摘要
为探究不同土地利用方式下土壤微生物氮循环功能基因的响应特征及驱动因子,以黄河冲积平原5种典型土地利用方式(柽柳林、白蜡林、草地、湿地和农田)为对象,采用宏基因组学方法测定土壤氮循环6个关键过程的22个功能基因相对丰度及土壤理化性质。结果表明:不同土地利用方式土壤氮循环功能基因相对丰度差异显著。湿地土壤的固氮(1.28×10^(-5))、硝化(4.91×10^(-4))和反硝化(7.03×10^(-4))基因相对丰度最高,而同化硝酸盐还原基因相对丰度(1.84×10^(-4))最低;农田的同化硝酸盐还原基因相对丰度(3.31×10^(-4))最高;草地氨化基因相对丰度(2.35×10^(-4))显著高于其他类型;柽柳林的硝化(2.77×10^(-4))与反硝化基因(5.25×10^(-4))相对丰度最低。冗余分析表明,土壤总氮、有机碳、全钾和电导率是驱动氮循环功能基因丰度变化的主要环境因子。土地利用方式通过改变土壤养分状况调控微生物氮循环功能基因丰度,进而影响土壤氮循环过程。
To investigate the responses and drivers of soil microbial nitrogen(N)-cycling functional genes under different land-use types,we analyzed five representative ecosystems in the Yellow River alluvial plain:Tamarix chinensis forests,Fraxinus chinensis forests,grasslands,wetlands,and farmlands.With metagenomic sequencing,we quantified the relative abundances of 22 functional genes associated with six critical N-cycling processes.Soil physicochemical properties were characterized.There were significant variations in soil nitrogen(N)-cycling functional gene abundances across land-use types.Wetlands exhibited the highest relative abundances of nitrogen fixation(1.28×10^(-5)),nitrification(4.91×10^(-4)),and denitrification(7.03×10^(-4))genes,but the lowest assimilatory nitrate reduction potential(1.84×10^(-4)).Farmlands showed maximal assimilatory nitrate reduction gene abundance(3.31×10^(-4)),while grasslands dominated in ammonification gene expression(2.35×10^(-4)),significantly higher than other ecosystems.T.chinensis forests maintained the most constrained N-cycling profile,with minimal nitrification(2.77×10^(-4))and denitrification(5.25×10^(-4))relative gene abundances.Redundancy analysis identified soil total nitrogen,organic carbon,total potassium,and electrical conductivity as the key environmental drivers of these variations.Our findings demonstrated that land-use types could shape microbial N-cycling functional gene abundances by altering soil nutrient conditions,with consequence on fundamental processes of soil nitrogen transformation.
作者
闻鸣
刘禹
冯朝阳
计伟
李卓卿
WEN Ming;LIU Yu;FENG Chaoyang;JI Wei;LI Zhuoqing(State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;College of Ecology,Lanzhou University,Lanzhou 730000,China)
出处
《应用生态学报》
北大核心
2025年第5期1387-1397,共11页
Chinese Journal of Applied Ecology
基金
生态环境部区域生态过程与功能评估重点实验室开放基金项目(2022YSKY-08)资助。
关键词
土地利用方式
氮转化微生物
黄河冲积平原
宏基因组学
land use type
nitrogen-transforming microorganism
Yellow River alluvial plain
metagenomics
作者简介
通信作者:李卓卿,E-mail:lzqhappy@hotmail.com;闻鸣,男,2000年生,硕士研究生。主要从事可持续生态学研究。E-mail:w1255270260@163.com。
