نتایج جستجو برای: vegetation cover density and type
تعداد نتایج: 17062927 فیلتر نتایج به سال:
The world is witnessing a dramatic shift of settlement pattern from rural to urban population, particularly in developing countries. The rapid Addis Ababa urbanization reflects this global phenomenon and the subsequent socio-economic and environmental impacts, are causing massive public uproar and political instability. The objective of this study was to use remotely sensed Landsat data to iden...
Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988...
In order to determine the optimum rate of Vigna sun-hum seed sowing for rangeland rehabilitation in sandy soil of North Kordofan, Sudan, two trials were conducted separately under managed and unmanaged conditions at El-obeid Agricultural Research Farm in Sheikan locality of North Kordofan State in 2015 and 2016. Seed rates were 1, 2, 3, 4 and 5 Kg/feddan (4200m) and arranged by a Completely Ran...
Although numerous small-scale laboratory, mesocosm, and field experiments have demonstrated that abundance, survival, and growth of juvenile fish and invertebrates are higher in vegetated than in unvegetated habitats, the effect of habitat quality (i.e. habitat complexity) within vegetated habitats has not been documented at a broad spatial scale. We examined the relationship between percent co...
Undoubtedly, land degradation linked to desertification causes a decrease in qualitative and quantitative features of natural resources. This research aimed to assess land desertification by local residents and their role in controlling desertification in Isfahan province, Iran in 2016. The criteria were soil climate, vegetation, erosion, and demography. The indicators of soil texture, stone fr...
Plant species distribution, composition and diversity in deserts of arid and semi-arid areas, especially saltland; depend on soil physical and chemical gradients. The aim of this research was to investigate changes in the plant species diversity and richness along a soil salinity gradient in the margin rangelands of Petregan Playa. After vegetation zoning in relation to soil salinity, random-sy...
Fires in mountain big sagebrush [Artemisia tridentata spp. vaseyana (Rydb.) Beetle] plant communities historically shifted dominance from woody to herbaceous vegetation. However, fire return intervals have lengthened with European settlement, and sagebrush dominance has increased at the expense of herbaceous vegetation in some plant communities. Management actions may be needed to decrease sage...
Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988...
Harvester ants are known as one of the most renowned bio-disturbances in the arid and semi-arid ecosystems that affecte vegetation by collecting seeds and harvesting plants. It seems that physiognomy of plant association in steppe shrub land of Roodshoor, Saveh, Iran has been highly changed by harvester ants’ activities that caused to conduct this research. The study was carried out on active a...
This study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. The study was carried out in steppe rangelands of Saveh, Markazi province, Iran. Four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. To study various vegetation and...
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