نتایج جستجو برای: extent of area by forest type relative to total forest area

تعداد نتایج: 22688644  

2017
Peter Potapov Matthew C Hansen Lars Laestadius Svetlana Turubanova Alexey Yaroshenko Christoph Thies Wynet Smith Ilona Zhuravleva Anna Komarova Susan Minnemeyer Elena Esipova

An intact forest landscape (IFL) is a seamless mosaic of forest and naturally treeless ecosystems with no remotely detected signs of human activity and a minimum area of 500 km2. IFLs are critical for stabilizing terrestrial carbon storage, harboring biodiversity, regulating hydrological regimes, and providing other ecosystem functions. Although the remaining IFLs comprise only 20% of tropical ...

Journal: :تحقیقات آب و خاک ایران 0
آرش کرمی کارشناسی ارشد، دانشگاه تهران قوام الدین زاهدی دانشیار، دانشگاه تهران جهانگیر فقهی دانشیار، دانشگاه تهران

some soil physical and chemical characteristics were analyzed in order to reveal the relationship between forest soils and regeneration patches. gorazbon district of kheyrud was selected as a case study for the research area. all regeneration patches were recorded using gps device. to assess the spatial structure and to quantify the metrics of regeneration patches, analyzing of landscape metric...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

today, scouring is one of the important topics in the river and coastal engineering so that the most destruction in the bridges is occurred due to this phenomenon. whereas the bridges are assumed as the most important connecting structures in the communications roads in the country and their importance is doubled while floodwater, thus exact design and maintenance thereof is very crucial. f...

Journal: :Ecological applications : a publication of the Ecological Society of America 2011
Patrick M A James Brian R Sturtevant Phil Townsend Pete Wolter Marie-Josée Fortin

Increases in the extent and severity of spruce budworm (Choristoneura fumiferana Clem.) outbreaks over the last century are thought to be the result of changes in forest structure due to forest management. A corollary of this hypothesis is that manipulations of forest structure and composition can be used to reduce future forest vulnerability. However, to what extent historical forest managemen...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی 1393

abstract: the present study is an attempt to find out cultural exophoric references in iranian high-school elt textbooks and touch stone series to compare the frequency of occurrence of such references in these books. the purpose is to find out which of the series of the books under investigation impose a greater referential burden on efl learners as far as their reading comprehension of the ...

Journal: :caspian journal of environmental sciences 2010
m. nikooy

in the shafaroud forest, logging operation is generally performed by using selective cutting methods. chainsaw and cable skidder are two main forest machines for harvesting of this forest. however, forest harvesting operations result in serious residual stand damage during felling, winching and skidding operations in this forest. residual stand damage resulting from selective cutting was assess...

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیخ بهایی - دانشکده زبانهای خارجی 1390

in one pole of the continuum of language learning, theoreticians and practitioners traditionally consider english as english as a second language or english as a foreign language. however, in the other pole of this continuum where english is thought of as the most effective tool for international communication, it is referred to as a lingua franca. those who favor an approach to english growing...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده اقتصادو علوم اجتماعی 1390

today, the route for economic development in most countries is the same as international open competitive economy. economic institutes well known that supportive public economy belonged on the past and they may compete in the global economy. it is obvious that if they have no competitive potency or not familiar with competition technique, they may be devastated. banking system aims to collect t...

Journal: :جنگل و فرآورده های چوب 0
الهه علی بابایی عمران دانشجوی کارشناسی ارشددانشگاه تهران مهدی قربانی استادیار دانشگاه تهران محمدرضا مروی مهاجر استاد دانشگاه تهران محمد عواطفی همت استادیار دانشگاه تهران

forest management as one of the important source of production is crucial and critical. in taking over the forest resources as one of the most important of natural resources in the world, it is essential to consider local stakeholders to implement forest action plan for forest co-management. therefore, this study aims at achieving to proper management of forests based on evaluating the stakehol...

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