C Sharples

Geodiversity in the wilderness: a brief history of geoconservation in Tasmania

Abstract Since the early 1980s, conservation-orientated Earth scientists in Australias island state of Tasmania have developed an approach to geoconservation that places emphasis on geomorphology, soils and landform processes, in contrast to the stronger emphasis in some places on the scientific values of bedrock geological features. Although bedrock geoheritage has not been ignored, this geomorphological emphasis emerged from Tasmanias recent political history, during which the conservation of large areas of wilderness has dominated local political debate from the early 1970s to the 1990s. With the recognition of undisturbed natural landscapes and ecosystems (wilderness) as having conservation value, it was only a short step to valuing natural landforms, soils and ongoing geomorphological processes as the key abiotic elements of that broader focus. With popular and political acceptance during the 1980s and 1990s of the conservation of wilderness values as a legitimate government policy, Earth scientists within Tasmanian state government land management agencies had a mandate to develop and implement geoconservation policies. The optimum strategy for the small community of geoconservation workers in Tasmania has been to focus on developing theoretical, legislative and management tools for geoconservation in public land management agencies. Tasmanian workers found existing theoretical frameworks for geoconservation inappropriate for their needs, and adopted additional concepts to identify, justify and implement geoconservation. The concept of geodiversity has proven to be a powerful framework for developing classification systems which in turn allow thematic, georegional analyses to provide a systematic, objective and scientifically defensible context for identifying well-expressed representative examples of the various elements of geodiversity. This approach has resulted in the adoption of a terminology distinct from that previously used on mainland Australia, which is, however, convergent with terminology now used in Europe.

Appropriate terminology for karst-like phenomena: the problem with 'pseudokarst'

The practice of referring to certain morphologically karst-like phenomena as ‘pseudokarst’ is problematic, because it ignores basic principles of sound classification, logical naming conventions and accepted geomorphic classifications and terminology. These problems have compounded the difficulty in establishing an accepted classification of ‘pseudokarst’ types. The practice embodies a karst-centric perspective which should be avoided in favour of using conventional geomorphic terminology for non-karstic features. We illustrate this by providing existing conventional terms for many ‘pseudokarst’ types reported in the literature.

Stromatolites on the rise in peat-bound karstic wetlands

Stromatolites are the oldest evidence for life on Earth, but modern living examples are rare and predominantly occur in shallow marine or (hyper-) saline lacustrine environments, subject to exotic physico-chemical conditions. Here we report the discovery of living freshwater stromatolites in cool-temperate karstic wetlands in the Giblin River catchment of the UNESCO-listed Tasmanian Wilderness World Heritage Area, Australia. These stromatolites colonize the slopes of karstic spring mounds which create mildly alkaline (pH of 7.0-7.9) enclaves within an otherwise uniformly acidic organosol terrain. The freshwater emerging from the springs is Ca-HCO3 dominated and water temperatures show no evidence of geothermal heating. Using 16 S rRNA gene clone library analysis we revealed that the bacterial community is dominated by Cyanobacteria, Alphaproteobacteria and an unusually high proportion of Chloroflexi, followed by Armatimonadetes and Planctomycetes, and is therefore unique compared to other living examples. Macroinvertebrates are sparse and snails in particular are disadvantaged by the development of debilitating accumulations of carbonate on their shells, corroborating evidence that stromatolites flourish under conditions where predation by metazoans is suppressed. Our findings constitute a novel habitat for stromatolites because cool-temperate freshwater wetlands are not a conventional stromatolite niche, suggesting that stromatolites may be more common than previously thought.

Geodiversity and Geoconservation in Land Management in Tasmania – A Top-Down Approach

Abstract The development of geoconservation ideas and practices in Tasmania (Australia) has from its beginnings during the 1980s and 1990s been driven primarily by workers within state government land management agencies, particularly the Tasmanian Forestry Commission and the Parks & Wildlife Service. The initial focus of these workers was on landform values and processes because of the potential for the land uses regulated by these agencies to impact on landforms whose natural heritage values were becoming recognised at the time. However bedrock geoheritage sites have subsequently been strongly integrated into geoheritage efforts in Tasmania. With only limited precedents to guide their efforts at the time, Tasmanian geoconservation workers put considerable effort during the 1990s into developing theoretical frameworks to guide the practical implementation of geoconservation on public lands. A major element of this early work was the development of inventories of sites of geoheritage significance. Following the early phase of theoretical development, the major focus over the last 15 years or so has been the consolidation and incremental development of practical methods of identifying and protecting geoheritage. The merging of multiple early geoheritage inventories into a single digital Tasmanian Geoconservation Database, managed by a specialist reference group, has proved a powerful tool in Tasmanian geoconservation work.