Everyone wants a healthy forest but what exactly does this mean? In general, the idea of forest health takes into account ecological conditions of forests and woodland stands (age, growth, diversity, insect pests, diseases, invasive plants, wildlife attributes, aesthetics, resilience to disturbance), weighed against land management goals. But, it is important to keep in mind that definitions of what constitutes a healthy forest vary widely and can be different depending on where you are and what you want.


While some tree death is healthy (and unavoidable) in woodlands, other threats can jeopardize entire forests and/or forestry operations. Invasive insects (like the emerald ash borer and hemlock woolly adelgid) and diseases (like chestnut blight and Dutch elm disease) are perhaps the most noticeable threats, causing widespread tree mortality and changing forest ecosystems worldwide. Invasive plants are also a serious issue, outcompeting native plants and reducing diversity and regeneration. In addition, many other stressors, from native pests to fire to extreme weather, cause occasional or incremental damage that can predispose trees to other factors or act synergistically to decrease forest health overall, especially for aging trees.


Sustainable management is forest health applied. While poor management practices can decrease health (for example high grading degrading stands and logging damage that leads to heart rot), effective management can increase tree vigor, resilience, and long-term sustainability of both forests and related industries.


Click on one of the following topics to learn more about forest health threats.



Woodland Threat Alerts



Timber Theft


Storm Damage

Invasive Plants