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


Crown Condition Indicator


Many physical and biological components influence forest trees. Individual sapling and tree growth and vigor are determined by a variety of physiological and external effects, such as age, available light, water, and nutrients. Since tree crowns are a component of forest ecosystem structure, they directly affect the composition, processes, and vigor of the understory plant and animal components of the forest.

Why is the Crown Condition Indicator Important?

Information about crowns can be used to answer questions about forest ecosystems such as:

  • What proportion of trees (by species and forest type) in a region have more crown dieback or less crown density than normal?

  • Is there a regional change in the proportion of trees (by species and forest type) that show a change in crown condition?

The crown is one component of net primary production and its dimensions reflect general tree health. Large, dense crowns are associated with potential or previous vigorous growth rates. Small, sparse crowns suggest unfavorable site conditions (such as competition from other trees, moisture stress, or moisture excess) or other influences (such as insect defoliation, foliage diseases, or hail storms). Some changes in crown measurements may be temporary, especially when the stressing condition can be eliminated or reduced. Continued poor conditions however, may be reflected in a tree with increasingly poor vigor.

Tree crown information contributes to the investigation of several key forest ecosystem attributes: biodiversity, productivity, sustainability, aesthetics, forest environment, and wildlife.

For more information about the Crown Condition Indicator view the FIA Crown Condition Indicator Fact Sheet.

Click here to go to the Crown Condition Indicator website.

USDA Forest Service
Last Modified: January 12, 2018

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