中国农业科学 ›› 2024, Vol. 57 ›› Issue (8): 1517-1532.doi: 10.3864/j.issn.0578-1752.2024.08.008

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

陕西省土壤无机碳的时空分布特征及影响因素

冯晓琳1(), 张楚天1, 许晨阳1,2(), 耿增超1,2(), 胡斐南3,4, 杜伟1,2   

  1. 1 西北农林科技大学资源环境学院,陕西杨凌712100
    2 西北农林科技大学西北农业农村部植物营养与农业环境重点实验室,陕西杨凌 712100
    3 西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌 712100
    4 中国科学院水利部水土保持研究所,陕西杨凌 712100
  • 收稿日期:2023-05-30 接受日期:2023-07-17 出版日期:2024-04-16 发布日期:2024-04-24
  • 通信作者:
    许晨阳,E-mail:
    耿增超,E-mail:
  • 联系方式: 冯晓琳,E-mail:fxl20170901@163.com。
  • 基金资助:
    国家自然科学基金(41701261); 陕西省自然科学基金(2023-JC-YB-263); 中央高校基本科研业务费(2452020165)

Spatiotemporal Distribution Characteristics and Influencing Factors of Soil Inorganic Carbon in Shaanxi Province

FENG XiaoLin1(), ZHANG ChuTian1, XU ChenYang1,2(), GENG ZengChao1,2(), HU FeiNan3,4, DU Wei1,2   

  1. 1 College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, Shaanxi
    2 Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture and Rural Affairs, Northwest A&F University, Yangling 712100, Shaanxi
    3 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Northwest A&F University, Yangling 712100, Shaanxi
    4 Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling 712100, Shaanxi
  • Received:2023-05-30 Accepted:2023-07-17 Published:2024-04-16 Online:2024-04-24

摘要:

【目的】土壤无机碳对于调节全球碳循环有重要作用,然而我国区域尺度上土壤无机碳的分布特征及影响因素尚不明确。对陕西省土壤无机碳时空分布和关键影响因子进行研究可为明确无机碳在陆地生态系统碳循环中的作用和地位提供参考和依据。【方法】收集陕西省1980s和2010s两期的65个和142个土壤样本以及相关的地形因素、气候条件、土地利用类型、植被状况和土壤性质数据,采用方差分析和随机森林(Random Forest,RF)模型分析土壤无机碳含量的时间和空间分布特征,并探讨土壤无机碳含量变化的影响因素。【结果】陕西省1980s各区域的土壤无机碳含量表现为:陕北>关中>陕南;与1980s相比,2010s陕北土壤无机碳含量下降了31.5%,关中地区基本保持不变,陕南小幅度上升。1980s到2010s,0—100 cm剖面上不同土层无机碳含量的降幅范围为20.6%—27.7%,其中以0—20和80—100 cm土层降幅最大。随机森林模型分析表明,年平均降水量、容重、pH是影响1980s和2010s土壤无机碳含量变化的重要因素,在年平均降水量450—650 mm时土壤无机碳含量最高;土壤无机碳含量随着pH的增加而增加;低容重土壤无机碳含量高于高容重土壤。【结论】总体来看,陕西省土壤无机碳含量呈现从北向南逐渐降低的趋势。与1980s相比,2010s陕西省表层土壤和陕北地区整个土壤剖面无机碳含量显著下降,1980s和2010s陕西省土壤无机碳含量主要受年平均降水量、pH、容重的调控。

关键词: 土壤无机碳, 时空分布, 随机森林模型, 陕西省

Abstract:

【Objective】Soil inorganic carbon (SIC) plays an important role in regulating global carbon cycle. However, the distribution characteristics and influencing factors of SIC at regional scales are not clear. The study on the temporal and spatial distribution of SIC and its key influencing factors in Shaanxi Province can provide the reference and basis for clarifying the role and status of inorganic carbon in the terrestrial ecosystem carbon cycle. 【Method】This study collected 65 and 142 soil samples from the 1980s and 2010s in Shaanxi Province, along with relevant data on geographical factors, climatic conditions, land use types, vegetation status and soil properties. Variance analysis and Random Forest (RF) model were used to analyze the temporal and spatial distribution characteristics of SIC content. The influencing factors of SIC content in Shaanxi Province were also discussed. 【Result】SIC content in the 1980s of Shaanxi Province was in the order of Northern Shaanxi > Guanzhong of Shaanxi > Southern Shaanxi. Compared with the 1980s, SIC content in Northern Shaanxi Province was decreased by 31.5% in 2010s, while it remained almost unchanged in Guanzhong of Shaanxi Province, which increased slightly in southern Shaanxi Province. From the 1980s to 2010s, the decrease of inorganic carbon content in different soil layers in 0-100 cm section ranged from 20.6% to 27.7%, with the greatest decreases in 0-20 cm and 80-100 cm soil layers. Random Forest model analysis showed that average annual rainfall, bulk density and pH were the top three most important factors affecting SIC content in both 1980s and 2010s, and SIC content was the highest when the average annual rainfall were 450-650 mm. Soil inorganic carbon content increased with the increase of pH. The inorganic carbon content of soil with low bulk density was higher than that of soil with high bulk density. 【Conclusion】In general, SIC content in Shaanxi Province showed a decreasing trend from north to south. Compared with the 1980s, SIC content in topsoil of Shannxi Province and also the whole soil profile of northern Shaanxi Province decreased significantly in the 2010s. The SIC content in the 1980s and 2010s were mainly influenced by average annual rainfall, pH and bulk density.

Key words: soil inorganic carbon (SIC), spatiotemporal distribution, Random Forest model, Shaanxi Province