Ma Honghong, Peng Min, Yang Zheng, Yang Ke, Zhao Chuandong, Li Kuo, Guo Fei, Yang Zhongfang, Cheng Hangxin
Institute of Geophysical & Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China; Key Laboratory of Geochemical Cycling of Carbon and Mercury in the Earth's Critical Zone, Chinese Academy Geological Sciences, Langfang 065000, China; Geochemical Research Center of Soil Quality, China Geological Survey, Langfang 065000, China.
Institute of Geophysical & Geochemical Exploration, Chinese Academy of Geological Sciences, Langfang 065000, China; Key Laboratory of Geochemical Cycling of Carbon and Mercury in the Earth's Critical Zone, Chinese Academy Geological Sciences, Langfang 065000, China; Geochemical Research Center of Soil Quality, China Geological Survey, Langfang 065000, China.
Sci Total Environ. 2024 Feb 10;911:168602. doi: 10.1016/j.scitotenv.2023.168602. Epub 2023 Nov 14.
Soil organic carbon (SOC) is a critical component of soil fertility and plays a crucial role in the global carbon cycle. Despite the widespread reports of a decrease in SOC content and stock in the Northeast China Plain in recent decades, the current status and driving factors of its content and distribution are unclear. In this study, the surface soil (0-20 cm) SOC content data of 1920 sampling points within the Northeast China Plain covering an area of 2.6 × 10 km were obtained based on the Land Quality Geochemical Monitoring Network established in 2018. Random forest model and correlation analysis were used to identify the main driving factors of SOC distribution. The results showed that the SOC content, soil organic carbon density (SOCD), and soil organic carbon storage (SOCS) in the Northeast China Plain were 13.48 g·kg, 3.45 kg·C·m, and 898.95 Tg, respectively. SOC content in paddy land was the highest among different land use types, which reached 18.77 g·kg. SOC content showed strong spatial dependence and gradually increased from southwest to northeast in the monitoring area. The results of the random forest analysis showed that the SiO, mean annual temperature, and FeO explained 39.4 %, 18.9 %, and 12.8 % of the spatial variation of SOC, respectively. Although the SOCS (0-20 cm) in the Northeast China Plain has decreased by 8.68 % in the last 40 years compared to the Second National Soil Survey (1980), it's important to note that the SOCS has transitioned from a decreasing trend between 1980 and 2006 to an increasing trend from 2006 to 2018.This study provides important information for decision-makers on the spatiotemporal changes of SOC and its driving factors in the Northeast China Plain, which has a great significance for soil carbon sequestration and the development of management strategies to maintain soil fertility.
土壤有机碳（SOC）是土壤肥力的关键组成部分，在全球碳循环中起着至关重要的作用。尽管近几十年来有广泛报道称中国东北平原的土壤有机碳含量和储量有所下降，但其含量和分布的现状及驱动因素仍不明确。在本研究中，基于2018年建立的土地质量地球化学监测网络，获取了中国东北平原2.6×10⁵平方千米范围内1920个采样点的表层土壤（0 - 20厘米）有机碳含量数据。采用随机森林模型和相关分析来确定土壤有机碳分布的主要驱动因素。结果表明，中国东北平原的土壤有机碳含量、土壤有机碳密度（SOCD）和土壤有机碳储量（SOCS）分别为13.48克/千克、3.45千克碳/平方米和898.95太克。水田的土壤有机碳含量在不同土地利用类型中最高，达到18.77克/千克。土壤有机碳含量表现出强烈的空间依赖性，在监测区域内从西南向东北逐渐增加。随机森林分析结果表明，SiO₂、年均温度和Fe₂O₃分别解释了土壤有机碳空间变异的39.4%、18.9%和12.8%。尽管与第二次全国土壤普查（1980年）相比，中国东北平原过去40年（0 - 20厘米）的土壤有机碳储量下降了8.68%，但需要注意的是，土壤有机碳储量已从1980年至2006年的下降趋势转变为2006年至2018年的上升趋势。本研究为决策者提供了关于中国东北平原土壤有机碳时空变化及其驱动因素的重要信息，这对于土壤碳固存以及制定维持土壤肥力的管理策略具有重要意义。
