نتایج جستجو برای: natural rangelands

تعداد نتایج: 483631  

Journal: :محیط زیست طبیعی 0
منصوره کارگر دانشکده منابع طبیعی دانشگاه علوم کشاورزی و منابع طبیعی ساری زینب جعفریان دانشیار دانشگاه علوم کشاورزی و منابع طبیعی ساری

natural fire inflicting irreparable damage to rangelands and forest areas is cause changes in landscape ecology. the purpose of this research is comparison of artificial neural network (ann) and line regression (lr) models to predict of forest and rangelands fires to this end, the data consist fire burned area and fire were used weather data over a period of 7 years (2006-2012(.the result indic...

2013
Nathan F Sayre Ryan RJ McAllister Brandon T Bestelmeyer Mark Moritz Matthew D Turner

www.frontiersinecology.org © The Ecological Society of America R – including grasslands, shrublands, savannas, deserts, prairies, steppe, and tundra – comprise 30–40% of Earth’s ice-free terrestrial surface (depending on one’s definition and data sources; Asner et al. 2004) and account for 91% of the world’s grazing lands (Reid et al. 2008). Encompassing watersheds for vast downstream populatio...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1391

the present study has tried to accomplish an analysis of margaret atwood’s novels oryx and crake, and the year of the flood in the light of posthuman and cyborg theories. considering posthumanism as a critical reading of some notions of humanism focus of which in this thesis has been identity, new definitions for humanity and human identity are formed. haraway’s cyborg, as one possible new figu...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
José D Anadón Osvaldo E Sala B L Turner Elena M Bennett

A large fraction of the world grasslands and savannas are undergoing a rapid shift from herbaceous to woody-plant dominance. This land-cover change is expected to lead to a loss in livestock production (LP), but the impacts of woody-plant encroachment on this crucial ecosystem service have not been assessed. We evaluate how tree cover (TC) has affected LP at large spatial scales in rangelands o...

2016
Iris Bumb Eric Garnier Denis Bastianelli Jean Richarte Laurent Bonnal Elena Kazakou

In spite of their recognized ecological value, relatively little is known about the nutritional value of species-rich rangelands for herbivores. We investigated the sources of variation in dry matter digestibility (DMD), neutral detergent fibre content (NDF) and nitrogen concentration (NC) in plants from species-rich Mediterranean rangelands in southern France, and tested whether the dry matter...

Journal: :Rangeland Ecology & Management 2021

Woodland expansion is a global challenge documented under varying degrees of disturbance, climate, and land ownership patterns. In North American rangelands, mechanical chemical brush management practices prescribed fire are frequently promoted by agencies used private landowners to reduce woody plant cover. We assess the distribution agency-supported cost sharing (2000−2017) in southern Great ...

Journal: :Ecological processes 2021

Abstract Background Studies of the African savannas have used national parks to test ecological theories natural ecosystems, including equilibrium, non-equilibrium, complex adaptive systems, and role top-down bottom-up physical biotic forces. Most such studies excluded impact pastoralists in shaping grassland ecosystems and, over last half century, growing human on world’s rangelands. The mount...

2012
A. Jamalian M. Shams-Ghahfarokhi A. Amani

Department of Mycology, Pasteur Institute of Iran, 13164 Tehran, Iran Department of Biology, Islamic Azad University, Science and Research Branch, Tehran, Iran Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, 14115-331 Tehran, Iran Department of Medicinal Plants and By-Products, Research Institute of Forest and Rangelands, 13185 Tehran, Iran Medicinal Chemistry L...

2017
Greg R. Guerin Ben Sparrow Andrew Tokmakoff Anita Smyth Emrys Leitch Zdravko Baruch Andrew J. Lowe

Australian rangelands ecosystems cover 81% of the continent but are understudied and continental-scale research has been limited in part by a lack of precise data that are standardised between jurisdictions. We present a new dataset from AusPlots Rangelands that enables integrative rangelands analysis due to its geographic scope and standardised methodology. The method provides data on vegetati...

Journal: :Environmental management 2011
Dustin D Johnson Kirk W Davies Peter T Schreder Anna-Marie Chamberlain

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass invading rangelands in the western United States. Medusahead is a serious management concern because it decreases biodiversity, reduces livestock forage production, and degrades the ecological function of rangelands. Despite the obvious importance of ranchers as partners in preventing and managing medusahead in rangel...

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