长江口北支水域营养盐的季节性变化

Seasonal variation of nutrients in the north branch of the Yangtze River estuary

于2010年12月—2011年9月,2012年9月—2013年6月按季度采样对长江口北支水域氮、磷营养盐的季度变化规律、形态组成以及环境因子间相互关系进行了分析。结果显示溶解性无机氮存在形态主要是硝酸盐,占90%以上,浓度变化规律为夏秋高于春冬两季;溶解性无机氮、总氮峰值分别为3.99 mg/L及1.70 mg/L,均出现在2011年夏季,该现象与当年洪期长江流域连日降雨有关。长江径流所携带营养盐是导致北支无机氮、总磷浓度变化的主要原因。对理化因子进行相关性分析表明,盐度、pH值是营养盐最主要的限制因子。

During the sampling period from Dec. 2010 to Sep. 2011 and Sep. 2012- Jun. 2013,the seasonal variation,morphological composition of nitrogen and phosphorus were analyzed,and relationship between environmental factors was studied,respectively.Results indicated that the main presence of DIN was nitrates,which accounted for more than 90% in all seasons,its concentration in summer /autumn was higher than that in spring /winter. The concentration peaks of DIN and TP were 3. 99 mg /L and 1. 70 mg /L,respectively,appeared in summer of 2011 during the flood period.