نتایج جستجو برای: and diameter at breast height

تعداد نتایج: 17216176  

Journal: :caspian journal of environmental sciences 2011
p. parhizkar al. et

we studied 11 gaps covered with beech saplings (< 1.30 m tall) in a reserve compartment (compartment 139, district one, langa forest, watershed 36: kazemrood) of the caspian beech forest in n iran. two transects, each 2 m wide, were laid along the longest (n-s) and shortest (e-w) axis of each gap. five micro sample plots, each 4 m2, were established: one at the center, and one at each corner. q...

Dynamic behavior of ground supported cylindrical storage tanks (CST) is of crucial importance because of its applications in industrial complexes. Seismic behavior of tanks is greatly affected by the height to diameter ratio, fluid height and fluid type. Five CSTs with different height to diameter ratios, three CSTs with the same height and diameters but various fluid heights and one CST with t...

Journal: :environmental resources research 2014
mojtaba amiri ramin rahmani khosro sagheb-talebi hashem habashi

investigation on structure and dynamics of natural forest ecosystems is an important issue for silvicultural decisions. the aim of this study is to analysis dynamics and structure of a beech stand during 5-year period in the shast kalateh forest in the caspian region, north of iran. data were collected from a 16.9ha permanent research plot established in a natural unlogged stand in 2006. all li...

2013
Liyuan Jiang Wenbin Li Jiangming Kan Zhibin Hao Qing Xu

Studies show that there is electric potential difference between the internal part of tree and the soil, but the mechanism is not clear, possibly associated with tree species, environmental factors and DBH (diameter at breast height) of tree. In order to research the mechanism and change rules, it is necessary to measure bioelectricity, environmental factors and DBH of tree, among which the DBH...

توانکار, فرزام, نیکوی, مهرداد,

Rotten and dead trees are the main component of forest ecosystems and play an important role in maintaining forest biodiversity. In this research frequency and characteristics of large diameter trees (normal, rotten, and dead trees) with diameter at breast height greater than 60 cm were studied in two compartments (selective logged and protected) in Asalem-Nav forest. Random systematic sampling...

Journal: :journal of theoretical and applied vibration and acoustics 0
mohsen yazdanian young researchers and elite club, ahvaz branch, islamic azad university, ahvaz, iran vahid razavi department of civil engineering, jundi-shapur university of technology, dezful, iran mahmoud mashal department of irigation engineering, aburaihan campus, tehran university, tehran, iran

dynamic behavior of ground supported cylindrical storage tanks (cst) is of crucial importance because of its applications in industrial complexes. seismic behavior of tanks is greatly affected by the height to diameter ratio, fluid height and fluid type. five csts with different height to diameter ratios, three csts with the same height and diameters but various fluid heights and one cst with t...

Iranian mangrove forests provides valuable information to prevent genetic erosion in the gene pool of these ecosystems. The aim of this study was to investigate the genetic diversity among mangrove forests located in four different regions of Iran, based on morphological characteristics and microsatellite markers. Cluster analysis of molecular data, using neighbor joining algorithm classified t...

Journal: :تحقیقات جنگل و صنوبر ایران 0
عیسی انیسی کارشناس ارشد جنگل داری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران هادی کیادلیری استادیار، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران رضا اخوان استادیار پژوهش، موسسه تحقیقات جنگلها و مراتع کشور ساسان بابایی کفاکی استادیار، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران

this study was performed in order to consider the effect of management plans on forest, through comparison between qualitative and quantitative characteristics of managed and unmanaged forests. compartment no. 149 from shourab district (52.8 ha) and compartment no. 218 from jamand district (68.7 ha) were selected as managed and unmanaged forests, respectively and were inventoried using a system...

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