Growth response following variable espacement of 28-year-old Alpine Ash regeneration in New South Wales

Abstract

Summary Analysis of stand growth-response patterns have shown that small increases in sawlog volume resulted from thinning fast grown, fire regenerated alpine ash (Eucalyptus delegatensis R.T. Bak.) from below to a range of regular tree-spacings, at age 28 years. No significant correlation was found between basal area growth response and increased spacing for four treatments that ranged from 3.7 m to 7.3 m. Rapid natural stocking-attrition occurred in both thinned and unthinned stands during the 31 post-thinning years of measurement. Maximum density diagrams indicated that these alpine ash stands were fully-stocked at lower densities than have been recorded for many other forest species. As a consequence of the propensity to self-thin, little additional stand growth was gained from the thinning treatments. The 150 trees ha−1 with the largest diameters from all thinned stands averaged a basal area increase of only 0.59 mha−1 over the 31 year period of measurement (<0.2 mha−1 yr−1), when compared with the e...