Abstract
Insects are essential components of forest ecosystems, representing most of the biological diversity and affecting virtually all ecological processes (Schowalter 1994). Most species are beneficial (Coulson and Witter 1984, Haack and Byler 1993), yet others periodically become so abundant that they threaten ecological, economic, social or aesthetic values at local to regional scales (tables 6.1 through 6.3). Insects influence forest ecosystem structure and function in complex and dynamic ways, for example, by regulating certain aspects of primary production; nutrient cycling; ecological succession; and the size, distribution and abundance of plants and other animals (Mattson 1977, Mattson and Addy 1975). Effects on forest vegetation range from being undetectable, to short-term reductions in crown cover, to modest increases in background levels of tree mortality, to extensive amounts of tree mortality observed at regional scales.
Parent Publication
Citation
Fettig, Chris J.; Progar, Robert A.; Paschke, Jeanine.; Sapio, Frank J. 2021. Insects. In: Barrett, Tara M.; Robertson, Guy C., eds. Disturbance and sustainability in forests of the Western United States. Gen. Tech. Rep. PNW-GTR-992. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 81-121. Chapter 6.