Forests can be dark and forbidding places, but they are overflowing with life. You only have to step into a forest to discover a world filled with plants and animals of all different sizes and shapes. The world's forests depend on help from some of these plants and animals for survival. Many forests are in danger of disappearing. People take up more room and resources on our planet than ever before. Keystone species like ring-tailed lemurs, coast redwoods, white-tailed deer, strangler figs, and flying foxes lend a helping hand to forests. Without these keystone species, the Earth's forests could vanish as well.