闽江福州段湿地沉积物中各形态磷的分布特征及其影响因素

Spatial Distribution of Phosphorus Forms and Influencing Factors in Marsh Sediments in Fuzhou Reach of the Minjiang River

为了明确闽江福州段湿地沉积物中磷赋存形态的变化特征及其影响因素,于2019年10月18日,在闽江福州段河岸带和河口区不同类型的湿地中,采集0~10 cm深度的沉积物样品,测定不同形态磷含量并分析其分布特征,采用相关分析法,分析影响不同形态磷分布的因素。研究结果表明,闽江福州段河口区沉积物中铁铝磷、钙磷、无机磷和全磷含量相对最大,城市河段和淡水河段沉积物中各形态磷含量依次减小;河口区[(152.19±100.34)mg/kg]和淡水河段[(152.32±177.29)mg/kg]有机磷含量相对较大,而城市河段[(132.49±113.77)mg/kg]的较小;水产养殖塘沉积物中的铁铝磷[(417.65±328.38)mg/kg]、无机磷[(562.52±361.40)mg/kg]、有机磷[(196.04±101.26)mg/kg]和全磷[(758.56±421.91)mg/kg]含量相对最大,而淤泥质海滩[(213.70±79.24)mg/kg]、水产养殖塘[(183.48±94.34)mg/kg]和潮间盐水沼泽[(167.10±30.74)mg/kg]的钙磷含量相对较大。沉积物颗粒组成、全碳和全氮含量是影响闽江福州段湿地沉积物中各形态磷分布的主要因素,但是铁铝磷含量还受pH和频率磁化率的影响,钙磷含量还受总无机硫含量和电导率的影响;人类活动以及河流和海洋水动力也在一定程度上影响沉积物中各形态磷的分布。

In order to explore the spatial distribution of phosphorus forms and its key influencing factors in marsh sediments along Fuzhou reach of the Minjiang River,sediment samples were collected from the depth of 0-10 cm in marshes in riparian zone or estuary along Fuzhou reach of the Min River on 18 October 2019 to analyse the contents and distribution characteristics of different phosphorus forms.The correlation analytical method was applied to analyse factors which influencing the distribution of phosphorus forms.The results showed that the contents of iron aluminum-bound phosphorus,calcium-bound phosphorus,inorganic phosphorus and total phosphorus in marsh sediments of estuarine segment are relatively highest,while the contents of phosphorus forms in the sediment of urban and freshwater river segments decreases sequentially.Relatively larger content of organic phosphorus was found in the estuarine segment[(152.19±100.34)mg/kg]and freshwater segment[(152.32±177.29)mg/kg],while lower content was found in the urban segment[(132.49±113.77)mg/kg].For the different marshes,the contents of iron aluminum-bound phosphorus[(417.65±328.38)mg/kg],inorganic phosphorus[(562.52±361.40)mg/kg],organic phosphorus[(196.04±101.26)mg/kg]and total phosphorus[(758.56±421.91)mg/kg]in sediments were the highest in aquaculture farm,while those of calcium-bound phosphorus were much higher in mudflat[(213.70±79.24)mg/kg],aquaculture farm[(183.48±94.34)mg/kg]and salt marsh[(167.10±30.74)mg/kg].This study found that sediment grain composition,total carbon and nitrogen contents were key factors influencing the spatial distribution of phosphorus forms in marsh sediments in Fuzhou reach of the Minjiang River.Besides,iron aluminum-bound phosphorus was also influenced by the spatial distributions of pH and frequency magnetic susceptibility,while calcium-bound phosphorus also rested with total inorganic sulfur and electrical conductivity.In addition,human activities and the hydrodynamic forces of rivers and oceans also influence the spatial distribution of phosphorus forms in marsh sediments to a certain extent.