Nitrogen transformation processes in soil along a High Arctic tundra transect  

作　　者：GUO Mengjie WANG Qing ZHANG Wanying JIAO Yi SUN Bowen HOU Lijun ZHU Renbin 

机构地区：[1]Institute of Polar Environment&Anhui Province Key Laboratory of Polar Environment and Global Change,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China [2]State Key Laboratory of NBC Protection for Civilian,Beijing 102205,China [3]Terrestrial Ecology Section,Department of Biology,Copenhagen University,CopenhagenØDK-2100,Denmark [4]State Key Laboratory of Estuarine and Coastal Research,East China Normal University,Shanghai 200241,China

出　　处：《Advances in Polar Science》2023年第2期105-124,共20页极地科学进展（英文版）

基　　金：This study was funded by the National Key Research and Development Program of China(Grant no.2020YFA0608501);the National Natural Science Foundation of China(Grant no.41976220);the State Key Laboratory of NBC Protection of Civilians(Grant no.SKLNBC2020-10).

摘　　要：Soil nitrogen(N)transformation processes in the High Arctic tundra are poorly understood even though nitrogen is one of the main limiting nutrients.We analyzed soil samples collected along a High Arctic tundra transect to investigate spatial variability in key nitrogen transformation processes,functional gene abundances,ammonia-oxidizing archaea(AOA)community structures,and key nitrogen transformation regulators.The potential denitrification rates were higher than the nitrification rates in the soil samples,although nitrification may still regulate N2O emissions from tundra soil.The nutrient(total carbon,total organic carbon,total nitrogen,and NH_(4)^(+)-N)contents were important determinants of spatial variability in the potential denitrification rates of soil along the tundra transect.The total sulfurcontent was the main variable controlling potential nitrification processes,probably in association with sulfate-reducing bacteria.The nitrate content was the main variable affecting potential dissimilatory nitrate reduction to ammonium.AOA and ammonia-oxidizing bacteria amoA,nirS,and anammox 16S rRNA genes were found in all of the soil samples.AOA play more important roles than ammonia-oxidizing bacteria in soilnitrification.Anammox bacteria may utilize NO_(2)^(-)produced through nitrification.Phylogenetic analysis indicated that the AOA amoA sequences could be grouped into eight unique operational taxonomic units(OTUs)with a 97%sequence similarity and were affiliated with three group 1.1b Nitrososphaeraclusters.The results indicated that heterogeneous environmental factors(e.g.,the carbon and nitrogen contents of soil)along the High Arctic tundra transect strongly affected the nitrogen transformation rate and relevant functional gene abundances in soil.

关 键 词：Arctic tundra soil nitrogen transformation NITRIFICATION DENITRIFICATION functional gene abundance ammonia-oxidizing archaea 

分 类 号：S153.6[农业科学—土壤学]