Fujisaki Kenji auteur aut IRD Perrin A.S. auteur aut IRD Boussafir M. auteur aut IRD Gogo S. auteur aut IRD Sarrazin Max auteur aut IRD Brossard Michel auteur aut IRD text journalArticle eng text/pdf born digital access Large inputs of woody debris to soil can improve the soil. We examined the fate of woody debris buried in soil after fire-free forest conversion to cropland in French Guiana. We measured the mass loss of woody debris >4mm on five sampling dates for 4years after deforestation. Composition of the organic matter of woody debris was analysed with Rock-Eval pyrolysis, which enabled us to distinguish a labile carbon pool (C-lab) and a resistant carbon pool (C-res). Decomposition of woody debris followed a first-order function with a half-life of 17.6months. During the decomposition of woody debris >4mm, the C:N ratio, hydrogen index (HI) and pyrolysed carbon below 400 degrees C (R400) decreased, suggesting that decarboxylation and dehydrogenation of woody debris occurred. Both C-lab and C-res stocks decreased with time, but the decrease in C-lab was faster. There was little humification of the debris and no long-term biogeochemical preservation of a woody debris fraction, which accords with the first-order decay observed. We conclude that the benefits of ligno-cellulosic inputs for soil organic carbon contents in a tropical humid climate occur during the first year following deforestation. specialized GUYANE FRANCAISE ZONE TROPICALE HUMIDE 068 064 66 5 876-885 2015 1351-0754 https://www.documentation.ird.fr/hor/fdi:010065247 10.1111/ejss.12277 1351-0754 [F B010065247] https://www.documentation.ird.fr/hor/fdi:010065247 https://www.documentation.ird.fr/intranet/publi/depot/2015-10-08/010065247.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-10-08 2016-12-08 fdi:010065247 fre