Atmospheric contaminants are the principal source of external threats to national park ecosystems. This article examines the potential impact to national park resources by anthropic atmospheric inputs and summarizes present research methods and results regarding impacts. Air quality monitoring currently receives much more emphasis and support than effects research. Present research on effects focuses on vegetation impact, biomonitoring, and acid rain. This research and that of other investigators suggest that the most likely impacts will not be direct cause-effect situations, but indirect, incremental, and possibly synergistic effects on the interactions of ecosystem components. Conceptually, such alteration of interactions can be measured through long-term observation of biogeochemical cycles, energy transfer, and community structure and function. But traditional Park Service research has not emphasized the ecosystem and especially ecosystem processes and component interactions. Most research on effects, then, must begin with baseline data acquisition. A research program to mitigate present national data base deficiencies would require a fundamental change in present research priorities, administration, and funding.