نتایج جستجو برای: aged stand

تعداد نتایج: 232105  

Journal: :جنگل و فرآورده های چوب 0
محمود بیات دکتری جنگل داری، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران منوچهر نمیرانیان استاد، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران محمود زبیری استاد، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران تیمو پوکالا استاد گروه جنگل داری، دانشگاه شرقی فنلاند، جوئنزو، فنلاند

hyrcanian forests are the most valuable forests in the north of iran and industrial harvesting occurs only in this area. it is a productive region near the southern coast of caspian sea. in these forests mixed beech stands mostly shown uneven-aged structure that is managed under selection system. in order to determine the priority of uneven aged method not only from an ecological view, but also...

Journal: :caspian journal of environmental sciences 2007
m. tabari

composition and structure of a three-storied fagus orientalis-dominated forest was investigated in the caspian forests, north of iran. circular sampling plots of 1000 m2 occupied by advance growth and natural regeneration were randomly chosen where the initial cuttings (with shelterwood aim) were performed. abundance of species at different growth stages and quality of seedlings and saplings we...

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...

2003
Rebecca Ralston Joseph Buongiorno Jeremy S. Fried

The effects of different management regimes on uneven-aged Douglas-fir stands in the Pacific Northwest of the United States were predicted with a simulation model. Management alternatives were defined by residual stand structure and cutting cycle. The residual stand structure was set by basal area–diameter-q-ratio (BDq) distributions, diameter-limit cuts (assuming concurrent stand improvement),...

Journal: :محیط شناسی 0
فرزام توانکار دانشگاه آزاد اسلامی، واحد خلخال، استادیار علوم جنگل امیر اسلام بنیاد دانشکدة منابع طبیعی دانشگاه گیلان، صومعه سرا ، دانشیار علوم جنگل باریس مجنونیان دانشکدة منابع طبیعی دانشگاه تهران، استاد مهندسی جنگل

selection cutting using skidding system often causes physical damage to residual stand through felling and skidding resulting decline of bole quality and tree value. this research evaluated logging damage using skidding system on residual trees and stand regeneration in uneven aged hardwood forest of asalem, were selection cutting was practiced. in this regard, systematic sampling method was us...

حسن زاد ناورودی, ایرج, سیدزاده, سیدحسین,

The effect of management was studied on the variation of some crucial forest stand features in the district nine of Shafaroud Gilan during a 20-year period. The survey was conducted in the regeneration affectation on 1985 and 2007. The measurement were done with a similar design (systematic randomized sampling in a 150×200m grid and 0.1 ha circular field plots) in 1985 and 2007, respectively. A...

2010
Elisabet Rodby-Bousquet Gunnar Hägglund

BACKGROUND Knowledge of sitting and standing performance in a total population of children with cerebral palsy (CP) is of interest for health care planning and for prediction of future ability in the individual child. In 1994, a register and a health care programme for children with CP in southern Sweden was initiated. In the programme information on how the child usually sits, stands, stands u...

2003
Hubert Sterba

Stem number distributions in uneven-aged forests are assumed to be stable, if they follow special functions, e.g. de Liocourt’s reverse J-shaped breast height diameter distribution. These distributions therefore are frequently regarded as a target in all-aged forests. Intending to convert an even-aged forest or any other forest, not yet exhibiting this sort of equilibrium, towards a steady stat...

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