Agroforestry systems provide numerous environmental services. One of the advantages is the increase of biodiversity. Earthworms play a major role in soil fertility and have a key function in ecosystems. Abundance, biomass and the amount of species was measured to quantify the influences of trees on the earthworm population in integrated and organic farming systems. Results showed that in poplar stands the amount of earthworms, especially juvenile, was higher than in winter wheat or lucerne-clover-grass fields. Furthermore the organic farming system had higher earthworm abundance and species richness than the integrated farming system. Regarding tree species poplar had fewer earthworms in total and fewer epigeic species
