نتایج جستجو برای: moderate grazing

تعداد نتایج: 196293  

2014
Jae R. Pasari Daniel L. Hernández Erika S. Zavaleta

The interaction of resource availability and disturbance can strongly affect plant species richness and the spread of exotic plants. Several ecological theories posit that disturbance mediates the richness-reducing effects of increased competition as resource levels rise. In the low-nutrient serpentine grasslands of the San Francisco Bay Area, the fertilizing effects of atmospheric nitrogen (N)...

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 ...

1998
C. L. Alados J. M. Emlen D. C. Freeman

Developmental instability has been used to monitor the well-being of natural populations exposed to physical, chemical and biological stressors. Here, we use developmental instability to assess the impact of grazing on Chrysothamnus greenii and Seriphidium novum shrubs, and Oryzopsis hymenoides grass, common in the arid intermountain west of the U.S.A. Statistical noise in allometric relations ...

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...

2013
Just Cebrian Jason P. Stutes B. Christiaen

The effects of grazing and nutrients on epiphyte biomass in seagrass beds have received much attention, yet less is known about effects on other metrics of epiphyte growth dynamics, such as epiphyte productivity and biomass turnover rates. To help address this gap, we present here a number of mesocosm experiments in which we manipulate grazer presence and nutrient concentrations under initially...

2007
M. F. Wallis De Vries A. E. Parkinson J. P. Dulphy M. Sayer

Finding an optimal balance between livestock production and grazing impact on animal diversity is important for the development of sustainable grazing systems. This paper tests the hypothesis that extensification of grazing management enhances animal diversity. Similar treatments were applied over a period of three years to sites in the UK, France, Germany and Italy. There were three treatments...

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...

2015
Xiajie Zhai Tingting Lu Shiming Tang Xiaojuan Liu Xiuzhi Ma Guodong Han Andreas Wilkes Chengjie Wang

Methane (CH4) emissions from ruminants should be accounted for the natural grazed rangeland ecosystems when devising greenhouse gas budget inventory, in particular, their contribution to global warming. In this study, CH4 emission from sheep respiration at different grazing intensities (light grazing, 0.75 sheep/ha, LG; moderate grazing, 1.50 sheep/ha, MG; and heavy grazing, 2.25 sheep/ha, HG) ...

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