نتایج جستجو برای: taleghan rangelands
تعداد نتایج: 2471 فیلتر نتایج به سال:
Rangelands T he topic of global change is found almost daily in newspaper and magazine articles and on television. Global change refers to large-scale changes in the Earth’s biological, geological, hydrological, and atmospheric systems, whether of human or natural origin. The primary concern of global change has centered on the rapid increase in atmospheric concentrations of primary greenhouse ...
Nevada. The speakers, their affi liations, and topics are listed in the sidebar. Two important concepts emerged from the presentations and discussions. First, the ecological concepts and assumptions that underlie the development and implementation of ESDs are undergoing revision at a rapid pace. Most importantly, the assumption that reconstructing the ecological dynamics of a group of similar s...
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...
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...
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...
تعیین اندازه واحد دامی و نیاز روزانه گوسفند نژاد فشندی چرا کننده در مرتع (مطالعه موردی منطقه طالقان)
Information on animal requirements for determination of rangeland grazing capacity is essential. Animal requirements depend on its live weight, age, physiological condition and quality of available forage. There are more than 20 sheep breeds with different body sizes grazing in various climatic zone's rangelands of Iran, so animal unit equivalent of each breed should be determined independently...
There is a multifaceted approach of water resource in a watershed, which is accompanied by complexity and issues such as the interaction of natural and human systems. Achieving the consistent governance of water resources is one of the most important management approaches in the water sector, which requires a coherent structure of knowledge transfer and information on the organizations stakehol...
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...
the relationship between some habitat factors and fish assemblage was analyzed in the taleghan river, alborz province, iran. fish specimens from thirty-three sites were sampled by electrofishing device in october 2014. the habitat parameters, including elevation (m), water depth (cm), river width (m), river slope (%), current velocity (m.s-1), number of large stone (> 15 cm), average stone diam...
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...
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