Program Features
Forest
Health Indicators
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 visit the Crown Indicator website http://srsfia2.fs.fed.us/crowns/index.shtml
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