- This article is about forests as collectivities of trees. For other uses see Forest (disambiguation).
is an area with a high density of trees
(or, historically, an area set aside for hunting
). Forests can be found in all regions capable of sustaining tree growth, at altitudes up to the tree-line
, except where rainfall is too low, or natural fire frequency too high. Forests generally contain a large number of different trees growing to different heights, combined with an underbrush
, which makes most use of sunlight. A forest in its natural form is home to many animal and plant species, and the weight of the biomass
in any given square kilometre is high compared to other biomes.
Several types of forests exist. Among them can be noted the taiga, rain forest, tropical dry forest, and temperate hardwood forest.
In ecological terms, a forest may be differentiated from a woodland. In this case, a forest is considered to have a closed canopy, where the branches and foliage of trees interlock, whereas a woodland is considered to have an open canopy, where sunlight penetrates between trees.
The science of studying and managing forests, with a goal of sustainable extraction, is called forestry. Ecologists often study forests.