CLIMATIC-CHANGE AND THE RELEASE OF IMMOBILIZED NUTRIENTS FROM WELSH RIPARIAN WETLAND SOILS

The reduction in wetland water table height that could be anticipated from current climate change models was simulated within the laboratory using cores of peat-soil from a riparian wetland. The manipulation in creased the rate of release of many solutes including nitrate (1250%), sulphate (116%), dissolved organic carbon (37%), sodium (66%), chlori de (65%), iron (168%) and magnesium (16%). Calcium was the only solute to show a lower rate of release following the simulation (-26%). Thes e changes have major implications for the use of constructed wetlands in ameliorating water quality. The study suggests that without suitabl e design safeguards, wetlands may only represent a temporary solution to water quality problems. In the future, climatic change could revers e their beneficial effects.