中文摘要：

选取适当时段测定土壤呼吸以代表日平均值,可使短期土壤呼吸观测数据有效应用于土壤呼吸年总量的估算。笔者在西双版纳热带季节雨林使用土壤呼吸自动观测系统在不同月份（1月、4月、7月和10月）进行土壤呼吸连续日变化观测,评估了土壤呼吸代表性时段的有效性。结果表明：在4月、7月和10月使用9：00—11：00作为土壤呼吸代表性时段,与24 h日平均土壤呼吸值相对差异可控制在10%以内;不同月份9：00—11：00土壤呼吸平均值均与24 h日平均值存在偏差,10月相对差异最小,7月最大;选择9：00—11：00时段在多日尺度上可以代表日平均土壤呼吸值,所测算出的Q10值相对接近。

英文摘要：

Data of soil respiration taken at the proper time that can represent the daily average value was widely used in annual soil efflux evaluation.In this study,we used an automatic measuring system to observe and collect the data of Xishuangbanna tropical seasonal rain forest soil respiration in January,April,July and October,2009.The representative time period for soil respiration observation was estimated.Results showed that the errors of the mean values during 9：00—11：00 comparing with the daily average values in April,July and October were all less than 10 % under control,indicating that the values during the period could reasonably represent the daily average value.The errors could vary with months,were the lowest in October and the highest in July.Mean value of soil respiration and Q10 during 9：00—11：00,which was tested at multiple-day scale,could well fit the daily average value.