Explaining the distribution, structure and species composition of snow-patch vegetation in Tasmania, Australia

The term snow patch' indicates an area in an alpine zone with distinct vegetation because snow persists there longer than in the surrounding areas. Snow patches are a well known rare and threatened ecosystem on mainland Australia, but little is known of their distribution and vegetation in Tasmania. We describe, and determine the environmental relationships of, snow patches and their vegetation in Tasmania. There are 119 snow patches in Tasmania, covering 86ha in toto, 43 of which have some fjaeldmark vegetation and the rest of which have a complete vegetation cover. Snow patches are confined to the taller, more continental mountains where they occur on north-east- to east-facing slopes, with the surrounding alpine vegetation usually being free of persistent snow. Their considerable floristic and structural variability relates to substrate and climate. Within Tasmania, several species are largely restricted to snow patches. The high degree of Tasmanian endemism in the snow-patch vegetation makes it distinct from the snow-patch vegetation of mainland Australia. The Tasmanian snow patches are also distinct in their environmental conditions. In Tasmania, snow does not usually persist over the winter outside the 119 snow patches. There are five floristic communities in these patches, all being distinct from those in mainland Australian snow patches. The Tasmanian snow patches merit listing as a threatened ecosystem on the basis of their distinctiveness and restricted extent.