Identification and Management of Geoconservation Values in the Tasmanian Wilderness World Heritage Area

The development of geoconservation concepts and management practices in Tasmania, Australia, has been closely linked with the identification and protection of nature conservation values in the Tasmanian Wilderness World Heritage Area (TWWHA). The inundation of the outstanding glacio-fluvial landform of Lake Pedder for hydro-electric development in south-west Tasmania in 1972 was a major event in the history of environmental politics in Australia. In Tasmania it triggered the notion that landforms – and not just living things – should be a major focus of nature conservation. After two decades of political controversy the Tasmanian Wilderness World Heritage Area was inscribed on the UNESCO World Heritage List in 1989. Two of its key listed values were its possession of large areas in which geomorphic and soil processes (fluvial, karst, coastal and blanket bog) were ongoing in a way predominantly unmodified by contemporary human activities, and its possession of a range of relict glacial, glacio karstic, periglacial and uplifted coastal landforms and sediments providing the best southern hemisphere geomorphic record of the Late Cainozoic 'Ice Ages' phase of Earth history in a tectonically stable, temperate maritime environment. The significance of these values in the Tasmanian context has led to the development of geoconservation priorities focused on maintaining the natural geodiversity of landforms and soils, and on conserving natural rates and magnitudes of change in ongoing geomorphic and soil processes. This is in contrast to mainland Australia, where geological heritage work has historically had a much stronger emphasis on the preservation of bedrock features and exposures. However, landforms and ongoing geomorphic and soil processes are highly relevant to mainstream nature conservation since these underpin bioconservation, and this has made geoconservation easier for Tasmanian land managers to understand and perceive as relevant. Recognition of geoconservation values as key values underpinning the World Heritage listing of the TWWHA has made funding available for a variety of relevant research and management activities, including the following examples: – Monitoring and removal of incipient exotic dune grass infestations from TWWHA sandy coasts, since such infestations have significantly modified dune dynamics on other Tasmanian coasts and hence threaten natural coastal geomorphic processes in the TWWHA. – Innovative rehabilitation aimed at restoration of former natural hydrological processes associated with a quarry whose operation was degrading ongoing karst processes in the major Exit Cave system of the TWWHA. – Research into the effects of differing fire regimes on TWWHA blanket bog peat soils, which can be severely degraded by excessive firing yet are periodically burnt deliberately in some parts of the TWWHA for bioconservation management reasons. The TWWHA blanket bogs have World Heritage significance in their own right, and also play a major role in natural fluvial and hydrological processes in the TWWHA. – Monitoring of bank erosion caused by tourist boat wakes on the TWWHA Gordon River estuary, and development of techniques to minimise boat wake impacts. – Rehabilitation of mid-Holocene alpine lunette dunes damaged by former 'traditional' stock grazing and firing in the Central Plateau region of the TWWHA. Whilst much effort has been expended on researching and developing management practices aimed at protecting geoconservation values in the TWWHA, the same geomorphically focused conservation concerns have also led to significant measures to appropriately manage active karst systems, relict glacial landforms and other geoheritage in State forest and some other land tenures in Tasmania.