School of Agriculture, Food and Ecosystem Sciences - Theses
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ItemLogging residue assessment( 1993)A total logging residue assessment system is proposed specifically for application in the Pinus radiata D.Don. (radiata pine) plantations in South Australia and Western Victoria. The choice of line intersect sampling using pseudo-circular sample lines, believed not to have been tried before, ensures a robust sampling technique able to overcome any bias that exists in the alignment of residue following harvesting. An analysis is presented defining the bias and precision obtained from a variety of geometric sample line arrangements and sampling intensities. A cost effective residue sampling system of known efficiency can be implemented as an integral component in an overall yield regulation and control system.
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ItemGrowth and yield models for South Australian radiata pine plantations: incorporating fertilising and thinning( 2001)This thesis describes the development of models to predict the volume growth response of South Australian radiata pine plantations to the interaction of the silvicultural tools of thinning and fertiliser used in combination. Some years ago this issue was identified as the component of the ForestrySA yield regulation system most in need of addressing and as a result a large thinning and fertiliser experiment was established. This was designed to determine whether a thinning and fertiliser interaction existed and to enable this interaction to be modelled. At the time it was established it was believed to be the only experiment of its kind in the world and this still appears to be the case. The thinning and fertiliser interaction models described in this thesis were designed to integrate with the models already implemented in the ForestrySA yield regulation system so that more precise predictions of future log availability can be provided, and improved management decisions can be made. Three sets of component sub models are described which operate at a stand level to: • predict the total volume growth of the main crop between the time of fertilising and the next thinning, approximately seven years hence; • predict the total volume growth of the portion of the stand which will be thinned (known as the thinnings elect) at the next thinning, between the time of fertilising and the next thinning; • predict the annual volume growth response of the stand between the time of fertilising and the next thinning. Further research is described to identify the data sets that are likely to be required for future analysis and revision of the South Australian growth and yield models. Adopting the future research recommendations will ensure that the consideration of the financial and economic benefit of alternative silvicultural prescriptions is broadened to include a more diverse range of sites and include log and wood quality considerations.