نتایج جستجو برای: forest density

تعداد نتایج: 509797  

Azadnejad , Saeed , Taefi Feijani , Masoud ,

Mapping of forest extent is a prerequisite to acquire quantitative and qualitative information about forests and to formulate management and conservation strategies. forest canopy density (FCD) model is one of the useful RS methods for forest mapping using satellite images. One of the most serious challenges in FCD model is the weakness in the calculation of canopy density in low density forest...

Journal: :جنگل و فرآورده های چوب 0
رویا عابدی دانش آموخته دکترای جنگلداری/دانشکده منابع طبیعی، دانشگاه گیلان سید امیراسلام بنیاد استاد/دانشکده منابع طبیعی دانشگاه گیلان اسدالله شاه بهرامی دانشیار/دانشگاه گیلان

proper forest management needs quantitative and precise estimates of forest stands characteristics. remotely sensed imageries, due to accurate and broad spatial information, has become a cost-effective tool in forest management. classification of forest attributes and generation of thematic maps are among the common applications of remote sensing. the objective of this study was to optimize the...

Journal: :international journal of advanced biological and biomedical research 2013
maziar haidari nabiollah yarali naghi shabanian

for maintaining of zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. to detection of suitable sampling method to study tree diameter at breath height in the northern zagros forest, blake forest, in baneeh region, kurdistan province, and west of iran ...

سعدالدین, امیر, شتایی جویباری, شعبان, لطفعلیان, مجید, مصطفی, محسن,

     Planning, construction and assessment of road network are among the investigations for infrastructure development at watershed scales. The main aim of this study is assessing the road network connectivity in the Chehel-Chay Watershed, located in Golestan Province using Alpha (α), Beta (β), Gamma (γ), Eta (η), network density and detour indices in graph theory. The available road network ma...

A. Rohina M.R. Hemami S. Sobhani Ardakani, S.S. Mohaghegh

Since density is considered as one of the most important numerical indices to explain quantitative values of a plant community by affecting on many aspects and activity of ecosystem, on the other hand, awareness about plants distribution pattern in environment is an essential preparation for measurement and study of vegetative cover, therefore, in this research determination of density and dist...

Journal: :international journal of advanced biological and biomedical research 2013
maziar haidari manocher namiranian mahmood zobeiri loghman ghahramany

for maintaining of zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. to detection of suitable sampling method to study tree density in the northern zagros forest, blake forest, in baneeh region, kurdistan province, and west of iran was selected. 40 s...

Journal: :global journal of environmental science and management 0
m. yousefpoor faculty of natural resources, department of forestry, university of guilan, somehsara, guilan, iran t. rostamie shahraji faculty of natural resources, department of forestry, university of guilan, somehsara, guilan, iran a. eslam bonyad faculty of natural resources, department of forestry, university of guilan, somehsara, guilan, iran m. salahi faculty of basic sciences. university of guilan, rasht, iran

in order to evaluate the possible correlation between the tree density and the human population density, the forested area in nav asalem district located in guilan province was selected. the descriptors of tree number and basal area per hectare as well as the stand density index were used to determine the tree density, which was conducted from a 2014 forest inventory including 62 cluster (558 p...

Journal: :CoRR 2014
Sylvain Arlot Robin Genuer

Random forests are a very effective and commonly used statistical method, but their full theoretical analysis is still an open problem. As a first step, simplified models such as purely random forests have been introduced, in order to shed light on the good performance of random forests. In this paper, we study the approximation error (the bias) of some purely random forest models in a regressi...

Journal: :caspian journal of environmental sciences 2008
h. sobhani

the optimum road spacing has been studied by many researches. it is an important step of forest road network planning. the goals of this study are determining the optimum road spacing in kheiroudkenar forest of nowshahr in northern iran and study of effect of kind of skidder on skidding cost and road spacing. continues time study method was used to determine the production rate of taf and timbe...

Density and diversity of birds in two different forest zones, namely, Shasta Kalateh Protected Forest and Alangdareh Recreational Forest, were estimated and compared. Birds and environmental variables were recorded within 25 m radius in 100 sampling points. The first axis of Canonical Component Analysis segregated two main groups of birds. The first group consisted of Black Woodpecker, Great Sp...

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