نتایج جستجو برای: 160 soil samples belong to various ecological area of mazandaran province forest
تعداد نتایج: 22235544 فیلتر نتایج به سال:
since the change of land use accrued in the iran, especially in northern iran, this research aims tocompare the spatial variability of soil properties in three adjacent land uses including cultivated by wheat lands, grazing lands and forest lands covered by juniperus sp, fagus orientalis, quercus castanifolia, and acer velotinum species in kiasar region, mazandaran province, northern iran. som...
Forest fire is one of the important problems in Iran which is caused by different factors such as human and natural factors. One of these factors is climate conditions that can be created by heat wave and special circulation of atmospheric phenomena. Occurrence of forest fire in north of Iran have different impacts on environment such as destruction of natural. According to the position of Iran...
in the area of automotive engineering there is a tendency to more electrification of power train. in this work control of an induction machine for the application of electric vehicle is investigated. through the changing operating point of the machine, adapting the rotor magnetization current seems to be useful to increase the machines efficiency. in the literature there are many approaches wh...
in this project, some new polyaspartimides, (pas)s, have been synthesized form michael addition reaction between new synthetic bismaleimide (bmi) and some aromatic diamines. a characteristic property of this polyaspartimides is a pendent carboxylic group, which introduced to these polymers from new bismaleimide. bismaleimides (bmi) is one of the interesting compounds, which can be self-polymeri...
with regard to the mutual relations between plant and soil as the main component of rangeland ecosystems, this research has been identified the indicator species in environmental conditions of dry regions as the most important tools in ecological management of these ecosystems. therefore the steppe and dry rangelands of kooh - e- namak in qom province was selected. sampling was done by plot in ...
In present work, we studied the ecological-hydrological law of three manmade forest communities at a located site of the central Yunnan province from 1998 to 2000. The finding indicated that the interception of canopy, stem-flow, through-fall of E.maideni-A.mearnsii, E.maideni, P.Yunnanensis took respectively up 35.21%, 0.65%, 64.14%; 30.10%, 0.88%, 67.56%; 27.8%, 4.64%, 69.25% of total precipi...
Different land uses have various effects on the changes of soil properties. The purpose of this study was to evaluate the effects of natural forest, needle-leaved plantation and rangelands of central Alborz on new indices of soil quality (i.e. organic matter stratification, carbon management index and soil biological activities). For this purpose, eight samples from organic layer (litter) and m...
distribution and morphological variation of emys orbicularis in the coastal areas of the caspian sea
the coastal areas of the caspian sea are geographically unique and provide habitats for different flora and fauna. one of the remarkable inhabitants of this area is the european pond turtle, emys orbicularis (linnaeus, 1758), about which very little is known. in our study thirty seven (37) adult males of e. orbicularis have been identified in the golestan, mazandaran, ardebil, and east azerbaij...
Background and objectives: Satellite images and remote sensing technology are recognized as efficient and modern tools for extracting information related to earth sciences, which make it possible to evaluate and monitor ecosystems at a lower cost than field methods. One of the most important methods of extracting information from satellite data is various image classification techniques. The pr...
In order to investigate the diversity of plant species in forested areas, this study was carried out in forestry near the Khuzestan Steel Industries Company with a total area of 60 hectares in the southeast of Ahwaz, Khuzestan province. For this purpose, 30 plot of 20 × 20 meters in size were systematically randomized in the forested area and 30 samples were taken in the control area. Within ea...
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