Tropical Forests

Abstract

Tropical forests occupy approximately 10% of the world's total land area, but they play a disproportionate role in global carbon and water cycles, and are believed to house more than half of the world's species. Tropical forests occupy a wide range of environments, and the structure and species composition vary with dry season length, altitude above sea level, and the occurrence of extreme soil types or regular inundation by fresh or saline water. Lowland evergreen rain forests are the most diverse ecosystems on Earth, but the processes that generated and maintain this diversity are not fully understood. Forests are under threat throughout the tropics from clearance for agriculture, logging for timber, hunting, fires, climate change and other human impacts. Major conservation priorities include protecting large areas of intact forest ecosystems where still possible, improving the management of logged forests, controlling hunting, and reconnecting isolated forest fragments by restoring forest between them.

Key Concepts:

  • Tropical forests house the majority of the world's species.

  • Tropical forests have a large role in global carbon and water cycles.

  • Distinctive types of tropical forests occur in different climates, on extreme soil types, and in areas subject to flooding by fresh or saline water.

  • Forests in similar environments but different tropical regions also differ, because the forest communities in each region have different evolutionary histories.

  • Lowland rain forests are far more diverse than any other terrestrial ecosystem, at least partly because of the age and continuity of warm, wet tropical climates.

  • The most important commercial product from tropical forests is timber, but these forests also provide many other products and services to local human communities.

  • The biggest threats to tropical forests and their species are conversion to agriculture, hunting and unsustainable logging.

  • Legally protected areas are still the cornerstone of tropical forest conservation, but sustainable exploitation for timber and other products offers an alternative in countries with good governance capabilities.

Keywords: climate change; conservation; forests; species diversity; tropical forests; vegetation

Figure 1.

Global distribution of tropical forests.

Figure 2.

Latitudinal gradient in species richness of bird and tree species, in both cases showing a peak in tropical forest areas near the equator. Data adapted by permission from Macmillan Publishers Ltd. Gaston (). Data for the 0.1 ha forest plot from the archive of Alwyn Gentry (Gentry, and unpublished data).

Figure 3.

Lowland evergreen rain forest in the Amazon region. Photograph by Iubasi, Wikimedia Commons, reproduced under the Creative Commons Attribution‐Share Alike 2.0 Generic licence.

Figure 4.

Mangrove forest in Cambodia. Photograph by Leon Petrosyan, Wikimedia Commons, reproduced under the Creative Commons Attribution‐Share Alike 3.0 Unported licence.

Figure 5.

Deforestation in Sumatra for an oil palm plantation. Photograph by Aidenvironment, Wikimedia Commons, reproduced under the Creative Commons Attribution‐Share Alike 2.0 Generic licence.

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Further Reading

Kettle C and Koh LP (2014) Global Forest Fragmentation. Wallingford: CABI.

McShea WJ, Davies SJ and Bhumpakphan N (2011) The Ecology and Conservation of Seasonally Dry Forests in Asia. Washington, DC: Smithsonian Institution Scholarly Press.

Morley RJ (2011) Cretaceous and Tertiary climate change and the past distribution of megathermal rainforests. In: Bush MB, Flenley JR and Gosling WD (eds) Tropical Rainforest Responses to Climate Change, 2nd edn, pp. 1–34. Berlin: Springer‐Verlag.

Sanchez-Azofeifa A, Powers JS, Fernandes GW and Quesada M (2013) Tropical Dry Forests in the Americas: Ecology, Conservation, and Management. Boca Raton, FL: CRC Press.

Sodhi NS, Gibson L and Raven PH (2013) Conservation Biology: Voices from the Tropics. Oxford: Wiley‐Blackwell.

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How to Cite close
Corlett, Richard T(Nov 2014) Tropical Forests. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0003179.pub2]