On 3% of the Earth's surface, the rain forest is the habitat for half our animal species, even 80% of insects. For plants, the quest for light is key to stratification, paralleled by interacting animals eating fruits, leaves and other animals. Even the jungle cacophony is stratified. On the soil, recycling specialist like fungi restart the cycle of life. In Central Africa, herds of elephants specialize in following self-made forest paths. (imdb)