Measuring Forest Health
Forest health is a term used to describe the resiliency and productivity of forests in relation to public values, needs, and expectations. Definitions of healthy forests are based on values and management plans of the observers. Therefore it is difficult to define forest health because it is subjective.
Some of the obvious measures of forest health include the number of acres of forested land, the size of each block of forest, the rate of growth of trees and other plants, the number of trees that die from natural causes each year, the condition and diversity of plant species below the forest canopy, and the species of animals supported by the ecosystem. Other measures include foliage transparency of tree crowns, tree crown dieback, tree crown density, and the size and health of individual animals.
The Forest Health Monitoring Program studies trends in these forest health measures across the United States. The program is jointly administered by the USDA Forest Service, the Environmental Protection Agency's Environmental Monitoring and Assessment Program, and the National Association of State Foresters. The Forest Health Monitoring Program estimates current status, changes, and trends in the condition of forests, monitors species that indicate forest conditions, and identifies links between natural and human-caused stresses and ecological conditions.
Data from satellites and other aerial pictures of the earth have become useful in identifying trends in forest health and forest cover. For example, satellite pictures help predict where forests will be gained or lost. Also, streams with inadequate forest buffers can be identified for reforestation to reduce the amount of pollutants flowing into waterways, including the Chesapeake Bay.
Forest health can be enhanced by using ecosystem-based management. Ecosystem management presents an ecological approach to provide a variety of diverse benefits from forests. It blends the needs of people and environmental values while enhancing forest diversity, health, quality, and productivity.