The scientific study of the geographic distribution of plant and animal life. Factors affecting distribution include the geologic history of a region, its climate and soil composition, and the presence or absence of natural barriers like deserts, oceans, and mountains. Biotic factors such as interactions among competing species, coevolutionary influences, and the reproductive and nutritional requirements of populations and species are also studied.♦ A biogeographic region is a large, generally continuous division of the Earth's surface having a distinctive biotic community. Biogeographic regions are usually defined separately for floral and faunal communities and are largely restricted to the terrestrial areas of the Earth.
