In general, tropical evergreen rain forests can be classified into three main types: lowland, montane, and cloud.

Lowland Rain Forest

Lowland rain forests cover more territory than the other types and include such trees as mahogany. They grow in warm, wet lowland regions, such as the Amazon River basin in Brazil. Because little sunlight can penetrate the thick cover of trees, little vegetation grows on the forest floor. However, undergrowth may be thick near the forest edges, such as where a river cuts through because more sunlight is available. Where the rain forest meets a coastline and produces a swampy area, mangrove forests may form. Mangroves can survive in salty coastal conditions. (For more information about mangroves, see the chapter titled "Wetland.")

Montane Rain Forest

Montane, or mountain, rain forests, such as those found in Malaysia, usually grow on mountainsides at altitudes...