Soil erosion by water and loss of soil organic carbon (SOC) are two major contributors to global land degradation. However, the impact of soil erosion and its effect on SOC in the fragile, sensitive alpine ecosystem of the Tibetan Plateau, where climate change is amplified, is not well understood. We used the Universal Soil Loss Equation (USLE) ensemble model to analyse soil erosion, SOC loss, and their dynamics over the past 40 years (1981–2018) on the Tibetan Plateau. The mean soil erosion and SOC erosion rates were 5.91 ± 2.29 t ha yr and 0.374 ± 0.113 t C ha yr, respectively, with significant increasing trends because of increased rainfall. Spatially, we identified areas prone to soil and SOC erosion across the plateau. SOC erosion rates rose by 19.0 %, from 0.34 ± 0.03 t C ha yr in the 1980s to 0.40 ± 0.02 t C ha yr in the 2010s. The increasing erosion rates after 1999 were weakened because of the slow increase in rainfall and rapid vegetation greening. Two distinct erosion mechanisms emerged concerning land use: rainfall-dominated and slope-dominated. Our findings underscore the extreme vulnerability of soil erosion and SOC loss on the Tibetan Plateau to climate change, providing helpful insights for sustainable land resource management in this ecologically fragile environment and enhancing our understanding of the incipient impact of soil erosion on the carbon cycle.

中文翻译：

---

青藏高原土壤和碳的横向输送增加

水土流失和土壤有机碳（SOC）损失是全球土地退化的两个主要因素。然而，在气候变化加剧的青藏高原脆弱、敏感的高山生态系统中，土壤侵蚀的影响及其对土壤有机碳的影响尚不清楚。我们使用通用土壤流失方程（USLE）集合模型来分析青藏高原过去 40 年（1981-2018）的土壤侵蚀、SOC 损失及其动态。平均土壤侵蚀和SOC侵蚀率分别为5.91±2.29吨·年和0.374±0.113·吨·年，由于降雨量增加，呈显着增加趋势。在空间上，我们确定了整个高原容易发生土壤和有机碳侵蚀的区域。 SOC侵蚀率上升了19.0%，从1980年代的0.34±0.03吨查年上升到2010年代的0.40±0.02吨查年。 1999年以后，由于降雨量缓慢增加和植被快速绿化，侵蚀速率逐渐减弱。关于土地利用，出现了两种不同的侵蚀机制：降雨主导型和坡度主导型。我们的研究结果强调了青藏高原土壤侵蚀和有机碳损失对气候变化的极端脆弱性，为这一生态脆弱环境中的可持续土地资源管理提供了有益的见解，并加深了我们对土壤侵蚀对碳循环的早期影响的理解。