Modelling of diameter distribution according to tree numbers in sample area of the Brutian pine stands in Isparta region

44160

Brutian pine (Pinus brutia Ten.) is the most widely distributed main tree species of Turkey and it covers approximately 5.9 million ha, accounting for 27% of the Turkey’s forests. The stand parameters must be accurately estimated for an appropriate forest management. Besides, it is important to know the stand diameter distribution for the determination of the technique, time and economic feasibility of a stand maintenance treatment. The shape of the diameter distribution is one of the important elements characterising forest stand structure. In recent years, many researches have used the statistical frequency distributions in the field of forestry. Aim of this study, alteration of the diameter distribution by site quality and age, presented by the actual structure of even aged brutian pine stands in the Isparta Forest region, has been related to the models constructed by basing on the distributions of Gamma, Beta, Normal and Weibull. The data used in the computations of models has been obtained different size 88 temporary plots contain from 6 to 21 trees. . A linear model has been constructed for each distribution, and the coefficients in the model have been computed with the help of regression analysis. Besides, standard error and multiple correlation coefficients have also been determined. Later, the estimated values that the determined models gave have been graphically compared with the actual measurements. Gamma Distribution model seems to be more suitable than other distribution models (F=55.587; p 0.001; R²=0.519). Gamma distrubution model is usable in the region for diameter distribution model.

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Stand diameter distribution , Brutian pine , Site index , Stand age

Turkish Journal of Forestry

173

Turkish Journal of Forestry