نتایج جستجو برای: height of trees

تعداد نتایج: 21175163  

Journal: :Annals of Combinatorics 2009

Journal: :جنگل و فرآورده های چوب 0
فریده امیدوار حسینی دانشجوی کارشناسی ارشد رشتۀ جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، تهران، ایران رضا اخوان استادیار پژوهش، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران هادی کیادلیری استادیار گروه جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران اسداله متاجی دانشیار گروه جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران

one of the most visible aspects of a forest stand structure is the spatial patterns of trees. competition affects on forest structure and its understanding is important, when the purpose of forest management is to imitate the dynamic of natural ecosystems. for this purpose, an unmanaged intact forest was selected with 26 hectares area. all chestnut leaf oak (quercus castaneifolia) trees with a ...

Journal: :caspian journal of environmental sciences 2012
al. et e. ebrahimi

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...

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...

Michael Drmota,

The purpose of this article is to survey recent results on distributional properties of random binary search trees. In particular we consider the profile and the height.

رستمی, علی, شیخی, زهرا,

    Mistletoe (Loranthus europaeus Jacq) is an evergreen bush which is considered as a semi-parasitic plant of Ilam forests and show off in late autumn and winter in the northern forest of Ilam. The aim of this study was to investigate the effect of mistletoe on some Quantitative characteristics and nutrient uptake in oak forests (Quercus brantii L.) of Bankol in Ilam Province. For this study,...

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...

      In order to study the effect of altitude on some quantitative and qualitative characteristic of Populus deltoides in Mazandaran province, three sites were selected with elevations between 150 and 1200 m above sea level in Sari city. In each site, some tree traits such as diameter at breast height, total height, basal area, volume, form factor and qualitative variables including trunk heal...

Journal: :جنگل و فرآورده های چوب 0
فرهاد اسدی تحقیقات حسین میرزایی ندوشن عضو هیات علمی جمشید مختاری عضو هیات علمی

degradation of natural habitats and decreasing of genetic diversity of populus caspica led to vast reduction of its regeneration and growth potential in north of iran. hence, the growth potential of mass-produced seedlings was compared with their parents. for this purpose, the ramets of three selected seedlings from 17 parent trees belonging to north of iran, along with ramets of their parent t...

Journal: :caspian journal of environmental sciences 2008
f. fadaei a. fallah h latifi k. mohammadi

in order to determine the best form factor formula for loblolly pine (pinus taeda l.) plantations in talesh (western guilan province-iran), a number of 110 trees were selected based on their distribution in diameter classes, from 12 to 34 cm (in a two- cm diameter interval). first, several quantitative factors including diameter at breast height, diameter at 0.65 m of height, and diameter at st...

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