中文摘要：

利用2003年和2004年涡度相关系统通量观测资料，对青藏高原高寒灌丛非生长季节CO2通量特征及其主要影响因子进行了分析。（1）从净生态系统CO2交换（NEE）日变化特征看，除13：00～19：00时有较小的CO2净释放以外，其余时段NEE均很小；（2）高寒灌丛非生长季月份间NEE差异明显，4月和10月是CO2净释放量较大，1月和12月CO2净释放量较小；（3）相对温带草原（高杆草大草原）草地类型，低温抑制下的青藏高原高寒灌丛生态系统非生长季节日平均CO2释放率较低；（4）高寒灌丛非生长季NEE日变化模式与5cm土壤温度变化呈显著正相关，土壤温度是影响非生长季节青藏高原高寒灌丛NEE变化的主导气候因子，同时NEE变化还受降水的影响。

英文摘要：

Eddy covariance with an open path system was adopted to measure carbon dioxide flux without interruption in 2003 and 2004 in order to study the characteristics and affecting factors of carbon dioxide flux of alpine shrubs in Qinghai-Tibet Plateau beyond the growing season. （1）The net ecosystem carbon dioxide exchanges indicted that there existed a low net diurnal carbon dioxide release within 13.00-19：00 and an extreme low diurnal carbon dioxide release in the other period of time; （2） In the alpine shrubs the net ecosystem carbon dioxide exchanges significantly differed among the months beyond the growing season ,presenting high net carbon dioxide release in April and October and low net carbon dioxide release in January and December; （3） In Qinghai-Tibet Plateau the ecosystem of alpine shrubs suffering low temperature released carbon dioxide at lower rate beyond the growing season in contrast with those of temperate grasslands （tall grass prairie） ;（4） The variation pattern in the net ecosystem carbon dioxide exchanges of alpine shrubs appeared positively correlated with the variation in the temperature in 0-5 cm soil beyond the growing season,and soil temperature as well as rainfall was a dominating factor that affected the net ecosystem exchanges of alpine shrubs in Qinghai-Tibet Plateau.