To evaluate the wetland pollution and potential environmental risks in Min River Estuary

the effects of wetland vegetations and physicochemical properties on the distribution of sediment phosphorus were explored. From land to sea in the research area

sediments of four sites with different wetland vegetation types (Spartina alterniflora

Phragmites australis

Cyperus malaccensis and Cyperus compressus respectively) were sampled in 2017

and then phosphorus speciations were analyzed using SMT method. In all four vegetation types wetlands

organic phosphorus (OP) accounted for averagely 32.03% of total phosphorus (TP)

between 0.176~0.369 mg/g. Inorganic phosphorus (IP) accounted for averagely 66.49% of TP

between 0.308~0.666 mg/g. TP concentrations were from 0.491~0.998 mg/g

which were considered as moderate pollution level with the pollution index (moderate polluted 0.819~1.618). Results suggested that the distribution of phosphorus speciations varied from wetland vegetation types. The highest concentration of OP was found in the Phragmites australis wetland

and the lowest in Cyperus compressus. The Ca-P concentrations were obviously higher in Cyperus malaccensis and Cyperus compressus wetlands than in Spartina alterniflora. However

the Fe/Al-P concentrations were significantly higher in Spartina alterniflora wetland compared to other wetlands. Since TP was strongly related to IP

the trends of TP and IP were similar:The highest concentration in Cyperus compressus wetland and the lowest in Phragmites australis wetland. Finally

the Ca-P concentrations showed the significantly negative correlation with bulk density

and the positive correlation with water contents. TP concentrations were significantly negatively correlated to conductivity

and positively correlated to water contents. All these phenomenon described could relate to the comprehensive effects of vegetation types and growth stages

physicochemical properties

terrestrial materials

hydrological environment

litters

and human production activities.