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试验采用7层CO2廓线系统对安吉毛竹林生长季(5—10月)CO2浓度进行连续监测,同时结合同步CO2通量和气象资料,分析安吉毛竹林CO2浓度的时空动态和CO2储存通量的变化特征。结果表明:安吉毛竹林生长季CO2浓度表现出明显的日变化、季节变化和垂直梯度。日尺度上,CO2浓度在日出前后达到最大,随后出现一段快速释放过程,午后达到全天最低值;整个生长季尺度上,7月份林间CO2浓度最低(368.1μmol·mol-1),10月份最高(402.6μmol·mol-1);垂直梯度方面,林冠上层CO2垂直梯度明显小于林冠层和林冠下层;林冠层和林冠上层垂直梯度变化趋势较为一致,白天均为正值,呈现为碳汇,夜间为负值,呈现为碳源,林冠下层CO2梯度全天均为负值。利用廓线系统计算毛竹林CO2储存通量,半小时和日尺度上,CO2储存通量分别占净生态系统CO2交换量(NEE)的25.5%和8.9%,而在月尺度上仅占NEE的0.22%。因此,在半小时及日尺度上计算NEE时不可忽略CO2储存通量,而在计算月尺度及更长时间尺度NEE时可以忽略CO2储存通量。
The CO2 concentration of the bamboo growing season (May-October) in Anji bamboo forest was continuously monitored using a 7-layer CO2 profile system. The spatial and temporal dynamics of CO2 concentration and the CO2 storage flux in the bamboo forest of Anji were analyzed by simultaneous CO2 flux and meteorological data The changing characteristics. The results showed that the CO2 concentration in the growing season of Anji bamboo showed obvious diurnal variation, seasonal variation and vertical gradient. On the daily scale, the CO2 concentration reaches the maximum before and after sunrise, followed by a period of rapid release followed by the lowest value throughout the day in the afternoon. At the entire growing season, the CO 2 concentration in the forest was the lowest (368.1 μmol · mol -1) In the vertical gradient, the vertical gradient of CO2 in the upper canopy was significantly lower than that in the canopy and canopy. The vertical gradient of the canopy and canopy in the vertical gradient was consistent with the positive values in the daytime and presented as a carbon sink , Which is negative at night and presents as a carbon source. The CO2 gradient in the lower canopy is negative all day. The CO2 storage fluxes of Moso bamboo forests were calculated using the contour system. At the half-hour and daily scales, the CO2 storage fluxes accounted for 25.5% and 8.9% of net ecosystem CO2 exchange (NEE), respectively, while on the monthly scale only accounted for NEE 0.22%. Therefore, CO2 storage fluxes should not be neglected when NEEs are calculated for half an hour and on a day scale, while CO2 fluxes are negligible for the calculation of NEEs on a monthly scale and for longer time scales.