From Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/Old_growth_forest
Old growth forest, also called primary forest, ancient forest, virgin forest, primeval forest, frontier forest or (in the UK) Ancient Woodland, is an area of forest that has attained great age and so exhibits unique biological features. Old growth forests typically contain large live trees, large dead trees (sometimes called "snags"), and large logs. Old growth forests usually have multiple vertical layers of vegetation representing a variety of tree species and age classes.
Forest regenerated after severe disruptions, such as clear-cut or fire is often called second-growth or regeneration until a long 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.
Old growth forests may be home to rare species which depend on this now-rare habitat, making them ecologically significant. Biodiversity may be higher or lower in old growth forests than in second-growth forests depending on specific circumstances. Logging in old growth forests is a contentious issue in many parts of the world.
Forest regenerated after severe disruptions, such as clear-cut or fire is often called second-growth or regeneration until a long 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.
Old growth forests may be home to rare species which depend on this now-rare habitat, making them ecologically significant. Biodiversity may be higher or lower in old growth forests than in second-growth forests depending on specific circumstances. Logging in old growth forests is a contentious issue in many parts of the world.
