نتایج جستجو برای: livestock ecosystem

تعداد نتایج: 104389  

2002
Charles G. Curtin Nathan F. Sayre Benjamin D. Lane

10 Environmentalists, scientists, and land managers have long debated the role of ranching in landscape conservation with some contending that ranching represents the major threat to ecological systems, while others believe it is key to long-term conservation. We contrast the impacts of livestock grazing with those of the major alternative land use at this time, suburban and ex-urban developmen...

2010
W. Marc Jones Lauchlan H. Fraser

Wetlands are ecologically and economically important ecosystems with high conservation value. Although wetland vegetation is strongly determined by abiotic factors, grazing disturbance may also be an important influence on this community. We evaluated the effects of livestock grazing on wetland vegetation in marsh and wet meadow zones in intermountain depressional wetlands in the southern inter...

2006
Aliza Fleischer Marcelo Sternberg

Article history: Received 6 July 2005 Received in revised form 11 October 2005 Accepted 21 October 2005 Available online 4 January 2006 Global Climate Change (GCC) can bring about changes in ecosystems and consequently in their services value. Here we show that the urban population in Israel values the green landscape of rangelands in the mesic Mediterranean climate region and is willing to pay...

2006
DAVID H. BRANSON

G ecosystems cover 30% to 40% of the earth’s terrestrial surface, provide critical habitat for large numbers of species, and support extensive grazing economies on every continent except Antarctica (Coupland 1979, Samson and Knopf 1996). In the United States alone, there are approximately 312 million hectares of rangeland (NRC 1994). Fire, grazing, and climate combine to act as the primary ecos...

2002
N. T. Donkor J. V. Gedir R. J. Hudson E. W. Bork D. S. Chanasyk M. A. Naeth

Donkor, N. T., Gedir, J. V., Hudson, R. J., Bork, E. W., Chanasyk, D. S. and Naeth, M. A. 2002. Impacts of grazing systems on soil compaction and pasture production in Alberta. Can. J. Soil Sci. 82: 1–8. Livestock trampling impacts have been assessed in many Alberta grassland ecosystems, but the impacts of animal trampling on Aspen Boreal ecosystems have not been documented. This study compared...

2016
Matthew Heron Wilson Sarah Taylor Lovell

Agriculture faces the unprecedented task of feeding a world population of 9 billion people by 2050 while simultaneously avoiding harmful environmental and social effects. One effort to meet this challenge has been organic farming, with outcomes that are generally positive. However, a number of challenges remain. Organic yields lag behind those in conventional agriculture, and greenhouse gas emi...

2010
J. J. McDermott S. J. Staal H. A. Freeman M. Herrero J. A. Van de Steeg

Available online xxxx Smallholder livestock keepers represent almost 20% of the world population and steward most of the agricultural land in the tropics. Observed and expected increases in future demand for livestock products in developing countries provide unique opportunities for improving livelihoods and linked to that, improving stewardship of the environment. This cannot be a passive proc...

1999
J. T. du Toit D.H.M. Cumming

The African savanna biome supports a higher diversity of ungulate species than is found in any other biome or continent. This exceptional faunal diversity and herbivore biomass density is directly linked to the high spatial heterogeneity of African savanna ecosystems. The dependence of herbivore dietary tolerance on body size translates into important size-related differences between savanna un...

2017
Patrick Roberts Chris Hunt Manuel Arroyo-Kalin Damian Evans Nicole Boivin

Abstract: Significant human impacts on tropical forests have been considered the preserve of recent societies, linked to large-scale deforestation, extensive and intensive agriculture, resource mining, livestock grazing and urban settlement. Cumulative archaeological evidence now demonstrates, however, that Homo sapiens has actively manipulated tropical forest ecologies for at least 45,000 year...

2011
A. Ramoelo M. Cho

Information about the distribution of grass nitrogen (N) concentration is crucial in understanding rangeland vitality and facilitates effective management of wildlife and livestock. A challenge in estimating grass N concentration using remote sensing in savannah ecosystems is that these areas are characterised by heterogeneity in edaphic, topographic and climatic factors. The objective is to te...

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