نتایج جستجو برای: natural forest

تعداد نتایج: 576922  

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

the hyrcanian forests have been highly exploited in recent decades by human impacts. easy access, abundance and variety of valuable forest yields have led to population growth density, creation of new residential areas and deforestation activities. change detection is one of the main methods of management and evaluation of natural resources. we investigated forest changes in southern surroundin...

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...

2003
Timothy G. Wade Kurt H. Riitters James D. Wickham K. Bruce Jones

Because human land uses tend to expand over time, forests that share a high proportion of their borders with anthropogenic uses are at higher risk of further degradation than forests that share a high proportion of their borders with non-forest, natural land cover (e.g., wetland). Using 1-km advanced very high resolution radiometer (AVHRR) satellite-based land cover, we present a method to sepa...

Different land uses have various effects on the changes of soil properties. The purpose of this study was to evaluate the effects of natural forest, needle-leaved plantation and rangelands of central Alborz on new indices of soil quality (i.e. organic matter stratification, carbon management index and soil biological activities). For this purpose, eight samples from organic layer (litter) and m...

2014
Michael K. Young Lisa Eby Lisa Holsinger Daniel J. Isaak Robert E. Keane

Robert E. Keane USDA Forest Service, [email protected] Follow this and additional works at: http://digitalcommons.unl.edu/jfspresearch Part of the Forest Biology Commons, Forest Management Commons, Natural Resources and Conservation Commons, Natural Resources Management and Policy Commons, Other Environmental Sciences Commons, Other Forestry and Forest Sciences Commons, Sustainability Commons, a...

Journal: :نامه انجمن حشره شناسی ایران 0
مصطفی نیکدل اریش دایلر

during the study of natural enemies of insect pests of forest trees and shrubs in arasbaran forest of iranian province of east azarbaijan, a number of larvae of yponomeuta evonymella l. were collected on wild cherry trees. the specimens were reared in the laboratory, where parasitoid wasps of the family ichneumonidae emerged and later identified as agrypon canaliculatum (ratzeburg, 1844). the i...

Journal: :محیط زیست طبیعی 0
زهرا نوری دانش آموختۀ دکتری جنگل داری، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران محمود زبیری استاد گروه جنگل داری و اقتصاد جنگل، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران جهانگیر فقهی دانشیار گروه جنگل داری و اقتصاد جنگل دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران محمدرضا مروی مهاجر استاد گروه جنگل داری و اقتصاد جنگل، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران

beech forests in midland areas of hyrcanian forests of iran are the most important forests having the highest degree of naturalness. these forests are the valuable source of wood production and other forest products. one of the most important characteristics of plant communities is the spatial pattern of trees. ecological process in forest ecosystems are directly influenced by the spatial patte...

2016
R. Cenusa I. Biris F. Clinovschi I. Barnoaiea C. Palaghianu M. Teodosiu

The paper presents the importance of research which characterizes the natural forest structure for the forest management. The lessons learned in these particular forest ecosystems can be integrated by the forest management objectives, in order to increase the sustainability of this type of resources. The project NATFORMAN was focused on the structure of the natural forest, thus research methodo...

Journal: :Remote Sensing 2016
Grant Connette Patrick Oswald Melissa Songer Peter Leimgruber

We investigated the use of multi-spectral Landsat OLI imagery for delineating mangrove, lowland evergreen, upland evergreen and mixed deciduous forest types in Myanmar’s Tanintharyi Region and estimated the extent of degraded forest for each unique forest type. We mapped a total of 16 natural and human land use classes using both a Random Forest algorithm and a multivariate Gaussian model while...

2014
J. Pablo Arroyo-Mora Margaret Kalacska Robin L. Chazdon

We present an in-depth analysis of natural forest management practices in Costa Rica based on a new historical forestry GIS database encompassing five conservation regions in the country where selective logging has been prevalent for the last 18 years. Natural forest management refers to the selective logging practices for the production of timber in natural forest ecosystems. The study conside...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید