Structure of intact mixed broad-leaved stands in Hyrcanian Forests (case study: Loveh, Golestan province)

The importance of study on the structure of mixed stands is not less than that of studies on beech stands. For this purpose, nine sample plots, each one ha, were established in the control compartment of district four in Loveh forest. After recording the general characteristics of the stand, 100% inventory was done in the plots. Coordination and diameter at breast height (dbh) of all woody species with dbh larger than 7.5cm were measured. Spatial pattern of species was mapped using PAST software. Moreover, the locations of the stands were determined in the structure triangle. Results showed that the studied stands were three-storied uneven-aged and composed of 12 woody species with the highest abundance of hornbeam. Mean stem number was 384ha-1, height of trees varied between 3.6 and 34.7 m and large and extra-large trees of Lime and Chestnut-leaved oak with a total height of more than 25m appeared in the upper story. Mean basal area, total volume and dead wood volume accounted to 36.1 m2ha-1, 420.6 m3ha-1 and 17 m3ha-1, respectively. Spatial pattern of the trees was generally cluster. All nine plots were located on the upper part of the structure triangle indicating abundance of old and large trees which were far from the theoretical irregular structure. Considering this structure, immediate application of group selection method is too early in such stands; we suggest starting with silvicultural interventions and moving towards irregular structure, and later establishment of young generation keeping tree diversity and sustainability in mind.