The supporting information contains four databases. The first one (SoilFluxEnv) presents replicate data of soil N2O and CH4 fluxes and environmental variables measured in situ in the forests and oil palm plantation. The second one (CanalFluxEnvOP) presents average data of drainage canal N2O and CH4 fluxes and environmental variables measured in situ in the oil palm plantation. The third one (LitterfallPFDF) presents average litterfall rates and environmental variables measured in situ in the forests. The fourth one (CNLitterfallPFDF) presents average C, N, and C/N ratio of litterfall monitored in the forests. Plots were established in three land uses, representing the beginning (peat swamp forest), intermediate (drained degraded forest) and end stages (industrial oil palm plantation) of the land use change process in the region. GHG flux and environmental variable monitoring took place over the period October 2011-March 2013 at a monthly time step. Measurements were collected more intensively during two post-fertilization periods in the oil palm plantation. Diel variation was also monitored on two occasions in the oil palm plantation and one occasion in the drained degraded forest.
