نتایج جستجو برای: hyrcanian plant
تعداد نتایج: 395293 فیلتر نتایج به سال:
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...
Humus forms are good indicators of environmental conditions and thus important in forest ecological processes. Altitudinal gradients considered as natural laboratory for evaluating soil processes humus form distribution. The objective this study was to evaluate the macromorphology along an altitudinal gradient (0-2000 m a.s.l.) covered with plain forest, mixed pure forests forest-grassland ecot...
Saproxylic beetles play a vital role in conservation as indicators of the status unmanaged forests. In light concern regarding adverse impact anthropogenic pressure on biodiversity, an essential step forest conserva-tion strategy is identification saproxylic beetles. The Hyrcanian forests are unique remnant natural broadleaf temperate forests, with evolutionary history that can be traced to Ter...
the oak genus (quercus l.) is one of the most important genera of beach family (fagaceae) that has ecological and economical importance. chestnutleaf oak (quercus castaneifolia c.a. mey.) is native to iran and distributed in hyrcanian forests. pure and mixed stands of this taxon have covered about 6.5 % of hyrcanian forests. this study was undertaken to evaluate the effects of ecological factor...
For the identification of small to large wood samples and various types of composites that may not provide enough of all surfaces necessary to reveal diagnostic characteristics, such as sawdust, decayed wood fragments, archeological wood, and even large wood samples, morphological and anatomical characteristics of vessels are very useful. In this research, morphological and anatomical character...
Pterocarya fraxinifolia (Lam.) Spach., a relict tree species of the Juglandaceae family, is native to the Great Caucasus, Anatolia, and to the Hyrcanian forests of the southern Azerbaijan and Northern Iran. In this study, the phylogenetic relationship of the species, sampled in selected Iranian populations, and the global biogeography of the genus Pterocarya were addressed. Leaves were collecte...
The operating hourly cost of the machine is a suitable factor to analyze the cost fluctuation certain machinery in a changing environment and to find of economically feasible work concepts for the studied machine system. This paper, which is based on studies carried out in northern forests of IR-Iran, analyzed and compared costs of four skidding and excavation machines used in timber harvesting...
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 Optimum Road Density for Ground Skidding System in Dalak Kheyl Forest-Hyrcanian Zone
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...
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