The genus Dolichocephala Macquart, 1823 of the family Empididae is recorded for first time from Iran and Azerbaijan, including one species D. monae Joost, 1981. A neighbour-joining tree based on genetic divergences CO1 gene within nine provided. In addition, Oropezella Collin, 1926 Hybotidae (one O. sphenoptera (Loew, 1873)) two subgenus Empis s. str. Linnaeus, 1758 (E. (E.) earina 1960 E. temr...

Damage to residual stand is unavoidable and it is one of the main important issues in the forest harvesting. Trees damage may occur in felling and skidding work phase or during skid trail construction. In any case, damage can be very serious to residual stand. Detailed study is necessary to find out the amount and severity of damage to trees; therefore district 14 of Kilesara in Guilan Province...

Nacrtak Motor-manual tree felling is the most labor-intensive component of all harvesting operations and frequently represents a bottleneck in wood production. The study of motor-manual tree felling was carried out in two compartments in the Namkhaneh district of Kheyrud Forest. The objects of this study were as follows: time study of tree felling operations, estimate of chainsaw productivity a...

Determining the efficient density for forest roads is essential to decrease the costs of skidding and road constructing in forestry plans. In order to estimate the optimal density for road network in Dalak kheyl forest district (Mazandaran Wood and Paper Industries), we calculated the roading costs and hourly costs of Timber jack 450C and HSM 904 skidders. The length of skid trails was measured...

quantifying spatial structure is one of the most important components, describing natural ecosystems and their biodiversity. in this study, a set of indices and functions related to spatial structure using 102 established plots with an area of 1000 m2 were presented. to achieve spatial structure of carpinus-fagus type, a set of indices (clark & evans, uniform angle, shannon-wiener, mingling and...

studying forest degradation through evaluation of soil nutrient concentrations, which reveals soil functioning within the ecosystem, is necessary for sustainable management of land resources. this research was conducted to understand the changes of soil nutrient, resulting from exploitive management using some soil features and their spatial pattern. in the mid-summer of 2014, two sites were se...