The variation of greenhouse gas emissions from soils of various land-use/cover types in Jambi province, Indonesia

We measured fluxes of three greenhouse gases (N2O, CO2 and CH4) from soils of six different land-use types at 27 temporary field sites in Jambi Province, Sumatra, Indonesia. Study sites included natural and logged-over forests; rubber plantation; oil palm plantation; cinnamon plantation; and grassland field. The ranges of N2O, CO2 and CH4 fluxes were 0.13-55.8 mu g N m(-2) h(-1); 1.38-5.16 g C m(-2) d(-1); -1.27-1.18 mg C m(-2) d(-1), respectively. The averages of N2O, CO2 and CH4 fluxes at 27 sites were 9.4 mu g N m(-2) h(-1), 3.65 g C m(-2) d(-1), -0.45 mg C m(-2) d(-1), respectively. The values of CO2 and CH4 fluxes were comparable with those in the reports regarding other humid tropical forests, while the N2O flux was relatively lower than those of previous reports. The N2O fluxes in each soil type were correlated with the nitrification rates of soils of 0-5 cm depth. In Andisols, the ratio of the N2O emission rate to the nitrification rate was possibly smaller than that of the other soil types. There was no clear relationship between N2O flux and the soil water condition, such as water-filled pore space. Seventeen percent of CH4 fluxes were positive; according to these positive fluxes, we did not find a good correlation between CH4 uptake rate and soil properties. Although we performed a chronosequence analysis to produce some hypotheses about the effect of land-use change by a limited amount of sampling at one point in time, further tests. are required for the future.