Soil erosion rates and characteristics of typical alpine meadow using 137Cs technique in Qinghai-Tibet Plateau

Alpine meadow is the predominant ecosystem in Qinghai-Tibet Plateau. The firm turf of alpine meadow formed by sub-surface anfractuous roots can be effective in conserving water and soil. Alpine meadow is a primary contributor to the Chinese Water Tower. For quantitative assess anti-erosion ability of alpine meadow, this paper selected three typical meadow slopes with 〉60% vegetation coverage to evaluate soil erosion rates using 137Cs. The results showed that （1） soil erosion intensity of typical alpine meadow was slight to light. Erosion rates were 464 t km-2 a-1 in Malong Village, 415 t km-2 a-1 in Yeniugou Town and 875 t km-2 a-1 in Zhenqin Town respectively; （2） soil erosion rates were correlated negatively with vegetation coverage, and the relationship was clearer at the slope scale than plot scale; （3） the relationship between soil erosion and vegetation coverage showed that vegetation coverage was a predominant factor in retaining soil and water on slopes. With complete turf and high vegetation coverage, alpine meadow was of great significance for soil conservation and prevention of soil erosion.