基于稳定同位素自然丰度技术的土壤氧化亚氮产生与排放过程研究进展  

Stable isotope natural abundance techniques in the studies on nitrous oxide production and emission processes:a review

作　　者：黄瑾 余龙飞 李文娟 黄平[2] HUANG Jin;YU Longfei;LI Wenjuan;HUANG Ping(College of Architecture and Urban Planning,Chongqing Jiaotong University,Chongqing 400074,China;Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714,China;Chongqing School,University of Chinese Academy of Sciences,Chongqing 400020,China;Institute of Groundwater and Earth Sciences,Jinan University,Guangzhou 510632,Guangdong,China)

机构地区：[1]重庆交通大学建筑与城市规划学院,重庆400074 [2]中国科学院重庆绿色智能技术研究院,重庆400714 [3]中国科学院大学重庆学院,重庆400020 [4]暨南大学地下水与地球科学研究院,广东广州510632

出　　处：《浙江农林大学学报》2021年第5期906-915,共10页Journal of Zhejiang A&F University

基　　金：国家自然科学基金资助项目(41771266,41401243);土壤与农业可持续发展国家重点实验室开放基金项目(Y812000005);中国科学院西部青年学者项目(202082)。

摘　　要：氧化亚氮(N_(2)O)是主要的温室气体之一,并且对平流层臭氧层分解起到重要作用。土壤中N_(2)O的产生和排放过程复杂多样,对其进行精准溯源与过程区分有助于制定减排策略。稳定同位素自然丰度技术利用N_(2)O的同位素值δ^(15)N^(bulk)(N_(2)O中15N在整体水平上的同位素特征值)、δ^(18)O(N_(2)O中18O在整体水平上的同位素特征值)以及δ^(15)N^(sp)(N_(2)O分子内15N的位点特异性同位素值),可以示踪N_(2)O来源、指示N_(2)O产生的微生物作用途径,在N_(2)O转化过程溯源中已取得重要进展。而同位素分馏效应是稳定同位素自然丰度技术应用的理论基础,其中微生物过程及其导致的同位素分馏是需要重点关注的问题。本研究概述了同位素分馏效应在N_(2)O的产生、排放过程中的研究进展及其主要影响因素,梳理了同位素特征值δ^(15)N^(bulk)、δ^(18)O和δ^(15)N^(sp)在分析N_(2)O来源的研究进展,并且提出了影响准确区分过程的因素。因素包括单一产生路径的同位素特征值范围广、不同产生路径的同位素特征值范围的重叠、反应底物同位素组成的变化以及与N_(2)O还原相关的分馏因子的可变性等问题。明确了今后需加强δ^(15)N^(sp)等N_(2)O同位素特征值分馏效应的测定,利用组合同位素特征值及先进手段进行全面的N_(2)O溯源研究。Nitrous oxide(N_(2)O)is one of the potent greenhouse gases and also plays an important role in ozone layer decomposition.N_(2)O production and emission processes in soil are complexed.Therefore,accurate source partitioning will help to constrain emission budgets.The application of stable isotope natural abundance technique have stimulated significant progress in N_(2)O source partitioning and promoted identification in various N_(2)O microbial production processes,which make use of various N_(2)O isotope signaturesδ^(15)N^(bulk)(the average of15N),δ^(18)O(the average of 18O)andδ^(15)N^(sp)(site preference of 15N in different positions of N_(2)O molecule).However,some factors also add uncertainties to N_(2)O source partitioning,such as the range of isotope signatures,changes of isotope composition,and various fractionation factors associated with N_(2)O reduction.It is also noteworthy that microbial processes and related isotopic effects are critical.In this review,the isotopic effects during N_(2)O production and reduction and related factors are summarized;advances in approaches for N_(2)O source-partitioning are concluded,including isotope natural abundance and isotopomer methods.The review focused on the progress of isotopic signaturesδ^(15)N^(bulk),δ^(18)O andδ^(15)N^(sp)value in constraing N_(2)O sources.In the future,the measurement of isotope fractionation,a combination of isotope signatures and advanced methodologies are advised for better studying N_(2)O sources and pathways.

关 键 词：氧化亚氮 稳定同位素 硝化/反硝化作用 土壤微生物 位点特异性同位素值(δ^(15)N^(sp)) 同位素分馏效应 

分 类 号：S153[农业科学—土壤学]