Production, graphic design, and writing:
Jennifer Stoyenoff, John Witter, & Bruce Leutscher
University of Michigan
In cooperation with:
State Forestry Agencies
A healthy forest gives us...
How much forest is there?
How many big trees are there?
Who owns the forest?
1997 The fate of forest trees
There are 23 billion trees over 10 feet tall in the Mid-Atlantic Region. Let's look at the fate of 400 representative trees in a typical year during the last decade:
Trees are stressed by and die from a variety of causes. Some common reasons include:
How do the trees look?
On average, about 4% of the twigs and branches in a tree's crown are dead.
This amount of dead branches and twigs is normal; 30% is considered serious for a tree.
Overall, the forest is in good condition.
In a healthy forest you will see dead and dying trees. Trees die as a natural part of life in the forest. Dead and dying trees are more common in some places due to old age, poor soils, or weather extremes. Infact, having some dead trees is beneficial for wildlife habitat.
What about trees in the cities?
How do we know about the health of the forest?
No single measurement can summarize forest health. Instead, we need to look at a wide set of indicators which together serve as a reflection of existing conditions. Repeated monitoring of the forest over time allows us to identify trends in forest conditions and evaluate the effectiveness of our actions.
Information about forest health is obtained in a variety of ways. The USDA Forest Service conducts a program of Forest Inventory and Analysis, which provides information in each state on rates of tree growth and death, harvesting, and changes in forest types and tree species. The Forest Service and state agencies conduct regular ground and aerial surveys of forest damage and the causal agents, both in permanent plots and in other forest areas. Universities, private industry, and environmental groups cooperate with governmental agencies on a variety of forest research projects.
One major program aimed at understanding forest health is a joint federal/state program called the Forest Health Monitoring Program. This national program was developed in 1990 and is under the administration of the USDA Forest Service. It includes active participation of state foresters, other federal and state agencies, and universities. The program goal is to monitor, assess, and report on the status, changes, and long-term trends in the health of our nation's forests. The program involves a network of permanent plots and other off-plot areas that are regularly visited to monitor tree vigor, crown condition, and signs of damage. On a subset of the plots, plants are monitored for damage caused by ozone, a common gaseous pollutant. Structure of the plant communities and presence of lichens (pollution-sensitive life forms that are a combination of algae and fungi) also are evaluated on a subset of the plots. Currently, permanent plots are established in 19 states, with plans to expand the program to additional states in the future. In the Mid-Atlantic Region, participating states are Delaware, Maryland, New Jersey, and West Virginia.
ant to know more?
USDA Forest Service
USDA Forest Service
Delaware Department of
Maryland Department of Natural
New Jersey Department of Evironmental Protection State Forestry Services
Ohio Department of Natural Resources
Pennsylvania Dept. Conservation &
West Virginia Division of Forestry
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