鼎湖山针阔叶混交林CO2浓度及通量变化特征

活动及气候变化的影响，近年来鼎湖山森林生态系统的碳汇功能有所增强。

关键词：针阔叶混交林，CO2通量，涡度相关法，鼎湖山

Abstract：We analyzed the variation characteristics of the CO2 flux，net ecosystem CO2 exchange （NEE），CO2 concentration and the relationship with meteorological variables on the basis of the CO2 flux data and meteorological data of the southern subtropical evergreen broad-leaved forest flux observation station of Dinghu Mountain，a typical forest vegetation ecosystem in the Pearl River Delta. The research results were as follows：（1） The diurnal variation of CO2 concentration appeared to be in the form of “peak-valley”. Specifically，the CO2 concentration variation was nearly at its peak at night or around suise. And the CO2 concentration variation was nearly at its valley in the afternoon; Diurnal variation of CO2 flux generally appeared to be a “valley” curve，approaching minimum value （negative） around noon and reaching maximum （positive） in the morning and at night. （2） The seasonal average of CO2 flux could be shown as the following order：spring> summer> winter> autumn. The order of the seasonal average of CO2 concentration could be shown as the following order：winter> spring> autumn> summer，from which we could find that the non-growth season was higher than the growth season in that it was related to the seasonal variation of CO2 source/sink intensity caused by the seasonal variation of plant phenology. （3） In 2012，the average annual concentration of CO2 in Dinghushan forest ecosystem was 664.7 mg·m-3. The annual mean value of CO2 flux was -0.079 mg·m-2·s-1，and net ecosystem CO2 exchange capacity （NEE） was -611 g C·m-2·a-1，which indicates that mixed confer-broadleaf forest at the Dinghu Mountain has strong carbon sink function in rapid growth during recent years. （4） CO2 flux and CO2 concentration had a significantly negative correlation with the temperature and the pressure difference of saturated water，of which the correlation between CO2 concentration and the temperature was the highest，and the second was the saturated vapor pressure difference，which indicates that the temperature and saturated vapor pressure difference are the key meteorological factors that affect CO2 flux and CO2 concentration. We found that carbon sink function of Dinghu Mountain forest ecosystem had been enhanced in recent years，which could be influenced by human activities and climate change.

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