(Redirected from Tropical)

A noontime scene from the
Philippines on a day when the
Sun is almost directly overhead.
The 'tropics' are the geographic region of the
Earth centered on the
equator and limited in
latitude by the
Tropic of Cancer in the northern hemisphere, at approximately 23°30' (23.5°) N latitude, and the
Tropic of Capricorn in the southern hemisphere at 23°30' (23.5°) S latitude. This region is also referred to as the 'tropical zone' and the 'torrid zone'.
''(For the history of the term 'torrid zone', see
geographical zone and page of discussion of this article)''

World map with the tropics highlighted in red
This area includes all the areas of the Earth where the sun reaches a point directly overhead at least once during the solar year. (In the
temperate zones, north of the Tropic of Cancer and south of the Tropic of Capricorn, the sun never reaches an angle of 90° or directly overhead.) The word "tropics" comes from
Greek ''tropos'' meaning "turn", because the apparent position of the Sun oscillates between the two tropics with a period that defines the average length of a
year.
'Tropical' plants and animals are those species native to the tropics. ''Tropical'' is also sometimes used in a general sense for a
tropical climate, a
climate that is warm to hot and moist year-round, often with the sense of lush vegetation. However, there are places in the tropics that are anything but "tropical" in this sense, with even
alpine tundra and snow-capped peaks, including
Mauna Kea,
Mt. Kilimanjaro, and the
Andes as far south as the northernmost parts of
Chile and
Argentina. Places in the tropics which are drier with low humidity but extreme heat are such as the
Sahara Desert and Central Africa and Northern Australian Outback.
Tropical ecosystems
Tropical ecosystems may consist of
rainforests, dry deciduous forests, spiny forests,
desert and other habitat types. There are often significant areas of
biodiversity, and species
endemism present particularly in
rainforests and dry deciduous forests. Some examples of important biodiversity and/or high endicism ecosystems are:
Costa Rican and
Nicaraguan rainforests,
Madagascar dry deciduous forests,
Waterberg Biosphere of
South Africa and eastern
Madagascar rainforests. Often the soils of tropical forests are low in
nutrient content making them quite vulnerable to
slash-and-burn techniques, which are sometimes an element of
shifting cultivation agricultural systems.
In
biogeography, the tropics are divided into 'paleotropics' (Africa, Asia and Australia) and '
neotropics' (Central and South America). Together, they are sometimes referred to as the 'pantropics'. The neotropic region should not be confused with the
ecozone of the same name; in the Old World, this is unambiguous as the paleotropics correspond to the Afrotropical, Indomalayan, and partly the Australasian and Oceanic ecozones. The
Capensis region of
botany in western
South Africa is not part of the tropics; it has a
Mediterranean climate.
See also
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Tropic of Cancer
★
Tropic of Capricorn
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Geographical zone
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Equator