Forest Health

Healthy, vigorously growing forests are critical in protecting the Massachusetts environment. When considering forest health, it’s important to distinguish between the health of the overall forest and the health of individual trees. Every woodland is the site of a constant battle between trees for sunlight and nutrients. Inevitably some trees lose the contest
to stronger, taller neighbors and eventually decline and die. This is not necessarily bad. Dead and dying trees provide important habitat and food for mammals, insects, birds, and fungi and, as they rot, are slowly recycled to provide nutrients for growing trees and plants of the forest ecosystem. A balance between vigorous forest growth and the continual process of
mortality is key to a healthy and resilient forest.

Many factors can affect the health of trees and forests. Insects, disease, ice, hurricanes, drought, lightning, logging, fire, grazing, road salt, air pollution – any of these can affect individual trees or even entire woodlands. In general, trees in poor health and overcrowded trees fighting for survival are more likely to die if attacked by insects, disease or drought. Some pests, such as hemlock looper or chestnut blight, kill trees quickly. Others, such as the hemlock wooly adelgid or acid rain, kill trees by first weakening them and making them unable to survive violent winds, drought, or other pests.

While, in general, little can be done to prevent insect or disease outbreaks in forests, preventative measures can improve long-term forest health. Maintaining diverse stands of vigorous trees by controlling harvesting will help forests grow and thrive. A mix of tree species is less likely to be killed by a pest outbreak than would be a forest comprised of a single species.

Among the insects or other problems affecting the health of trees and forests in Massachusetts are:

• Hemlock wooly adelgid
• Hemlock scale
• Hemlock looper
• Beech nectria
• Chestnut blight
• Dutch Elm disease
• White pine blister rust
• Ash yellows
• Ash decline
• Gypsy moths
• Sugar maple borer
• Pear thrips
  
  
  If you have questions or concerns about the health of your trees, please contact MFA at info@massforests.org. or contact the Department of Environmental Management’s Forest Health Coordinator at http://www.state.ma.us/dem/programs/forestry/health/index.htm