نتایج جستجو برای: 26 forest cover types

تعداد نتایج: 833058  

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...

Journal: :Ecological applications : a publication of the Ecological Society of America 2006
Celia A Harvey Arnulfo Medina Dalia Merlo Sánchez Sergio Vílchez Blas Hernández Joel C Saenz Jean Michel Maes Fernando Casanoves Fergus L Sinclair

As tropical regions are converted to agriculture, conservation of biodiversity will depend not only on the maintenance of protected forest areas, but also on the scope for conservation within the agricultural matrix in which they are embedded. Tree cover typically retained in agricultural landscapes in the neotropics may provide resources and habitats for animals, but little is known about the ...

2004
Anne W. Nolin

Vegetation structure and density affect the dynamics of snow accumulation and ablation. Vegetation also affects our ability to estimate snow-covered area accurately from satellite-based sensors. The objective of this case study is to demonstrate how the angular pattern of reflectance from vegetation over snow can provide information on forest cover density. Imagery from the Multi-angle Imaging ...

2006
Jose M. Iniguez Joseph L. Ganey Peter J. Daugherty John D. Bailey

The objective of this study was to develop a rule based cover type classification system for the forest and woodland vegetation in the Sky Islands of southeastern Arizona. In order to develop such a system we qualitatively and quantitatively compared a hierarchical (Ward’s) and a non-hierarchical (k-means) clustering method. Ecologically, unique groups represented by only a few plots were appro...

2015
Dávid Bogyó Tibor Magura Dávid D. Nagy Béla Tóthmérész

We studied the distribution of millipedes in a forest interior-forest edge-grassland habitat complex in the Hajdúság Landscape Protection Area (NE Hungary). The habitat types were as follows: (1) lowland oak forest, (2) forest edge with increased ground vegetation and shrub cover, and (3) mesophilous grassland. We collected millipedes by litter and soil sifting. There were overall 30 sifted lit...

2011
Ekwal Imam

Monitoring changes in landscape cover types has been a great concern for forest and wildlife managers. Both managers find it very important to know how much area is suitable for wildlife species and what areas are affected due to anthropogenic pressure. To address these concerns, evaluation of Chandoli National Park was done to see the changes that have taken place over the past 28 years. The N...

2004
Robert V O’Neill Kenneth H. Reckhow Timothy G. Wade K. Bruce Jones

A survey of numerous field studies shows that nitrogen and phosphorous export coefficients are significantly d@erent across forest, agriculture, and urban land-cover types. We used simulah’ons to estimate the land-cover composition at which there was a sigt$cant risk of nutrient loads representative of watersheds without forest cover. The results suggest that at between 20 percent and 30 percen...

Forest fragmentation results in a loss of forest interior and an increase in edge habitat. We studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular Malaysia. Birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of...

Journal: :محیط زیست طبیعی 0
شریف جورابیان شوشتری کارشناس ارشد محیط زیست، دانشکدۀ منابع طبیعی، دانشگاه تربیت مدرس عباس اسماعیلی ساری استاد گروه محیط زیست، دانشکدۀ منابع طبیعی، دانشگاه تربیت مدرس سید محسن حسینی دانشیار گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس مهدی غلامعلی فرد دانشجوی مقطع دکتری و بورسیه هیئت علمی گروه محیط¬زیست، دانشکده منابع طبیعی، دانشگاه تربیت مدرس.

this study was performed with objective land cover change prediction (forest, agriculture, residential and orchard) using logistic regression and markov chain in the gis environment in east of mazandaran province. land cover change detected using satellite imageries belonging to the years 1987 and 2001. transition potential modeling was conducted using a logistic regression. seven variables (de...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Oliver T Coomes Yoshito Takasaki Jeanine M Rhemtulla

In this article we illustrate how fine-grained longitudinal analyses of land holding and land use among forest peasant households in an Amazonian village can enrich our understanding of the poverty/land cover nexus. We examine the dynamic links in shifting cultivation systems among asset poverty, land use, and land cover in a community where poverty is persistent and primary forests have been r...

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