Diseases of Hardwoods

Deciduous forests carry their own unique threats, including both native and nonnative diseases. Some of these diseases have been present in the United States for decades and have played a vital role in shaping forest structure. They generally attack individual weakened or severely stressed trees, often following insect invasions. 

It is important to understand the physiology and history of these hardwood and coniferous diseases to inact proper management when infestations occur.  Many diseases of hardwoods are species-specific, attacking a particular host species such as oaks, dogwoods, butternuts, chestnuts, or elms. Loss of any of these species could cause major devastation; the American chestnut tree, nearly lost to the chestnut blight, was not only a valuable timber species but also as the most important producer of hard mast for wildlife. Other generalized diseases often function in symbiotic relationships with other vectors, such as insects or fungi, to attack trees.

In this section, more detail is provided about 5 specific diseases, including dogwood anthracnose, beech bark disease, butternut canker, chestnut blight, and Dutch elm disease.  Three diseases associated with oaks are also presented, including oak wilt, oak decline, and sudden oak death.  Finally, some generalized diseases, such as plantation diseases, root and butt rot, and wood decay fungi, are discussed.