Natural forests are at risk to a host of native and exotic insect pests and diseases (Table 7). The intentional planting of plantations, or single species crops, can provide select insects, bacteria, and fungi the opportunity to flourish and overwhelm a short-rotation forest or damage wood quality for market products. The potential pests and diseases are significant in number and variety. In North Carolina, The Plant Disease and Insect Clinic, operated by the NC State University Department of Entomology and Plant Pathology, diagnoses plant and insect problems for farmers, growers, landscapers, homeowners, and gardeners in collaboration with the North Carolina Cooperative Extension Service. The Southern Group of State Foresters also has a list of common pests for trees of interest for short-rotation forests.

Some diseases occur due to site conditions such as chronic wet soils or drought. Other diseases require insect partners for transmission or development in trees. Stress from one disease or pest can create conditions for other pests and diseases to flourish. Also, native predators for indigenous pest insects do exist and are helpful in controlling pest populations during the growing season. Hence, any chemical control should follow recommended application times to limit deleterious impacts on native predators. Poor mitigation timing that kills predator insects can result in explosive pest insect populations a month or so later. First, identify the problem pest or disease, then utilize suggested resources for treatment or mitigation, and think critically about timing of mitigation measures as suggested by experts.

Figure 26. Images of select pests and diseases common to short-rotation forestry: