"a large naturally occurring community of flora and fauna occupying a major habitat, e.g., forest or tundra." Hope That Helps! (Ps: That isn't my definition, it's google's)
bi·ome ˈbīˌōm/ nounECOLOGY plural noun: biomes a large naturally occurring community of flora and fauna occupying a major habitat, e.g., forest or tundra.