Lowland tropical rainforests grow on flat land and have an elevation typically no greater than 3,300 feet. The majority of tropical rainforests are lowland forests. They have a large diversity of animals, trees and plants. Since lowland forests are easily accessibly, have good soil and more hardwoods that are used for timber, they face greater threats of deforestation and in many countries have been virtually wiped out.
Montane tropical rainforests are forests that grow on mountains and are above an altitude of 3,300 feet. High montane forests elevated above 6,600 feet are commonly known as "cloud forests" as the majority of their moisture is received from mist or fog. Cloud forest trees are shorter and have a less developed canopy than lowland forest trees. However, they are home to many epiphytes, which are plants that receive and thrive on nutrients from moist air such as mosses, bromeliads and orchids.
Monsoon tropical rainforests are found mainly in Asia and have a distinct dry and wet season. The tree sizes in this type of forest are a lot smaller and less diverse in comparison to a typical tropical rainforest. Monsoon forests are under threat worldwide, especially in West Africa where more than 90 percent have already been cleared for cultivation.
Igapo tropical rainforests are also known as "swamp forests" due to their wet, poorly drained soils. The trees in this forest are short in comparison to other forests because they are immersed in flooded waters four to 10 months of the year. Many of the igapo forest trees have stilt roots and a propped up base to steady its structure. Common trees found in this forest are cecropia, ceiba and mauritia palms.
Varzea tropical rainforests are forests situated on a tract of land that borders a stream or river and which flood seasonally. Unlike the swamp forests, this type of forest has soil that is rich due to the yearly replenishment of nutrients from whitewater rivers. For this reason, they are under threat of being cleared for development as the soil present in this type of forest is perfect for agriculture.
