作 者 ：魏 远,张旭东,江泽平,周金星,汤玉喜,吴立勋,黄玲玲,高升华

期 刊 ：林业科学研究 2010年 23卷 5期 页码：656-665

关键词：CO2通量；涡度相关法；动态变化；生态系统净碳交换；杨树人工林；

Keywords:CO2 flux, eddy-covariance, dynamic variation, net ecosystem exchange, poplar forest,

摘 要 ：利用涡度相关法对长江流域杨树人工林CO₂通量季节变化进行了研究。结果表明:CO₂通量的日变化特征与杨树所处生长阶段以及光合有效辐射(PAR)有关,夜间生态系统净碳交换(NEE)与5 cm土壤温度呈指数相关,全年的生态系统净碳交换(NEE)数值波动在-2 - 2 mg·m^-2·s^-1之间。生长季NEE的变化特点为:早上7点开始生态系统整体表现为吸收C

Abstract:The dynamics in different time-scale of Net Ecosystem Exchange(NEE) in poplar forest of the Yangtze River were studied by using an eddy covariance method . The following results were obtained: Daily CO₂ flux was closely related to growing stages and photosynthetic active radiation (PAR), and night CO₂ flux showed an exponential regression relationship with 5 cm depth soil temperature. The CO₂ flux between forest and atmosphere ranged from -2 mg·m^-2·s^-1 to 2 mg·m^-2·s^-1. As for the daily change of NEE in the growing season, it begin to absorb carbon dioxide and increase after 7:00 AM ,and keep stable from 11:00AM to 1:00 PM resulting from PAR then decrease and after 6:30PM change to discharge carbon dioxide to the atmosphere, lastly change gradually at night. The maximum uptake occurredat about 10 o’clock of local time in clear day. The NEE also had obviously seasonal variation that was mainly controlled by temperature. Remarkable uptake occurred in blooming growing season and weak respiration occurred in dormant season. Assimilation and respiration were nearly balanced during the transition of growing and dormant seasons. Poplar forests are one of carbon sinks. The annual carbon uptake of the ecosystem was -579 g·m^-2 in 2006. It is in 2006 when the serious water logging happened that plantation still absorbed carbon dioxide from the atmosphere in the whole year, which shows that the poplar forest plays an important role in improving the carbon sink of terrestrial ecosystem.