Spatial dependence of soil organic carbon, abundance, biomass and diversity of earthworms in 15 temperate agroforestry systems

In temperate regions, silvoarable systems associating parallel tree rows and annual intercrops are the most widespread types of agroforestry systems. Earthworms are involved in numerous ecosystem services such as pedogenesis, soil structure, and nutrient cycling. In agricultural landscape, land occupation and management highly influence earthworm communities. The objectives of this study were to i) compare earthworm communities (abundance, biomass and diversity) between agroforestry tree rows, alley and agricultural control systems (treeless) and relate it to the spatial distribution of Soil Organic Carbon (SOC) stocks. We used a network of 15 agroforestry French sites arranged on a North/South gradient compris- ing an adjacent agricultural control plot. Agroforestry alleys and control plot have been strictly managed (soil tillage, crop rotation, fertilization) in the same way since the tree planting. Mean earthworm abundance and biomass were significantly higher in the trees rows than in the agroforestry alleys and the agricultural control system across the sites. Earthworm species richness in the tree rows was not significantly different from the agricultural control system but was higher than in the agroforestry alleys across the sites. Interestingly, adult earthworm.