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.

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Biomass estimations in tropical peat swamp forests are quite complex when hollow trees are frequently found due to the unavailability of data on hollow size and the limited data on accurate measures of biomass. Destructive samplings were done for both above- (AGB) and belowground biomass (BGB) and hollow sizes of remained trees at a logged-over peat swamp forest in Sarawak, Malaysia. Subsequently, allometric equations taking hollows into account for both the above- and belowground biomass of tropical peat swamp forests were also being developed. It was observed that these were hollows in Shorea albida and Combretocarpus rotundatus trees with diameters at breast height (DBH) exceeding 40cm; S. albida is a dominant or co-dominant species, and C. rotundatus grows in peat swamp forests throughout Sarawak. The hollow volumes ranged from 0.23 to 1.08m³, and occupied 42.3% of stem volume on average. The larger biomass produced by previous allometric models were partially due to the presence of hollows. Thus, new models for estimating both AGB and BGB were developed that included one (only DBH), two (DBH and height [H] or wood density [WD]), or three (DBH, H, and WD) predictor variables, and [ln(DBH)]² was added as predictor variable indicating the biomass loss by cavity formation. AGB model with three predictor variables and BGB model with one predictor variable performed the best where; they had the highest adjusted coefficients of determination and lowest Furnival index and Akaike information criterion (AIC).

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In Indonesia, in recent years, line planting of valuable Shorea species has taken place on logged forest to maintain the timber yield. However, there exists scant information about the effectiveness of such a method. Neighboring trees along the planting lines affect the planted trees. We assessed the survival, growth, and crown exposure of the planted trees to evaluate the effect of neighboring trees in three 1 ha- monitoring plots, in which Shorea johorensis seedlings had been planted at a 5-m spacing along five parallel lines separated by 25m, all running in a north-south direction within a 3m-wide strip. The planted trees were monitored for 11 years after planting. The crown exposure was evaluated using a three-dimensional spatial structure model and SExI-FS software. Eleven years after planting, 77.6% of the planted S. johorensis had survived. The average diameter at breast height (DBH) was 16.7±5.6cm, ranging widely from 5.3 to 33.6cm. The initial growth 1 year after planting predicted the variance in DBH 11 years later. Trees showing rapid initial growth exhibited higher survival and subsequent growth rates. The variation in light conditions in the planting lines affects the growth and survival. The spatial structure model illustrated how neighboring tree crowns suppress the growth of the planted tree by casting shade. In a line-planting system, the neighboring tree effect influences the survival and growth of the planted trees, and this can be reduced by treatment of the canopy to ensure exposure of planted trees to sunlight.

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This study summarizes changes in traditional community-based mangrove resource use and discusses the relationships between the local people and mangroves at three study sites in South Sulawesi and Maluku, Indonesia: a planted mangrove, a secondary mangrove, and a natural mangrove. The results suggest that the highly diverse uses of mangrove resource are likely the result of long-term use by locals, based on their knowledge of the nature and characteristics of the materials that are available from each mangrove species. Specifically, we found that mangroves have important roles as supplies of fuel material and timber products, which are used in daily life by the residents of coastal areas. However, changes in the characteristics of mangrove resource use at each site suggest that the use of mangroves by locals depends on their daily needs. This indicates that a decrease in mangrove resources or loss of the need for them could threaten the relationship between mangroves and locals as the value of these resources in daily life declines. However, at the sites observed in this study, locals still conducted some activities such as cutting or collecting fuel material and fishing in the mangroves, demonstrating that resource use is affected by economic value. Our results indicate that the characteristics of mangrove resource use differ among regions and vary according to changes in the commercial value of mangrove products, local fishery trends, and the physical state of the mangroves.

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