Incredible diversity.
Tropical rainforests are available all year round. In these stable and relatively constant conditions, animal and plant life has been able to diversify more than anywhere else on Earth. Only coral reefs come close in the diversity of their species. In temperate ecosystems there are few species, but great numbers of each. In the tropical rainforest there is a huge number of different species, but not so many individuals of each. In temperate regions, the main reservior of nutrients is the soil. In the warm, moist conditions of the tropical forest, nutrients released into the soil are quickly taken up by the plants, leaving the soil thin and sandy. The trees themselves are the nutrient store, so if they are removed the ecosystem is disrupted.