【作者】 王进； 白洁； 陈曦； 罗格平； 王绍民；

【Author】 Wang Jin;Bai Jie;Chen Xi;Luo Geping;Wang Shaomin;Key Laboratory of Oasis Ecology Agriculture of Xinjiang Production and Construction Groups, College of Agriculture,Shihezi University;Wulanwusu Agrometeorological Experiment Station of Xinjiang;State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography;

【机构】 新疆生产建设兵团绿洲生态农业重点实验室； 乌兰乌苏农业气象试验站； 中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室；

【摘要】 基于涡度相关技术,对新疆典型绿洲棉田进行了连续4年的碳通量观测,探讨覆膜滴灌棉田生育期内碳通量构成和特征。结果表明:生长盛期(6-9月),棉田的总初级生产力(GPP)和净生态系统碳交换(NEE)日变化明显,峰值出现在14:00前后。生态系统呼吸(Res)日变化稳定,与膜下土壤温度日变化稳定有关。日间GPP随太阳净辐射(Rnet)增加而增大,可用直角双曲线方程描述;且最大光合速率的峰值出现在7月。碳通量的季节变化不同:GPP和NEE与LAI的季节变化一致,峰值出现在7月;而Res的峰值出现在6月。6-9月,月累积GPP主要分配给了NEE;而其余月份分配给了Res。整个生育期内(5-10月),总GPP平均为812±48.61 g C m-2,其中NEE占58.5%,这表明生育期内覆膜滴灌棉田表现为碳汇。更多还原

【Abstract】 In this study, the carbon and water fluxes of plastic mulch drip-irrigated cotton field were measured using an eddy covariance(EC) technique in 2009, 2010, 2012 and 2013 at Wulanwusu site, a representative agricultural oasis in northern Xinjiang. The diurnal pattern of mean monthly gross primary production(GPP) and net ecosystem exchange(NEE) showed an obviously sinusoidal dynamic from June to September, whilst that of ecosystem respiration(Res) stayed low and stable between daytime and night time. The response of daytime hourly GPP to net solar radiation(Rnet) can be expressed by a rectangular hyperbolic function. The variations of maximal assimilation rate(A) were followed changes in LAI, and the peak value occurred in July. The seasonal variations of GPP, and NEE were close to the cotton phenology, and they almost reached the peak value almost in July. However seasonal variations of Res didn’t follow that of LAI, and the maximum occurred nearly one month earlier than the LAI did. The seasonal NEE showed a carbon sink from squaring to harvest period, whilst it indicated a carbon source before the squaring time as well as after the harvest time. The cumulative GPP averaged 816.2±55.0 g C m-2 in the growing season(from April to October), and more than half of GPP was partitioned into NEE(mean-478.6±41.4 g C m-2).更多还原