137Cs-based Estimation of Soil Erosion and Organic Carbon Loss in Alpine Meadow Soil on Tibetan Plateau

Abstract

[Objective] Soil erosion and its associated carbon loss in an alpine meadow on the Tibetan Plateau were quantitatively analyzed in order to provide a reference for comprehensively evaluating the impact of soil erosion and for implementing effective soil and water conservation measures. [Methods] We used 137Cs tracing technology combined with the results of previous research studies to determine erosion rate and consequent carbon loss for an undisturbed alpine meadow soil on the Tibetan Plateau. [Results] The undisturbed meadow soil exhibited three distinct layers (A, B, and C) of physiochemical properties, and the distribution of 137Cs declined exponentially with increasing soil depth. The recent erosion rate of the alpine meadow soil was about 77—230 t/(km2·yr), and was estimated to result in an average annual soil organic carbon loss of not less than 4.86 t/km2. [Conclusion] Even though the overall soil erosion rate of the alpine meadow on the Tibetan Plateau was low, it’s organic carbon loss due to erosion cannot be underestimated. Both increased human activities and reduced meadow growth due to decreased soil moisture under future global warming are likely to result in further soil degradation and soil organic carbon loss in alpine meadows.

Keywords

• 137cs technology
• alpine meadow
• soil erosion
• organic carbon
• tibetan plateau