Examining Soil Erosion Responses to Grassland Conversation Policy in Three-River Headwaters, China

Abstract

Soil erosion in the Three-River Headwaters (TRH) region has continued to intensify in recent decades due to human activities and climate change. To reverse this situation, the Chinese central government has launched the Subsidy and Incentive System for Grassland Conservation (SISGC). As a sign of the effectiveness of SISGC implementation, the dynamic changes of soil erosion can provide timely feedback for decision makers and managers. The Revised Universal Soil Loss Equation (RUSLE) model was used to simulate the spatial distribution of soil erosion before and after SISGC implementation, and Mann–Kendall (MK) test to reveal the effect of policy implementation. The results showed that: (1) the soil erosion in the TRH was mainly mild (83.83% of the total eroded area), and the average soil erosion rate and the total erosion were 13.63 t ha−1 y−1 and 323.58 × 106 t y−1 respectively before SISGC implementation; (2) SISGC implementation has curbed soil erosion. After SISGC implementation, the total soil erosion decreased by 3.80%, which showed obvious differences between grassland types; (3) The influences of SISGC were mainly because it has increased vegetation cover, further decreasing soil erosion. However, soil erosion in Alpine grassland has deteriorated, indicating direct targeted policymaking should be on the agenda. Furthermore, SISGC should be continued and grassland-type-oriented to restore the grassland ecosystem.

Impacts of River Damming on Sediment Methylmercury Dynamics

“…36 The annual regional rainfall in the Nujiang basin is 1235 mm, and the sediment discharge in the downstream outlet is 0.45 × 10 8 t a −1 . 37 The Lancang River has a watershed area of 16.48 × 10 4 km 2 and an altitude range of 550−1826 m within the 1265 km length of the field investigation. The proportion of soil erosion area to watershed area is 21.83%.…”

“…The proportion of soil erosion area to watershed area is 21.83% . In this region, the annual rainfall is 1024 mm, and the sediment discharge in the downstream outlet is 1.60 × 10 8 t a –1 . Between 1993 and 2020, 11 hydropower dams were constructed, namely Lidi (LD), Tuoba (TB), Huangdeng (HD), Dahua (DH), Miaowei (MV), Gongguoqiao (GGQ), Xiaowan (XW), Manwan (MW), Dachaoshan (DCS), Nuozhadu (NZD), and Jinghong (JH) (Table ).…”

“…The ratio of soil erosion area to watershed area is 25.90% . The annual regional rainfall in the Nujiang basin is 1235 mm, and the sediment discharge in the downstream outlet is 0.45 × 10 8 t a –1 …”

“…The proportion of soil erosion area to watershed area is 29.29% . The annual regional rainfall is 1235 mm, and the sediment discharge in the downstream outlet is 2.55 × 10 8 t a –1 . Ten hydropower dams were constructed between 2010 and 2021, namely Liyuan (LY), Ahai (AH), Jinanqiao (JAQ), Longkaikou (LKK), Ludila (LDL), Guanyinyan (GYY), Wudongde (WDD), Baihetan (BHT), Xiluodu (XLD), and Xiangjiaba (XJB) (Table ).…”

The Molecular Mechanism of Yellow Mushroom (Floccularia luteovirens) Response to Strong Ultraviolet Radiation on the Qinghai-Tibet Plateau

“…In August 2018, three wild fruiting bodies of F. luteovirens were collected to transcriptome sequencing from Haiyan County (100°47′13″E, 37°0′37″N), Qinghai Province, China for transcriptome sequencing ( Table 1 ). The sampling area is 3,220 m above sea level, with annual sun light of 2517.6–2995.3 h and annual average radiation of 5210.2–6568.3 MJ/m 2 ( Zhao Y. T. et al, 2021 ). According to the pileus diameter, the stage of F. luteovirens can be classified into young fruiting bodies (YFB, diameter 2.5–4.5 cm) and fruiting bodies (FB, diameter 4.5–6.6 cm), all of which samples were collected for transcriptome sequencing in three replicates.…”