Awed by the tropical rainforests he saw on his travels, Christopher Columbus described them to King Ferdinand and Queen Isabella of Spain as being "filled with trees of a thousand kinds and tall, so that they seem to touch the sky. I am told that they never lose their foliage, and this I can believe, fore I saw them as green and lovely as they are in Spain in May, and some of them were flowering, some bearing fruit, and some at another stage, according to their nature."

Forming a green band around the equator, tropical rainforests thrive where the climate is warm and the rainfall high. Although they cover only about seven percent of the planet's surface, scientists estimate that these rich and complex forests harbor sixty to seventy percent of all the species on earth.