Effects of utilized trees’ diameter on the residual stand in the Savadkooh forest in Northern Iran

Cutting of trees, like other stages of utilization, causes many damages to the residual stand. Recognition of the type and severity of damages and the factors causing such damages may be important. This research was performed to study the effect of fallen trees’ diameter on the residual stand in the forest of Mazandaran province in northern Iran. At first, 50 trees (20%) out of 250 signed trees were selected at random, as per the diameter classes, and then considering the sample, a number of 50 trees were considered in a semi-circle with an area of 1500 square meters. Quantity (diameter breast height (D.B.H.) and height) and quality (up-rooted, crown break, injury to the bark and peeling of the bark) specifications were recorded before and after cutting. Results of the study indicate that thorax diameter of fallen trees, except for the up-rooted trees, may have a significant impact on the range of crown and trunk break, injury of the trunk and peeling of the trees. The most damaged stand happened when a diameter of 80 cm and more was used in cutting trees.