Intra-specific competition of beech using Mark Correlation Function (MCF) in the Hyrcanian forests of Iran

Point pattern analysis based on the spatial distribution of a mark, e.g., diameter; could be implemented using Mark Correlation Function (MCF). The purpose of this study was to quantify the spatial interaction and competition in the intact beech stands of Hycanian forests of Iran using MCF. To this end, nine 1-ha sample plots were established at three developmental stages of initial, optimal and decay in three intact natural, unmanaged and uneven-aged beech (Fagus orientalis Lipsky) stands in the north of Iran. Diameter at breast height (DBH) of all trees greater than 7.5 cm along with their coordinates were recorded and fully mapped in the plots. Analysis of intra-specific competition of beech trees using MCF showed that DBH in the initial stage had a negative correlation indicating high spatial competition at all distances, while it was independent or positive in optimal and decay stages, except at distances up to 12 meter. Consequently, there was no intra-specific competition in each of these two stages. The results demonstrates the utility of second – order analysis of marked point processes for characterizing the competition in the beech stands and planning silvicultural interventions, e.g., thinning, based on the competition intensity of trees.