Fujisaki Kenji auteur aut IRD Perrin A. S. auteur aut IRD Desjardins Thierry auteur aut IRD Bernoux Martial auteur aut IRD Balbino L. C. auteur aut IRD Brossard Michel auteur aut IRD text journalArticle eng text/pdf born digital access The impact of deforestation on soil organic carbon (SOC) stocks is important in the context of climate change and agricultural soil use. Trends of SOC stock changes after agroecosystem establishment vary according to the spatial scale considered, and factors explaining these trends may differ sometimes according to meta-analyses. We have reviewed the knowledge about changes in SOC stocks in Amazonia after the establishment of pasture or cropland, sought relationships between observed changes and soil, climatic variables and management practices, and synthesized the C-13 measured in pastures. Our dataset consisted of 21 studies mostly synchronic, across 52 sites (Brazil, Colombia, French Guiana, Suriname), totalling 70 forest-agroecosystem comparisons. We found that pastures (n=52, mean age = 17.6years) had slightly higher SOC stocks than forest (+6.8 +/- 3.1%), whereas croplands (n=18, mean age = 8.7years) had lower SOC stocks than forest (-8.5 +/- 2.9%). Annual precipitation and SOC stocks under forest had no effect on the SOC changes in the agroecosystems. For croplands, we found a lower SOC loss than other meta-analyses, but the short time period after deforestation here could have reduced this loss. There was no clear effect of tillage on the SOC response. Management of pastures, whether they were degraded/nominal/improved, had no significant effect on SOC response. C-13 measurements on 16 pasture chronosequences showed that decay of forest-derived SOC was variable, whereas pasture-derived SOC was less so and was characterized by an accumulation plateau of 20 Mg SOC ha(-1) after 20years. The large uncertainties in SOC response observed could be derived from the chronosequence approach, sensitive to natural soil variability and to human management practices. This study emphasizes the need for diachronic and long-term studies, associated with better knowledge of agroecosystem management. specialized annual crop carbon storage chronosequence deforestation grassland humid tropics rainforest soil organic matter soil tillage delta C-13 BRESIL COLOMBIE GUYANE FRANCAISE SURINAME AMAZONIE 068 076 082 021 21 7 2773-2786 2015 1354-1013 https://www.documentation.ird.fr/hor/fdi:010064720 10.1111/gcb.12906 1354-1013 [F B010064720] https://www.documentation.ird.fr/hor/fdi:010064720 https://www.documentation.ird.fr/intranet/publi/2015/07/010064720.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-07-29 2024-10-10 fdi:010064720 fre