The biodiversity of Tasmania is of exceptional biological and paleoecological interest. A state of Australia, it is a large South Pacific archipelago of one large main island and a range of smaller islands. The terrain includes a variety of reefs, atolls, many small islands, and a variety of topographical and edaphic regions on the largest island, all of which promote the development of unusually concentrated biodiversity. During long periods geographically and genetically isolated, it is known for its unique flora and fauna. The region's climate is oceanic.