نتایج جستجو برای: characteristics including tree density

تعداد نتایج: 2053766  

Journal: :پژوهش های تولید گیاهی 0

in order to determine radiation use efficiency and phenological and physiological characteristics of three maize hybrids on seven plant densities, an experiment was conducted during 2006 growing season in mashhad, iran. three maize hybrids including late-rippening maize (704), medium-rippening (504) and early-rippening maize (260) and seven plant densities including d1=3, d2=5, d3=7, d4=9, d5=1...

2017
Hongxiang Wang Qianxue Wang Ling Liu

Inter-tree competition is considered one of the most important ecological processes of forest development. However, its importance in structuring the spatial patterns of plant communities remains controversial. We collected observational data from two plots in a natural Mongolian Scots pine forest to study the contribution of competition to tree growth, mortality, and size inequality. We used t...

This research was conducted to investigate spatial variability and estimate tree attributes in a plantation forest in the Caspian region of Iran using geostatistical analysis. Sampling was performed based on a 50m?125m systematic grid in a maple stand (Acer velutinum Boiss) 18 years of age using circular samples of 200m2 area. Totally, 96 sample plots were measured in 63 hectares and 14.25 he...

Journal: :جنگل و فرآورده های چوب 0
مهدی کاکاوند دانشجوی کارشناسی ارشد، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران محمدرضا مروی مهاجر استاد گروه جنگل داری و اقتصاد جنگل دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران خسرو ثاقب طالبی دانشیار پژوهش، مؤسسة تحقیقات جنگل ها و مراتع کشور، تهران، ایران کیومرث سفیدی استادیار، دانشگاه محقق اردبیلی، دانشکدة منابع طبیعی، اردبیل، ایران

this study was designed to investigate the structural characteristics of beech forests in the middle stage of ecological succession. in order to this purpose undisturbed beech stands in kheyroud forest had chosen and three one hectare sampling plot laid out. all of tree species measured with full callipering method and diameter and height of trees were recorded. natural regeneration within one ...

Journal: :international journal of environmental research 2012
u. song b. waldman e.j. lee

sanitary landfills, created for the disposal of solid waste, usually are developed into parks afterthey are closed. however, soil amelioration with organic matter is usually needed to restore fertility andpromote revegetation. sewage sludge creates a massive waste disposal problem. the use of composted sewage sludge (biosolid) as a soil conditioner might restore the soil fertility at landfill s...

Vegetation due to its root system by creating cohesion of soil particles, significantly affects hill slope mechanical properties related to shallow landslides and slope stability. In this regard, the root engineering characteristics of forest species are important. The aim of this study was to investigate the distribution pattern of persian oak and hawthorn in Zagross forests. For this purpose,...

Persian juniper and Pistachio are grown in low density in the rangelands of North-East of Iran. These rangelands are populated by evergreen conifers, which are widespread and present at low-density and sparse shrub of pistachio in Iran, that are not only environmentally but also genetically essential as seed sources for pistachio improvement in orchards. Rangelands offer excellent opportunities...

2004
Xiaowei Yu Juha Hyyppä Hannu Hyyppä Matti Maltamo

High-density airborne laser scanner data has been previously shown to provide great opportunities for individual tree detection and measurement of variables characterizing the detected trees. This paper evaluates the effect of laser flight altitude on the tree height estimation at individual tree level in the boreal forest area mainly consisting of Norway spruce, Scots pine and birch. The test ...

Journal: :hepatitis monthly 0
yue feng yunnan provincial center for molecular medicine, faculty of life science and technology, kunming university of science and technology, kunming, china yue-mei feng academy of public health, kunming medical university, kunming, china yang feng yunnan provincial center for molecular medicine, faculty of life science and technology, kunming university of science and technology, kunming, china caixia lu institute of medical biology, chinese academy of medical sciences/peking :union: medical college, chinese academy of medical sciences/peking :union: medical college, kunming, china li liu yunnan provincial center for molecular medicine, faculty of life science and technology, kunming university of science and technology, kunming, china xiaomei sun institute of medical biology, chinese academy of medical sciences/peking :union: medical college, chinese academy of medical sciences/peking :union: medical college, kunming, china

conclusions according to the liver microrna data of chinese tree shrew, characteristics of the mir-122 and let-7 families further highlight the suitability of tree shrew as the animal model in hcv research. objectives this study aimed to construct a liver microrna (mirna) data of the tree shrew. materials and methods three second filial generation tree shrews were used in this study. total rna ...

Journal: :محیط زیست طبیعی 0
مرضیه نوبخت دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه گیلان، ایران حسن پوربابایی دانشیار دانشکده منابع طبیعی، دانشگاه گیلان، ایران مرضیه بیگم فقیر عضو هیأت علمی دانشکده علوم پایه، دانشگاه گیلان، ایران رویا عابدی دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی، دانشگاه گیلان، ایران

in order to investigate variations in plant diversity in dr. dorostkar's forest reservoir, located in gisoum talesh, 44 sampling plots were applied by the randomized-systematic method. the diameter of all tree species (dbh?5 cm) was measured in 400 m2 (20×20 m) square sampling plots. in addition, the number of individuals of shrubs and saplings (dbh?5 cm) were enumerated in circular 100 m2...

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