红树林湿地土壤是一个潜在的温室气体排放源．调查了夏季福建九龙江口的秋茄（Kandelia candel）红树林湿地土壤-大气界面3种温室气体的通量并分析土壤环境对其的影响．研究结果显示，九龙江口红树林夏季3种温室气体N2 O、CH4和CO2的通量分别是0.27～2.45、-0.28～341.43μmol /（m2· h）和-0.49～17.00 mmol/（m2· h），表明九龙江口夏季红树林土壤总体上是温室气体的排放源．根据3种温室气体的平均通量及其增温潜力计算它们的CO2当量通量以反映3种温室气体产生的增温效应，计算结果显示九龙江口红树林夏季土壤排放温室气体的CO2当量通量为82.33～674.92 mg /（m2· h），而CO2是最大的贡献因素．双因素方差分析结果表明，CO2通量和土壤理化性质因林地和滩面而异，CH4通量受林地的影响，但N2 O通量则不受林地和滩面的影响．相关性分析结果显示，土壤环境因子是影响红树林温室气体通量空间差异的重要原因，其中土壤有机质、氨态氮和总氮含量是影响N2 O和CO2通量的主要因子，而CH4则只与土壤氧化还原电位显著相关．%Mangrove swamps are considered to be a potential net source of greenhouse gases,but the fluxes of greenhouse gases from mangrove soils are still poorly characterized.The present study,conducted in July 2012 in 3 Kandelia candel mangrove forests in Jiulongjiang Estuary in southern China,aimed to investigate the summer fluxes of N2 O,CH4 and CO2 from the soil and the role of soil characteristics in regulating gas fluxes.Gas fluxes ranged from 0.27 to 2.45 μmol/(m2· h),-0.28 to 341.43 μmol/(m2· h)and -0.49 to 17.00 mmol/(m2· h) for N2 O,CH4 and CO2 ,respectively,indicating that mangrove soil was an emission source of greenhouse gases in Jiulongjiang Estuary in summer.Total CO2-equivalent fluxes of the three gases,indicating their global warming po-tential,ranged from 82.33 to 674.92 mg /(m2 · h),and CO2 was the most dominant in the total flux in the man-groves.This study recorded higher CO2 at the landward site than middle zone and seaward site,while there were no differences in both N2 O and CH4 fluxes among different tidal positions.Soil characteristics also varied with mangrove transect or sampling position.These characteristics,especially nutrient contents were factors regulating greenhouse gases emissions and their spatial variations in mangrove.N2 O and CO2 fluxes were positively related to soil organic matter,ammonium and total nitrogen concentrations,and CH4 flux showed significant and negative correlation with the redox potential(Eh ).
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