Tropical vegetation

Tropical vegetation is any vegetation in tropical latitudes. Plant life that occurs in climates that are warm year-round is in general more biologically diverse than in other latitudes. Some tropical areas may receive abundant rain the whole year round, but others have long dry seasons which last several months and may vary in length and intensity with geographic location. These seasonal droughts have a great impact on the vegetation, such as in the Madagascar spiny forests.^[1]

Rainforest vegetation is categorized by five layers. The top layer being the emergents, or the upper tree layer. Here you will find the largest and widest trees in all the forest, commonly 165 feet (fifty meters) and higher. These trees tend to have very large canopies so they can be fully exposed to sunlight. A layer below that is the canopy, or middle tree layer, averaging 98 to 130 feet (30 to 40 meters) in height. Here you will find more compact trees and vegetation. These trees tend to be more skinny as they are trying to gain any sunlight they can. The third layer is the lower tree area. These trees tend to be around five to ten meters (16 to 33 feet) high and tightly compacted. The trees found in the third layer include young trees trying to grow into the larger canopy trees, and "palmoids" or "Corner Model Trees". The fourth layer is the shrub layer beneath the tree canopy. This layer is mainly populated by sapling trees, shrubs, and seedlings. The fifth and final layer is the herb layer which is the forest floor. The forest floor is mainly bare except for various plants, mosses, Lycopods and ferns. The forest floor is much more dense than above because of little sunlight and air movement.^[2]

Plant species native to the tropics found in tropical ecosystems are known as tropical plants. Some examples of tropical ecosystems are the Guinean Forests of West Africa, the Madagascar dry deciduous forests and the broadleaf forests of the Thai highlands and the El Yunque National Forest in Puerto Rico. Dr. Ghillean Prance has estimated that, as of 1979, there are 155,000 known species of tropical plants, with 90,000 species in the Neotropics, 35,000 in southern Asia and the East Indies and 30,000 in Africa,^[3] about half of those in Madagascar. There are also 50,000 Neotropical Fungi and about 20,000 fungal species each from Asia and Africa.^[4]