Le Mer G. auteur aut IRD Bottinelli Nicolas auteur aut IRD Dignac M. F. auteur aut IRD Capowiez Y. auteur aut IRD Jouquet Pascal auteur aut IRD Mazurier A. auteur aut IRD Baudin F. auteur aut IRD Caner L. auteur aut IRD Rumpel C. auteur aut IRD text journalArticle eng text/pdf born digital access The role of earthworms on biogeochemical carbon cycling is a major knowledge gap resulting from the difficulty of isolating and exploring the effects provided by the diversity of organisms. In this study, we investigated the effect of six earthworm species belonging to three ecological categories on soil organic carbon (SOC) mineralization. To this end, we produced casts in microcosms with the six species in the same soil and with the same litter material. The casts were subjected to laboratory ageing for 140 days. During this process, we monitored physicochemical parameters, CO2 emissions and determined the micro-scale organization of the casts' particulate organic matter and pores using X-ray microtomography. Our results showed contrasting properties of fresh casts of the three ecological categories, in accordance with the earthworm species' morphological or behavioral strategies, indicating that those were maintained in artificial environments. However, species-specific changes in cast properties throughout ageing increased intragroup variability among ecological categories. As a result we observed earthworm species-specific evolution of CO2 mineralization rates during casts ageing. We found that at least half of the variability in CO2 emissions was explained by cast microstructural changes, related to the spatial arrangement between particulate organic matter, porosity, and mineral particles. We conclude that earthworm species-specific traits may play a role in organic carbon protection through their impact on microstructural cast properties. specialized Earthworm Cast features Microstructure C mineralization Physical protection 068 074 427 116151 [10 ] 2022 0016-7061 https://www.documentation.ird.fr/hor/fdi:010086319 10.1016/j.geoderma.2022.116151 0016-7061 [F B010086319] https://www.documentation.ird.fr/hor/fdi:010086319 https://www.documentation.ird.fr/intranet/publi/2022-11/010086319.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2022-11-09 2025-02-24 fdi:010086319 fre