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: Monitoring

Monitoring Air Quality and Air Pollution Effects:

[Photo]:Setting up a battery powered ozone monitor on a ridge overlooking urban areas to the west.Projected increases in the population of California continues to translate into increased pollution and its deposition to forest ecosystems in the Sierra Nevada, the Transverse Range (San Gabriel and San Bernardino Mountains), as well as into desert ecosystems to the east. The global average tropospheric ozone level has doubled since pre-industrial times, and is expected to double again by 2020, making it the fastest increasing greenhouse gas. Nitrogenous compounds associated with fossil fuel use and agriculture are less well quantified, but our numbers suggest that N deposition is exponentially correlated with oxidant pollution.

[Photo]:A transect of throughfall collectors with snow tubes A full evaluation of air pollution effects on ecosystems requires an estimate of total deposition fluxes. Collection of throughfall, the hydrologic flux of nutrients from the canopy to the forest floor, is widely acknowledged as a practical method of monitoring atmospheric deposition to forests. We have developed a "passive" throughfall collector in which the deposition is captured in ion exchange resin columns. This method of throughfall collection is much less expensive than conventional methods and provides an opportunity to quantify nitrogen and sulfur deposition at a greater number of sites than previously possible. Using this method we are increasing our understanding of what nitrogen deposition inputs cause various effects on forests throughout California and in other western ecosystems. Description of IER methods

[Photo]: Passive Samplers We are currently investigating reliable, easy to use passive samplers and active monitors for monitoring air pollutants (Ozone, Nitric Acid, Ammonia, NOx, and Nitrogen Dioxide) in forested and remote areas on a large scale. Using low-cost monitoring devices at many sites allows maps of spatial distribution of pollutant concentrations to be developed. Using this approach, a spatial model for prediction or estimation of ozone and N concentrations can be derived.

[Photo]: Ozone injury on pine needles To monitor the effects of air pollution on ecosystem health, a networks of tree plots have been established and periodically observed since the 1960's. The San Bernardino Mountains network is currently being revised so that long-term studies on the effects of multiple air pollutants -- deposition, physiological and biochemical changes in trees, growth and composition of overstory species, biogeochemical cycling including carbon cycling and sequestration, water quality, and biodiversity of forest ecosystems can be conducted.


TITLE: Intensified Ozone Monitoring and Assessment of Ozone Impacts on Conifers in Southern California

Funded by: USDA Forest Service - Forest Health Monitoring

Project Objectives: The overall objective of this project is to quantify ambient ozone concentrations and tree conditions that constitute a risk to forest health in southern California national forests. Specific objectives include:

  1. Installation of and collection of data from passive ozone monitors at 25 sites in southern California.
  2. Evaluation of 50 ponderosa and/or Jeffrey pine at each site for ozone injury, mortality, and damage by other agents such as insects or diseases.
  3. Co-location of 4 of the 25 passive monitors with existing active continuous monitors.
  4. Analysis of ozone data and tree health data to characterize ozone distribution at landscape or forest stand scales, identify ozone hot-spots, and correlate ozone measurements among active, passive, and biological systems to tree injury and mortality.

TITLE: Southern California Wilderness Air Deposition and Stream Water Inventory

Funded by: Southern California Province, Air Resources Program, USDA Forest Service

Project objectives: To better understand the link between air quality and water quality in Class I Wilderness Areas of southern California. Specific objectives include:

  • Monitor the atmospheric deposition of nitrogenous species for one year in eight Class I Areas (including Domeland in the Southern Sierra Nevada) to help establish deposition baselines.
  • Sample streams for nitrogen species and toxics three times during the deposition monitoring period.
  • Investigate linkages between deposition quality and stream water quality.
  • Prioritize the eight Areas for further deposition and water quality monitoring.
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Last Modified: Mar 28, 2013 03:38:21 PM