CONCENTRATIONS AND DEPOSITIONS OF SO2, SO42- ETC IN A CHONGQING SUBURBAN FORESTED AREA

During the period from 25 May 1991 to 30 May 1992 the atmospheric conc entrations and depositions of oxides of sulfur were continuously measu red in a suburban masson pine forest which is currently experiencing s evere dieback, in Chongqing, China. The annual mean concentrations of SO2 and particulate SO42- were 220 mu g/m(3) (77 ppbv) and 32 mu g/m(3 ) respectively. The atmospheric concentrations of these sulfur compoun ds were high in late autumn and winter. The annual wet and dry deposit ions of sulfur to the forest as measured by throughfall and stemflow w ere 93.1 and 46.6 kgSha(-1)a(-1) respectively. These depositions are a mong the highest level ever reported in the world. Althogh the cause o f the dieback of the masson pine trees has not been unequivocally dete rmined, it is' probable that the direct impact of SO2 is more likely t he cause than acid deposition.