نتایج جستجو برای: over grazing

تعداد نتایج: 1149418  

Journal: Desert 2010
D.A. Saghi H. Tavakoli M. Kazemi

Three grass species, Agropyron desertorum (Agde) and Agropyron elongatum (Agel) and recently, Bromus tomentellus (Brto) are mainly used for range improvement as mixed seeding in semi-arid areas of Iran. Because there is little information about management of these grasses, this study was conducted at the Sisab Research Station in northern Iran to evaluate their responses to grazing management a...

2000
C. C. BOSWELL

Controversy has surrounded the possible differences in pasture production which result from grazing by cattle or sheep. Experiments conducted over the 1972-76 period show that pasture production under grazing by sheep is greater than under grazing by cattle under similar intensive managements. A change from sheep grazing to cattle grazing can cause a rapid deterioration in pasture production, w...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2007
Tara G Martin S McIntyre

We investigated the impact of pastoral management on birds in subtropical grassy eucalypt woodland in southeastern Queensland, Australia, where the patterns of land management have made it possible to disentangle the effects of livestock grazing from those of tree clearing. We recorded changes in bird species composition, density, and relative abundance across two woodland habitat types (ripari...

Journal: :desert 0
gh.a. dianati tilaki assistant professor, faculty of natural resource & marine sciences, tarbiat modares university a.a naghipour borj m.sc.student, faculty of natural resource & marine sciences, tarbiat modares university h. tavakoli staff member, khorasan agricultural and natural resources research center m. haidarian aghakhani m.sc.student, faculty of natural resource & marine sciences, tarbiat modares university

abstract over the last fifty years, most of the semi-arid rangeland in iran has been converted to cropland without an equivalent reduction in grazing animals. this shift has led to heavy grazing pressure on rangeland vegetation. the present study has been conducted in sisab research station in the north khorasan province to evaluate effects of long-term grazing exclosures on biodiversity of ran...

2009
Daniel Hamermesh

Grazing, Goods and Girth: Determinants and Effects Using the 2006-07 American Time Use Survey and its Eating and Health Module, I show that over half of adult Americans report grazing (secondary eating/drinking) on a typical day, with grazing time almost equaling primary eating/drinking time. An economic model predicts that higher wage rates (price of time) will lead to substitution of grazing ...

ژورنال: علوم آب و خاک 2012
فایز رئیسی, , مریم ریاحی, ,

Mountainous landscapes in Central Zagros are mainly used as grazing rangelands to feed animals and are heavily degraded. Overgrazing may impose a negative effect on rangeland productivity and sustainability through significant changes in soil properties. Soil nitrogen (N) mineralization is one of the key biological processes that might be affected by biotic and abiotic factors including range g...

Journal: :desert 2011
h. tavakoli d.a. saghi m. kazemi

three grass species, agropyron desertorum (agde) and agropyron elongatum (agel) and recently, bromus tomentellus (brto) are mainly used for range improvement as mixed seeding in semi-arid areas of iran. because there is little information about management of these grasses, this study was conducted at the sisab research station in northern iran to evaluate their responses to grazing management a...

2011
J. L. Beck R. D. Mealor B. W. Hess G. E. Moss S. L. Lake

Changes in commodity pricing and environmental concerns are changing animal agriculture throughout the United States. Adopting multispecies grazing as an alternative production system could result in improved forage utilization, increased animal performance, and reduced production costs, and thereby improve the financial stability of livestock operations. This study focused on the Silver Spur R...

2008
Daniel S. Hamermesh

Using the 2006 American Time Use Survey and its Food and Health Module I show that over half of adult Americans report grazing (secondary eating/drinking) on a typical day, with grazing time averaging over 2/3 of primary eating/drinking time. An economic model predicts that higher wage rates will lead to substitution of grazing for primary eating/drinking, especially by changing the relative nu...

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