闽江河口湿地围垦稻田对土壤铁碳结合特征的影响  

Effects of reclamation of paddy fields on soil iron-bound organic carbon in Minjiang River estuarine wetland

作　　者：刘旭阳 王纯[1,2] 郭萍萍 方云英 沈李东 胡世文 黑杰 王亚非 胥佳忆 王维奇 LIU Xuyang;WANG Chun;GUO Pingping;FANG Yunying;SHEN Lidong;HU Shiwen;HEI Jie;WANG Yafei;XU Jiayi;WANG Weiqi(Key Laboratory of Humid Sub-tropical Eco-geographical Process of Ministry of Education,Fujian Normal University,Fuzhou 350117,China;Wetland Ecosystem Research Station of Fujian Minjiang Estuary(National Forestry and Grassland Administration),Fuzhou 350215,China;Fujian Minjiang River Estuary Wetland National Nature Reserve Administrative Office,Fuzhou 350200,China;Australian Rivers Institute and School of Environment and Science,Griffith University,Nathan Campus,Queensland 4111,Australia;School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China;National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China,Guangzhou 510650,China)

机构地区：[1]福建师范大学湿润亚热带生态-地理过程教育部重点实验室,福州350117 [2]福建闽江河口湿地生态系统国家定位观测研究站(国家林业和草原局),福州350215 [3]福建闽江河口湿地国家级自然保护区管理处,福州350200 [4]格里菲斯大学澳大利亚河流研究所和环境与科学学院,南森校区,昆士兰4111 [5]南京信息工程大学应用气象学院,南京210044 [6]广东省科学院生态环境与土壤研究所,广州510650

出　　处：《海洋地质与第四纪地质》2024年第1期44-54,共11页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金“河口湿地围垦稻田后土壤铁结合态有机碳的演变趋势和稳定机制”(42077086)。

摘　　要：土壤铁氧化物结合态有机碳是有机碳长期维持的主要途径,但其机理研究仍较为薄弱。为探究河口湿地围垦稻田对土壤铁碳结合特征的影响,本研究选择福建省闽江河口天然芦苇湿地与围垦稻田为研究对象,对两种类型土壤中的铁结合态有机碳(Fe-OC)及其相关指标进行测定与分析。结果显示:①芦苇湿地围垦稻田改变了土壤氧化还原过程,显著影响土壤中铁相的转化。围垦后土壤二价铁[Fe(Ⅱ)]、三价铁[Fe(Ⅲ)]、活性总铁含量(HCl-Fe_(t))及Fe(Ⅲ)/Fe(Ⅱ)分别显著下降了24.68%、52.56%、51.45%、35.68%(P<0.05)。游离态氧化铁(Fe_(d))与无定形态铁(Fe_(o))含量分别显著下降了21.64%和29.24%(P<0.05),络合态铁(Fe_(p))含量则有所增加。②芦苇湿地围垦稻田显著影响土壤碳固存,Fe-OC与土壤有机碳含量(SOC)在围垦稻田后分别显著下降了39.03%和18.42%(P<0.05);芦苇湿地与稻田土壤Fe-OC均主要以吸附途径结合,稻田土壤Fe-OC对土壤有机碳的贡献率(fFe-OC)显著高于芦苇湿地(P<0.05)。③土壤全氮、含水量、电导率、铁以及土壤有机碳、溶解性有机碳与Fe-OC呈显著正相关(P<0.01)。本研究可为退耕还湿、土壤碳增汇提供科学参考。Iron oxide bound organic carbon is the main pathway for long-term stability of organic carbon.However,study of its mechanism remains weak.To understand the impact of estuarine wetland reclamation of paddy field on soil iron-carbon binding characteristics,we measured the soil iron-bound organic carbon(Fe-OC)and its related indicators in the natural reed(Phragmite australis)wetland and paddy field reclamation in Minjiang River estuary,Fujian Province.Results show that the wetland reclamation significantly affected the soil oxidation and reduction condition,and the redox process significantly affected the transformation of iron(Fe)phase in soil.After the wetland reclamation,the content of bivalent iron[Fe(Ⅱ)],trivalent iron[Fe(Ⅲ)],active total iron(HCl-Fe_(t)),and Fe(Ⅲ)/Fe(Ⅱ)in the soil significantly decreased by 24.68%,52.56%,51.45%,and 35.68%,respectively(P<0.05).The content of free Fe oxide(Fe_(d))and amorphous iron(Fe_(o))in the soil significantly decreased by 21.64%and 29.24%,respectively(P<0.05),but the content of complex iron(Fe_(p))increased.In addition,the wetland reclamation significantly affected the soil carbon retention,and the content of Fe-OC and soil organic carbon(SOC)in the soil significantly decreased by 39.03%and 18.42%after the reclamation(P<0.05).In both reed wetland and paddy field,soil Fe-OC was combined dominantly through adsorption.The contribution rate of paddy field soil Fe-OC to SOC(fFe-OC)was significantly higher than that of reed wetland(P<0.05).Finally.there were significant positive correlations(P<0.01)between soil TN,water content,conductivity,Fe,SOC,dissolved organic carbon,and Fe-OC.This study provided scientific guidance for wetland restoration and increasing soil carbon sequestration.

关 键 词：铁 铁结合态有机碳 芦苇湿地 稻田 闽江河口 

分 类 号：P736.4[天文地球—海洋地质]