中文摘要：

2010年4、5月份,用黑白瓶法对小江回水区春季浮游植物初级生产力进行了原位监测,并研究了初级生产力的分布特征及其与光强、叶绿素a浓度（Chl.a）、水温、二氧化碳分压（pCO2）等影响因素的相关关系.结果表明,4、5月份小江回水区的水柱总初级生产力（GPP）分别为1927.5、1325.0mg O2/（m2.d）,平均值为1626.3mg O2/（m2.d）;总呼吸作用（GR）分别为1037.5、1062.5mg O2/（m2.d）,平均值为1050.0mg O2/（m2.d）;总净生产力（GNP）分别为890.0、262.5mgO2/（m2.d）,平均值为576.3mg O2/（m2.d）;GPP/GR分别为1.86、1.25,均大于1,表明4、5月份小江属于自养型水体.各层总生产量（P）和生产量与呼吸量的相对值（P/R）有相似的垂直分布特征,最大值出现在表层水中,然后随水深增加而减小.相关分析结果表明,P同光强（I）和Chl.a呈显著正相关关系,建立相应的线性回归模型分别为：P=0.154Chl.a-0.278,R2=0.570;P=0.001I-0.013,R2=0.942.

英文摘要：

During April and May in 2010,the primary production in the Xiaojiang River backwater area,Three Gorges Reservoir was measured using the black-white-bottle method.The distribution features and relationships with light intensity,chlorophyll-a concentration（Chl.a）,water temperature and partial pressure of carbon dioxide（pCO2） were studied.The results showed that the gross primary productivities（GPP） were 1927.5 mg O2/（m2·d） and 1325.0 mg O2/（m2·d） in April and May,respectively,the average value was 1626.3 mg O2/（m2·d）.The gross respirations（GR） in the two months were 1037.5 mg O2/（m2·d） and 1062.5 mg O2/m2·d,respectively,and the average value was 1050.0 mg O2/（m2·d）.The gross net productivities（GNP） in the two months were 890.0 mg O2/（m2·d） and 262.5 mg O2/（m2·d）,and the average value was 576.3 mg O2/（m2·d）.Ratio of GPP/GR were 1.86 and 1.25.These indexes suggested that the Xiaojiang River was autotrophic in the spring season.Primary productivity（P） in each depth and the ratio of productivity to respiration（P/R） had similar vertical distribution feature,showing that the maximum values occurred near the surface and they decreased with depth.Correlation analysis showed that light intensity（I） and Chl.a were significantly positive correlation with the P.Equations of the linear regression model P with Chl.a and with I were respectively： P =0.154 Chl.a-0.278,with coefficient R2=0.570,and P =0.001 I-0.013,with coefficient R2=0.942.