滇池草海沉积物磷形态、空间分布特征及影响因素

Sediment phosphorus form, space distribution characteristic and influencing factor of Cao Hai in Dian Lake,Yunnan, China.

研究滇池草海沉积物中磷的分布特征、影响因素对研究草海水体富营养化具有重要的意义.研究表明:草海中各形态磷含量和空间分布特征呈现明显差异,O-P、Ca-P、Al-P、Fe-P平均含量分别为804.08、768.35、167.29、63.01mg/kg.沉积物磷形态平均含量O-P>Ca-P>Al-P>Fe-P.沉积物总磷及各形态磷在空间上存在差异,滇池草海西南部、北部和东部区域中全P、O-P、Ca-P、Al-P、Fe-P各形态磷都属于高含量区域.沉积物理化性质与上覆水性质是影响沉积物中磷形态的重要因素.其中沉积物全磷与O-P(R2=0.741*)、Ca-P(R2=0.678*)呈现显著性正相关关系;pH值与Al-P(R2=0.714*)、Fe-P(R2=0.664*)呈现显著负相关关系;沉积物有机质与O-P呈显著正相关性(R2=0.758*).沉积物上覆水DO与Fe-P呈显著负相关(R2=0.750*),上覆水中叶绿素a和Al-P存在显著正相关关系(R2=0.601*).表明沉积物磷形态释放与沉积物中有机质、pH值有关;同时上覆水中溶解氧制约沉积物Fe-P释放,叶绿素a含量促进沉积物Al-P的释放.

Internal phosphorus contamination plays a key role in eutophication when the external contamination be controlled effectively. Therefore, it is significant that study the distribution of phosphorus in the sediments, influence factors of the control of eutrophication at Lake Dianchi. This paper uses sediment sampling in Caohai of Dianlake. The main results were as following： Every form phosphorus contents and the space distribution characteristic displayed the obvious difference. Average contents of O-P, Ca-P, Al-P, Fe-P were 804.08mg/kg, 768.35mg/kg, 167.29mg/kg, 63.01mg/kg in Cao Hai respectively. The contents of phosphorus form in sediment were ：O-P〉 Ca-P〉 Al-P〉 Fe-P. The O-P contents that the organic compound were maximal, and every form phosphorus existed difference. The contents of total P, O-P, Ca-P, Al-P, Fe-P of sediment in southwest, north and middle east area were the higher than the other areas of Dian Lake. The physics and chemistry of sediment and overlying water were the key factors of the effect on phosphorus form character in sediment. Firstly, there were significant correlations between the total phosphorus and O-P （R^2=0.741^＊）, Ca-P（R^2=0.678^＊） of sediment. And the pH displays significant negative correlations with AI-P（R^2=0.714^＊）, Fe-P（R^2=0.664^＊）. Organic matter and O-P were significant correlations （R^2=0.758^＊）. Secondly, there were significant negative correlations between DO of overlying water and Fe-P （R^2=0.750^＊）. And the chlorophyll a of overlying water displayed significant correlations with Al-P （R2=0.601^＊）.The result showed that the relations existed between organic, pH and phosphorus form release of sediment. At the same time, DO of overlying water restricted Fe-P release and thechlorophyll a of overlying water promoted Al-P release of sediment.