نتایج جستجو برای: open grazing

تعداد نتایج: 408252  

Journal: :Epidemiology and infection 2000
G K Gitau J J McDermott J M Katende C J O'Callaghan R N Brown B D Perry

A prospective cohort study was conducted in five purposively-sampled agro-ecological zone (AEZ)-grazing system strata in Murang'a District, Kenya, between March 1995 and June 1996. The study strata were selected based on a preliminary characterization study to represent the widest range of risks to East Coast fever (ECF) in the District and included zero-grazing and open-grazing farms. In total...

Journal: :مرتع و آبخیزداری 0
زهرا نیکبخت دانشجوی کارشناسی ارشد مرتع داری، گروه مرتع و آبخیزداری، دانشگاه فردوسی مشهد، ایران محمد فرزام دانشیار؛ گروه مرتع و آبخیزداری، دانشگاه فردوسی مشهد، ایران. محمد خواجه حسینی دانشیار، گروه زراعت، دانشگاه فردوسی مشهد، ایران حمید اجتهادی استاد، گروه زیست شناسی، دانشگاه فردوسی مشهد، ایران

the study of soil seed bank provides useful information on management and restoration of natural ecosystems. in the arid environments, some perennial plants may cause accumulation of seed bank under their canopy, thereby protecting them against the livestock herbivory and the other environmental factors. this study was conducted with objective to investigate effect of perennial plants on densit...

Spiny and aromatic species in rangelands can play important role in the conservation of plant species in rangelands; however, few studies  have been done on the role of these plants under different levels of livestock grazing. In this research, the facilitation effects of spiny (Astragalus chrysostachys Boiss) and aromatic (Artemisia kopetdaghensis (Poljakov) Y.R.Ling) shrubs were studied on sp...

Journal: :آب و خاک 0
کبری محمدپور سید حمیدرضا صادقی قاسمعلی دیانتی تیلکی

abstract quantitative investigation of effects of range management treatments on different soil and water components in rangeland ecosystems has been rarely taken into account. in the present research, the kodir summer rangeland in the southeast nowshahr in mazandaran province was selected for studying effects of open grazing and exclosure managements on infiltration, runoff and microrelief. ex...

Quantitative study of species diversity across different land use units and districts is important to document status of local plant biodiversity, to evaluate impact of management and for planning future management. This study aimed at determining impacts of land use units on species diversity and spatial distribution of species in two districts of Borana zone, Oromia, Ethiopia. Stratification ...

2005
M. R. Landry A. Calbet

Dolan and McKeon (2005) have recently criticized microzooplankton grazing rate estimates by the dilution approach as being systematically biased and significantly overestimated. Their argument is based on observed mortality responses of ciliated protozoa to reduced food in several coastal experiments and a global extrapolation which assumes that all grazing in all ocean systems scales to the ab...

2015
Hasen M. Yusuf Anna C. Treydte Jauchim Sauerborn Raffaella Balestrini

High grazing intensity and wide-spread woody encroachment may strongly alter soil carbon (C) and nitrogen (N) pools. However, the direction and quantity of these changes have rarely been quantified in East African savanna ecosystem. As shifts in soil C and N pools might further potentially influence climate change mitigation, we quantified and compared soil organic carbon (SOC) and total soil n...

Journal: :مرتع و آبخیزداری 0
طاهره صادقی شاهرخت کارشناس ارشد مرتع داری، دانشگاه فردوسی مشهد محمد جنگجو دانشیار گروه مرتع و آبخیزداری دانشکده منابع طبیعی و محیط زیست، دانشگاه فردوسی مشهد منصور مصداقی استاد مدعو، دانشکده منابع طبیعی و محیط زیست دانشگاه فردوسی مشهد

rangeland shrubs may provide mechanical facilitation on their understory plants, by protecting themagainst the livestock grazing. however, such a facilitation effect may vary depending on the rangelandutilization rate. in a field research, mechanical facilitation of rangeland shrubs was compared in ahighly grazed, a moderately grazed and an enclosure site; in an arid rangeland, kakhak, gonabad,...

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...

2014
Hugh W. McGregor Sarah Legge Menna E. Jones Christopher N. Johnson Paul Adam

Intensification of fires and grazing by large herbivores has caused population declines in small vertebrates in many ecosystems worldwide. Impacts are rarely direct, and usually appear driven via indirect pathways, such as changes to predator-prey dynamics. Fire events and grazing may improve habitat and/or hunting success for the predators of small mammals, however, such impacts have not been ...

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