نتایج جستجو برای: vegetation cover 0119
تعداد نتایج: 148663 فیلتر نتایج به سال:
Improving biodiversity conservation in fragmented agricultural landscapes has become an important global issue. Vegetation at the patch and landscape-scale is important for species occupancy and diversity, yet few previous studies have explored multi-scale associations between vegetation and community assemblages. Here, we investigated how patch and landscape-scale vegetation cover structure wo...
Negative impacts of gully erosion in marly areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate gully thresholds related to plant vegetation cover and landuse change in the Agriculture (AG), Fair Rangeland (FR) and Weak Rangeland (WR) areas of Ghaasr-e-Shirin, Kermanshah, I...
Determining the factors that influence the distribution of woody vegetation cover and resolving the sensitivity of woody vegetation cover to shifts in environmental forcing are critical steps necessary to predict continental-scale responses of dryland ecosystems to climate change. We use a 6-year satellite data record of fractional woody vegetation cover and an 11-year daily precipitation recor...
In this investigation, the effects of enclosure, restal delayed grazing andcontinued grazing treatments on the production rate and vegetation cover were studied.Study area was SadrAbad pasture. After selecting three bands (1+1+1=3 hectare area) asthree treatments in the restricted and non restricted area, they were transected to threetransects. Then plots (1×2m2 ) were selected to measure the p...
the objective of this study was to assess the relationship betweenvegetation, landform and physicochemical properties of soil. at the first terrainmap unit were provided using the landsat thematic mapper (tm) satellite images,aerial photograph, topographical and geology map. field sampling was done in therepresentative area using plot sampling. 104 plots 100 m2 were sampled in eachplot landform...
remote sensing and aerial photographs are used to produce medium to small scale images. however, for detailed information especially to estimate rangeland vegetation canopy cover there is a need to larger scale images. it is therefore necessary to study the technical applicability of different devices such as short range light airplanes, kites, gliders and balloons. in this research, we focused...
The study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. Theresearch was accomplished in semi-steppe KhoyBilehvar area, from 1999 to2005. Vegetation cover was annually measured within fixed plots during transact.The results showed that during nine...
Abstract. Rangeland vegetation dynamics encompass all processes of changes in vegetation composition and structure over time. Investigating the rangeland ecosystem dynamics makes it possible to determine the effects of climatic and management conditions on qualitative and quantitative changes of the vegetation in a specific period of time. Accordingly, data collection and measurements for evalu...
The savannas of Southern Africa are an important dryland ecosystem as they cover up to 54% of the landscape and support a rich variety of biodiversity. This paper evaluates landscape change in savanna vegetation along Chobe Riverfront within Chobe National Park Botswana, from 1982 to 2011 to understand what change may be occurring in land cover. Classifying land cover in savanna environments is...
The objective of the present study was to investigate the pasture vegetation changes using satellite data in Semirom, Isfahan province. This study was conducted in 2004 as a wet year and 2009 as a dry year. The WiFS and AWiFS satellite images were acquired and used for the year 2004 and 2009, respectively. First, the vegetation percentage was simultaneously measured in the two years. Then, cons...
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