Spatial pattern of regeneration gaps in managed and unmanaged stands in natural Beech (Fagus orientalis) forests

The spatial structure of a forest stand plays a key role in its dynamics. It also determines the chance of establishing seedlings and the renewal capacity of the stand. However, this relation between spatial pattern and forest dynamics is two sided and information can refine our understanding of natural processes. Regarding to importance of seedling establishment in forest dynamics, the aim of this study was to investigate on spatial pattern of gaps in managed and unmanaged forests. The study site is located in Kheiroudkenar research forest – Noshahr. For this purpose, two sites in beech stands with similarity in physiographical condition were selected and the position of all gaps in each site was surveyed. Also, some quantitative parameters were recorded in each gap. Then, Ripley's M function was used to obtain the spatial structure of gaps. The null hypothesis is a random distribution of gaps which was tested by using of Monte Carlo technique. The results showed that frequency of gaps in managed area is more than unmanaged area. Regarding to average area of gaps (235 m2 in managed area and 210 m2 in unmanaged area), gaps cover 9% of the study area in managed and 4% in unmanaged stand. It means that silvicultural practices intensity was high and it could not be suitable for develop stand structure. Also, spatial pattern of gaps are regular for both area in 60m and 80m radius, respectively. Based on this trend, spatial structure is regular within each stand and random among them