生态学报2017，Vol.37Issue(2)：395-404,10.DOI:10.5846/stxb201508041639
氮素类型和剂量对寒温带针叶林土壤N2O排放的影响
The effects of types and doses of nitrogen addition on soil N2O flux in a cold-temperate coniferous forest, northern China
摘要
Abstract
Increasing atmospheric nitrogen (N) deposition would change soil N availability,and thereby changes N2O production and emission from N-limiting forest soils.However,it is still unclear about the contrasting effects of different N ion (i.e.,oxidized NO3--N and reduced NH4+-N) deposition on soil N2O emission in boreal forests.In the present study,a cold-temperate coniferous forest in the Great Khingan region was selected for conducting the manipulative N addition experiment,including three forms of N fertilizers (NH4Cl,KNO3,and NH4NO3) and four rates of N addition (0,10,20,and 40 kg N hm-2 a-1).Soil-atmospheric N2O exchanging fluxes were measured four times per month using static chambergas chromatography.Simultaneously,soil temperature,moisture,and inorganic N contents were measured to explore how the main factors affect soil N2O emission.The results showed that the types and doses of N addition significantly changed soil inorganic N contents,and the accumulation of soil NH4+-N was significantly higher than that of soil NO3--N due to N addition.N addition increased N2O emission from the boreal forest soil,and the NH4NO3 addition treatments promoted high soil N2O fluxes,with an increase of 442％ to 667％,which was higher than the global average (134％).There were positive correlations between soil N2O fluxes and soil temperature,and between soil N2O fluxes and soil NH4+-N contents in the litter layer.Soil N2O fluxes were driven by soil temperature,followed by soil NH4+-N contents in the litter layer.These findings suggest that atmospheric N deposition cannot lead to a significant soil NO3--N leaching and loss in boreal forests over the short term,but it can significantly promote soil N2O emission.Furthermore,exogenous NH4+ and NO3-inputs into boreal forests have synergic effects on soil N2O emission,which should be distinguished in N cycle and balance in terrestrial ecosystems using 15N tracer methods in the future.关键词
大气氮沉降/土壤N2O通量/氮素有效性/主控因子/北方森林Key words
atmospheric N deposition/soil N2O flux/N availability/controlling factors/boreal forest引用本文复制引用
耿静,程淑兰,方华军,于贵瑞,徐敏杰,王磊,李晓玉,司高月,何舜..氮素类型和剂量对寒温带针叶林土壤N2O排放的影响[J].生态学报,2017,37(2):395-404,10.基金项目
国家自然科学基金项目(41471212,31470558,31290221,31130009,31290222) （41471212,31470558,31290221,31130009,31290222）
国家重点基础研究发展计划项目(2012CB417103) （2012CB417103）
中国科学院地理科学与资源研究所“秉维”优秀青年人才基金项目(2011RC202) （2011RC202）
中国科学院战略性先导科技专项(XDA05050600) （XDA05050600）
