OPTIMUM THINNING RANGE OF PINUS RADIATA IN SOUTH AUSTRALIA

SUMMARY The thinning guide presented with this paper is a graph of stocking per acre on predominant height, and it indicates what is considered to be the optimum range of stocking within which thinning should maintain P. radiata stands in South Australia, if an optimum compromise between certain factors is to be achieved. These factors include a commercial first thinning as a pre-requisite, full site use, reasonable rates of diameter growth, and stability to wind. It is suggested that representation of a thinning guide in terms of stand height and in graphical form gives it a flexibility to individual stand characteristics which is not possible in tabular form, and that such flexibility is necessary if a thinning guide is to be a ready practicable guide to logging officers. A special value of the graphical form is that past and proposed thinning of a stand can be represented diagrammatically, against a background of growth and stability criteria. By indicating long-term possibilities, this should assist with short-term decisions.