Deciduous forests, composed primarily of hardwood trees that lose their leaves each autumn, are generally located at elevations up to 6000 feet; along this elevation gradient, average humidity may be low to high, and rainfall usually averages 25-60 inches per year.
Trees provide shelter and habitat for various species; prevent soil erosion and maintain watersheds; provide food to many insects, birds, and mammals; absorb potentially harmful carbon dioxide gases during photosynthesis; and sequester large amounts of carbon.
Human benefits from forests extend beyond ecosystem benefits, as forests have long provided building materials for shelter, food for consumption, and wood for fuel. In some regions of the world, forests are being harvested for human use at rapid and unsustainable rates. This is particularly true in economically disadvantaged regions where forests are cleared for agriculture or grazing, cut down as an only source for fuel, or harvested for export to "first world" nations.