滨海湿地土壤溶解性无机碳淋溶动态及机理研究  

The leaching dynamics of soil dissolved inorganic carbon in coastal wetlands and its underlying mechanism

作　　者：于纪民 王筱彤 王艺霖 李毛毛 郗敏 YU Jimin;WANG Xiaotong;WANG Yilin;LI Maomao;XI Min(College of Environmental Science and Engineering,Qingdao University,Qingdao 266071;Carbon Neutrality and Eco-Environmental Technology Innovation Center of Qingdao,Qingdao 266071;College of Water Sciences,Beijing Normal University,Beijing 100875)

机构地区：[1]青岛大学环境科学与工程学院,青岛266071 [2]青岛市碳中和生态环境技术创新中心,青岛266071 [3]北京师范大学水科学研究院,北京100875

出　　处：《环境科学学报》2025年第3期361-372,共12页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.42171116);山东省高等学校青年创新团队计划(No.2022KJ147)。

摘　　要：土壤溶解性无机碳(Dissolved Inorganic Carbon,DIC)在滨海湿地碳循环中扮演重要角色,其淋溶过程与海洋碳汇的形成密切相关.本研究以碱蓬(Suaeda salsa)和芦苇(Phragmites australis)两种湿地类型土壤为研究对象,通过室内土柱淋溶模拟实验,测定并分析淋溶过程中淋出液和土壤的理化指标及碳组分含量,探究滨海湿地土壤DIC的淋溶动态及机理.结果表明:①淋溶过程中,碱蓬和芦苇湿地土壤淋出液DIC浓度均呈先升高后降低趋势,表明DIC的剖面淋失主要发生在淋溶的前-中期;相关性分析表明,淋出液DIC分别与pH和电导率(EC)呈显著正相关和负相关关系.②淋溶结束后,两种湿地类型土壤DIC含量均增加,在垂直剖面上,0~20 cm深度土壤DIC含量下降,20~60 cm土壤DIC含量升高,表明淋溶促进了土壤DIC的形成及其向土壤深层的迁移和积累;从湿地类型来看,碱蓬湿地土壤DIC变化量(ΔDIC)与ΔEC呈显著负相关关系,而在芦苇湿地,ΔDIC与土壤无机碳变化量(Soil Inorganic Carbon,ΔSIC)和土壤有机碳变化量(Soil Organic Carbon,ΔSOC)均呈显著正相关关系;从垂直剖面来看,40~60 cm深度土壤ΔDIC与ΔEC和ΔSOC均呈显著相关关系.由此可见,淋溶不仅通过DIC的剖面淋失直接促进DIC向土壤深层的迁移和积累,还通过土壤pH、EC和SOC间接影响土壤DIC的形成及动态分布.Soil dissolved inorganic carbon(DIC)plays a key role in the carbon cycle of coastal wetlands,and its leaching process is intricately linked to the establishment of marine carbon sinks.This study focused on soils from Suaeda salsa and Phragmites australis wetland.An indoor soil column leaching simulation experiment was conducted to study the physicochemical properties and carbon components of the leachate and soil during the leaching process,aiming to explore the dynamics and mechanisms of DIC in coastal wetlands.The results showed that:①During the leaching,the pH and DIC concentrations in the leachate of S.salsa and P.australis soil increased first and then decreased,suggesting that the vertical loss of DIC mainly occurs in the early-middle stage of leaching.Correlation analysis showed that the leachate DIC was significantly positively and negatively correlated with pH and electrical conductivity(EC),respectively.②After the leaching,the soil DIC content of both wetlands increased,while its content decreased at the depth of 0~20 cm and increased at the depth of 20~60 cm.This indicates that the leaching promoted the formation of soil DIC and its migration and accumulation in deep soil layers.For different wetland types,the changes of soilΔDIC were significantly negatively correlated withΔEC in S salsa wetland,and significantly positively correlated with the changes of soil inorganic carbon(ΔSIC)and soil organic carbon(ΔSOC)in P australis wetland.Vertically,soilΔDIC was significantly correlated withΔEC andΔSOC in 40~60 cm depth,respectively.Based on the above,leaching not only directly promotes the migration and accumulation of DIC to the deep soil through the leaching of DIC,but also indirectly affects the formation and dynamics of soil DIC by influencing soil pH,EC and SOC.

关 键 词：溶解性无机碳 淋溶过程 碳循环 滨海湿地 

分 类 号：X142[环境科学与工程—环境科学]