%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Fujisaki, Kenji
%A Perrin, A.S.
%A Boussafir, M.
%A Gogo, S.
%A Sarrazin, Max
%A Brossard, Michel
%T Decomposition kinetics and organic geochemistry of woody debris in a ferralsol in a humid tropical climate
%D 2015
%L fdi:010065247
%G ENG
%J European Journal of Soil Science
%@ 1351-0754
%K GUYANE FRANCAISE ; ZONE TROPICALE HUMIDE
%M ISI:000361187000006
%N 5
%P 876-885
%R 10.1111/ejss.12277
%U https://www.documentation.ird.fr/hor/fdi:010065247
%> https://www.documentation.ird.fr/intranet/publi/depot/2015-10-08/010065247.pdf
%V 66
%W Horizon (IRD)
%X 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.
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