Investigation on gap characteristics in the managed and intact oriental beech (Fagus orientalis Lipsky) forests, Iran

Hyrcanian forests are rare and unique ecosystems and their sustainability is essential. Gaps, as part of a general process, help to establish and stabilize the structure of the Hyrcanian forests and the dynamism of its society. This study seeks to identify possible differences in the gap characteristics in the two managed and intact compartments. For this purpose, compartments No. 114 (intact) and No. 115 (managed) from district one of Livan-Banafshtapeh forestry plan in Golestan province of Iran were selected to compare some gap characteristics (gap fraction, distribution of gap sizes, number of gaps per hectare and status of gapmaker trees). In these compartments, all gaps>100 m2 caused by mortality of at least one tree with remnants of the gapmaker or detectable tree stumps, were identified and recorded. The results showed that the gap fraction in the intact and managed compartments was 10.7% and 6.3%, respectively. The average number of gaps varied from 1.4 ha-1 in the managed to 2.9 ha-1 in the intact compartment. The spatial pattern of gaps was randomly spaced up to a distance of 30 (managed) and 40 (intact) meters and then reached the cluster pattern. The differences between the characteristics in the two compartments were not statistically significant and management did not have a significant effect on these variables. However, no significant differences between the two compartments were due to the low harvest intensity in the managed compartment. The biodiversity of Hyrcanian forests must always be taken into account so that it is not endangered by mismanagement; otherwise irreparable effects on the ecosystem of the managed compartment may occur.