page_title: Old-growth forest
hierarchical_section_title: Old-growth forest
caption_attribution_description: English: Redwood trees in Muir Woods National Monument in Marin County, California (United States).
context_page_description: An old-growth forest — also termed primary forest, virgin forest, primeval forest, late seral forest, or forest primeval — is a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem. Virgin forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
  The world still has at least 1.11 billion ha of primary forest – that is, forests composed of native species in which there are no clearly visible indication of human activities and the ecological processes have not been significantly disturbed. Combined, three countries – Brazil, Canada and the Russia Federation – host more than half of the world’s primary forest.
context_section_description: An old-growth forest — also termed primary forest, virgin forest, primeval forest, late seral forest, or forest primeval — is a forest that has attained great age without significant disturbance and thereby exhibits unique ecological features and might be classified as a climax community. Old-growth features include diverse tree-related structures that provide diverse wildlife habitat that increases the biodiversity of the forested ecosystem.  Virgin forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
  The world still has at least 1.11 billion ha of primary forest – that is, forests composed of native species in which there are no clearly visible indication of human activities and the ecological processes have not been significantly disturbed. Combined, three countries – Brazil, Canada and the Russia Federation – host more than half (61 percent) of the world’s primary forest. The area of primary forest has decreased by 81 million ha since 1990, but the rate of loss more than halved in 2010–2020 compared with the previous decade.
  Old-growth forests are valuable for economic reasons and for the ecosystem services they provide. This can be a point of contention when some in the logging industry desire to cut down the forests to obtain valuable timber, while environmentalists seek to preserve the forests for benefits such as maintenance of biodiversity, water purification, flood control, and nutrient cycling. Proforestation — the practice of purposefully growing an existing forest intact toward its full ecological potential — aims to promote old-growth forests.
caption: Coast redwoods in old-growth forest in Muir Woods National Monument, Marin County, California
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