Tropical rainforests comprise a unique and vital portion of the earth's surface. (Percentages and square miles given here do not add up.) Nations, an anthropologist who specializes in the human use of tropical ecosystems, explains their importance as home for half the world's plants and animals--preserving the genetic pool for future evolution, providing medicine and food, and protecting the atmosphere. He also examines threats to the rain forest and efforts to protect it, concluding with suggestions for individuals active in preserving tropical forests. Unfortunately, though, the many grainy black-and-white photos, compressed type and tight binding do little to enhance his vivid, clearly written, well-documented text. An excellent addition to the ""Important Environmental Issues"" series, on a timely, important topic. Useful for both students and general readers interested in conservation. Guide words; glossary; bibliography; index.