the effect of exclosure on the changes of vegetation cover of rangelands of ahmad-abad region located in zanjan province has been studied during 2002 to 2006. three transects comprises of 60 fixed quadrate were establish within exclosure area and outside as well. the changes of vegetation cover were studied to made comparison between the changes of manipulated factors and soil elements using t ...

Land use may be regarded as one of the most important factors affecting theenvironment with respect to human activities. So far, destroying the rangelands andchanging them into the waste lands and poor rangelands has been proposed as the mostsignificant variations of land use done by human beings. This paper has been conducted toevaluate the variations of vegetation percentage and land uses in ...

Growth and productivity of plants are mainly affected by various environmentalfactors in different ecosystems and natural habitat in the world. This research aims to studythe existing relationships between the phytosociology characteristics of Thymuskotschyanus and environmental factors in order to find the most important factorsgoverning development of the species in middle Taleghan rangelands...

A technique for inferring long term time trends in vegetation from permanent quadrat data using the different patterns in the scattergram of the mean and rates of change of attributes, e.g., cover, from individual quadrats over short periods is described. The technique is illustrated using point intercept cover data for Hieracium species from permanent transects in the Waimakariri measured at i...

Crop coefficient values are used to estimate crop evapotranspiration (ETc) for determining irrigation scheduling. Many important crop biophysical properties such as Percentage Vegetation Cover and Leaf Area Index can be estimated from remotely sensed Vegetation Index, in order to quantify real time vegetation growth dynamics. The objective of this study was to understand the effectiveness of ba...

The paper presents results of a comparative study of the vegetation-caused elevation bias of the space shuttle topographic mission data product, both Cand X-band (SRTM.C/X). The SRTM.C/X bands data were compared against a high-resolution digital terrain model. Pixel-based differences in SRTM.X minus SRTM.C were correlated with land cover (‘agriculture’, ‘house’, ‘tree’, ‘water’). Findings of th...

Planting shrub seedlings under oil mulches has frequently been used for stabilizing mobile sands in Iran for during the last three decades. Sandy desert of Samad Abad, Sarakhs, northeast Iran, has been fixed by cultivating seedling of Haloxylon aphyllum under the oil mulches. Therefore this study was designed to investigate the effects of the sand fixation project on soil and vegetation propert...