The Qinghai-Tibetan Plateau has unique geographical and climatic conditions that predetermine soil erosion. In-situ monitoring of soil erosion at high altitudes is extremely difficult and challenging due to harsh environmental conditions. This study examines the in-situ effects of different mixed cultivated grassland on runoff and sediment yield through runoff plots. The results showed that the cultivated grasslands could increase 41.5%-175.9% runoff and reduce 51.2%-58.8% sediment concentration compared to bare land. The combination of rhizomatic type (Poa pratensis L.cv. Qinghai) and dense-plexus type (Deschampsia cespitosa) cultivated grasslands appears an effective approach to prevent soil erosion on extremely degraded grassland. The aboveground characteristics and root system of plants determined rainwater movement in the soil and shifted the runoff and sediment in cultivated grassland community. Our findings indicate that plant morphological characteristics should be considered when alleviating soil erosion in the early stage of cultivated grassland in alpine areas. These results provide a new insight into vegetation restoration and soil and water conservation in alpine areas.

青藏高原独特的地理和气候条件决定了水土流失。由于恶劣的环境条件，高海拔地区土壤侵蚀的现场监测非常困难和具有挑战性。本研究通过径流地块考察了不同混合耕作草地对径流和产沙量的原地影响。结果表明，与裸地相比，耕地草地可增加41.5%-175.9%的径流，减少51.2%-58.8%的泥沙浓度。根茎型（Poa pratensis L.cv.Qinghai）和密丛型（Deschampsia cespitosa) 耕地草地似乎是防止极度退化草地土壤侵蚀的有效途径。植物的地上特征和根系决定了土壤中的雨水运动，并转移了耕地草地群落的径流和泥沙。我们的研究结果表明，在缓解高寒地区耕地草地早期土壤侵蚀时应考虑植物形态特征。这些结果为高寒地区植被恢复和水土保持提供了新的视角。