【摘要】 为了探讨杉木Cunninghamia lanceolata纯林和杉木-阔叶树混交林土壤温室气体通量的差异及其影响因素,采用静态箱-气相色谱法,对杉木纯林及3种杉木-阔叶树混交林（杉木-樟树Cinnamomum camphora混交林、杉木-栲树Castanopsis fargesii混交林、杉木-桤木Alnus cremastogyne混交林）的土壤温室气体通量进行了原位观测。结果表明:杉木纯林土壤二氧化碳（CO₂）的排放通量(490.48 mg·m^-2·h^-1)高于杉木-栲树混交林(254.27 mg·m^-2·h^-1)和杉木-桤木混交林(331.51 mg·m^-2·h^-1),杉木纯林(32.29μg·m^-2·h^-1)和杉木-桤木混交林(32.24μg·m^-2·h^-1)土壤氧化亚氮（N₂O）的排放通量高于杉木-栲树混交林(2.66μg·m^-2·h^-1)。在杉木-栲树混交林、杉木-桤木混交林和杉木纯林中,土壤二氧化碳排放通量与土壤温度呈线性相关,杉木人工林土壤氧化亚氮排放通量与土壤硝态氮质量分数和土壤孔隙含水量（WFPS）呈极显著相关。回归分析显示:杉木-栲树混交林、杉木-桤木混交林、杉木纯林的土壤氧化亚氮排放通量与土壤WFPS呈指数增长关系, 4种林分中土壤氧化亚氮排放通量与土壤硝态氮质量分数呈线性关系。森林的树种组成对土壤温室气体排放通量有影响。杉木纯林转换为杉木-阔叶树混交林后,土壤二氧化碳排放通量减少。土壤氧化亚氮排放通量的变化来源于样地土壤硝态氮质量分数的变化。更多还原

【Abstract】 To investigate the differences in soil CO₂ and N₂O fluxes as well as CO₂ and N₂O flux factors from Chinese fir（Cunninghamia lanceolata） stands（CL） and mixed stands of Chinese fir and Cinnamomum camphora（CL-CC）,Castanopsis fargesii（CL-CF）,and Alnus cremastogyne（CL-AC）,CO₂ and N₂O fluxes were quantified with a static chamber-gas chromatography method with 5 replications.Results of one-way ANOVA showed that CO₂ fluxes in CL(490.48 mg·m^-2·h^-1) were significantly higher（P<0.05） than in CL-CF(254.27 mg·m^-2·h^-1) and CL-AC stands(331.51 mg·m^-2·h^-1),and N₂O fluxes in CL(32.29 μg·m^-2·h^-1) and CL-AC(32.24 μg·m^-2·h^-1) were higher（P<0.05） than in CL-CF(2.66 μg·m^-2·h^-1).In CL-CF,CL-AC,and CL,a linear relationship was observed between CO₂ and soil temperature.Also nitrate-N and water filled pore space（WFPS） were significantly correlated with soil N₂O flux.In CL-CF,CL-AC,and CL,an exponential relationship was observed between N₂O fluxes and WFPS.A linear relationship was also observed between N₂O and nitrate-N.Forest species composition,usually considered an important factor influencing CO₂ and N₂O fluxes,decreased net CO₂ emissions with conversion from a pure Chinese fir stand to a mixed Chinese fir stand with differences in soil N₂O flux among the stands possibly being attributed to differences in soil NO3-N content.更多还原