Effects of thinning, liming, and nitrogen application on the growth of a young oriental beech (fagus orientalis lipsky) forest stand

Abstract

Each of the 45 study plots within a stand of oriental beeches, 25 years old, was subjected to one of the following treatments, either singly or in combination: thinning (moderate or heavy), liming (5 t ha(-1)), application of varying quantities of nitrogen (17.5, 35, and 70 kg ha(-1)), and a control (none of the above treatments). From 2008 to 2016, the diameter at breast height (dbh) and height of 12 trees chosen at random from each plot were recorded annually. The thickest and the tallest trees were seen in the heavily thinned and limed plots. By the end of the 8th year, compared to the initial values, trees in the heavily thinned plots had increased their dbh by 72% and their height by 41%; the corresponding figures in the moderately thinned plots were 52% (dbh) and 30% (height); and those in the control plots were 35% (dbh) and 25% (height). Liming in the heavily thinned plots contributed to an additional 24.2% gain in dbh and 4.3% in height, with the corresponding gains in the moderately thinned plots being 19.9% (dbh) and 9.3% (height). These results suggest that thinning combined with liming may shorten the rotation period of oriental beech to 3040 years from the present duration of 100 years in Turkey.