Old Growth Forest, Scottish Highlands 1600x1200
Old-growth forest (also termed primary forest, ancient forest, virgin forest, primeval forest, frontier forest or in Britain, ancient woodland) is a forest which contains trees which have attained great age (and associated structural features) and so exhibits unique ecological features.
Old-growth forest typically contains large and old live trees, large dead trees (sometimes called \"snags\"), and large log. Individual tree mortality creates gaps in the main canopy layer, allowing light to penetrate the main canopy and create favorable photosynthetic conditions for the understory (which is why old-growth understory is more developed than in immature stands).
Forest that is regenerated after severe disruptions, such as clear-cutting or fire, is often called second-growth or regeneration until enough time passes that the effects of the disturbance are no longer evident. Depending on the forest, this may take anywhere from a century to several millennia. Hardwood forests of the eastern United States can develop old-growth characteristics in one or two generations of trees, or 150-500 years.
Many old-growth forest stands are threatened by habitat destruction through excessive logging. The resulting destruction reduces biodiversity, affecting not only the old-growth forest itself, but also indigenous species that rely upon old-growth forest habitat.
Old-growth forests are often home to rare species, threatened species, and endangered species of plants and animals, making them ecologically significant. One example of a rare species reliant upon old-growth forest is the Northern Spotted Owl. Levels of biodiversity may be higher or lower in old-growth forests compared to that in second-growth forests, depending on specific circumstances, environmental variables and geographic variables (where the forest is located). Logging in old-growth forests is a contentious issue in many parts of the world.
Old-growth forest typically contains large and old live trees, large dead trees (sometimes called \"snags\"), and large log. Individual tree mortality creates gaps in the main canopy layer, allowing light to penetrate the main canopy and create favorable photosynthetic conditions for the understory (which is why old-growth understory is more developed than in immature stands).
Forest that is regenerated after severe disruptions, such as clear-cutting or fire, is often called second-growth or regeneration until enough time passes that the effects of the disturbance are no longer evident. Depending on the forest, this may take anywhere from a century to several millennia. Hardwood forests of the eastern United States can develop old-growth characteristics in one or two generations of trees, or 150-500 years.
Many old-growth forest stands are threatened by habitat destruction through excessive logging. The resulting destruction reduces biodiversity, affecting not only the old-growth forest itself, but also indigenous species that rely upon old-growth forest habitat.
Old-growth forests are often home to rare species, threatened species, and endangered species of plants and animals, making them ecologically significant. One example of a rare species reliant upon old-growth forest is the Northern Spotted Owl. Levels of biodiversity may be higher or lower in old-growth forests compared to that in second-growth forests, depending on specific circumstances, environmental variables and geographic variables (where the forest is located). Logging in old-growth forests is a contentious issue in many parts of the world.
