重庆小南海表层沉积物磷形态分布特征及影响因素

Distribution characteristics and the associating influencing factors of phosphorus species in surface sediments of Xiaonanhai Lake,Chongqing

以重庆黔江小南海表层沉积物为研究对象,研究了沉积物磷的赋存形态及其分布特点和含量。结果表明:(1)小南海表层沉积物总磷(TP)、有机磷(OP)、无机磷(IP)、铁铝结合态磷(Fe/Al-P)、钙结合态磷(Ca-P)分别为(549.84±77.49)、(136.79±52.16)、(277.39±28.98)、(70.12±23.67)、(166.57±47.01) mg/kg。(2)OP、Fe/Al-P与TP均呈显著正相关性(P<0.001),而IP与TP相关性低(P>0.05),表明OP、Fe/Al-P与TP的空间特征类似而IP与TP的空间特征差异大。(3)黏土、水深分别是影响冗余分析轴1、轴2的重要环境因子。水深通过影响颗粒和Fe的输移而影响磷形态空间分布。(4)TP、OP、Fe/Al-P远离河口含量增加,而IP、Ca-P在河口富集。各磷形态占比与其浓度变化趋势一致,其中变化最大的是Ca-P,从河口浅水到远离河口处Ca-P衰减了23.16百分点。磷形态在远离河口、湖心深水、河口浅水的空间异质性表明湖泊参数能明显影响磷组分变化,可能是引起沉积物磷变化的重要因素。

Taking the surface sediment of Xiaonanhai in Qianjiang,Chongqing as the research object,the occurrence forms,distribution characteristics,and content of phosphorus in the sediment were studied.The results showed:(1)the total phosphorus(TP),organic phosphorus(OP),inorganic phosphorus(IP),iron-aluminum bound phosphorus(Fe/Al-P)and calcium-bound phosphorus(Ca-P)in surface sediments of Xiaonanhai Lake were(549.84±77.49),(136.79±52.16),(277.39±28.98),(70.12±23.67)and(166.57±47.01)mg/kg respectively.(2)OP,Fe/Al-P were positively correlated with TP(P<0.001),while the correlation between IP and TP was low(P>0.05),indicating that the spatial characteristics of OP and Fe/Al-P were similar to those of TP,while IP and TP were quite different.(3)Clay and water depth were important environmental factor affecting the axis 1 and axis 2 of redundancy analysis,respectively.The water depth affected the spatial distribution of phosphorus forms by affecting the transport of particles and Fe.(4)TP,OP and Fe/Al-P contents increased distanced from estuaries,while IP and Ca-P were enriched in estuaries.The proportion of each phosphorus component were consistent with its concentration change trend,with the largest change being Ca-P,which attenuated by 23.16 percentage points from shallow water to far away from the estuary.The spatial heterogeneity of phosphorus forms in deep water far away from estuaries,deep in the lake center,and shallow in estuaries indicated that lake parameters could significantly affect changes in phosphorus components,which might be an important factor causing changes in sediment phosphorus.