湖南岳阳地区杨树人工林生态系统净碳交换季节动态研究  

Study on the Seasonal Dynamic of Net Ecosystem Exchange over a Poplar Plantation of Yueyang City in Hu'nan Province

作　　者：魏远[1] 张旭东[1] 江泽平[1] 周金星[1] 汤玉喜[2] 吴立勋[2] 黄玲玲[1] 高升华[1] 

机构地区：[1]中国林业科学研究院林业研究所,国家林业局林木培育重点实验室,北京100091 [2]湖南省林业科学院,湖南长沙410004

出　　处：《林业科学研究》2010年第5期656-665,共10页Forest Research

基　　金：国家“十一五”科技支撑资助项目(2006BAD03A15)

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CO2,到午时（11：00—13：00）NEE的值较为稳定,日落（18：30—19：00）开始生态系统呼吸作用占主导,而晚上NEE的值变化不大。CO2的最大吸收出现在早上10点左右。NEE同时表现为较为明显的季节变化,在生长季节（4-9月）NEE多为负值,生态系统整体表现为对CO2的吸收,而在非生长季表现为一定强度的碳释放,值得注意的是在2006年的6月碳固定能力弱于生长季的其他月份,原因是长期降雨导致土壤呼吸加剧和水淹的生理胁迫导致杨树呼吸作用加剧。2006年全年NEE为-579 g.m-2,说明该生态系统具有明显的碳汇功能。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.

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 

分 类 号：S792.11[农业科学—林木遗传育种]