Document: KAT-3-9-5

Air pollution: a chronic stressor in Western mountains

TONNESSEN, K.A*

University of Montana, Missoula, MT 59812 USA ¹

Abstract:
The objective of this presentation is to summarize what we know about air pollution stressors and ecological response in major mountain ranges of the western United States, with a focus on the Rocky Mountains, the Sierra Nevada, the Cascades and the Coast Ranges of southern California. Regional air pollutants of concern include visibility-reducing particles, deposition of nitrogen and sulfur compounds and ozone. Air pollution threats to species, biogeochemical processes, and human health range from severe in southern California to low in parts of the Cascades, Sierra Nevada and northern Rockies. Many mountain watersheds include sensitive lakes, streams and soils, with low acid-neutralizing capacities, that respond to acidic deposition. Native plant species that respond to ozone occur in these environments. Deteriorating visibility has been measured in all of these ranges, with particle contributions from fossil-fuel burning, agricultural practices and forest fires. Emerging air pollution issues in the western mountains include elevated concentrations of persistent organic pollutants in snow, the influence of climate change on air pollution and the effects of prescribed fire on air quality.

Keywords: air quality, western mountains

This abstract is being presented at: 10:15 AM in session:
Symposium # 2: Stressors in Western Mountain Ecosystems: Detecting Change and Its Consequences.