نتایج جستجو برای: heavy grazing

تعداد نتایج: 139962  

Journal: :Ecology letters 2013
Brandon T Bestelmeyer Michael C Duniway Darren K James Laura M Burkett Kris M Havstad

Theoretical models predict that drylands can cross critical thresholds, but experimental manipulations to evaluate them are non-existent. We used a long-term (13-year) pulse-perturbation experiment featuring heavy grazing and shrub removal to determine if critical thresholds and their determinants can be demonstrated in Chihuahuan Desert grasslands. We asked if cover values or patch-size metric...

2002
M. Gutman A. Perevolotsky

Widely -contrasting stocking rates and grazing schedule treatments were imposed upon a Mediterranean herbaceous community in northern Israel. Botanical composition was monitored for 3 years. The vegetative community was found to be highly resilient to the treatments. Perennial grasses and legumes were among the resilient plants. These results are consistent with the view that Mediterranean ecos...

2009
Jaime Kigel

Question: Is the assumption of trait independence implied in Westoby’s (1998) leaf-height-seed (LHS) ecology strategy scheme upheld in a Mediterranean grazing system dominated by annuals? Is the LHS approach applicable at the community level? Location: Northern Israel. Methods: LHS traits (specific leaf area [SLA], plant height and seed mass), and additional leaf traits (leaf dry matter content...

2013
Jixin Cao Xiaoping Wang Xiangyang Sun Lin Zhang Yun Tian

Grazing can cause changes in soil carbon (C) level. This study aimed to elucidate the response of soil labile organic carbon (SLOC) under four different grazing intensities: non grazing (NG), 0 sheep·ha(-1); light grazing (LG), 0.91 sheep·ha(-1); moderate grazing (MG), 1.82 sheep·ha(-1), and heavy grazing (HG), 2.73 sheep·ha(-1). Results showed that there was no significant difference in total ...

Journal: :Ecological applications : a publication of the Ecological Society of America 2016
David J Eldridge Alistair G B Poore Marta Ruiz-Colmenero Mike Letnic Santiago Soliveres

Reports of positive or neutral effects of grazing on plant species richness have prompted calls for livestock grazing to be used as a tool for managing land for conservation. Grazing effects, however, are likely to vary among different response variables, types, and intensity of grazing, and across abiotic conditions. We aimed to examine how grazing affects ecosystem structure, function, and co...

2013
Liang Yan Guangsheng Zhou Feng Zhang

BACKGROUND Grazing is one of the main grassland disturbances in China, and it is essential to quantitatively evaluate the effects of different grazing intensities on grassland production for grassland carbon budget and sustainable use. METHODS A meta-analysis was conducted to reveal general response patterns of grassland production to grazing in China. We used weighted log response ratio to a...

2007
James W. Bartolome

This experiment compared California ground squirrel (Spermophilus beecheyi) activity on replicated grazed and ungrazed pastures in a blue oak (Quercus douglasii) savanna. During the 4-year study, squirrel activity, measured as the number of active burrows, generally declined in grazed and ungrazed pastures without oak canopy. Squirrel activity declined least in grazed pastures with blue oak can...

Journal: :Journal of animal science 1992
D P Mowrey A G Matches R L Preston

Sainfoin (Onobrychis viciaefolia Scop.) is adapted to the calcareous soils of the southern Great Plains and can provide early season forage that does not induce bloating; however, little is known about performance by ruminants grazing sainfoin. Our objective was to determine the effect of plant growth stage and grazing pressures on potential animal production from sainfoin as predicted from ene...

1999

Chaparral lands of central Arizona are important for water production. They are also used as grazing lands for livestock and as habitat for wildlife. An understanding of the relation of grazing to runoff and erosion is thus essential to the development of management systems for sustained high yields. This paper reports the effects of grazing on runoff and erosion as determined on four experimen...

2009
H.M.A. Gaafar

Twenty four dairy cows and buffaloes were divided in two locations with 6 dairy cows and 6 dairy buffaloes in each. The animals in the first location were fed on berseem irrigated by Nile water, while in the second location (Burullus Lake) they were kept on reed plants. The obtained results showed that the contents of heavy metals (lead, cadmium, copper, nikel, aluminum, arsenic and mercury) in...

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