不同水淹梯度下河漫滩湿地土壤有机碳特征及其影响因子  

Characteristics of soil organic carbon and its influencing factors in floodplain wetland under different flooding gradients

作　　者：滕怡敏 李丛笑 张天昱 张宁[1] 李德生[1] 刘福德[1] TENG Yimin;LI Congxiao;ZHANG Tianyu;ZHANG Ning;LI Desheng;LIU Fude(School of Environmental Science and Safety Engineering,Tianjin University of Technology,Tianjin 300384)

机构地区：[1]天津理工大学环境科学与安全工程学院,天津300384

出　　处：《环境科学学报》2023年第8期362-371,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金项目(No.41303057);天津市应用基础与前沿技术研究计划项目(No.14JCYBJC23000)。

摘　　要：水淹梯度是河漫滩湿地中的重要环境变量,其对湿地土壤有机碳特性的影响尚不明确.本文以天津独流减河河漫滩湿地为研究对象,研究不同水淹梯度下盐地碱蓬根际与非根际土壤中有机碳的分布特性,同时结合土壤理化性质、植物根际作用和细菌区系特征分析影响土壤有机碳分布的非生物和生物因子.结果表明:水淹梯度的变化显著影响了湿地土壤的理化性质(p <0.05).盐地碱蓬根际效应对多数土壤理化性质均无显著影响,但根际及其与水淹的交互作用显著影响了铵氮的变化(p <0.05),且铵氮是影响土壤细菌区系变化的关键元素.土壤盐度和水分变化对土壤有机碳的含量有显著影响(p <0.05),盐度还显著影响了土壤可溶性有机碳的含量(p <0.05),表明合理的水盐调控措施可促进入海河流河漫滩湿地土壤有机碳的固存.研究同时发现,土壤细菌的α-多样性和群落结构沿着水淹梯度的变化较明显,但其代谢功能在水淹和半水淹处并无明显差异,表明短期或周期性水位变化并未明显改变生境功能.该研究结果对入海河流河漫滩湿地的生态修复非常重要,同时也为河漫滩与河流主干河道作为同一个功能区进行一体化修复提供了理论基础.Flooding gradient is an important environmental variable in floodplain wetland,and its effects on the changes of soil organic carbon(SOC)of wetland are still unclear.In this study,we took the floodplain wetland of Duliujian River in Tianjin as the research object,and the distribution characteristics of SOC in rhizosphere and non-rhizosphere soils of Suaeda salsa under different flooding gradients were studied,then the abiotic and biotic factors affecting the distribution of SOC were analyzed in combination with soil physicochemical properties,plant rhizosphere effects,and bacterial flora characteristics.The results showed that the variation of flooding gradient had a significant effect on the physicochemical properties of wetland soil(p<0.05).The rhizosphere effect of Suaeda salsa had no significant impact on most soil physicochemical properties,but the rhizosphere and its interaction with flooding significantly affected the change of NH_(4)^(+)-N(p<0.05),and NH_(4)^(+)-N was the key elemental parameter affecting the changes of soil bacterial flora.SOC content can be affected significantly by soil salinity and moisture content(p<0.05),and dissolved organic carbon content also significantly increased with increases in salinity(p<0.05),indicating that reasonable measures for water and salt regulation can promote SOC sequestration in the floodplain wetlands of coastal rivers.The study also discovered that soil bacterialα-diversity and community structure varied obviously along the flooding gradient,but their metabolic functions did not differ significantly between flooded and semi-flooded soils,suggesting that short-term or periodic water level changes did not significantly alter the habitat functions.The findings of this study are important for the ecological restoration of floodplain wetlands in coastal rivers,and also provide a theoretical basis for the integrated restoration of floodplain wetlands and main river channels as the same functional area.

关 键 词：河漫滩湿地 水淹梯度 土壤细菌区系 土壤有机碳 生态修复 

分 类 号：X171[环境科学与工程—环境科学]