Biomes are the major regional groupings of plants and animals discernible at a global scale. Their distribution patterns are strongly correlated with regional climate patterns and identified according to the climax vegetation type. However, a biome is composed not only of the climax vegetation, but also of associated successional communities, persistent subclimax communities, fauna, and soils. The biome concept embraces the idea of community, of interaction among vegetation, animal populations, and soil. A biome (also called a biotic area) may be defined as a major region of distinctive plant and animal groups well adapted to the physical environment of its distribution area.