|
(364) Traditional, laboratory-based risk assessment versus field studies: Effects of copper on plants. Bruus Pedersen, Marianne1, Kjaer, Christian1, Elmegaard, Niels1, Strandberg, Beate1, 1 ABSTRACT- Chemical toxicity is expected to differ between laboratory and field conditions due to a number of factors, some of which may increase toxicity in the field compared to the laboratory, while others may reduce field toxicity compared to the laboratory. We attempted to improve the realism of laboratory test conditions for extrapolation to field conditions by increasing the complexity of the test system in the following steps: 1) One species tested in copper spiked soil in the laboratory, under optimal conditions. Both lethal and sublethal effects were recorded; 2) Single species laboratory test with copper contaminated soil from a field site; 3) Field study of single species population(s); 4) Field study at community level. Differences in effect concentrations of the different set-ups were compared to differences in measures of copper availability. The main results showed that 1) In laboratory tests, field contaminated soil was less toxic than spiked soil; 2) Field soil was less toxic in laboratory tests than in the field; 3) These differences in effect concentrations could not be explained by differences in bioavailability, but were probably a consequence of multiple stress, e.g. species interactions and climate; 4) Effects on the plant community in the field occurred at low copper concentrations compared to effects on single species populations in the field. Key words: laboratory, field, species, community |
