Determination of stand structure in even-aged Oriental Beech Forests in Turkey

This study aimed at developing a stand yield model for even-aged and pure Oriental beech (Fagus orientalis) stands in Sinop Province, located in the north of Turkey. The data used in this study were obtained from 238 sample plots. The sample plots are 24-131 years of stand age range, 19.0-35.9 m of site index range, and 2.2-10.8 of stand density range (relative density index). With the generated equation systems, stand age, site index and density of the three main factors in Oriental beech stands, including the effects of individual, dual and triple factor interactions on the stands were numerically determined. As for even-aged Oriental beech stands, the main stand volume values increase depending on age, site index and density. The number of stems per hectare decreases as the stand grows older, and site index rises; the number, however, increases in parallel with stand density. The current annual volume increment reaches a peak at 30-35 years at all site index groups and density levels, and begins to fall afterwards. Mean annual volume increment peaks up at 65-75 years at all site index classes and density levels, before beginning to decline. The results were in arrangement with the acknowledged growth rules. Stand yield models were assessed as Density-Variable Yield Table used for estimation of the remaining, removal and total stands.