نتایج جستجو برای: arid rangelands
تعداد نتایج: 20677 فیلتر نتایج به سال:
Rangelands are expansive, unimproved lands located in arid or semi–arid regions, spanning a variety of landscapes including savannahs, high and low altitude deserts, mountain meadows, and tundra. Rangelands are generally unsuitable for crop production due to aridity, topography, and extreme temperatures. Rangelands support varying mixtures of native and nonnative grasses, grass–like plants, for...
The objective of this research was to identify the vegetation-soil relationships in Nodushan arid rangelands of Yazd. 5 sites were selected for measuring the cover of plant species and soil attributes. Soil samples were taken in 0-10 and 10-80 cm layers. The species studied were Salsola tomentosa, Salsola arbuscula, Peganum harmala, Zygophylum eurypterum and Eurotia ceratoides. Canonical corres...
The evaluation of vegetation covers using conventional methods is difficult over arid areas due to several reasons such as lack of the suitable roads to these regions. Moreover, this task is time-consuming. For these reasons, remote sensing has been considered as an economic alternative for conventional field work. In this study, the feasibility of using IRS images in vegetation cover evaluatio...
Livestock grazing potentially has substantial influence on fuel characteristics in rangelands around the globe. However, information quantifying the impacts of grazing on rangeland fuel characteristics is limited, and the effects of grazing on fuels are important because fuel characteristics are one of the primary factors determining risk, severity, continuity, and size of wildfires. We investi...
Climate change and degradation of natural resources pose daunting challenges in arid semi-arid rangelands southern Mediterranean region. Overcoming these requires considerable man...
In previous papers we have considered the optimal mix of biodiversity in semi-arid rangelands, focusing on the steady state. This paper addresses the question of conservation in the optimal use of rangelands, where conservation is understood to mean maintenance of the system in a ‘natural’ state. We consider a rangeland that may exist in one of two states. In the ‘natural’ state, its dynamics a...
the purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelandsof nodushan, yazd. the plant species cover and the environmental variables were measured at 9 sites. soil sampleswere taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. vegetation was classified using twowayindicator species analysis (twinspan). data was analyzed u...
Over more than a century there has been debate about the interactions of kangaroos and introduced domestic stock, especially sheep, in the semi-arid and arid rangelands. The potential for competition between the species is still controversial, with pastoralists generally assuming that exploitative competition is a continuing feature of the rangelands, with competition by kangaroos leading to re...
This paper reviews the predictions and management implications of two current paradigms in the ecology and management of arid and semi-arid rangelands. The equilibrium model stresses the importance of biotic feedbacks such as density-dependent regulation of livestock populations and the feedback of livestock density on vegetation composition, cover and productivity. Range management under this ...
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