نتایج جستجو برای: hyrcanian forests
تعداد نتایج: 39508 فیلتر نتایج به سال:
Unmanned aerial vehicles (UAVs) images have high spatial resolution. They are a valuable source of information for mapping land cover and thematic information, particularly in the identification of tree species. The aim of this study was to investigate the capability of drone images and the base object method for detecting tree species in the Hyrcanian forests. For this purpose, part of an area...
Distribution and growth of plant species is affected by many factors including abiotic (topography, altitude and soil) and biotic (root symbiosis) factors. In light of global warming, recent findings advocate microhabitats and micro-conditions of the root zone and canopy ambiance as determining factors in sustaining of plant populations. Although, occurrence of ectomycorrhizal (ECM) and non...
The effects of initial spacing layout on some allometric characteristics of 12-year-old Quercus castaneifolia trees grown in Central Mazandaran, north of Iran were examined. Trees were planted in 5 different layouts (1?1, 1.5?1.5, 2?2.5, 2?3 and 4?4 m). Tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. Tree basal area and...
راش شرقی (Fagus orientalis Lipsky) مهمترین گونه درختی جنگلهای هیرکانی ایران است. جنگلنشینان این منطقه بهطور سنتی با توجه به شکل ظاهری درختان راش، دو نوع راش بهنامهای راش سفید و راش سیاه را تفکیک میکنند. در پژوهش پیشرو سعی شد ویژگیهای ریزریختشناسی برگ و دانه گرده راش سفید و راش سیاه در جنگلهای هیرکانی ارزیابی شود. نتایج نشان داد که ازنظر ویژگیهای ریزریختشناسی تفاوت معنیداری بین دو ف...
Natural treefall gaps have a substantial role in maintaining soil and plant diversity old-growth forests. However, the amount of information on effects recovery physical chemical properties compacted soils is scarce. We tested hypothesis that natural accelerate restoration by enhancing biological microbial activity topsoil after period five years. Five years ground-based skidding operation Hyrc...
The growth and quality of natural seedlings are important goals forest management in uneven-aged high stands. In this study, the recovery process physical chemical properties soil, as well variables beech on skid trails after skidding operations three time periods (10, 20, 30 years) were investigated Hyrcanian forests Iran. Results revealed that soil (organic C, total N, pH) fully recovered 20 ...
forest types mapping, is one of the most necessary elements in the forest management and silviculture treatments. traditional methods such as field surveys are almost time-consuming and cost-intensive. improvements in remote sensing data sources and classification –estimation methods are preparing new opportunities for obtaining more accurate forest biophysical attributes maps. this research co...
Water-yield assessment is crucial to effectively achieve water supply management at the basin scale. It affected by climate change, and Land Use/Land Cover Change (LULCC). This paper quantifies combined impact of LULCC change on yield over short long-term periods in Haraz basin, Iran. has experienced severe forest degradation, agricultural expansion, urbanization. Most lands are within plains c...
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