نتایج جستجو برای: desert lands and also steppes
تعداد نتایج: 16861261 فیلتر نتایج به سال:
One of the most important calamities that affect the arid and semi- arid regions and is taken into account as threatening factors for human- life and destroying the natural resources is desertification, so recognizing and forecasting this phenomenon is very important. Desertification is a complex phenomenon, which as environmental, socio-economical, and cultural impacts on natural resources. In...
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...
Under the prevailing variable natural conditions nomadic pastoralism was the most suitable form of land use in Mongolia and the neighboring countries in the past. Furthermore, small areas were used for agriculture in some regions. Therefore, anthropogenic influence was present throughout history. In the forest steppe zone this led to the disappearance of forest sites which then gave way to mead...
Abstract. From the perspectives of many environmental and conservative policy makers, improving and diversifying the livelihoods have been found as a mechanism to promote the livelihoods and persuade people to avoid the overexploitation and degradation of natural resources. Due to the fragility of the environment and inconsistency of incomes, the alternative income sources may be promised to wa...
abstract. from the perspectives of many environmental and conservative policy makers, improving and diversifying the livelihoods have been found as a mechanism to promote the livelihoods and persuade people to avoid the overexploitation and degradation of natural resources. due to the fragility of the environment and inconsistency of incomes, the alternative income sources may be promised to wa...
The aim of the study. Analysis changes in productivity dwarf shrub-moss-lichen, pine-dwarf shrub-sphagnum and sedge-sphagnum grass ecosystems along latitudinal gradient. Methodology. For a number bog located gradient from 65 to 50° N range longitudes 63 95° E stocks live dead, aboveground belowground phytomass, as well values (ANP), (BNP) total production (NPP) were analyzed. data are given for...
Climate change plays an important role in the transition of ecosystems. Stratigraphic investigations have suggested that the Asian interior experienced frequent transitions between grassland and desert ecosystems as a consequence of global climate change. Using maternally and bi-parentally inherited markers, we investigated the population dynamics of Agriophyllum squarrosum (Chenopodiaceae), an...
Wild burros (Equus asinus), protected by the 1971 Wild Free-Roaming Horse and Burro Act on some federal lands but exotic animals many ecologists and resource mangers view as damaging to native ecosystems, represent one of the most contentious environmental management problems in American Southwest arid lands. This review synthesizes the scattered literature about burro effects on plant communit...
The Mongolian steppes with a long history of nomadic pastoralism cover large area the Palaearctic steppe biome and are still relatively intact. As livestock number has increased over last two decades, grazing been considered as main reason pasture degradation. However, impact on vegetation dynamics, its interaction climate, is not clear. We reviewed 44 publications in language, covering 109 sit...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید