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The Forest Practices Authority

FPA earth science research and monitoring (soil & water and geoscience)

The earth sciences projects being undertaken at present are:

Documenting the erosion history of land in the forest estate, so that natural rates of erosion can be defined and present erosion risk more accurately determined

  • A paper has been presented at a Quaternary geology conference in Canada and published in Quaternary Science Reviews; updated research was presented at the Institute of Geographers conference in Wollongong in July 2011.

Stream erosion in areas of northeast Tasmania subject to high-intensity rainfall

  • An internal report has been written with the aim of improving risk management in this area.

Determining the risk of mass movement in dolerite talus deposits

  • A paper on the dating of dolerite talus landforms on the eastern slopes of the Nicholas range has been published. Further work is being done on the northern slopes of the Nicholas Range, in conjunction with staff at the University of Exeter (UK). Results indicate that most landforms are relict and inactive, but on the steepest slopes (mostly outside the commercial forest zone) active movement is still occurring.

Assessing the effects of plantation harvest on karst development in limestone terrain

  • The planned harvest of plantation pine on soils derived from limestone on the floor of the Florentine valley provides an opportunity for measuring the effect of tree removal and increased runoff of karst development. A reconnaissance survey has been done and further work will concentrate on detailed mapping of control and treatment areas, so that the effect of harvest (if any) can be quantified. This is a joint project with Norske-Skog, Boyer.

Cave development in bouldery dolerite talus deposits

  • Preliminary work has been done to describe and map caves in bouldery dolerite on Mt Victoria and Mt Nicholas.

Vegetation history of Surrey Hills grasslands

  • Since the early explorations of Hellyer, the native grasslands, buttongrass moorlands and sedgelands on Surrey Hills in northwest Tasmania have been recognised as unusual because they occur as isolated areas surrounded by contrasting vegetation - rainforest or wet eucalypt forest. It is possible that some areas of Surrey Hills have been regularly burnt by Aborigines since forests began expanding during the amelioration of the climate which began about 15 000 years ago, in an attempt to maintain an open landscape suitable for game. Alternatively, some areas of forest may have been burnt quite recently, to provide 'green pickings' to entice game out of the surrounding forests. Although it can be argued that the wetter grasslands and moorlands on Surrey Hills may never have supported forest, this may not be true in all areas, and it is possible that some buttongrass moorlands have replaced vegetation associations that previously occurred on soils with better drainage. These issues affect how foresters manage the grasslands and moorlands, especially as they need to be managed for their high conservation values. If we knew the species associations previously present in a grassland or moorland we would have a better idea what the aim of current land management should be - have there been cycles of vegetation in the past or have the species present always been what we see today? To help answer these questions staff from Gunns, the FPA and the University of Queensland are cooperating on a project to collect sediment cores from sites on Surrey Hills so that the pollen, charcoal and insect record in the cores can be examined for evidence of local and regional vegetation change, as well as for changes in climate and possible impacts of Aboriginal burning.

Content last modified September 21, 2011, 9:54 am