Abstract: Corbicula fluminea is a kind of macrobenthos commonly seen in the coastal wetland ecosystem of Changjiang estuary.This paper studied the temporal and spatial distribution characteristics of its population density and biomass,and analyzed the heavy metals concentrations in its body and in suspended particles and sediments.The results showed that the distribution of C.fluminea was discrepant in different seasons,sampling sites,and even,sampling sections of same sampling site.The population density and biomass of C.fluminea were higher in spring and autumn but lower in summer,and higher in mid-tidal flat than in low and high flats of Chongming.Its annual average population density and biomass was the maximal in Xupu.C.fluminea had definite accumulation ability to copper and zinc,but not to lead and chromium.There was a significant negative correlation between the lead concentrations in C.fluminea and sediments.

Key words: Atmospheric CO₂ concentration, Soil water level, Spring wheat, Rhopalsiphum padi, Population increase, Damage tendency