CO_2浓度升高对水体硝化、反硝化作用的影响研究进展  

Influence of elevated CO_2 on nitrification and denitrification in water bodies: A review

作　　者：施曼 张维国[1] 李江叶 严少华[1] 高岩[1] SHI Man;ZHANG Wei-guo;LI Jiang-ye;YAN Shao-hua;GAO Yan(Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Science,Nanjing 210014,China;College of Forestry,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]江苏省农业科学院农业资源与环境研究所,南京210014 [2]南京林业大学林学院,南京210037

出　　处：《应用生态学报》2018年第12期4239-4247,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41571458;41471415;31600419)资助~~

摘　　要：大气CO_2浓度升高潜移默化地影响着水体生态系统的碳循环过程.然而,该过程如何影响与其耦合的氮循环过程仍不明确.水体硝化、反硝化过程作为水体氮循环的重要环节,必然会对大气CO_2浓度升高产生一系列的响应.本文总结了国内外关于大气CO_2浓度升高对水体理化性质、硝化作用、反硝化作用及N形态转化影响方面的研究工作,发现大气CO_2浓度升高会降低水体的p H,增加水中CO_2和HCO_3^-含量,但对富营养化与寡营养化水体中硝化、反硝化作用的影响具有明显差异.大气CO_2浓度升高抑制寡营养化水体的硝化作用和反硝化作用,降低N2_O的释放通量,抑制富营养化水体的硝化作用,但当水体pH在7～9时,可能促进反硝化作用,增加N2_O的释放通量,最终可能导致水体中NH_4^+的积累及NO_3^-浓度的降低,影响水体中微生物的多样性.在此基础上提出目前相关研究存在的瓶颈问题及值得深入探讨的科学问题,为进一步深入理解温室效应背景下全球CO_2浓度升高对水体生态系统N循环的影响提供参考.Elevated atmospheric CO2 has imperceptible impacts on carbon cycle in aquatic ecosystems. However, it remains a question how this process will impact nitrogen cycle that is naturally coupled with carbon cycle. The nitrification and denitrification are two critical processes in the nitrogen cycle. It is reasonable to expect that elevated atmospheric CO2 will influence both processes. We reviewed the previous literatures concerning the effects of elevated atmospheric CO2 on the physico-chemical properties, nitrification, denitrification and nitrogen transformation in water bodies. The published results revealed that the elevated CO2 would reduce the water pH, increase CO2 and HCO3^- concentrations, but with different effects on the nitrification and denitrification between eutrophic and oligotrophic water. Elevated atmospheric CO2 could inhibit nitrification and denitrification in oligotrophic water, thereby reduce N2O flux from water. The nitrification process in the eutrophic water bodies was also inhibited, but its denitrification might be promoted by the elevated CO2. In the eutrophic water bodies, there could be an increase of N2O flux when pH was maintained in the range of 7-9. These might eventually result in the accumulation of NH4+ and reduction of NO3^- in water, producing an impact on the microbial diversity. Based on these reviews, we proposed some research gaps related to the relevant research fields as well as some scientific questions that is worth to be further explored. This review would be helpful to better understanding on how the greenhouse effect caused by the elevated atmospheric CO2 would affect nitrogen cycle in aquatic ecosystem.

关 键 词：CO2浓度升高 硝化作用 反硝化作用 微生物 氮循环 

分 类 号：X701[环境科学与工程—环境工程] X143