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为研究荷木(Schima superba)个体间树干CO2释放通量(Es)的差异以及树干液流对Es的影响,提高森林生态系统呼吸计算准确性,利用红外气体分析仪及自制式气室于2009年湿季和干季监测了华南荷木人工林5棵样树的Es,并同步监测了树干温度(θs)、气温及液流密度.结果显示:θs与气温之间呈显著线形正相关;Es与树干温度之间存在显著指数函数关系;Es干湿季的差异显著,并呈现明显的季节变化;5株样树之间Es存在显著差异,平均Es分别为3.12、3.60、5.52、6.98、8.09μmol m-2 s-1;同时,样树之间树干CO2释放通量的温度系数(Q10)差异显著(1.97～4.24之间).Tree1、Tree2和Tree4白天的Es与液流速度(v)显著正相关,白天的标准化树干CO2释放通量(R25,温度为25℃时的Es)高于晚上.荷木Es个体之间及时间上的差异主要受树干温度、生长状况和液流速度的影响.图3表6参35
In order to study the difference of trunk CO2 fluxes (Es) and the effect of sap flow on Es among Schima superba individuals, and to improve the accuracy of forest ecosystem respiration calculation, infrared gas analyzer and self-made air chamber were used in 2009 The Es and the tree species temperature (θs), air temperature and liquid density of the five tree species were monitored in wet and dry seasons in summer.The results showed that there was a significant linear positive correlation between θs and air temperature, There was a significant exponential relationship between Es and trunk temperature. The difference between Es and wet season was significant and showed obvious seasonal variation. There were significant differences in Es between 5 sample trees with average Es of 3.12, 3.60, 5.52, 6.98, 8.09μmol m-2 s-1. Meanwhile, the temperature coefficient (Q10) of trunk CO2 fluxes between the sample trees was significantly different (between 1.97 and 4.24) .Tree1, Tree2 and Tree4 Es and the flow velocity (R25, Es at 25 ℃) were higher than those at night.The differences among the individuals of Schima superba were mainly due to the temperature of the trunk, the growth status and the flow velocity Figure 3 Table 6 参 35