The state of California, a third larger than Ecuador, has only 5,000. Tropical rain forests are a valuable natural resource. Millions of people live in rain forests, relying on them to fulfill their needs for food and fuel. The rest of the world relies on rain forests for such products as rubber, wood, dyes, oils, foods, and medicines. More than 40 percent of prescription drugs in the United States contain ingredients derived from plants, many of them from rain forests.
Rain forests play a role in recycling the earth's water.
Much of the moisture absorbed by the trees transpires from the leaves and evaporates into the atmosphere to return as rainfall. The roots of the trees help anchor the soil and slow water runoff. Vanishing Rain Forests Clearing forestlands for farming, ranching, logging, and mining is rapidly decreasing the remaining rain forests. Some scientists estimate that an area of tropical rain forest the size of the U.S. state of Delaware is cleared every month. Although the land is often used for agriculture, the nutrient-poor tropical soils can support crops or cattle for only a few years.