An old-growth forest (also called primary forest, virgin forest, primeval forest, late seral forest, or in Britain, ancient woodland) is a forest that has reached a great age without much disturbance.
It has unique ecological features, and might be classified as a climax community. Old-growth features include various tree-related structures. These provide wildlife habitats which increase the bio-diversity of the forested ecosystem.
Usually old-growth forests have multi-layered, open canopies. The interwoven canopy often blocks sunlight from reaching lower trees or the forest floor. The old forests also include varied tree heights and diameters, with large fallen logs (or tree trunks) across the forest floor. In Europe, less than 7% of forests are old-growth, as mainly due to industrial logging in the 20th century. In the United States, estimates are that only 10% of old-growth forests remain. In Asia old-growth forests are sometimes lost in regional conflicts.
- White, David; Lloyd, Thomas (1994). "Defining old growth: implications for management". Eighth Biennial Southern Silvicultural Research Conference. Retrieved 23 November 2009.
- Ramon Bravo Gonzalez, NGO influence on forest legislation: experiences from federal forest management in the United States (Lunds universitet/Internationella miljöinstitutet 2003), p. 7
- Marjatta Hytönen 2001. Social sustainability of forestry in northern Europe: research and education (Copenhagen: Nordic Council of Ministers, p. 206
- Forest Ecosystem Management Assessment Team (U.S.); United States. Forest Service, Forest ecosystem management: an ecological, economic, and social assessment (Washington, DC: US Forest Service, 1993), p. 79
- Takehisa Awaji & Shun'ichi Teranishi (eds.) 2005. The state of environment in Asia: 2005/2006, eds. (Tokyo: Springer-Verlag, p. 95.