复湿对退化泥炭沼泽土壤有机碳和铁结合有机碳含量的影响——以白江河泥炭沼泽为例  

Effects of Rewetting on Soil Organic Carbon and Fe-bound Organic Carbon Contents of A Degraded Peatland:A Case Study of Baijinghe Peatland

作　　者：徐光远 吴帆[1,2,3] 王钰婷 董彦民 徐志伟 王升忠[1,2,3] XU Guangyuan;WU Fan;WANG Yuting;DONG Yanmin;XU Zhiwei;WANG Shengzhong(Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains,Ministry of Education,School of Geographical Sciences,Northeast Normal University,Changchun 130024,Jilin,P.R.China;Institute for Peat and Mire Research,State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration,Northeast Normal University,Changchun 130024,Jilin,P.R.China;Jilin Provincial Key Laboratory for Wetland Ecological Processes and Environmental Change in the Changbai Mountains,Northeast Normal University,Changchun 130024,Jilin,P.R.China)

机构地区：[1]东北师范大学地理科学学院,长白山地理过程与生态安全教育部重点实验室,吉林长春130024 [2]东北师范大学泥炭沼泽研究所,国家环境保护湿地生态与植被恢复重点实验室,吉林长春130024 [3]吉林省长白山湿地生态过程与环境变化重点实验室,吉林长春130024

出　　处：《湿地科学》2024年第6期823-833,共11页Wetland Science

基　　金：国家重点研发计划青年科学家项目(2023YFF0806900);国家自然科学基金项目(32241033和32071599)资助。

摘　　要：作为陆地生态系统中重要的碳库之一,泥炭沼泽土壤碳的变化对全球碳平衡具有重要意义,土壤中的酶和铁是影响土壤有机质分解的重要因素。以长白山白江河泥炭沼泽为研究对象,于2021年4月,采集自然区、排水区和水位恢复区0~20 cm深度的土壤样品,测定其土壤理化性质、不同形态铁含量、土壤酶活性、土壤铁结合有机碳及土壤有机碳含量,阐明“酶闩”与“铁门”在泥炭沼泽土壤有机碳循环中的相对重要性,为退化泥炭沼泽恢复过程中的碳库管理工作提供数据支撑。研究结果表明,水位恢复2 a后,水位恢复区土壤pH升高,土壤全氮含量降低;土壤中Fe^(2+)和络合态铁氧化物含量高于排水区,排水区土壤中Fe^(3+)、无定型态铁氧化物和游离态铁氧化物含量都高于水位恢复区;0~5 cm深度土壤水解酶活性降低,氧化酶活性增高,而>5~20 cm深度土壤酶活性无明显变化规律,土壤酶活性主要受土壤全氮和铁含量的影响;总体上,水位恢复区土壤有机碳和铁结合有机碳含量高于排水区;水位恢复后,络合态铁氧化物含量升高,促进了铁结合有机碳含量的升高,但“铁门”机制并不是土壤有机碳变化的主要原因;土壤铁含量主要通过影响酶活性,进而使得“酶闩”机制在春季泥炭沼泽土壤有机碳变化中发挥重要作用。As one of the significant carbon pool within terrestrial ecosystems,changes in soil carbon in peatlands have considerable implications for the global carbon balance.Soil enzymes and iron are important substances which affect the decomposition of soil organic matter.This article focuses on the Baijianghe peatland as the research subject,with soil samples collected from the natural area,drained,and water level restoration area at depths of 0-20 cm in April 2021.Soil physical and chemical properties,different forms of iron contents,soil enzyme activity,iron contents,Fe-bound soil organic carbon,and soil organic carbon were measured.The aims of this study were to clarify the relative importance of‘enzyme latch’and‘iron gate’mechanisms in soil organic carbon cycling within peatlands and to provide a data foundation for carbon pool management during the restoration of degraded peatlands.The results showed that after two years of rewetting,soil pH increased but soil total nitrogen content decreased.Soil Fe^(2+)and pyrophosphate-extractable iron oxides(Fep)exhibited a trend where the restoration area surpassed the drained area.In contrast,the contents of soil Fe^(3+),oxalate-extractable iron oxides(Feo),and dithionite-citrate-bicarbonate-extractable iron oxides(Fed)demonstrated a trend of the drained area exceeding the restoration area.Soil hydrolytic activities of the 0-5 cm depth decreased but the oxidase activities increased after rewetting.However,the activities of soil enzymes in the 5-20 cm depth did not change uniformly.Changes in soil enzyme activities were mainly affected by soil total nitrogen and iron content.In general,soil organic carbon and Fe-bound soil organic carbon contents in the restoration area were higher than those in the drained area.After rewetting,soil pyrophosphate-extractable iron oxides content increased which was benefit for the increasing of Fe-bound soil organic carbon content.However,the'iron gate'mechanism was not the main cause of soil organic carbon increasing after rewetting.S

关 键 词：泥炭沼泽 水位恢复 土壤铁 酶活性 铁结合有机碳 白江河泥炭沼泽 

分 类 号：S153.6[农业科学—土壤学]