Soilerosionratesandcharacteristicsoftypicalalpinemeadowusing137CstechniqueinQinghai-TibetPlateau

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.