The effects of logging on soil greenhouse gas (CO2, CH4, N2O) flux in a tropical rain forest, Peninsular Malaysia

To evaluate the effects of logging on soil greenhouse gas flux in a tropical rain forest, we measured CO2, CH4, and N2O fluxes at logged and unlogged sites in Peninsular Malaysia (N = 7–27 at each site). Although soil temperature at the logged sites was higher than at unlogged sites, soil CO2 flux did not differ between sites. The CH4 consumption at the logged sites tended to be less than that at unlogged sites, and some soils at the logged sites emitted CH4. These results suggest that logging can decrease CH4 consumption or even convert CH4 sinks into sources. The increase in soil bulk density after logging might lowered the effective diffusivity of CH4 and O2 availability in soils, which might limit the CH4 consumption at the logged sites. N2O fluxes were increased significantly for at least 1 year after logging because of an increase in soil nitrogen availability. Logging decreased the CH4 absorption rate and increased the N2O emission rate of the soil. Based on these findings, we conclude that logging in tropical rain forests increases the emission of CH4 and N2O for at least 1 year after logging, thus potentially contributing to global warming.