威海湾营养盐季节变化特征及与环境因子的相关性分析

根据2006-2007年威海湾4个航次营养盐的调查资料,分析该海域海水中无机氮(DIN)、磷酸盐(PO43--P)和硅酸盐(SiO32--Si)的季节变化规律及其与环境因子的典型相关性。结果表明,NO3--N是DIN的主要存在形式,比例达50%以上。营养盐季节性变化明显,秋冬季DIN和PO43--P浓度较高,春夏季较低,SiO32--Si的变化则相反。四季DIN和PO43--P浓度均大于浮游植物生长阈值,仅冬季SiO23--Si浓度低于浮游植物生长阈值。冬季浮游植物生长的限制因子是Si,其他季节具有P限制的潜在性。营养盐和环境因子具有较大的典型相关性,其中,盐度、pH和NO3--N、PO43--P、SiO23--Si相关性最大,典型相关系数达到0.979。

Seasonal Variation Features of Nutrients and Influenced Environmental Factors in Weihai Bay

The variation features of nutrients include inorganic nitrogen(DIN),phosphate(PO34--P),and silicate(SiO23--Si) in Weihai Bay were analyzed based on the four investigations during 2006-2007.The results showed that the main form of DIN was NO3--N with the percentage above of 50%.The seasonal variation of nutrients was significant.The concentrations of DIN and PO43--P was higher in autumn and winter than that in spring and summer.However,the seasonal variation of SiO23--Si was contrary to DIN and PO34--P.The concentrations of nutrients in all the seasons were higher than the growth threshold of phytoplankton,except SiO23--Si concentration was lower than the growth threshold of phytoplankton in winter.Si was the limiting factor for the growth of phytoplankton in winter,and P was the potential limiting factor in other seasons.There was a great canonical relationship between nutrients and environmental factors with the maximum coefficient of 0.979 between salinity,pH and NO3--N,PO34--P,SiO23--Si.