نتایج جستجو برای: shannon and wiener species diversity

تعداد نتایج: 16927632  

Journal: :جنگل و فرآورده های چوب 0
بیت الله امان زاده دانشجوی دکتری علوم جنگل، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران محمد رضا پورمجیدیان دانشیار، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران خسرو ثاقب طالبی دانشیار پژوهش، مؤسسة تحقیقات جنگل‏ها و مراتع کشور، تهران، ایران سید محمد حجتی دانشیار، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران

in order to study the effect of canopy gap size on species diversity and composition in mixed stands, a reserved area which located in asalem forests was selected. all of gaps in this area identified and were divided into four categories: small gaps (1000 m2). in each category, 21 of gaps with a relatively homogeneous in terms of an aspect and slope were selected. the major and minor diameter o...

Abas Jamshidi Bakhtar, Khosro Sagheb-Talebi Maziar Haidari, Mohamad Reza Marvi Mohajer

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

Journal: :جنگل و فرآورده های چوب 0
مهرداد میرزایی دانشجوی دکتری جنگلداری دانشکدة منابع طبیعی دانشگاه گیلان، صومعه‏سرا، ایران امیر اسلام بنیاد دانشیار گروه جنگلداری دانشکدة منابع طبیعی دانشگاه گیلان، صومعه‏سرا، ایران حسن پوربابایی دانشیار گروه جنگلداری دانشکدة منابع طبیعی دانشگاه گیلان، صومعه‏سرا، ایران محبوبه محبی بیجارپس دانشجوی دکتری جنگلداری دانشکدة منابع طبیعی دانشگاه گیلان، صومعه‏سرا، ایران

aim of this research was evaluated and compared of density (number tree per hectare), basal area and volume characteristics for estimation of tree species diversity in degraded forests. in order to, 73 hectares of kouhmian forests was inventory based on random systematic pattern with circular plots (10r and 26 plots). in each plot species, dbh and number of tree were measured and recorded. to e...

Abas Jamshidi Bakhtar, Khosro Sagheb-Talebi Maziar Haidari, Mohamad Reza Marvi Mohajer

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

Abas Jamshidi Bakhtar, Khosro Sagheb-Talebi Maziar Haidari, Mohamad Reza Marvi Mohajer

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

Abas Jamshidi Bakhtar, Khosro Sagheb-Talebi Maziar Haidari, Mohamad Reza Marvi Mohajer

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

the aim of this study is comparison of soil characteristics and biodiversity in plantation of bald cypress and caucasian alder forest stands in kludeh region (mazandaran province). in order to study biodiversity in forest stands and control region, 10 sample plots (releve) were selected and the name and abundance of plant species of the forest floor were recorded. biodiversity of herbal plants ...

al. et M. Sharifinia

The distribution of macroinvertebrate communities from 5 sampling sites of the Tajan River were used to examine the relationship among physiochemical parameters with macroinvertebrate communities and also to assess ecological classification system as a tool for the management and conservation purposes. The amount of variation explained in macroinvertebrate taxa composition is within values r...

Journal: :محیط زیست طبیعی 0
زهرا نوری دانشجوی دکترای جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران جهانگیر فقهی دانشیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران قوام الدین زاهدی امیری دانشیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تهران، ایران رامین رحمانی دانشیار گروه جنگلداری، دانشگاه گرگان، ایران

the aim of this study is to investigate the tree species' diversity in a region with no management planning and introduce the calculated indices as the norm for sustainability assessment. dbh of all tree individuals, and their stories were recorded in the inventory grid (75 m × 100 m) sample plots. subsequently, richness, evenness (simpson, smith & wilson) and heterogeneity (simpson, shann...

Salinity is one of the environmental parameters that its impact on plant species diversity requires further studies. In this research, change of plant diversity was studied along a salinity gradient that was resulted from proximity of water table to the land surface in Incheh Borun plain due to the altitudinal change in northern part of Aq-Qala city. A transect with the length of 1 km was laid ...

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