%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Song, Chao
%A Zi, Yacouba
%A Dignac, M. F.
%A Bottinelli, Nicolas
%A Felbacq, A.
%A Song, S. S.
%A Rumpel, C.
%T The role of earthworms in the transformation of labile plant litter into mineral-associated organic matter
%D 2025
%L fdi:010093609
%G ENG
%J Soil Biology and Biochemistry
%@ 0038-0717
%K Earthworms ; Neutral sugars ; Soil types ; Organo-mineral complex ; Casts
%M ISI:001501687100001
%P 109859 [10 ]
%R 10.1016/j.soilbio.2025.109859
%U https://www.documentation.ird.fr/hor/fdi:010093609
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2025-07/010093609.pdf
%V 208
%W Horizon (IRD)
%X Although it has been recognized that the formation of organo-mineral complexes may be fostered by soil fauna, their formation pathways are far from understood. The objective of this study was to investigate the processes involved in earthworm-mediated mineral-associated organic matter (MAOM) formation. To this end, we used microcosms to produce casts with three different temperate earthworm species (epigeic Lumbricus castaneus [LC], epi-anecic Lumbricus terrestris [LT], endogeic Aporrectodea icterica [AI]) fed with C-13-enriched Miscanthus litter in two contrasting soil types (Luvisol, Cambisol). To investigate MAOM formation processes, we used C-13 isotope tracing to track litter-derived carbon origin and neutral sugar biomarkers to resolve microbial transformation pathways. Our results indicated that cast MAOM-C concentrations increased compared to the control treatment without earthworms, with LC casts in Luvisol exhibiting the highest MAOM-C concentration (24.1 mg g(-1)). MAOM-C contribution to casts decreased in the order LC > LT > AI. Sugar biomarkers revealed species- and soil-dependent stabilization pathways: MAOM of LC casts in Luvisol contained high proportions of plant-derived arabinose, while MAOM of AI casts in Cambisol were enriched in microbial-derived hexoses (mannose) and deoxy-hexoses (rhamnose, fucose). We conclude that earthworms depending on species and soil type accelerated MAOM formation via synergistic pathways: (1) direct stabilization of plant sugars and (2) microbial transformation of labile litter into necromass during cast formation. We suggest that earthworm-driven MAOM formation depends on species-specific traits (e.g., LC's capacity for litter fragmentation) and soil properties (e.g., clay and CaCO3 content).
%$ 074 ; 068