نتایج جستجو برای: over grazing
تعداد نتایج: 1149418 فیلتر نتایج به سال:
water quality is a serious issue in tropical grasslands that must be addressed to ensure the continuity and sustainability of water resources. this study aimed to assess the stream water quality of tropical grassland under long-term moderate (2.7 animal unit ha-1 y-1 for 34 years) and short-term heavy (5 animal unit ha-1 y-1 for 2 years) grazing systems at catchment and farm scales in kuala lum...
Changes in vegetation from 1990 to 2000 were examined at 10 high country localities, representing four grassland types: fescue tussock (Festuca novae-zelandiae), snow tussock (Chionochloa rigida), red tussock (C. rubra), and silver tussock (Poa cita). At each locality, three treatments were established: ambient sheep+rabbit grazing, rabbit grazing only, and no grazing. The mutivariate methods o...
Hybrid systems are typified by strong coupling between continuous dynamics and discrete events. For such piecewise smooth systems, event triggering generally has a significant influence over subsequent system behaviour. Therefore it is important to identify situations where a small change in parameter values alters the event triggering pattern. The bounding case, which separates regions of (gen...
BACKGROUND Methane (CH(4)) uptake by steppe soils is affected by a range of specific factors and is a complex process. Increased stocking rate promotes steppe degradation, with unclear consequences for gas exchanges. To assess the effects of grazing management on CH(4) uptake in desert steppes, we investigated soil-atmosphere CH(4) exchange during the winter-spring transition period. METHODOL...
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...
In the present study, we aim to analyze the effect of grazing, precipitation and temperature on plant species dynamics in the typical steppe of Inner Mongolia, P.R. China. By uncoupling biotic and abiotic factors, we provide essential information on the main drivers determining species composition and species diversity. Effects of grazing by sheep were studied in a controlled experiment along a...
Amphibians are experiencing a precipitous global decline, and population stability on public lands with multiple uses is a key concern for managers. In the Sierra Nevada Mountains (California, USA), managers have specifically identified livestock grazing as an activity that may negatively affect Yosemite toads due to the potential overlap of grazing with toad habitat. Grazing exclusion from Yos...
A grazing trial compared the effect of stocking rate on corn residue removal and nutrient quality over a 55 d period. Treatments included no removal (control), light grazing (2.5 animal unit months/ha), heavy grazing (4.9 animal unit months/ha), and baling (bale), that were applied to eight 6.6 ha paddocks (2 replications) on a 53 ha center pivot irrigated field of corn residue from mid-Decembe...
Grazing incidence mirrors for X–ray astronomy are usually designed in the parabola-hyperbola (Wolter I) configuration. This design allows for optimal images on-axis, which however degrade rapidly with the off-axis angle. Mirror surfaces described by polynomia (with terms higher than order two), have been put forward to improve the performances over the field of view. Here we present a refined p...
investigation of the grazing behavior of grazing animals on the rangeland is one of the basic necessities of grazing management in different climatic regions. the current study with the aim of exploring the grazing behavior of makuyi sheep breed was conducted in the mountainous rangelands of kelid daghi of jolfa as representative rangelands for makuyi sheep breed dispersion in east azerbayjan p...
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