In the north of France, a century of industrial metallurgic activities produced significant heavy metal soil pollution. In the north
of France zinc smelter waste created a gradient of zinc concentration from 171 to 19 000 ppm in 35 m. The aim of this study
was to evaluate the effects of soil pollution on the composition, density and diversity of macrofauna communities. The results
showed that heavy metals reduce the overall density of earthworms and other macrofauna populations. The composition of the
macrofauna community changed with the degree of pollution. There was no simple relationship between soil zinc content and
species richness. In polluted areas, the number of species could be lower, equal or higher than in unpolluted zones. Increase
of species richness in some polluted zones was due to the settlement of tolerant arthropod taxa. Coleoptera and some Arachnida
were possibly favoured by the litter accumulation resulting from the reduced population densities of earthworms and other
decomposers. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.