【摘要】 土壤有机碳矿化及其温度敏感性(Q₁₀)是评价土壤碳排放与固持的重要指标,对未来全球气候变化的预测具有重要意义。本研究以福建中亚热带阔叶林表层土壤（0¹0 cm）为研究对象,通过观测不同温度（10、20和30℃）下土壤有机碳矿化速率、Q₁₀、可溶性有机碳（DOC）、微生物生物量碳（MBC）、呼吸熵（qCO₂）的变化,探讨福建中亚热带阔叶林土壤有机碳矿化的温度敏感性及其影响因素。结果表明:温度对土壤有机碳矿化具有显著影响,温度越高,土壤有机碳平均矿化速率、土壤有机碳累积矿化量、平均qCO₂越大（P<0.05）。其中,10、20和30℃累积矿化量分别为369.29、559.85、1 077.18μg·g^-1。土壤有机碳矿化速率、DOC、qCO₂的均值随时间延长呈降低趋势。此外,MBC含量与温度呈显著负相关关系,土壤有机碳矿化速率与土壤DOC、MBC含量均显著线性相关（P<0.05）。温度敏感性随着培养时间延长有降低趋势,且第1天的Q₁₀值（4.7）显著大于第180天的Q₁₀值（1.4）。因此,增温影响土壤DOC、MBC转换,促进土壤有机碳矿化,且高质量碳具有更高的土壤温度敏感性。更多还原

【Abstract】 Soil organic carbon（ SOC） mineralization and temperature sensitivity( Q₁₀) are the important indices for evaluating soil carbon emission and sequestration,and of great significance for the forecast of future global climate change. To better understand temperature sensitivity of SOC and its influencing factors,surface soils（ 0 10 cm） from mid-subtropical broadleaved forest in Fujian was selected,the SOC mineralization rate,Q₁₀,soil dissolved organic carbon（ DOC）,microbial biomass carbon（ MBC） and respiratory quotient（ qCO₂） during incubation period were measured under different tem perature（ 10,20 and 30 ℃）. The results showed that the incubation temperature had significan effects on SOC mineralization,the average SOC mineralization rate,cumulative SOC mineralization and microbial respiratory quotient（ qCO₂） rose significantly with the increase of temperature（ P <0. 05）. Among them,the cumulative SOC mineralization of 10,20 and 30 ℃ were 369. 29,559. 85,1 077. 18 μg·g^-1,respectively. While the SOC mineralization rate,DOC,MBC and qCO₂ tended to decrease with time. In addition,the content of MBC had a negative correlation with soil temperature,and SOC mineralization rate was linearly correlated with the content of DOC and MBC（ P < 0. 05）.The temperature sensitivity tended to decrease with incubation time. Q₁₀ value at the first day（ 4. 7）was significantly greater than that at the 180 th day（ 1. 4）. Thus,warming influences the transforma tion of soil DOC and MBC,promotes the SOC mineralization,moreover high quality carbon has highe soil temperature sensitivity.更多还原