Investigating the changes of soil surface indices along grazing gradient in semi-arid lands

In this research, grazing effect on ecosystem function has been analyzed at different distances from water point to identify critical area. In 338 plots of the size 2×2 meter that were plotted in 8 main directions from 3 selected water points, 11 soil surface indices were estimated based on LFA method. Then soil stability, infiltration and nutrient cycle functional attributes have been evaluated by 11 soil surface indices. MANOVA and correlation analysis showed that functional attributes were not significant in 8 main directions (P<0/01) but they were significant with distance from water point (P<0/01) and ecosystem function increased with distance from water point. Duncan results showed that grazing intensity in close proximity to water point has been induced a critical area in 200 m from water point.