热带季节雨林林冠碳通量不同校正方法的比较分析

利用西双版纳热带季节雨林2003年3月1～9日的CO²和水汽通量数据，比较了不同校正方法的差异.结果表明,对季节雨林林冠碳通量观测数据进行校正是必要的，但不同校正方法所起的作用有所差异；昼间WPL校正的作用最大，虚温校正的作用最小；t检验证明，经WPL修正后的碳通量值与基准值、无显著差异；聚类分析表明，进行自然风3次旋转校正有利于数值精度的提高.夜间是自然风旋转校正的贡献最大、虚温校正贡献最小；t检验表明，经过WPL修正和平面旋转校正及其组合得到的碳通量值与基准值均有显著差异；而经包含有自然风旋转校正处理后的碳通量值与基准值均无显著差异；聚类分析表明，经过自然风坐标旋转后，再进行WPL修正，有利于数值精度的提高.

A comparison of various correction methods for calculating carbon flux above tropical seasonal rainforest

In this paper, various correction methods were compared, based on the observation data of the CO2 and water fluxes above the canopy of a tropical seasonal rainforest in Xishuangbanna during 1 - 9 March, 2003. The results showed that it was necessary to correct the observation data when calculating the carbon flux, though various correction methods contributed differently to the results. For daytime data, WPL made the most important contribution, while sonic temperature correction did the least, t test indicated that no significant difference was found between the carbon fluxes corrected by WPL and the standard values. Cluster analysis showed that triple-rotation correction was helpful to improve the precision of the data. For nighttime data, it was the triple-rotation correc- tion that made the most important contribution, and sonic temperature correction also did the least. There existed significant differences between the carbon fluxes corrected by WPL, planar-fit correction and their combination and the standard values, while the differences between the carbon fluxes corrected by double-or triple-rotation and the standard values were not significant. Cluster analysis showed that the data corrected orderly by coordinate axes-rotated correction and WPL would be propitious to improve the precision. The results would provide a basis for calculating the fluxes within tropical rainforest in the future, and supply reference to the fluxes calculation for other areas.