COPPER ACCUMULATION AND FITNESS OF FOLSOMIA-CANDIDA WILLEM IN A COPPER CONTAMINATED SANDY SOIL AS AFFECTED BY PH AND SOIL-MOISTURE

Collembolans of the species Folsomia candida Willem were exposed to co pper at different concentrations (11-122 mg kg(-1)) and pH levels (pH- CaCl2 between 3.8 and 5.4) in soil collected from a field site. Total (HNO3 extractable) soil copper was determined, and the copper fraction available to the collembolans was estimated by extracting copper from the soil by different methods (extraction with 0.01 M CaCl2, extracti on with artificially composed rainwater, and centrifugation to obtain the pore-water of the soil). Results were compared with the copper con tent of the collembolans and the effects of copper on three fitness pa rameters of the collembolans, viz. adult survival, reproduction and gr owth. For one soil treatment the influence of soil moisture content on the fitness of the collembolans and on the toxicity of copper was stu died by applying four levers of soil moisture (30, 50, 79 and 90% of t he field capacity of the soil). Desorption of copper from the soil was best described by a two-species Freundlich equation that includes the influence of pH. No effects of copper were found on F. candida at the levels tested. Total soil copper was the best predictor of copper con centrations in the adult collembolans, and the inclusion of pH as a se cond factor improved the predictive value. Soil moisture had a large e ffect on fitness parameters of and copper accumulation by the collembo lans, but there was no correlation between accumulation and fitness. ( C) 1997 Elsevier Science.