Articles

Effect of thinning on the diameter increment in black locust (Robinia pseudoacacia L.) stands

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Abstract

Black  locust is one of the most important stand forming species in Hungary,  covering    approximately 20% of the forested land (340 thousand ha) and providing 25%  of the annual    timber cut of the country. Hence, during the past two decades several  experiments with this    species have been carried out. This paper investigates the influence of  thinning on the diameter    increment in an experiment including four plots. One plot was left as an  unthinned control plot    and three plots were thinned with various thinning intensities at age 22.  The experiment was    measured at ages 22, 27, 32, and 36. Apparently the thinning intensities  applied on two of the plots did not come up to the intensity required to influence the diameter growth of the remaining    upper-storey trees. Therefore, for a given tree size the growth of the  trees on these two plots did    not differ significantly from the growth of similar trees in the unthinned  plot. By contrast,    significant thinning effects on the diameter increment of individual trees  were observed on the    most heavily thinned plot. Here the diameter increment was enhanced for  trees with diameters of    less than 20 cm, whereas the largest trees of the stand exhibited reduced  growth. Apparently a    stand density corresponding to the heavy thinning treatment (Fw values of 22-23) is  required to    get a significant thinning response. On the other hand, to avoid thinning  shocks, it may be    recommendable to apply two moderate thinning treatments instead of a single  heavy one.

How to Cite:

Redei, K. & Meilby, H., (2000) “Effect of thinning on the diameter increment in black locust (Robinia pseudoacacia L.) stands”, Silva Gandavensis 65. doi: https://doi.org/10.21825/sg.v65i0.812