نتایج جستجو برای: forest and rangelands

تعداد نتایج: 16850589  

2009
R Mathieu K Wessels G Asner D. Knapp J. van Aardt M Cho B. Erasmus I. Smit

Land degradation is one of the most significant environmental problems in the semi-arid and arid savannas of Southern Africa. Degradation affects vegetation structure, cover and patchiness and this result in the loss of vegetation resources used by rural populations (grazing, fuel wood, and other non-timber forest products) and wildlife. Land degradation processes are influenced by rainfall, la...

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

in the past, forest road network designing was mainly done for its main goals-management and exploitation. this study was performed to pay attention for multilateral goals of forest roads, especially its role in forest villages’ development, in estakhr-posht of neka (6 villages) in series 2, section 6 of neka-zalem rood forest management plan. at first, constructed forest roads and suggested ro...

Journal: :Remote Sensing 2015
Abdoul Aziz Diouf Martin Brandt Aleixandre Verger Moussa El Jarroudi Bakary Djaby Rasmus Fensholt Jacques André Ndione Bernard Tychon

Timely monitoring of plant biomass is critical for the management of forage resources in Sahelian rangelands. The estimation of annual biomass production in the Sahel is based on a simple relationship between satellite annual Normalized Difference Vegetation Index (NDVI) and in situ biomass data. This study proposes a new methodology using multi-linear models between phenological metrics from t...

2014
Kari E. Veblen David A. Pyke Cameron L. Aldridge Michael L. Casazza Timothy J. Assal Melissa A. Farinha

Public land management agencies, such as the Bureau of Land Management (BLM), are charged with managing rangelands throughout the western United States for multiple uses, such as livestock grazing and conservation of sensitive species and their habitats. Monitoring of condition and trends of these rangelands, particularly with respect to effects of livestock grazing, provides critical informati...

Journal: :environmental resources research 2014
syavash kalbi asghar fallah shaban shataee

forest types mapping, is one of the most necessary elements in the forest management and silviculture treatments. traditional methods such as field surveys are almost time-consuming and cost-intensive. improvements in remote sensing data sources and classification –estimation methods are preparing new opportunities for obtaining more accurate forest biophysical attributes maps. this research co...

1999

L and-use change in the United States represents an enormous uncontrolled experiment in the ways habitat changes influence plants and animals. When cities were built, land was plowed, or forests were cut, the effects on our native biota were not considered. Of course, humans have influenced the flora and fauna of North America over the ages. Native Americans established settlements, practiced a...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی صنعتی کرمان - دانشکده برق و کامپیوتر 1390

عملکردهای زیستی پروتئین ها به واکنش های شیمیایی آنها با محیط پیرامون و سایر پروتئین ها بستگی دارد. به عبارت دیگر، ساختار سه بعدی و نحوه تاخوردن اجزای پروتئین ها در فضا، چگونگی این تعاملات را تعیین می کند. تشخیص صحیح الگوی تاخوردگی پروتئین با استفاده از اطلاعات استخراج شده از توالی آن، یکی از مسائل پیچیده و بحث برانگیز در زمینه بیوانفورماتیک می باشد. در این پایان نامه، سه روش نوین مبتنی بر الگور...

Journal: :جنگل و فرآورده های چوب 0
پریسا مقدسی کارشناس ارشد مهندسی جنگل، دانشکدة منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران عطاالله حسینی دانشیار گروه جنگلداری و اقتصاد جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران اصغر فلاح دانشیار گروه علوم جنگل، دانشکدة منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران

forests as a renewable source has effective and useful role in economic and social activities of society. network of forest roads as infrastructure division’s forest planning units (compartments) of forest management plans, management, logging, exit of wood and plays a major role forest protection. aim of this study, designed forest road network according to multi-purpose forestry using the net...

Extended abstract Introduction The present study was performed to investigate the effects of slope percentage and land use type on the produced sediment by an artificial rainfall simulator in Kakasharaf watershed, a branch of Karkhe watershed (Lorestan province).   Methodology The rainfall simulator used in this research was designed and constructed by the Soil Conservation and...

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