Tasmania are very infertile spodosols or psamments, with some even less fertile "lateritic podzolic soils" in the latter region. Most of these lands are thus not used for agriculture, but there is much productive forestry in Tasmania—which remains one of the state's major industries. On the north coast, apart from some relatively fertile alluvial soils used for fruit-growing, there are also deep red, easily workable soils known as "krasnozems" ("red land"). These soils are highly acidic and fix phosphate very effectively, but their extremely favourable physical properties make them extensively used for dairying, beef cattle and fodder crops. The Midlands and the Lower Derwent present a different story from the rest of the state. Owing to a relatively dry climate and alkaline (mostly dolerite) parent material, these soils are relatively unleached and contain lime in the deeper subsoil. They are mostly classified as "prairie soils" or "brown earths" and bear some resemblance to the chernozems of Russia and North America, although they are much lower in available phosphorus and somewhat acidic in the surface levels. Their higher nutrient levels, however, allow them to support productive pasture, and large numbers of sheep are grazed in these regions. Some grain crops are also grown in the driest areas. In the alluvial areas of southeastern Tasmania, rich alluvial soils permit apples to be grown. Tasmania became known as the "Apple Isle" because for many years it was one of the world's major apple producers. Apples are still grown in large numbers, particularly in southern Tasmania. Ecology and conservation Flora and fauna Tasmania has extremely diverse vegetation, from the heavily grazed grassland of the dry Midlands to the tall evergreen eucalypt forest, alpine heathlands and large areas of cool temperate rainforests and moorlands in the rest of the state. Many species are unique to Tasmania and some are related to species in South America and New Zealand through ancestors which grew on the supercontinent of Gondwana, 50 million years ago. Nothofagus gunnii, commonly known as Australian beech, is Australia's only temperate native deciduous tree and is found exclusively in Tasmania. Eucalyptus regnans (mountain ash) is the tallest flowering plant and hardwood in the world, reaching 100 m (328 ft). Tasmania also has a number of native edibles, known as bush tucker in Australia. Tasmania has many endemic species. Some, such as the platypus are larger than their mainland relatives. The island of Tasmania was