Spatial variation of earthworm communities and soil organic carbon in temperate agroforestry

Rémi Cardinael (1, 2, 3) , Kevin Hoeffner (4) , Claire Chenu (2) , Tiphaine Chevallier (1) , Camille Béral (5) , Antoine Dewisme (4) , Daniel Cluzeau (4)

1 UMR Eco&Sols - Ecologie fonctionnelle et biogéochimie des sols et des agro-écosystèmes
2 ECOSYS - Ecologie fonctionnelle et écotoxicologie des agroécosystèmes
3 UPR AIDA - Agroécologie et Intensification Durables des cultures annuelles
4 ECOBIO - Ecosystèmes, biodiversité, évolution [Rennes]
5 Agroof SCOP

The aim of this study was to assess how soil organic C (SOC) stocks and earthworm communities were modified in agroforestry systems compared to treeless control plots and within the agroforestry plots (tree rows vs alleys). We used a network of 13 silvoarable agroforestry sites in France along a north/south gradient. Total earthworm abundance and biomass were significantly higher in the tree rows than those in the control plots, but were not modified in the alleys compared to those in the control plots. Earthworm species richness, Shannon index, and species evenness were significantly higher in the tree rows than those in the alleys. Total abundance of epigeic, epi-anecic, strict anecic, and endogeic was higher in the tree rows. Surprisingly, earthworm individual weight was significantly lower in the tree rows than that in the alleys and in the control plots. SOC stocks were significantly higher in the tree rows compared to that in the control plots across all sites. Despite higher SOC stocks in the tree rows, the amount of available C per earthworm individual was lower compared to those in the control. The absence of disturbance (no tillage, no fertilizers, no pesticides) in the tree rows rather than increased SOC stocks therefore seems to be the main factor explaining the increased total abundance, biomass, and diversity of earthworms. The observed differences in earthworm communities between tree rows and alleys may lead to modified and spatially structured SOC dynamics within agroforestry plots.

Mots clés: alley cropping; earthworm diversity; lumbricidae; earthworm abundance; silvoarable system

Domaines: Sciences de l'environnement; Biodiversité et Ecologie

Rémi Cardinael, Kevin Hoeffner, Claire Chenu, Tiphaine Chevallier, Camille Béral, et al.. Spatial variation of earthworm communities and soil organic carbon in temperate agroforestry. Biology and Fertility of Soils, 2019, 55 (2), pp.171-183. ⟨10.1007/s00374-018-1332-3⟩. ⟨hal-01978499⟩