The influence of admixture and co-dominant species on the height and DBH of silver fir (Abies alba Mill.) and on the growing stock of fir stands in the Carpathian Forest-Natural Region

摘要

The best growth function for silver fir was selected from 30 models, based on adequacy of height and DBHapproximation, as well as growing stock, in the pure fir stands on the fertile mountain and highland sites. This modelwas then applied to evaluate the growth of fir in mixed (rather than pure) stands growing together with differentproportions of spruce, beech and sycamore. It was found that the DBH of fir at a given age is larger in some stands withadmixture of beech and spruce than in pure fir stands, although no such relationship was found for height. At the fertilemountain (LG) site and highland forest (Lwy? site, fir stands reached the highest growing stock. At the mixedmountain (LMG) forest site the growing stock of fir stands with admixtures of different species, especially a relativelyhigh proportion of spruce, was greater than in pure fir stands. At the LG site the lowest growing stock was in fir standswith admixture of beech and spruce, in which the proportion of beech was higher than that of spruce. Fir stands withadmixture of spruce and sycamore alone had a lower growing stock than pure fir stands.