Modelling diameter distribution of brutian pine stands in Mediterranean Region using Johnson's Sb distribution

This study aimed to model the diameter distribution of natural Brutian pine (Pinus brutia Ten.) stands in the Mediterranean region. Johnson's SB distribution was preferred because it has a more flexible structure in representing stand organizations compared to other diameter distribution models. Johnson's SB distribution was used with the 3 and 4 parameter solution method used in the study. A total of 193 sample plots were collected from pure and natural Brutian pine stands within the borders of Antalya, Adana and Mersin Regional Directorates of Forestry. The prediction success of the 3 and 4 parameter recovery method and Johnson's SB distributions were determined using the Kolmogorov-Smirnov (K-S) test and Error Index (EI) values. It was observed that the 4-parameter Johnson's SB distribution produced lower EI values for Antalya and Adana OBM and the 3-parameter Johnson's SB distribution for Mersin OBM. The error indices for Adana, Mersin and Antalya were found to be 12.77, 12.92 and 15.65 for the 3-parameter recovery approach and 12.28, 19.72 and 14.90 for the 4-parameter recovery method approach, respectively. These results revealed that Johnson's SB distribution can be successfully used to reveal stand organizations in order to improve the management strategies of natural Brutian pine stands in the Mediterranean region.