增温对寒潮期间亚热带常绿阔叶天然林土壤呼吸的影响

全球变暖增加寒潮天气发生的频率和强度，影响土壤呼吸及其各组分，但有关增温和寒潮对亚热带森林土壤呼吸及其各组分的影响研究仍十分缺乏。通过壕沟法分离土壤呼吸，并利用土壤呼吸高频自动监测系统研究增温对寒潮期间亚热带常绿阔叶天然林土壤总呼吸、根呼吸与微生物呼吸的影响。结果表明：(1)寒潮发生时，对照和增温处理中土壤总呼吸速率分别显著下降45.93%和25.68%,土壤微生物呼吸速率分别显著下降51.25%和35.54%。但寒潮并没有影响增温处理中根呼吸速率，而对照处理中根呼吸速率在寒潮时显著下降39.72%。(2)观测期间，增温对总呼吸和根呼吸的日动态模式的影响在寒潮不同阶段具有明显差异，增温导致寒潮发生前后土壤总呼吸和根呼吸日峰值出现时间分别提前1,2 h,而寒潮发生时，对照和增温处理中土壤总呼吸和根呼吸的日峰值出现时间同步。(3)观测期间，增温后土壤总呼吸、根呼吸和微生物呼吸的温度敏感性(Q₁₀值)均下降，而根呼吸的Q₁₀值均高于微生物呼吸。因此，准确了解寒潮等极端天气下的土壤总呼吸、根呼吸和微生物呼吸的变化及其对增温的响应，对于提高气候变暖后土...

Effect of Warming on Soil Respiration in Subtropical Evergreen Broad-leaved Natural Forest During Cold Wave

Global warming has increased the frequency and intensity of cold waves,which changes soil respiration and its components,but studies on the effects of warming and cold waves on soil respiration and its components in subtropical forests are still scarce.Soil respiration was separated by trench method,and the effects of warming on total soil respiration,root respiration and microbial respiration in a subtropical evergreen broad-leaved natural forest during a cold wave were studied by using a soil respiration high-frequency automated observation system.The results showed that:(1) When the cold wave occurred,total soil respiration rate was decreased significantly by 45.93% and 25.68%,and the soil microbial respiration rate was decreased significantly by 51.25% and 35.54% in the control and warming treatments during the cold wave,respectively.However,the cold wave did not affect the root respiration rate in the warming treatment,while the root respiration rate in the control treatment was significantly decreased by 39.72% during the cold wave.(2) Soil warming changed diel patterns of total soil respiration and root respiration during the observation period,with the warming causing the daily peak of total soil respiration and root respiration to occur 1 and 2 h earlier,but the daily peaks of total soil respiration and root respiration were synchronized between the control and warming treatments when the cold wave occurred.(3) The temperature sensitivity (Q₁₀) of total soil respiration,root respiration and microbial respiration was reduced after soil warming during the observation period,respectively,while the Q₁₀ of root respiration was higher than that of microbial respiration.Thus,to accurately understand the changes of total soil respiration,root respiration and microbial respiration and their response to soil warming under extreme weather such as a cold wave is important to improve the prediction accuracy of soil carbon emissions after climate warming.