He Guoxing, Liu Xiaoni, Li Yali, Xu Heguang, Ji Tong, Yang Zhuoli, Qi Hao, Ma Chenglong, Wang Yunjun, Zhang Degang, Lin Dong, Shi Yafei, Jiang Jiachang
College of Grassland Science, Gansu Agricultural University, No. 1, Yingmen Village, Anning District, Lanzhou, 730070, Gansu, China.
Key Laboratory of Grassland Ecosystem, Ministry of Education, Gansu Agricultural University, Lanzhou, 730070, Gansu, China.
Sci Rep. 2024 Dec 28;14(1):31124. doi: 10.1038/s41598-024-82434-3.
Near-natural restoration is acknowledged as an effective strategy for enhancing soil organic carbon (SOC) sequestration in degraded grasslands. However, the alterations in SOC fractions, stability, and relative sequestration capacity after restoration of degraded alpine meadows remain uncertain. In this study, we utilized the degraded alpine meadows on the northeastern edge of the Tibetan Plateau as a research area, with grazing as the control (CK) and restoration of 20 years of banned grazing (BG) and growing season resting grazing (RG). We analyzed the characteristics of SOC, SOC fractions, recalcitrant index (RI), and relative capacity of soil C sequestration (SCS) under near-natural restoration measures. The objective of this study was to assess the recovery of SOC following near-natural restoration. The results showed that soil water content (SWC), SOC, soil total nitrogen (TN), and soil total phosphorus (TP) increased, while bulk density (BD) decreased in the degraded alpine meadow after near-natural restoration. In addition, near-natural restoration led to significant increases in particulate organic carbon (POC), readily oxidizable carbon (ROC), dissolved organic carbon (DOC), and microbial biomass carbon (MBC) content (P < 0.05). The SOC stock significantly increased, while the RI decreased. Compared to RG, BG had a greater increase in SOC stock. The study showed that 20 years of near-natural restoration in degraded alpine meadows mainly enhanced soil active carbon pools, while short-term restoration did not increase soil carbon stability. Therefore, avoiding re-exposure to overgrazing is essential to maintaining the restoration effect.
近自然恢复被认为是提高退化草地土壤有机碳（SOC）固存的有效策略。然而，退化高寒草甸恢复后SOC组分、稳定性和相对固存能力的变化仍不确定。本研究以青藏高原东北边缘的退化高寒草甸为研究区域，以放牧为对照（CK），设置禁牧20年（BG）和生长季休牧（RG）的恢复措施。我们分析了近自然恢复措施下SOC、SOC组分、难分解指数（RI）和土壤碳固存相对能力（SCS）的特征。本研究的目的是评估近自然恢复后SOC的恢复情况。结果表明，近自然恢复后，退化高寒草甸的土壤含水量（SWC）、SOC、土壤全氮（TN）和土壤全磷（TP）增加，而容重（BD）降低。此外，近自然恢复导致颗粒有机碳（POC）、易氧化有机碳（ROC）、溶解有机碳（DOC）和微生物生物量碳（MBC）含量显著增加（P<0.05）。SOC储量显著增加，而RI降低。与RG相比，BG的SOC储量增加幅度更大。研究表明，退化高寒草甸20年的近自然恢复主要增强了土壤活性碳库，而短期恢复并未增加土壤碳稳定性。因此，避免再次过度放牧对于维持恢复效果至关重要。
