Leaf physiological and morphological responses were studied in seedlings of seven dipterocarp species planted in three degraded forest environments: grassland, logged remnant forest and secondary forest. Dryobalanops beccarii, Parashorea macrophylla, Shorea macrophylla, S. ovata, S. parvifolia, S. seminis and S. virescens were used as study species. The leaf photosynthetic rate at light saturation (A_max), the dark respiration rate (R_d), light compensation point (I_c), leaf mass per area (LMA) and SPAD value were measured during the 38 months after planting. Water loss by detached leaves was also determined at 13 months after planting. In the grassland, LMA and A_max increased from three months after planting in all species except S. ovata. The time by which 50% of total leaf water content had been lost from detached leaves was positively correlated with LMA, suggesting that species with high LMA (D. beccarii, S. ovata and S. parvifolia) have high tolerance to desiccation in the grassland. The positive correlation found between LMA and A_max indicates that LMA accelerated the photosynthetic rate, although those species with higher A_max/LMA (P. macrophylla, S. macrophylla and S. seminis) had low tolerance of desiccation in the grassland. The seedlings planted in the remnant forest had lower leaf R_d and higher SPAD values than in the other environments. Large increase in SPAD value and decrease of I_cin P. macrophylla and S. virescens suggest that both species have acclimation ability to the remnant forest. The lowest mortality and l_c in the remnant forest was in S. seminis and suggests high shade tolerance in this species. In contrast, S. ovata, which maintained the highest l_c over the measurement period, may suffer greatest mortality in the remnant forest In the secondary forest, the leaf A_max, LMA and SPAD value were intermediate in value between the other two environments. We conclude that leaf ecophysiological traits in dipterocarp seedlings differ significantly between species. This is information needed for enrichment planting in degraded tropical rainforest areas in Southeast Asia.

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We measured the flux of nitrous oxide (N₂O) in three different land uses (primary forest, oil palm plantation, and rubber plantation) in Peninsular Malaysia. The N₂O emission rate in the primary forest was higher than those in the plantations throughout the experimental period. This result suggests that primary forest soil is a greater source of N₂O than that of oil palm and rubber plantations. The rate of N₂O emission in the primary forest showed a clear variation during the experimental period, with higher values from wet soils and lower values from dry soils, whereas N₂O emission rates in the plantations showed little variation. The proportions of soil surface carbon and nitrogen in primary forest were three times those in the plantations. The difference in soil carbon and nitrogen contents between the primary forest and plantations may have affected the rates of N₂O emission from the soils.

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The influence of site conditions and human activities on vegetation composition was studied in savannas of the Diambour Forest Reserve of southeastern Senegal. Vegetation inventories were carried out in areas of homogeneous vegetation in savanna woodland, tree-shrub savanna, grass savanna and gallery forest based on the Braun-Blanquet (1964) methodology. At each site, substrate data (soil types and moisture content), micro-topographic features and disturbance factors (cutting, fire and cattle grazing) were recorded. The vegetation of the Diambour Forest Reserve was classified into six communities, seven subcommunities and two other subunits. The drier savanna areas affected by fire tend to be richer in species than the wetter parts restricted to the riverside and depressions with tree cutting and cattle grazing. The communities on drier sites and affected by fire show higher values of Simpson’s index of diversity and species richness. The lower diversity of wetter sites is caused by tree cutting, micro-topography and soil with a high content of laterite and other clays. Riverside communities are mostly composed of microphanerophytes, while the communities of drier sites show more diversified life-form spectra. This paper is the first phytosociological study of the Diambour Forest Reserve (DFR) in Senegal.

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To clarify feeding effects of the Orii’s flying-fox, Pteropus dasymallus inopinatus, on seed germination, germination experiments were conducted for 11 food plant species between February 2004 and April 2005. For Ficus microcarpa, the main food of the Orii’s flying-fox, the percentage of seeds germinated from ejecta pellets was significantly higher than those from intact fruits, although there was high variation among individual trees. The percentage of seeds germinated from fecal pellets was also higher than those from fruits, although it was not significant. For four of the other 10 food plant species, the percentages of seeds germination from ejecta pellets and fecal pellets were greater than those from fruits. For the remaining six species, percentages of germination consumed seeds, maintained at least, normal viability. Germination time of five of the 11 plant species differed significantly according to seed sources. These results suggest that the Orii’s flying-fox is an effective seed dispersal agent on Okinawa-jima Island.

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Trunk diameter (D, cm) and tree height (H, m) growth curves were produced for 49 timber tree species from planted forests in West Java, Indonesia. Data were available covering a period of more than 40 years. The D and H of all trees of various ages were measured and coefficients of the Gompertz growth function were determined for each tree species. The tree species were then classified according to their wood production potential, on the basis of the relationship between their potential growth rate k, and asymptotic maximum carrying capacity A. The relationships between k and A, for both D and H growth curves of the tree species investigated, were negatively correlated (p < 0.05). Tree species of the Dipterocarpaceae exhibited a variety of growth characteristics with respect to D. In contrast the H growth characteristics for this family tended to be similar, with lower k values and higher A values than other tree species. These growth performance data for specific timber tree species will be useful to aid in the selection of tree species to plant, and in facilitating the establishment of forestry systems with long-term rotations (30 to 50 years) in the humid tropics.

