USDA Forest Service

Forest Inventory and Analysis National Program


Forest Inventory & Analysis
National Office
U.S. Forest Service
1400 Independence Ave., SW
Washington, D.C. 20250-0003

(703) 605-4177

United States Department of Agriculture Forest Service.

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Program Features


Forest Health Indicators


Ozone Crown Condition Soil Quality Lichen
Down Woody Materials Vegetation Tree Mortality Tree Growth


Ozone Indicator


The Ozone Indicator is one of the forest health variables measured by the FIA program. It is designed to detect and monitor ozone stress in the forest environment. Ozone-induced foliar injury data is collected from field sites on a nation-wide grid of ozone biomonitoring plots. Sampling intensity varies across the landscape according to differing air quality regimes and perceived risk to ozone sensitive forest types.


Why is the Ozone Indicator Important?

Air pollutants, such as ground-level ozone, are known to interact with forest ecosystems. Ozone pollution has been shown to reduce tree growth, alter species composition, and predispose trees to insect and disease attack. Ozone also causes direct foliar injury to many plant species. Affected leaves are often marked with discoloration and lesions, and they age more rapidly than normal leaves. This approach is known as biomonitoring and the plant species used are known as bioindicators.

For more information about the Ozone Indicator visit our Ozone Indicator website or view the FIA Ozone Indicator Fact Sheet.

USDA Forest Service
Last Modified: January 26, 2005

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