洱海表层沉积物有机磷形态分布特征及其影响因素

利用IVANOFF法，研究了洱海表层沉积物有机磷形态及其空间分布特征，探讨了有机质对各形态有机磷含量分布的影响. 结果表明:洱海北部和南部的浅水湖区沉积物w(OM)较高(2.50%～11.72%)，而中部的深水湖区沉积物w(TP)较高(710.29～1 961.22 mg/kg)；沉积物w(OP)为212.71～526.23 mg/kg，与w(TP)分布趋势一致；沉积物不同形态有机磷的含量为Residual-Po(残渣态有机磷)> Fulvic-P(富里酸结合态有机磷)> HCl-Po(酸提取态有机磷)>NaHCO₃-Po(活性有机磷)>Humic-P(腐殖酸结合态有机磷). 沉积物w(OM)与w(OP)/w(TP)，w(Fulvic-P)和w(Humic-P)之间均呈显著正相关(P<0.01)，与w(Residual-Po)呈显著负相关(P<0.01)，与w(NaHCO₃-Po)和w(HCl-Po)之间相关性不显著(P>0.05). 洱海沉积物有机磷主要以非活性有机磷(Residual-Po和Humic-P)为主(平均占58.74%)，且w(Fulvic-P)占w(OP)的百分比均高于营养水平较高的湖泊，而w(HCl-Po)占w(OP)的百分比相对较低(除E7采样点外). 即洱海沉积物有机磷形态特征决定了其生物有效性较低. 沉积物有机磷赋存形态特征很可能是上覆水磷浓度相对较低的重要原因，而沉积物w(TOC)/w(OP)<200则意味着其有机磷的潜在释放风险较大. 

Distribution Characteristics of Organic Phosphorus Fractions and Influencing Factors in Surface Sediments of Lake Erhai

Organic phosphorus fractions and their spatial distribution characteristics in surface sediments of Lake Erhai were investigated by the IVANOFF method,and the impacts of organic matter(OM) on the contents of different organic phosphorus fractions were discussed.The results indicated that the higher OM contents of the sediments,ranging from 2.50% to 11.72%,were distributed in the shallow lake districts in the northern and southern areas of Lake Erhai.However,the higher TP contents,ranging from 710.29 to 1961...