Tropical Forests

Tropical Forests


forests distributed in the equatorial, subequatorial, and tropical zones (that is, between 25° N lat. and 30° S lat.).

Tropical rain forests have the greatest diversity of plant species and consist of extremely tall trees (heights to 60–70 or even 80 m). There is an abundance of lianas and epiphytes and an absence of a dominant species. Tropical rain forests occur in regions where the precipitation rate (2,000–7,000 mm annually) and temperatures (23°–32°C) remain uniform year-round.

Semideciduous tropical forests also develop in a moist climate, with an 80–90 percent relative air humidity and no less than 1,500–2,000 mm of precipitation annually. The forest canopy is lower than that of a rain forest, but there is a very diverse species composition, including lianas and epiphytes. Often there are marked seasonal changes, such as leaf fall and renewal. Semideciduous tropical forests are characteristic of the West Indies (Trinidad), Central America (Costa Rica), and South and Southeast Asia (India, Burma). In western Africa the upper story of such forests is made up of deciduous trees, especially Triplochiton scleroxylon.

In the tropics of Asia semideciduous forests are known as monsoon forests (seeMONSOON FORESTS). The forests are made up of evergreen trees and deciduous trees, including Xylia xylocarpa and Tetrameles nudiflora. Tropical monsoon forests include the relatively sparse sal forests of India, in which the sal tree (Shorea robusta) predominates.

Seasonal leaf fall in tropical forests is particularly marked near the boundary of the tropical zone, even if the climate there is very wet. In arid regions (such as the forests of western Sri Lanka) tropical forests are dense and evergreen but consist of low-growing xeromorphic species. Tropical regions of Indochina having a marked dry season have light deciduous forests of Dipterocarpus tuberculatus, Pentacme siamensis, and Terminalia tomentosa. Pine forests are found under similar conditions but on poor soils. While resembling the pine forests of the north, they consist of particular pine species, for example, Pinus insularis in South and Southeast Asia and P. caribaea, P. tropicalis, and P. occidentalis in the West Indies.

Mountain tropical forests, usually consisting of evergreen species and characterized by the presence of treelike ferns and some conifers, are found in the mountains at elevations above 800 m above sea level (the upper boundary of rain forests). Coniferous trees include species of Araucaria in New Guinea and species of Agathis, Podocarpus, and Dacrydium in Southeast Asia. Higher elevations—about 2,000 m above sea level—are characterized by mossy and low-growing forests made up of species of the families Lauraceae, Fagaceae, and Ericaceae. The forests of the Himalayas and China have many treelike rhododendrons and epiphytes; epiphytic mosses and a mossy soil covering are characteristic. The floristic composition includes species that are purely tropical and species characteristic of forests in temperate latitudes. For this reason, mountain tropical forests are often considered subtropical.


Geografiia lesnykh resursov zemnogo shara. Moscow, 1960. (Translated from English.)
Richards, P. W. Tropicheskii dozhdevoi les. Moscow, 1961. (Translated from English.)
Richards, P. W. The Life of the Jungle. New York, 1970.


References in classic literature ?
It is rather an elevated table- land, though there are stretches of tropical forest, but it is not so tropical a country as many suppose it to be.
Behind us rose a dark and forbidding wood of giant arborescent ferns intermingled with the commoner types of a primeval tropical forest. Huge creepers depended in great loops from tree to tree, dense under-brush overgrew a tangled mass of fallen trunks and branches.
And then there was the sound of a body falling on the floor and being dragged along and a door slammed and then nothing, nothing more around us save the scorching silence of the south in the heart of a tropical forest!
She was working at a great design of a tropical river running through a tropical forest, where spotted deer would eventually browse upon masses of fruit, bananas, oranges, and giant pomegranates, while a troop of naked natives whirled darts into the air.
"Listen to this," he said after a few minutes, and he read several pages descriptive of a great flooded tropical forest being navigated by boys on a raft.
TEEKA, STRETCHED AT luxurious ease in the shade of the tropical forest, presented, unquestionably, a most alluring picture of young, feminine loveliness.
He saw her bending over pythons coiled upon the sand, or considering the brown rock breaking the stagnant water of the alligators' pool, or searching some minute section of tropical forest for the golden eye of a lizard or the indrawn movement of the green frogs' flanks.
The deforestation of tropical forests is creating a patchwork landscape where natural habitat is disconnected and confined to smaller spaces between a mass of farmland.
Tropical forests, from which most of the useful trees grow, are what Prof.
Researchers estimate that tropical forests currently take in as much carbon from the atmosphere through growth as they generate through deforestation -- the loss of forest to commercial activities -- and degradation -- the removal of trees for timber or fuel.
ISLAMABAD -- Florida State University researchers have revealed a surprising relationship between surging atmospheric carbon dioxide and flower blooms in remote tropical forests.

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