The once densely forested dry sclerophyll landscapes of the Midlands of Tasmania are now characterized by vast spans of agricultural pasture with intermittent dead and ailing eucalypt trees. This landscape changing phenomenon, rural tree dieback, has come into the focus of a collaborative research team at the University of Tasmania sponsored by the nonprofit organization, Greening Australia. Through the efforts of this team of scientists of diverse backgrounds, Greening Australia aims to create an ecologically viable reforestation plan for the Midlands.
I conducted a pilot study focusing on a 400 ha plot within the Dennistoun Farm property in Bothwell, Tasmania in which I analyzed stand structure and substrate geology for 8 transects selected for 4 different combinations of either forested or unforested land type and either sandstone or dolerite substrate. I also analyzed the effect of substrate type on elements of tree physiology for Eucalyptus tenuiramis and Eucalyptus viminalis, the dominant eucalypt species in the mixed species stands within the area of interest. Finally, I calculated the aboveground and soil carbon content and carbon dioxide sequestration for each land type and underlying geology of the 400 ha plot of Dennistoun property.
The 400 ha plot of Dennistoun Farm property is mostly composed of 248 ha of unforested landscapes and only 152 ha of forested landscapes. The forested landscapes on dolerite substrate sequestered the most CO2 relative to total area. Mean SLA was significantly greater for individuals of the same species on sandstone substrate than on dolerite substrate for both E. tenuiramis and E. viminalis in forested landscapes but mean SLA was not significantly different between individuals of the same species but different geologies from unforested landscapes. The top 5 cm of soil was 4.72% carbon in the dolerite soil from a forested landscape. The data collection and analysis methodologies established for this pilot study will be expanded across the Clyde River catchment. The results of the continuation of study will be submitted to Greening Australia to aid in the creation and establishment of a forest regeneration plan, hopefully in the near future.
Environmental Indicators and Impact Assessment | Forest Management
Superak, Claire, "Rural Tree Decline in Tasmania’s Midlands: Stand Structure, Substrate Geology, and Carbon Content Analysis" (2010). Independent Study Project (ISP) Collection. 866.