نتایج جستجو برای: habitat degradation

تعداد نتایج: 203316  

Journal: :محیط شناسی 0
فرود آذری دهکردی استادیار گروه برنامه ریزی و مدیریت دانشکدة محیط زیست، دانشگاه تهران نوشین خزاعی دانشجوی کارشناسی ارشد، دانشکدة محیط زیست دانشگاه تهران

degradation model was introduced as an instrument of environmental impact assessment (eia) in iran. several methods are introduced in rapid environmental assessment, but none of them have evaluated landscape level. thus, the main objective of this research is to introduce a new spatial method for eia by using landscape metrics. a benefit of rapid assessment by using ecological landscape metrics...

Journal: :جنگل و فرآورده های چوب 0
بیت الله محمودی استادیار گروه جنگلداری دانشکدة منابع طبیعی و علوم زمین دانشگاه شهرکرد، شهرکرد، ایران احمد بازگیر دانشجوی دکتری جنگلداری دانشکدة کشاورزی دانشگاه لرستان، خرم آباد، ایران جهانگیر فقهی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران فاطمه جعفری کارشناس ارشد مدیریت کشاورزی دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

one of the indicators of management and sustainability control of forest resources is the definition deforestation and degradation types. these factors hazard quantitative and qualitative of the iranian forests. in this study with integrated approach, different forms of forest degradation identified in the forest areas with a reviews of library resources and then investigation the degree of sta...

2013
Boris Worm Hunter S. Lenihan

hroughout history, people have preferentially settled along coastlines, and they continue to do so today. Coastal people make up more than half of the total human population, and coastal settlements are transforming marine habitats at a rapid pace. Coastal people have also been long engaged in the extraction of marine resources, mostly animals such as marine mammals, fi sh, and invertebrates as...

Some riparian areas of the country are in danger of deterioration due to uncontrolled exploitation coupled with loose implementation of environmental protection policies and regulations. Muleta River, a major watershed in Bukidnon, Philippines, was assessed to determine the present condition of its riparian habitat. Abiotic and biotic conditions of the river were assessed. Other factors includi...

2011
Phil Pollett Ross McVinish

We construct a stochastic patch occupancy metapopulation model that incorporates variation in habitat quality and an Allee-like effect. Using some basic results from stochastic ordering, we investigate the effect of habitat degradation on the persistence of the metapopulation. In particular, we show that for a metapopulation with Allee-effect habitat degradation can cause a dramatic decrease in...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه هنر اصفهان - دانشکده معماری و شهرسازی 1389

reserches show that relationship between human and residential places is based upo both emotional and identity structures. in other words, habitat place is not only the creator of a part of humanistic identity but also form a kind of sentimental and emotional bond that may result in tendency to maintain closeness to a specific place. therefor, formaton of emotional and identity relationship wit...

Journal: :Ecological applications : a publication of the Ecological Society of America 2011
Virgilio Hermoso Miguel Clavero Francisco Blanco-Garrido José Prenda

Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driv...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2008
Elizabeth B Harper Tracy A G Rittenhouse Raymond D Semlitsch

Much of the biodiversity associated with isolated wetlands requires aquatic and terrestrial habitat to maintain viable populations. Current federal wetland regulations in the United States do not protect isolated wetlands or extend protection to surrounding terrestrial habitat. Consequently, some land managers, city planners, and policy makers at the state and local levels are making an effort ...

2011
Christopher P. Johnstone Alan Lill Richard D. Reina

Habitat fragmentation and degradation seriously threaten native animal communities. We studied the response of a small marsupial, the agile antechinus Antechinus agilis, to several environmental variables in anthropogenically fragmented Eucalyptus forest in south-east Australia. Agile antechinus were captured more in microhabitats dominated by woody debris than in other microhabitats. Relative ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده کشاورزی 1390

abstract this study is carried out to determine the chemical composition in the three vegetative stages of the haloxylon sp., degradation parameters, with adding naoh and ca(oh2 ). for this purpose, in may and october and january 2010 enough some haloxylon sp. of the ammary area was prepared. crude protein and ash percentage are decrease, neutral detergent fiber percentage with pragress stage ...

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