Tropical forests are forested landscapes in tropical regions: i.e. land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds.
Some tropical forest types are difficult to categorise. While forests in temperate areas are readily categorised on the basis of tree canopy density, such schemes do not work well in tropical forests. There is no single scheme that defines what a forest is, in tropical regions or elsewhere. Because of these difficulties, information on the extent of tropical forests varies between sources. However, Tropical Forests are extensive, making up just under half the world’s forests. The tropical domain has the largest proportion of the world’s forests (45 percent), followed by the boreal, temperate and subtropical domains.
More than 3.6m hectares of virgin tropical forest was lost in 2018.
Types of tropical forest
Tropical forests are often thought of as evergreen rainforests and moist forests, but these account for only a portion of them (depending on how they are defined - see maps). The remaining tropical forests are a diversity of many different forest types including: Eucalyptus open forest, tropical coniferous forests, savanna woodland (e.g. Sahelian forest), and mountain forests (the higher elevations of which are cloud forests). Over even relatively short distances, the boundaries between these biomes may be unclear, with ecotones between the main types.
The nature of tropical forest in any given area is affected by a number of factors, most importantly:
Geographical: location and climatic zone (see sub-types), with:
- Precipitation levels and seasonality, with strong dry seasons significantly affecting flora (e.g. the predominance of lianas);
- Temperature profile, which is relatively even in equatorial rainforest or with a cooler season towards subtropical latitudes;
- Elevation affects the above, often creating "ecological islands" with high endemism (e.g. Mount Kinabalu in the Borneo rainforest).
Historical: prehistoric age of forest and level of recent disturbance (see threats), changing primary (usually maximum biodiversity) into secondary forest, degenerating into bamboo forest after prolonged swidden agriculture (e.g. in several areas of Indo-China).
Soil characteristics (also subject to various classifications): including depth and drainage.
Source: Wikipedia contributors. "Tropical forest." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 25 May. 2021. Web. 28 Jun. 2021.