营养物质添加对黄河口潮滩湿地脱氮过程的影响  

Effect of nutrient addition on nitrogen removal process in Yellow River tidal flat wetland

作　　者：赵春宇 尹涵宇 张芬 王文彬 张晓黎[2] 赵逸昳 ZHAO Chunyu;YIN Hanyu;ZHANG Fen;WANG Wenbin;ZHANG Xiaoli;ZHAO Yiyi(School of Ecology,Resources and Environment,Dezhou University,Dezhou 253023;Key Laboratory of Coastal Environmental Processes and Ecological Remediation,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003;School of Public Health and Health Management,Shandong First Medical University and Shandong Academy of Medical Sciences,Jinan 250117)

机构地区：[1]德州学院生态与资源环境学院,德州253023 [2]中国科学院烟台海岸带研究所,海岸带环境过程与生态修复重点实验室,烟台264003 [3]山东第一医科大学公共卫生与健康管理学院,济南250117

出　　处：《环境科学学报》2024年第10期368-377,共10页Acta Scientiae Circumstantiae

基　　金：山东省自然科学基金(No.ZR2020QC052);国家自然科学基金(No.42307315);德州学院博士启动基金(No.2019xjrc338);德州学院学科(平台)建设项目(No.2023XKZX030)。

摘　　要：为探究人类活动引起的营养物质输入对湿地土壤脱氮过程的影响,采集黄河口芦苇湿地土壤进行加富盆栽实验,测定并分析了土壤反硝化(DNF)速率和厌氧氨氧化(AMX)速率、功能基因丰度、酶活性及理化因子等指标的变化.结果发现,不同营养物质输入对微生物量碳氮、总有机碳和总氮的含量具有促进作用.与对照组相比,硝酸钾、氯化铵、尿素和凋落物的添加均显著促进了土壤脱氮过程,使脱氮潜力分别提升了51.9%、34.9%、69.5%和97.0%,其中,凋落物的促进作用最显著.凋落物主要通过增加土壤活性有机质含量,并提高反硝化限速环节中亚硝酸还原酶(Nir)的活性,进而对DNF产生促进作用.对AMX而言,凋落物则通过增加土壤铵态氮含量和提高矿化作用关键酶脲酶(UE)活性,为AMX提供反应底物提高其速率.此外,AMX与硝酸还原酶(Nar)之间的显著正相关性表明NO2--N供给可能是制约厌氧氨氧化过程的重要因素.尿素和氯化铵通过提高土壤UE和Nar活性,而硝酸钾通过提高Nar和Nir活性,促进氮形态转化,进而为脱氮过程提供反应底物.综上,外源营养物质输入在一定程度上能促进黄河口芦苇湿地土壤的脱氮潜力,从而减缓未来人类活动导致的近岸富营养化.To investigate the impact of anthropogenic nutrient input on the process of soil nitrogen removal in wetland,an enrichment pot experiment was conducted using soil samples from the Yellow River Estuary reed wetland.The rates of soil denitrification(DNF)and anaerobic ammonia oxidation(AMX)were measured and analyzed,along with changes in functional gene abundance,enzyme activity and other physicochemical factors.The results showed that different nutrient inputs had a stimulating effect on the levels of microbial biomass carbon and nitrogen,total organic carbon and total nitrogen.Compared with the control group,the addition of KNO_(3),NH4Cl,urea and litter significantly promoted the soil nitrogen removal processes,enhancing the nitrogen removal potential by 51.9%,34.9%,69.5%and 97.0%,respectively,with the most significant effect observed with the addition of plant litter.The promotion by plant litter was primarily attributed to an increase in the content of soil active organic matter in the soil,which also boosted the activity of nitrite reductase(Nir),the rate-limiting enzyme in the denitrification process.For AMX,the promotion by plant litter occurred by increasing the content of NH4-N in soil and enhancing the activity of urease(UE),a key enzyme in mineralization,thereby providing more substrate for AMX and increasing its rate.Furthermore,the significant positive correlation between AMX and Nar indicates that NO2--N supply may be a key factor limiting the anammox.Urea and NH4Cl mainly promoted the nitrogen removal processes by increasing UE and Nar activity in soil,while KNO_(3) did so by enhancing Nar and Nir activity,thereby facilitating nitrogen transformation and providing more substrate for the nitrogen removal processes.Overall,the input of exogenous nutrients can promote the nitrogen removal potential of soil in the Yellow River Estuary reed wetland,which may help mitigate coastal eutrophication caused by future human activities.

关 键 词：营养物质添加 反硝化作用 厌氧氨氧化作用 影响因素 黄河口芦苇湿地 

分 类 号：X171[环境科学与工程—环境科学]