Crown competition in the selection forests with the different tree species composition

Abstract

The presented paper is oriented on the analysis of interspecific crown competition within the middle and upper layer of the selection forest. The research was conducted in the Norway spruce and silver fir dominated selection forest (demonstration object Donovaly-Mistríky) and in the common beech dominated selection forest in the territory of School Forestry Enterprise of the Technical University in Zvolen, Slovakia. We intended to evaluate the species specific crown-stem relation through the tightness of correlation between the crown volume and the stem volume. Our research confirmed the obvious effect of crown capacity on the production of stem biomass in the selection forest. The analysis revealed significant differences between coniferous and broadleaved species. However the low correlation for both middle and upper layers did not exceed r2 = 0.46 for common beech, the high significant correlations were for spruce and fir (r2 = 0.82 and 0.78, respectively). There were also significant differences between separated canopy layers. In the middle layer, the crown-stem correlations were lower than in the upper layer, what points out the obvious spatial competitiveness in the middle canopy layer, despite the relatively autonomous position of tree crowns within the canopy.