Provenance-dependent variability of Abies grandis stem form under mountain conditions of Beskid Sądecki (southern Poland)

Abstract

This study compared the stem form of different provenances of Abies grandis Lindl. under the mountain conditions of Poland. Seven partial populations of this species, originating from two regions in its natural range, were tested. It was concluded that creating separate stem form models is an effective method for comparing stem forms, because the model curves for the groups under comparison are not affected by tree dimensions. The results of this study showed distinct variation in the tested populations of A. grandis in respect to stem form according to provenance (genotype). These differences are particularly evident between provenances from the different regions determined by Müller (K.M. Müller. 1935. Mitt. Deutcsh. Dendrol. Ges. 44: 54–123 and K.M. Müller. 1936. Mitt. Deutcsh. Dendrol. Ges. 47: 82–132). In general terms, trees representing provenances from region II are characterized by greater cylindricity in comparison with trees from region I. At equal DBH and height, the volume of trees from regions I was smaller than the volume of trees from region II by an average of approximately 7.6%.