Duan Xu-Meng, Han Mei, Kong Xiang-Lun, Sun Jin-Xin, Zhang Hui-Xin
Characteristic Laboratory for Soil and Water Resources Protection and High-Quality Development of the Yellow River Delta, College of Geography and Environment, Shandong Normal University, Jinan 250358, China.
Huan Jing Ke Xue. 2024 Oct 8;45(10):5943-5956. doi: 10.13227/j.hjkx.202310021.
Under the background of "dual carbon", the impact of the implementation of the Grain for Green project on the carbon storage of the ecosystem in the Yellow River Basin must be explored, which can serve as an important reference for improving the policy implementation of the new round of the Grain for Green project and improving the carbon sink capacity of the ecosystem in the Yellow River Basin. In this study, 1990, before the implementation of the project, was selected as the starting year of the research period, and 2020, after the implementation of the two rounds of the project, was selected as the end year of the research period. Based on the ecosystem type data from 1990 to 2020, the InVEST model was used to calculate the soil carbon pool, underground carbon pool, below carbon pool, dead organic matter carbon pool, and total carbon storage of ecosystems in the Yellow River Basin and the area where the project was implemented from 1990 to 2020. The results showed that： ① From 1990 to 2020, the area of forest ecosystem in the Yellow River Basin expanded by 26 610.06 km, and the area of farmland decreased by 46 849.06 km after the implementation of two rounds of the project. Spatially, the upper reaches of the Yellow River were dominated by grassland and other ecosystems； the middle reaches of the Yellow River were dominated by farmland, forest, and grassland ecosystems； and the lower reaches of the Yellow River were dominated by farmland ecosystems. ② From 1990 to 2020, the carbon storage in the project implementation area showed a fluctuating and increasing trend, and the total carbon storage reached a peak （219.47×10 t） in 2009 and decreased to 218.59×10 t in 2020 due to the decrease of grassland ecosystem from 2010 to 2020. Spatially, the high-value areas of carbon storage were distributed in Aba Tibetan and Qiang Autonomous Prefecture of Sichuan Province and the southern tip of Gansu Province in the upper reaches of the forest and grass accumulation and in the whole of Shanxi Province and the central and southern parts of Shaanxi Province in the middle reaches. Shangluo City in Shaanxi Province and Alxa League in Inner Mongolia Autonomous Region were prefecture-level cities with the highest and lowest average carbon density. ③ In 2035, the carbon storage loss of the natural development scenario was predicted to be 0.83×10 t, and the other three scenarios would increase this loss. Under the moderate farmland return scenario, the Yellow River Basin ecosystem had the strongest carbon sequestration capacity, and the predicted carbon storage would increase by 2.72×10 t compared with that in 2020, and the deep farmland return scenario was the comprehensive optimal scenario. Therefore, in the future, the Yellow River Basin could refer to the deep farmland return scenario to optimize and adjust the implementation plan of the Grain for Green project, and the predicted value of carbon storage can provide some data support for achieving the dual carbon goal.
在“双碳”背景下，必须探究退耕还林工程的实施对黄河流域生态系统碳储量的影响，这可为完善新一轮退耕还林工程政策实施及提升黄河流域生态系统碳汇能力提供重要参考。本研究选取工程实施前的1990年作为研究期起始年，选取两轮项目实施后的2020年作为研究期末年。基于1990—2020年生态系统类型数据，运用InVEST模型计算1990—2020年黄河流域及工程实施区域的土壤碳库、地下碳库、地上碳库、死有机物质碳库及生态系统总碳储量。结果表明：①1990—2020年，黄河流域森林生态系统面积增加了26610.06平方千米，两轮工程实施后农田面积减少了46849.06平方千米。空间上，黄河上游以草地等生态系统为主；黄河中游以农田、森林和草地生态系统为主；黄河下游以农田生态系统为主。②1990—2020年，项目实施区域碳储量呈波动上升趋势，2009年总碳储量达到峰值（219.47×10吨），2010—2020年因草地生态系统减少，2020年降至218.59×10吨。空间上，碳储量高值区分布在森林和草地积累的上游四川省阿坝藏族羌族自治州及甘肃省南端，以及中游山西省全境和陕西省中南部。陕西省商洛市和内蒙古自治区阿拉善盟分别是平均碳密度最高和最低的地级市。③预测2035年自然发展情景下碳储量损失为0.83×10吨，其他三种情景会加剧这一损失。在适度退耕情景下，黄河流域生态系统碳汇能力最强，预测碳储量比2020年增加2.72×10吨，深度退耕情景为综合最优情景。因此，未来黄河流域可参照深度退耕情景优化调整退耕还林工程实施方案，碳储量预测值可为实现双碳目标提供一定数据支撑。
