Phosphorus speciation and its coupling with organic matter in the water–sediment system of Lake Dian, southwestern China

The distribution characteristics, concentration dynamics, and organic matter (OM) interactions of different phosphorus (P) species in lake sediments are fundamental to understanding P cycling and release mechanisms. This study investigated P speciation, concentrations, and their associations with OM in the sediments and pore water of Lake Dian, with a focus on spatial heterogeneity and centennial-scale evolution. Results showed that sedimentary P was predominantly retained in relatively stable f