نتایج جستجو برای: shrub and brush rangeland
تعداد نتایج: 16829791 فیلتر نتایج به سال:
sabzkouh protected area, with the variety of natural ecosystems and landscapes, is very rich from the point of diversity in climate, topography, habitats and wildlife that is located in central zagros. evidences show that its ecosystems such as other iranian semiarid natural ecosystems, undergone changes in their vegetation structure over the past years. obtaining multi-spectral and multi-tempo...
In ecosystems with alternative stable states, restoration success can be thought of as overcoming the resilience of an undesirable state to promote an alternative state that yields greater ecosystem services. Since greater resilience of undesirable states translates into reduced restoration potential, quantifying differences in resilience can enhance restoration planning. In the context of shru...
in arid and semi-arid ecosystems, shrubs may act as fertility islands but theireffect may vary depending on their morphology and ecological impacts. this research wasaimed to study effect of three shrubs scariola orientalis, astragalus heratensis, and rosapersica on soil properties and on the microclimate conditions (temperature, luminance, andsoil moisture) of their understory in the steppe ra...
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...
this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...
Increasing shrub density hinders cattle raising in central Argentina rangelands. While roller-chopping and hand-cutting are used to remove shrubs make land accessible for grazing, studies on the effects of these practices ecosystem composition, structure functioning scarce. We assessed impact removal (a) vegetation cover, species richness diversity (b) green biomass seasonal phenological dynami...
In the long-term, wind erosion has considerable impact on rangelands. The aim of this study is to understand the changes of Hanitiyeh Rangelands located 30 kilometers east of Ahvaz and its function. Two transects, 42 meters in length, in wind gradient, patch and inter patch with 5 repeats that included shrub log complex, bush, grass, shrub, shrub-grass and bare open soil were measured. In addit...
This study describes the components of available forage in Vahregan watershed, Central Iran and highlight issues relating to forage endowment and environmental dynamics. In this study, proper use factor and palatability models and their components use to develop the model of available forage and measure it. The components climatic, topography, land systems, vegetation, land use and grass and sh...
Calibrated predictive relationships obtained from simple and multiple regression of thematic mapper or broad-band (BB) and 1.4 nm interval or narrow-band (NB) spectral data were evaluated for quantifying 11 rangeland components (including total vegetation, forb, grass, shrub, litter, and bare soil) and distinguishing among 6 long-term grazing treatments of sagebrush steppe. In general, all 4 da...
Shrub encroachment in arid and semiarid rangelands, a worldwide phenomenon, results in a heterogeneous landscape characterized by a mosaic of nutrient-depleted barren soil bordered by nutrient-enriched shrubby areas known as ‘‘fertile islands.’’ Even though shrub encroachment is considered as a major contributor to rangeland degradation, little is known about mechanisms favoring the reversibili...
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