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.