BMP - Tree Inventories - 22

For deciduous trees, tree structure is easiest to evaluate when leaves are
not on the tree. Tree health is usually best judged when the tree is in leaf, as
stress is reflected by foliage condition.

Figure 10. Example of inventory output. Tree condition is broken down in this table by
size classes, providing an overview of future management needs.

Rating Tree Risk

Risk of harm from a tree failure is a major component of many inventories.
The level of risk assessment needs to be determined in the inventory goals.
If a limited visual assessment is to be used, only information on the tree,
location, and defects needs to be collected. If a higher level of assessment is
the goal, a basic risk assessment should be conducted. To be consistent with
the ISA's Best Management Practices: Tree Risk Assessment, this requires
walking completely around the tree examining the site and the whole tree.
Three attributes need to be rated to determine the level of risk when
using the basic assessment method: likelihood of failure, likelihood of impact,
and consequences of failure.
Categories from ISA's BMP: Tree Risk Assessment are:
Likelihood of failure
	Improbable-the tree or branch is not likely to fail during normal
weather conditions and may not fail in many severe weather conditions
within the specified time period.
	Possible-failure could occur, but it is unlikely during normal weather
conditions within the specified time period.
	Probable-failure may be expected under normal weather conditions
within the specified time period.

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BMP - Tree Inventories

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