Forest ecosystems represent unique challenges to insect ecologists. Their complex three-dimensional structure complicates experimental designs to test insect effects on multiple ecosystem processes and services, including timber harvest, hunting, recreation and carbon sequestration, over longer periods of time than typical research projects. Advances in forest insect ecology have led to greater understanding of the nuanced roles of insects in forest ecosystems. Some insect species clearly cause substantial growth loss and mortality to timber resources, at least in the short term. However, outbreaks typically reflect environmental changes, such as drought, storm or climate change, that stress host trees or reduce predation or disease incidence and are concentrated on abundant and/or stressed host tree species. Defoliation or tree mortality often increase fluxes of water and nutrients and lead to replacement of stressed host tree species by more tolerant tree species. In some cases these long-term benefits may offset short-term economic losses. Current management recommendations for some forests would return forest structure to historic conditions that were more resistant to drought, fire, insects and disease. This paper reviews ways in which insect responses to environmental changes affect forest ecosystem processes and services.
Schowalter et al. (Thu,) studied this question.