نتایج جستجو برای: steppe rangelands

تعداد نتایج: 6506  

2008
E. G. King

Livestock overgrazing can threaten the ecological integrity of rangelands, and can also threaten the sustainability of pastoralist societies who depend on rangelands for their livelihood. Using facilitator plants in the restoration of degraded semi-arid rangelands offers a promising strategy because in such environments, facilitators can ameliorate harsh conditions that often limit the establis...

2005
P. B. Adler M. F. Garbulsky J. M. Paruelo W. K. Lauenroth

Previous work in climatically similar sagebrush steppe, USA and Patagonian steppe, Argentina suggested that a more intense evolutionary history of grazing in Patagonia selected for graminoids of lower forage quality, resulting in a plant community more resistant to livestock grazing. Here we consider whether subtle abiotic differences might create greater water or nutrient limitation in Patagon...

Journal: :Environmental pollution 2002
G E Schuma H H Janzen J E Herrick

The USA has about 336 Mha of grazing lands of which rangelands account for 48%. Changes in rangeland soil C can occur in response to a wide range of management and environmental factors. Grazing, fire, and fertilization have been shown to affect soil C storage in rangelands, as has converting marginal croplands into grasslands. Carbon losses due to soil erosion can influence soil C storage on r...

Journal: :Bulletin of the Ecological Society of America 2006

2016
Hua Liu Runguo Zang Han Y. H. Chen

Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respirati...

2011
K. J. Wessels R. Mathieu

People in the rural, communal areas of South Africa rely on live fuel wood for more than 90% of their energy requirements. Using airborne lidar from the Carnegie Airborne Observatory (CAO) we compared tree canopy cover and height distributions between communal landscapes with heavy utilization to fully protected public and private reserves in the Lowveld of South Africa. Rangelands and fields i...

2006
E. Durant

_______________________________________ The 11 papers in this document address issues and needs in the development and stewardship of Central Asia rangelands, and identify directions for future work. With its vast rangelands and numerous pastoral populations, Central Asia is a region of increasing importance to rangeland scientists, managers, and pastoral development specialists. Five of the pa...

Journal: :مرتع و آبخیزداری 0
سپیده فاضلیان دانشجوی کارشناسی ارشد مرتع داری، دانشگاه شهرکرد پژمان طهماسبی استادیار گروه مرتع و آبخیزداری دانشکدة منابع طبیعی دانشگاه شهرکرد حمزه علی شیرمردی کارشناس ارشد پژوهش مرکز تحقیقات کشاورزی و منابع طبیعی استان چهارمحال و بختیاری اسماعیل اسدی دانشیار گروه مرتع و آبخیزداری دانشکده منابع طبیعی دانشگاه شهرکرد

endozoochory is one of the seed dispersal modes through animal’s digestive systems transmission and the increases rate germination and plant establishment. the aim of this study, investigated the relationship between seed characteristics and the passage through the digestive tract of livestock and domestic animals (cattle, sheep and goats) in the 7 species perennial grass 8 species perennial fo...

Journal: :desert 2008
n. baghestani-maybodi m. jankju-borzelabad m. taghi zare

one of the key factors in managing a rangeland is to determine the relative preference of its major plant species by thegrazing livestock. preference value of each plant species is affected by plant type, companion plants, availability byanimals, phenological stage, climate condition, and the livestock species. we investigated the grazing behaviour of anative goat (garizi) in the steppe rangela...

In the rangelands of Iran, the lack of appropriate grazing management is one of the major problems ultimately leading to untimely and excessive grazing intensity of forage. Accordingly, most of the rangelands show a retrogression trend and poor conditions. In forage species, phenological stage is one of the most important criteria for range management. Bromus tomentellus species is an ...

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