نتایج جستجو برای: over grazing
تعداد نتایج: 1149418 فیلتر نتایج به سال:
Browse and cereal stubble represent the two most important resources for grazing small ruminants in dry Mediterranean areas. The purpose of the present review is to provide updated information regarding their nutritional value. In a mixed Mediterranean environment, browse represents at least 40% of goat’s diet. Most browse species in the Mediterranean are rich in tanniferous phenolic substances...
one of the key factors in managing a rangeland is to determine the relative preference of its major plant species by thegrazing livestock. preference value of each plant species is affected by plant type, companion plants, availability byanimals, phenological stage, climate condition, and the livestock species. we investigated the grazing behaviour of anative goat (garizi) in the steppe rangela...
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...
A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumula...
Over eight years we measured the effects of plant community composition, vegetation structure, and livestock grazing on occurrence of three grassland bird species-Western Meadowlark (Sturnella neglecta), Horned Lark (Eremophila alpestris), and Grasshopper Sparrow (Ammodramus savannarum)-at sites in central California during breeding season. In California's Mediterranean-type climatic region, co...
The foraging behaviour (grazing time and diet composition), live-weight (LW) changes and parasitic infection (faecal egg counts of gastrointestinal nematodes) of 12 beef cows, 84 ewes and 84 goats suckling their offspring, managed in mixed grazing on heathlands with 24% of improved pasture of perennial ryegrass-white clover, were studied during the years 2003 and 2006. The results showed that g...
The aim of this study was to provide preliminary quantitative information on selenium and iodine statusof sheep in Markazi province, Iran. Selenium and iodine status of grazing sheep were measured for 57different flocks in 14 regions over one year. The districts were selected to represent major sheep growingareas in the province. Blood samples were collected from 2 to 3-year-old ewes during sum...
Grazing lawns are a distinct grassland community type, characterised by short-stature and with their persistence and spread promoted by grazing. In Africa, they reveal a long co-evolutionary history of grasses and large mammal grazers. The attractiveness to grazers of a low-biomass sward lies in the relatively high quality of forage, largely due to the low proportion of stem material in the swa...
The structure and dynamics of insect community in grasslands can be influenced by grazing management via altered characteristics of plant community. However, attempts to better understand the complex relationships among plants, insects, and large herbivores is still hampered largely by the interactive effects of plants, insects, and large grazers on each other. In this study, we test the hypoth...
Herbivory and fire are natural interacting forces contributing to the maintenance of rangeland ecosystems. Wildfires in the sagebrush dominated ecosystems of the Great Basin are becoming larger and more frequent, and may dramatically alter plant communities and habitat. This synthesis describes what is currently known about the cumulative impacts of historic livestock grazing patterns and short...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید