Pub. date: 2006 | Online Pub. Date: September 15, 2007 | DOI: 10.4135/9781412952453 | Print ISBN: 9780761930297 | Online ISBN: 9781412952453| Publisher:SAGE Publications, Inc.About this encyclopedia
Tropical Rain Forests
Leslie E. Sponsel
About one third of the world's forests are tropical rain forests. They are the most ancient, diverse, complex, and productive ecosystems on the terrestrial surface of the Earth. Although they cover only about 6–8% of the land surface, they contain about half of all life, whether this is measured by the number of species (biological diversity) or organic weight (biomass). These forests form a discontinuous green belt around the equatorial regions of the planet, concentrated within ten degrees latitude north and south of the equator but extending in many areas to 23.5 degrees north and south within the tropical zone. About half of the world's tropical rain forest is in the Amazon region, and about 80% of that is in Brazil. In tropical rain forests the average yearly temperature is 20–28°C or more, while the average yearly rainfall is above 2,000 mm. The climate is the closest to the optimal ...