Geoscience Reference
In-Depth Information
some areas, influenced the diversity of other plants and animals. Trees in the tropi-
cal rainforests of Africa tend to be shorter, and the forest is less dense than other
regions. The African region shows the highest diversity of primates, as well as an
abundance of large ground-dwelling mammals, such as elephants and ungulates.
The Asian-Pacific rainforests are distinctive due to the presence of the Diptero-
carpaceae family that dominates the forest trees. These trees are among the tallest
trees in the entire Tropical Rainforest Biome and occur in large clumps. Asian for-
ests also display an abundance of primate species and gliding animals, while the
rainforests of New Guinea and Australia contain an abundance of marsupial mam-
mals and a diverse radiation of endemic, flamboyant birds.
Table 3.1 provides a few of the differences among the various regions in terms
of elevation and major geological and biological features. Although each region
has both a shared and a separate evolutionary history, many of the plants and ani-
mals resemble each other or fill similar niches. Adaptations to regional environ-
ments in distinct locations reveal similar habitats separated by thousands of miles
and millions of years. Convergent evolution, mimicry, and adaptive radiation are
all apparent in the three regional expressions of the Tropical Rainforest Biome.
The Neotropical Rainforest (Central and South America)
The Neotropical expression of the Tropical Rainforest Biome occurs within the
tropics of Central and South America. Three main subregions of rainforest occur:
the Atlantic and the Caribbean, the Choco in Colombia, and along the Amazon
and its tributaries. Belize, Bolivia, Brazil, the Caribbean Islands, Colombia, Costa
Rica, Cuba, Ecuador, El Salvador, French Guiana, Guatemala, Guyana, Hondu-
ras, Mexico, Nicaragua, Panama, Peru, Suriname, and Venzuela all contain parts
of the Neotropical rainforest (see Figure 3.1).
In Central America, tropical rainforests occur in patches from the Yucatan Pen-
insula through Central America and into northern Venezuela. In this region, tropi-
cal rainforests are more abundant on the Caribbean side than on the Pacific.
However, there are some large areas of rainforest on the Pacific side, particularly
in Costa Rica. Remnants of tropical rainforest exist on the Caribbean islands of
Cuba, Jamaica, and Hispaniola (Haiti and the Dominican Republic), and to some
extent, on the Lesser Antilles and in Puerto Rico.
In South America, tropical rainforests are found along the Pacific coast from
Panama and Colombia into northern Ecuador, in the area known as the Choco.
The Choco experiences the greatest rainfall of all Neotropical subregions. The larg-
est area of rainforest in the world lies on the eastern side of the northern Andes
throughout the Amazon Basin. About the size of the 48 contiguous United States,
the Amazon Basin covers 40 percent of the South American continent. The Basin
is drained by the Amazon River, the world's largest river in terms of discharge, and
the second longest river in the world. The Amazon River is made up of more than
