نتایج جستجو برای: dbh of trees

تعداد نتایج: 21171343  

Journal: :جنگل و فرآورده های چوب 0
سمیرا ساسانی فر دانشگاه ارومیه منوچهر نمیرانیان دانشگاه تهران نصرت الله ضرغام دانشگاه تهران

knowing and conducting studies on size characters of trees is essential for assessing the tree volumeand/or other statistical parameters and also forest management. the characteristics of 529 treesincluding diameter at breast height (dbh) and total height were measured in an even-aged fraxinusstand for two periods from 2005 to 2012 in chelir district, a part of experimental kheyrud forest.resul...

Journal: :جنگل و فرآورده های چوب 0
مجتبی آذریان دانشجوی کارشناسی ارشد جنگل شناسی و اکولوژی جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران محمد رضا مروی مهاجر استاد گروه جنگل داری و اقتصاد جنگل دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران وحید اعتماد استادیار گروه جنگل داری و اقتصاد جنگل دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران انوشیروان شیروانی استادیار گروه جنگل داری و اقتصاد جنگل دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران سید محمد معین صادقی دانشجوی دکتری جنگل شناسی و اکولوژی جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران

the aim of study was to evaluate qualitative and quantitative characteristics of old trees in pattom and namkhaneh districts in the nowshahr, northern iran. the trees quantitative characteristics of dbh, total height, slenderness coefficient, trunk height, crown length, buttress height, and canopy cover area and qualitative characteristics of crown and trunk, i.e., health, vitality, and concurr...

اعظمی, ایاد, حسینی, احمد,

This study was conducted in oak forests of Ilam province in order to evaluate the morphological characteristics of old trees including diameter at breast height, trunk height, whole tree height, minimum and maximum crown diameter, crown health, crown vitality, crown symmetry, health and form of the trunk, Was investigated. Selection of old trees was performed based on the criteria of DBH and wi...

Journal: :international journal of environmental research 0

we investigated the relations among infection intensity of european mistletoe (viscum album l.) with host tree features in nour forest park, located in caspian forests in north of iran. the number of 30 circular plots with an area of 0.1 ha were sampled in all places have an aggregation of infested trees. parameters including dbh, height, distance to stand edge, distance to conspecific tree, ba...

Old trees as the most important genetic reserves of the country have great importance and value in various aspects of ecology, forest restoration management, ecotourism and even history. In this research, after identification of the old trees in the forests of Ilam province, their morphological characteristics including DBH, trunk height, total height, crown length, min & max crown diameter, cr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده مهندسی عمران 1388

چکیده روش های متعددی برای برآورد رواناب حاصل از بارش در حوضه های آبریز وجود دارد. یکی از این روش ها استفاده از مدل های هیدرولوژیکی است. با استفاده از مدل های هیدرولوژیکی و شبیه سازی فرآیندهای هیدرولوژیکی می توان با صرف کمترین زمان و هزینه، رواناب و مولفه های دیگر چرخ? هیدرولوژیکی را برآورد کرد. از آنجا که در حوضه های آبریز اندازه گیری تمام کمیت های مورد نیاز برای تحلیل رواناب ممکن نیست، انتخاب...

2011
Zhudong Liu Bo Wang Bingbing Xu Jianghua Sun

Several studies suggest that some bark beetle like to attack large trees. The invasive red turpentine beetle (RTB), Dendroctonus valens LeConte, one of the most destructive forest pests in China, is known to exhibit this behavior. Our previous study demonstrated that RTBs preferred to attack large-diameter trees (diameter at breast height, DBH ≥30 cm) over small-diameter trees (DBH ≤10 cm) in t...

2016
Xixi Wang Wenxing Long Brandon S. Schamp Xiaobo Yang Yong Kang Zhixu Xie Menghui Xiong

Vascular epiphytes are important components of biological diversity in tropical forests. We measured the species richness and abundance of vascular epiphytes along four vertical crown zones and five horizontal orientations on 376 trees, as well as the diameter at breast height (DBH) of host trees in tropical cloud forests in Bawangling, Hainan, China. The relationship between vascular epiphyte ...

2016
Matthew R. Evans Aristides Moustakas

Woodlands provide valuable ecosystem services, and it is important to understand their dynamics. To predict the way in which these might change, we need process-based predictive ecological models, but these are necessarily very data intensive. We tested the ability of existing datasets to provide the parameters necessary to instantiate a well-used forest model (SORTIE) for a well-studied woodla...

Journal: :ecopersia 0
ramin naghdi associate professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran mehrdad nikooy assistant professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran ismael ghajar assistant professor, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran mona ershadifar m.sc. student, department of forestry, faculty of natural resources, university of guilan, sowmeh sara, iran

directional felling of trees plays a key role in reducing of damages to forest residual trees and can also facilitate skidding. the aim of this study was presents a practical linear model for estimation of tree falling direction error in an uneven-aged mixed stand in northern forests of iran. to conduct the study a number of 95 trees of four species fagus orientalis lipsky, carpinus betulus l.,...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید