نتایج جستجو برای: degraded rangelands

تعداد نتایج: 29078  

The aim of localization of rangeland species plantation is to predict the potentials and limitations of rangelands for plantation. Aellenia subaphylla is resistant to drought and salinity. It produces considerable forage in winter rangelands. In this research, the geographic information system and two methods of classic and fuzzy logic were used to locate this species in winter rangelands of Go...

Journal: :Remote Sensing of Environment 2021

Rangelands cover 70% of the world's land surface, and provide critical ecosystem services primary production, soil carbon storage, nutrient cycling. These are governed by very fine-scale spatial patterning carbon, nutrients, plant species at centimeter-to-meter scales, a phenomenon known as “islands fertility”. Such dynamics challenging to detect with most satellite manned airborne platforms. R...

Journal: :Int. J. Applied Earth Observation and Geoinformation 2014
Paula D. Blanco Héctor F. del Valle Pablo J. Bouza Graciela Metternicht Leonardo A. Hardtke

Ecological sites are the basic entity used in rangeland health assessment. This study evaluates the synergistic use of multiand hyper-spectral satellite imagery for sub-pixel classification of ecological sites in semiarid rangelands. Hyperion and Landsat enhanced thematic mapper (ETM) data are included in a two-step procedure to mapping ecological sites in Patagonian rangelands of Argentina. Fi...

2017
Terence Dawson Adam Munn

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...

2010
Kirk W. Davies Jonathan D. Bates Tony J. Svejcar Chad S. Boyd

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...

2010
Rhonda Skaggs

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...

2001
K. Kellner

The biophysical environment is an important determinant of land degradation in both commercial and communal land tenure systems in South Africa. According to a recent study on the status of land degradation, approximately 25% of the total land cover in South Africa is degraded. Several technologies exist to restore the soil and vegetation degraded areas in natural pastures. To improve the produ...

2008
Elizabeth G. King Maureen L. Stanton

Under the harsh environmental conditions present in severely overgrazed, semiarid rangelands, facilitator plants offer a promising tool for ecological restoration. This study investigated facilitative effects of Aloe secundiflora—a native drought-tolerant, unpalatable, thorny shrub—on grass establishment in degraded rangelands in Kenya. We planted native perennial grass seeds adjacent to three ...

Journal: :journal of rangeland science 2013
ezatollah moradi gholam ali heshmati ali hosein bahramian

rangeland health assessment provides qualitative information on ecosystemattributes. we examined changes in rangeland health in the zagros semi-arid rangelands ofiran at fixed sites between 2001 and 2011, over the 10-year period. the rangelandfragments significantly declines in the quality of the vegetation, and changes in plantspecies were driven largely by seasonality, and to a lesser extent,...

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