Spatial variation in soil respiration in relation to a logging road in an upper tropical hill forest in Peninsular Malaysia

抄録

The spatial gradient of soil respiration from a logging road to the inner part of a forest, and the major environmental factors controlling soil respiration were studied in a hill dipterocarp forest in Peninsular Malaysia to examine the spatial effects of logging road construction on soil respiration. Soil respiration, soil temperature, and soil water content were measured at six points along a total of twenty-five 35-m transects. The logging road at the study site was constructed in 2009. The soil respiration rate on the logging road was very low (0.376μmol CO₂ m^-2 s^-1), and there were no significant differences between the roadside and inside the forest (4.76-5.95μmol CO₂ m^-2 s^-1). Path analysis showed that the soil respiration rate was affected by soil temperature and distance from the logging road. This finding differs from those of previous studies conducted in lowland tropical rain forests. We speculate that the low soil respiration rate on the road is primarily because of soil compaction and low concentrations of carbon-containing material. The soil temperature at the roadside (which was positively correlated with soil respiration) was higher than inside the forest. Despite the differences in soil temperatures, differences in soil respiration between the roadside and the inner parts of the forest were not significant, probably because of the small amount of litter present as a substrate for microbial respiration at the roadside and/or the occurrence of different microbial communities and biomass between the roadside and the inner parts of the forest.