a forest in a tropical area which receives a lot of rain rainforest to keep alive sustain a set of animals or plants that have similar characteristics to each other species the branches and leaves that spread out at the top of a group of trees forming a type of roof canopy a measurement of how much water there is in the air humidity the cutting down of trees in a large area; the destruction of forests by people deforestation being rubbed away gradually erosion https://339efcb25eb75e967b0d-ff8eeadd950d51fd1fc939dca75b3973.ssl.cf1.rackcdn.com/assets_green.swf