Saturday, June 25, 2011

Australia - Tasmanian Wilderness

Alpine Meadows, Waterfall Valley, Tasmanian Wilderness.

Sent by Roderick, a WiP partner from NSW, Australia.

Covering an area of over 1 million hectares, the Tasmanian Wilderness constitutes one of the last expanses of temperate rainforest in the world. It comprises a contiguous network of reserved lands that extends over much of south-western Tasmania including several coastal islands.

In contrast to the mainland, the island of Tasmania is a rugged region with fold structures in the western half and fault structures in the east, both of which are represented in the property. The fold structure province in the south-west is an extremely rugged and densely vegetated region with north-south oriented mountain ranges and valley systems. Changing climates have also influenced landscape development, highlighted most recently by late Cainozoic and Pleistocene glacial and periglacial events. Glacial erosion has contributed to spectacular landform features including horns, arêtes, cirques, U-shaped valleys and rock basins (tarns). The coastline has been subjected to a number of sea-level changes during the glaciations and now provides a classic example of a drowned landscape, as shown by the discordant coastline in the south. Special landforms associated with the development of karst have formed through the solution of carbonate rocks such as (Precambrian) dolomite and (Ordovician) limestone. Features include cave systems, natural arches, clints and grikes, dolines, karren, pinnacles and blind valleys.

The vegetation has as much in common with cool, temperate regions of South America and New Zealand as with the rest of Australia. In addition to climatic and edaphic factors, the vegetation has developed in response to fire. Aboriginal occupation over the last 30,000 years has constituted a major source of fire; more recently, much fire can be attributed to the interests of fishermen, logging concerns and prospectors. The fauna is of world importance because it includes an unusually high proportion of endemic species and relict groups of ancient lineage. Owing to the diverse topography, geology, soils and vegetation in association with harsh and variable climatic conditions combining to create a wide array of animal habitats, the fauna is correspondingly diverse.

The insularity of Tasmania, and of the Tasmanian Wilderness in particular, has contributed to its uniqueness and has helped to protect it from the impact of exotic species which has seriously affected the mainland fauna. Tasmania was cut off from mainland Australia by the flooding of Bass Strait at least 8000 years ago, thereby isolating the aboriginal inhabitants. The Tasmanian Aborigines were, until the advent of the European explorer Abel Tasman, the longest isolated human group in world history, surviving some 500 generations without outside influence.

Surveys and excavations of inland river valleys have located 37 cave sites, all considered to have been occupied between 30,000 and 11,500 years ago on the basis of the finds. Recent discoveries of rock art at three cave sites have shown that this painting had a ceremonial significance; hand stencils predominated. Stone artefact scatters and quarries and rock shelters in the Tasmanian highlands indicate a distinctive adaptation to this subalpine environment in the later Holocene. The south coast contains a range of shell middens; evidence available so far suggests changing patterns of shellfish exploitation over several thousand years until the arrival of Europeans in the early 19th century. (Source)

No comments: