نتایج جستجو برای: grazed and ungrazed area
تعداد نتایج: 16875616 فیلتر نتایج به سال:
The large number of threatened species, both insects and plants, in the European agricultural landscape, has often been attributed to the abandonment of semi-natural grasslands. Species may also be threatened in the remaining managed grasslands due to a changed and intensified management, compared to the historical use. In this study, effects of grazing management and population characteristics...
Human communities in the Intermountain West depend heavily on subalpine rangelands because of their importance in providing water for irrigation and forage for wildlife and livestock. In addition, many constituencies are looking to managed ecosystems to sequester carbon in plant biomass and soil C to reduce the impact of anthropogenic CO2 on climate. This work builds on a 90-year-old grazing ex...
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...
Cattle grazing and invasion by non-native plant species are globally-ubiquitous changes occurring to plant communities that are likely to reverberate through whole food webs. We used a manipulative field experiment to quantify how arthropod community structure differed in native and non-native California grassland communities in the presence and absence of grazing. The arthropod community was s...
Understanding the impacts of livestock grazing on wildlands is important for making appropriate ecosystem management decisions. Using livestock exclosures, we examined the effects of moderate cattle grazing on the abundance of California ground squirrels (Spermophilus beecheyii Richardson) and the spatial distribution of active burrows within their colonies in grassland and blue oak (Quercus do...
BACKGROUND To assess population persistence of species living in heterogeneous landscapes, the effects of habitat on reproduction and survival have to be investigated. METHODOLOGY/PRINCIPAL FINDINGS We used a matrix population model to estimate habitat-specific population growth rates for a population of northern wheatears Oenanthe oenanthe breeding in farmland consisting of a mosaic of disti...
The Brown-headed Cowbird (Molothrus ater) is a widespread brood parasite which often engages in a commensalistic feeding relationship with domestic livestock. We studied the behavior of female cowbirds breeding in pinyon–juniper woodlands in New Mexico, USA, on two adjacent sites, one an active cattle ranch, and the other a site that was not grazed by domestic livestock throughout the songbird ...
Proper grazing management reduces ET from grasslands by reducing transpiration losses and grazingManagement of forage production for livestock grazing on semiarid induced surface energy relationships that reduce evapograsslands depends on water availability. Evapotranspiration (ET) ration (Svejcar and Christiansen, 1987; Wraith et al., was measured using the Bowen ratio energy balance method on...
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