USDA Forest Service

Pacific Southwest Research Station

Pacific Southwest
Research Station

800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830
United States Department of Agriculture Forest Service. USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.

Research Topics

Air Quality

Plume of air pollution moving into Sierra Nevada Mtns. Southern California and California's Central Valley are among the most heavily polluted areas in North America. Ozone, acidic gases and particulates are transported long distances to forests of the central and southern Sierra Nevada and the transverse mountain ranges of southern California. Although pollution control devices required in the state of California on both industrial and mobile sources have significantly reduced the number of days that exceed state and federal ozone standards, overall pollutant exposures are high and are expected to increase.

Our goal is to provide high quality scientific information that will provide a scientific basis to set protective air quality standards, and to provide estimates of future changes in forest ecosystems.

Emerging Research Needs

Critical Load: the concentration of air pollution [loading rate, e.g., kg/ha/yr] above which a specific deleterious effect may occur. A critical load or concern threshold value should:

  • protect the most sensitive AQRVs (Air Quality Related Values);
  • be based on the best science available;
  • ensure that no unacceptable change occurs to the resource.

Major Research Initiatives:

Air Pollution and Global Change: We need a basic understanding of tree response to atmospheric pollutants and drought stress. More about this topic.

Monitoring: Monitoring of air pollution concentrations, deposition, and effects is needed to determine the extent and magnitude of pollutant deposition in areas at risk and determine forest stand structure and composition response. More about this topic.

Smoke Effects / Smoke Emissions: Management of visibility/regional haze is an important issue facing the Forest Service, especially in Class 1 Wilderness areas. Scientists in PSW are involved in these issues from a smoke management and smoke chemistry perspective, as well as, the impacts of industrial development and urbanization.

Photo of a prescribed firePrescribed fire is an important management tool for National Forest managers. There is a critical need to determine whether prescribed burns comply with local and regional air quality regulations, and if not, what conditions lead to non-compliance. Existing models of smoke chemistry, transport and dispersion need to be tested under local and regional conditions. Ground based, low-cost monitoring equipment for measuring smoke emissions has been developed and will be tested to quantify the location, chemistry, concentration, and deposition of air pollutants from prescribed and wildland fire.

More about this topic.
Last Modified: Apr 20, 2015 02:32:49 PM