Turkish Journal of Forestry (Mar 2020)
Determination of relationship stump diameter - diameter at breast height for sessile oak (Quercus petraea (Matt.) Liebl) stands in Northern Marmara Region
Abstract
If the tree is cut planned or unplanned, the DBH (the diameter at breast height) cannot be measured and only the stump aboveground. Therefore, other dimensions of the tree (DBH, volume, etc.) need to be estimated based on the variables of stump. In this study, it is aimed to be determined the relationship between the stump diameter at 0.30 m and DBH for each age class and general level in pure sessile oak (Quercus petraea (Matt.) Liebl) stands of Northern Marmara. In addition, estimating the DBH with the stump height (hdk) and stump diameter (ddk) at this height is another purpose of this study. In this context, measurements were carried out on 726 trees determined by 1 Subject - 10 neighboring tree method in 66 sample points taken from pure sessile oak stands of the northern part of the Marmara Region which are distributed in different sites and in age classes II, III, IV, V and VI., whose age classes are 20 years in width. The tree regression models in the form of linear, polynomial and power function were tested in order to estimate DBH with the stump diameter at 0.30 m. In addition, 3 different regression models were formed in logarithmic form to estimate the DBH with the stump height and stump diameter at this height. It was concluded that the models tested for the stump diameter at 0.30 m with DBH explained the variation in DBH between 89.8% and 96.7% and the linear model was suitable for this relationship. The age classes were compared with the F test in terms of the relationship between the stump diameter at 0.30 m and DBH, it was concluded that the age classes differ from each other except III. and IV. age classes. It was determined that regression models established to estimate the DBH with the stump height and stump diameter at this height and explain the variation in DBH between 91.4% and 92.8% and estimate the DBH with 1.76-1.96 cm standard error. It is also important to model the stump diameter-the diameter at breast height relationship for oak tree species other than sessile oak.
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