The portions of P fractions were Fe-P>OrgP>OcP>Ca-P>Al-P>LP. (5) The seasonal changes of P fractions in sediments: the maximum value of TP and Fe-P were recorded in autumn, while organic P and occluded P reached their minimum value at that time.

• 钙磷(Ca-P)、有机磷(OrgP)和闭蓄磷(OcP)随沉积深度的变化复杂。