In tropical rainforests, very few days pass without rain; 2000-8000 mm (6-26 ft.) of rain falls each year. In most rainforests, warm days persist month after month. Since little light penetrates the dense rainforest canopy, few plants except trees grow on the ground. Instead, plants-and most animals-flourish on lofty branches. Trees supporting the canopy generally have straight, relatively slender trunks with few limbs near the ground. They seldom grow more than 50 m (165 ft.) tall. But a few trees have trunks so thick that 35 sixth graders could barely stretch their arms around them!

Click on the images to learn more about tropical rainforests.