Tropical rain forest is a common biota in tropical areas between north latitude 10 degree and south latitude 10 degree, which is mainly distributed in Southeast Asia, Australia, Amazon River basin in South America, Congo River basin in Africa, Central America, Mexico and many Pacific islands. According to the classification of various biological communities by WWF, tropical rain forest, or tropical moist broad-leaved forest, can also be classified as equatorial lowland evergreen rain forest, so tropical rain forest is also called equatorial rain forest.

Tropical rain forest area is hot all year round with abundant rainfall. The normal annual rainfall is about 65,438+0,750 mm to 2,000 mm, and the annual average monthly temperature exceeds 26℃. The seasonal difference is extremely insignificant, and the succession speed of biological communities is extremely fast. It is the habitat of more than half of the animal and plant species on the earth. At present, more than a quarter of modern drugs are extracted from tropical rain forest plants, so the tropical rain forest is also called "the largest pharmacy in the world".

Although the tropical rain forest has dense trees and diverse species, forming a huge layered structure, in fact, because sunlight is difficult to penetrate the layered structure to reach the ground, there are not many undergrowth vegetation, which also provides convenience for humans and animals to walk through the forest. If the crown at the top of this structure is damaged or reduced for other reasons, because the tropical rain forest provides excellent growth conditions for plants, sunlight will quickly occupy the surface with densely entangled vines, shrubs and saplings, thus forming a jungle.