Extrapolation from laboratory to field and from individual to populations: pitfalls to avoid

Abstract

To evaluate the effect of pollutants on populations of animals, (a number of) studies are usually performed under laboratory conditions or field circumstances. Problems arise when these studies are not carried out at the right hierarchical level or the controlled conditions do not reflect the situation in the real world. These experiments do not always provide the required information because of ill-thought design errors. A substantial number of these errors can be avoided. Important factors to consider are of an abiotic and biotic nature. The careful combination of laboratory and field studies facilitates extrapolation from one to the other. Also knowledge of the population regulation mechanism helps to design an experiment at a lower hierarchical level so that it still provides information to be used at a higher level. It is concluded that an essential improvement of the autecological work helps to avoid some pitfalls.