Afsaneh Khalili - Ph.D. student of Forestry, Dept. of Forestry, Faculty of Natural resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Asadollah Mataji - ۲ Prof., Dept. of Forestry, Faculty of Natural resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Khosro Sagheb Talebi - Prof., Research Institute of Forests and Rangelands (RIFR), Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran.
Seyed Mohammad Hodjati - Prof., Dept. of Forestry, Faculty of Natural Resources and Environment, Sari Agricultural Science and Natural Resources University, Sari, Iran.

The ecological significance of deadwoods has led to an ever-increasing collection of related information to be taken into account in management plans. The Coarse woody debris (CWDs) is a significant component of forest ecosystems. Here, managed and one unmanaged forest stands were selected in Gorazbon district of Kheyrudkenar Experimental Forest, Noshahr, Mazandaran Province, Iran. Based on the full-calipering inventory method, CWD attributes were collected in both stands. The distribution pattern of CWD was evaluated using univariate O-ring statistics. Results showed that the highest and lowest decay classes in two forest stands were ۳-۶ and ۱-۲, respectively. Results from distribution pattern analysis showed a random distribution pattern of CWD in the managed forest stand. Overall, the unmanaged forest stand with ۳-۶ decay classes showed a random distribution pattern of CWD. Conclusively, disturbances in the managed and the unmanaged forest stands occur in small scales.

CWDs, Decay classes, Distribution pattern, O-rings statistic