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Tropical Rainforest
Tropical rainforests are a world like none other. Unparalleled in terms of their biological diversity, tropical rainforests are a natural reservoir of genetic diversity. They offer a rich source of medicinal plants and other useful forest products. They are an important habitat for migratory animals and preserve as much as 50 percent of the species on earth, as well as a number of diverse and unique originating cultures. Tropical rainforests play an elemental role in regulating global weather in addition to maintaining regular rainfall, while buffering(缓冲)against floods, droughts, and soil erosion (腐蚀).
Despite their monumental role, tropical forests are restricted to the small land area between the latitudes 22. 5 degrees north and 22. 5 degrees south of equator. The majority of the earth's land is located north of the tropics.
Tropical rainforests are a scarce resource in the 21st century. Whatever carpeted the earth's land surface a mere five generations ago has been reduced to scattered fragments(碎片); today, more than two-thirds of the world's tropical rainforests exist as fragmented remainings. Over half of this forest lies in Brazil, which holds about one-third of the world's remaining tropical rainforests. Another 20 percent of the world's remaining rainforests exists in Indonesia and Congo Basin, while the balance of the world's rainforests are scattered around the globe, in tropical regions
It is based roughly on four forested continental regions: the Ethiopian or Afrotropical, the Australasian or Australian, the Oriental or Indomalayan Asian, and the Neotropical.
A. They take in adequate fresh water and oxygen.
B. In that case, new rain forests are seen to be discovered.
C. Their global distribution can be broken up into four biogeographical areas.
D. Their importance to the global ecosystem and human existence is vital.
E. As a consequence, rainforests are naturally limited to a relatively small area.
F. They store vast quantities of carbon while producing a significant amount of the world's oxygen.
G. The largest unbroken stretch of rainforest is found in the Amazon river basin of South America.