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To understand soil organic matter (SOM) dynamics in agricultural land in Indonesia, soil respiration rate was determined by both field measurement and laboratory incubation in small home gardens (pekarangan) in different regions of Java and East Kalimantan and extensive survey on the general distribution patterns of SOM-related properties was also conducted. The primary factor controlling field soil respiration rate was often the moisture factor under savanna climate or cropland-like plots, though its contribution was poor under rainforest climate. Annual field soil respiration was typically very high, often exceeding 20 Mg C ha^-1 y¹, indicating a high contribution of plant root respiration. Comparison of the field data with laboratory incubation data revealed that: 1) surface 15-cm layers of soils are the likely source of microbial respiration and 2) annual soil respiration derived from both plant root and microbial respiration (determined by field measurement) was primarily controlled by the temperature factor, while that from microbial decomposition of SOM (determined by laboratory incubation) was strongly affected by SOM pool size. Application of the parameters determining soil respiration, which were obtained at the intensive monitoring plots, to the dataset collected in the extensive survey revealed that: 1) annual soil respiration in fields shows a clear regional trend, that is, it is highest in East Kalimantan, followed by low-elevation areas of Java and then high-elevation areas of Java, and 2) both SOM stock and annual soil respiration with microbial origin are higher under more forest-like land use, with exceptionally high accumulation of SOM relative to its decomposition (soil respiration) in plots derived from volcanic tephra. Generally pekarangan land management in Java is advantageous because a high population density can provide continuous input of organic materials, such as domestic waste or crop residues, into the soils and there are tephra-derived soils, which are more resistant to rapid decreases in SOM because of the high potential of these soils for retaining SOM.

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Cassava pulp is a solid waste that is produced as a byproduct of starch production in tropical regions. This product still contains high levels of starch, and constitutes a serious environmental concern as a disposal. Cassava pulp can be used as feed for poultry by enriching the protein content (CP). Cassava pulp was added with 3% urea and 2.5% zeolite (clinoptilolite) and was fermented by Aspergillus niger for six days. Due to CP and crude fiber concentration, it was formed good in quality. Fermented cassava pulp-urea-zeolite had the lowest true metabolized energy compared with rice bran and unfermented cassava pulp (2,524 kcal/kg vs. 3,310 and 2,959 kcal/kg, respectively). However, this product had the highest efficiency of protein utilization (72% vs. 39 and 41%, respectively). Broilers were fed diets containing 0, 5, 10, or 15% fermented cassava pulp-urea-zeolite with a commercial diet used for comparison ratio. All treatment diets had no significant effect on the body weight gain, feed conversion, yield of carcass, internal organs and abdominal fat as compared with broiler fed with commercial diet. Results suggest that fermented cassava pulp-urea-zeolite can successfully constitute up to 15% of the diet of broilers without causing health problem.

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Seasonal and daily use of natural licks by sambar deer (Cervus unicolor) was examined with camera traps in the Deramakot Forest Reserve, Sabah, Malaysian Borneo. The visitation frequency by females was significantly higher in the wet season (October to March) than in the dry season (April to September) (0.277/day and 0.120/day, respectively), while that by males was not significantly different between seasons (0.190/day and 0.138/day, respectively). Our results imply that the increased female visitation frequency in the wet season reflects the peak of their physical demands (e.g., lactation). The visitation frequency in the dark period (1800 h - 0600 h) was significantly higher than that in the light period (0600 h - 1800 h) (85% and 15%, respectively). Sambar deer are generally assumed to forage at night, and the utilisation of natural licks corresponded to their foraging habits. This study suggests that, for sambar deer, natural licks are among the most important habitats not only for daily sustenance but also for reproductive support.

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Acid sulfate soil is one of the most serious regional environmental problems after destruction of the peat layer over pyrite-containing sediment after agricultural land development and deforestation. Sulfuric acid discharged from acid sulfate soil causes acidification of river water. In pyrite distributing areas within the lower basin of the Sebangau and Kahayan rivers in Central Kalimantan, the water of the mainstream of the rivers as well as water discharged from canals into the mainstream in the rainy season show much higher acidity and a higher concentration of sulfate ions than in the dry season. The objective of the present study was to obtain information on utilization of natural water from local inhabitants in the basin with water pollution including sulfuric acid contamination. We held interviews with local inhabitants in sulfuric acid polluted areas in Paduran and Pangkoh as well as areas around Sigi village concerning the sources of water and evaluation of water quality in their habitat. Inhabitants around Sigi mostly depended on well water both in the rainy and dry seasons, whereas the sources of drinking water for inhabitants in Paduran and Pangkoh differed significantly between dry and rainy seasons. River water chemistry showed little difference between the dry season and the rainy season in the Sigi area, whereas river and canal water in the rainy season in Paduran and Pangkoh showed lower pH than in the dry season due to a high concentration of sulfuric acid in the rainy season. Accordingly, river and canal water in the rainy season in polluted areas was not available as drinking or cooking water and thus they avoided using river water for drinking or cooking in the rainy season. Although sulfuric acid concentration in river water both in Pangkoh and Paduran were higher in the rainy season than in the dry season, people in Pangkoh evaluated that water in the rainy season to be better than that in the dry season, whereas people in Paduran evaluated that water in the dry season to be better than that in the rainy season. Paduran people would evaluate water quality by SO₄^2- concentration, whereas Pangkoh people would evaluate water quality by salt concentration because of the lower concentration of SO₄^2- of water in Pangkoh in the rainy season than that in Paduran. Pangkoh people recognized that water contaminated with sulfuric acid was much preferable than water contaminated with sea salt, but they avoided using water contaminated with sulfuric acid in the rainy season. More than 70% of the Paduran people answered that river water presents a high risk for drinking and swimming, whereas only 11% or less of the Pangkoh people knew about the risk of sulfuric acid for human health. The Pangkoh people avoided using river water contaminated with sulfuric acid, but the knowledge about sulfuric acid’s effects on human health was not sufficient. Thus we concluded that although selectivity of water was similar for the local inhabitants of the two villages in polluted area, awareness about the risks of sulfuric acid pollution for human health proved to be quite different between the two villages.

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