小兴安岭天然阔叶混交林生长季CO_2通量特征分析

森林生态系统CO2通量的研究已成为全球变化研究的热点之一。本文采用开路式涡度相关系统对小兴安岭天然阔叶混交林CO2通量进行为期1a的连续观测（2008年）,分析了生长季（5-9月）CO2通量的变化特征。结果表明,在生长季,天然阔叶混交林系统的CO2通量变化范围为-0.46～0.42mg.m-2.s-1;最大吸收量出现在6月份的9：00,最大释放量出现在7月份的5：00。白天气温低于26.63℃时,碳吸收量随气温的升高而加大;但气温超过26.63℃后,则呈相反趋势。夜晚气温在13.50℃时的碳释放量最大。2008年整个生长季呈现白天碳吸收,夜晚碳释放的现象,总体表现为碳吸收,吸收总量为212.32g.m-2。

Analysis on CO2 Flux during Growth Season of Natural Broadleaved Mixed Forest in Xiaoxinganling Mountains

The research on CO2 flux in forest system was one of the hot topics in global changes.The CO2 flux during growth season of natural broadleaved mixed forest in Xiaoxinganling mountains was analyzed,based on observed data continuously in 2008 by using open-path eddy covariance system.The results showed that the CO2 flux changed from-0.46 to 0.42 mg·m-2·s-1 during the whole growth season.The maximum uptake occurred at 9 o＇clock during June and the maximum efflux occurred at 5 o＇clock during July.During daytime,the carbon uptake increased with the temperature increasing when it was below 26.63℃.On the contrary,it decreased with temperature increasing when it was above 26.63℃.During nighttime,the maximum efflux occurred 13.50℃.In all,it showed that carbon assimilation was 212.32 g·m-2 during the whole growth season of natural broadleaved mixed forest in Xiaoxinganling mountains in 2008.