Abstract
In this paper, a beech thinning experiment aimed at qualitative production issues was analysed. Two beech stands (93- and 105-year-old), growing at acid sites with similar ecological conditions were compared. The stands differ in the stand age, when their tending started (at the age of 40 years in one experiment versus 60 years for the second one). In the first stand, the thinning interventions were carried out during last 45 years, while in the second stand a 53-year-long period of investigation was recorded. The research was conducted in four treatment plots: (i) heavy thinning from below (C degree according to the German forest research institutes from 1902), (ii) free crown thinning with thinning intervals of 5 years, (iii) free crown thinning with thinning intervals of 10 years, and (iv) control plot (without thinning). The stand qualitative parameters (stem and crown quality, proportion of the best quality assortment and share of crop trees) were evaluated. From the point of qualitative production, the best results were most frequently obtained at the plots with the free crown thinning followed by heavy thinning from below. The worst parameters were found at the control plot