| Popis: |
Summary The effects of commercial thinning on stand structure and productivity were investigated in a 28-y-old stand of silvertop ash (Eucalyptus sieberi) near Orbost, Victoria. Thinning reduced basal area by 40–50% in treated areas and stocking from about 1400 to 250 merchantable stems ha-1. Replicated experimental plots were established in unthinned, thinned-only, and thinned and coppice-treated forest to measure the effects of thinning and coppice competition on the growth of retained trees. Stand basal area increments averaged 1.76 m2 ha-1 y-1 and thinning did not significantly reduce stand basal area increment even in the first year after treatment. Over the 6 y of measurement, the relative basal area growth in thinned-only forest was 47–67% higher than in unthinned forest, and in thinned and coppice-treated forest basal area increases were 60–89% greater than in unthinned (a further 15–23% over thinned-only). Basal area increment for the potential sawlog trees (the largest 150 stems ha-1) in thinned... |
