The tropical peat swamp forests of Southeast Asia are unique and valuable forest types. Because of the difficulty of approaching the interior, these forests have remained untouched for many years. In the last two decades, however, development projects and forest fires have caused serious damage. Drawing from my experience in Sumatra and Borneo from the 1970s to the present, I describe here the original forest patterns, development typologies, and hazards. I also propose a new concept of “eco-resources” to promote better preservation and more healthy forms of development. Eco-resources are richest and most diverse in the tropics; and shifting to higher latitudes they become progressively more simplified. As peat swamp forests represent the last frontier of unspoiled nature, a total understanding of the relationship between human activities and nature is inevitably a central issue.

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It is known that the tropical pastures or grasses; Arachis pintoi, Brachiaria ruziziensis, Panicum maximum, Panicum repensi, Pueraria phaseoloides, and Stylosanthes hamata, and the tropical trees; Acacia mangium, Anacardium occidentale, Hevea brasiliensis, and Melaleuca cajuputi adapt well to acid soils which have low phosphorus (P) and high aluminum (Al). In this study, top and sub soils were collected from highly weathered soils in peninsular Thailand for chemical analysis and phosphorus fractionation, and the adaptive mechanisms of these plants were examined from the aspect of phosphorus utilization efficiency and root exudation of organic acids and acid phosphatase by culturing plant seedling in complete, phosphorus deficient (-P), high Aluminum (+Al), and P deficient / high Al (-P/+Al) solutions. Results showed that both available P and total P in soils were low, and organic P was the main fraction. Fe-P and Al-P were the dominant inorganic P sources in these soils. The secretion of acid phosphatase increased distinctly in -P treatment from roots of Stylosanthes hamata only. Tropical trees that adapt well to these soils were able to secrete oxalic and citric acids to acquire P by solubilizing of Fe-P and Al-P, whereas tropical pastures or grasses showed high P utilization efficiency and high root-shoot ratio by P deficiency.

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Most of acid sulfate soil areas in South Kalimantan are recommended for growing rice. Due to unfavourable soil conditions such as low pH and unpredictable water level, farmers grow local rice varieties. The farmers use a multiple transplanting system not only to multiply the seedling population but also to cope with the conditions. In addition, most farmers do not apply fertilizer after the last transplanting, but the yield level is not low. Nutrient (particularly nitrogen, N) availability and utilization by the rice crop are the key for this, but N balance in the local multiple transplanting system has been poorly understood. We therefore studied the balance between soil N supply from the mineralization and crop N uptake in the local transplanting system in South Kalimantan. The experiment took place in Tambaksirang Baru (03°26’31”S, 114°35’29”E), Gambut District South Kalimantan. Two farmers, paddocks separated by a village road were chosen for the study. The N mineralisation measurements were carried out on a monthly basis after the planting. At each sampling date, above and belowground parts of rice plants were collected for biomass and N content determination. At the end of the growing season, we observed that the biomass, N uptake and release from the soil were 9.5 and 7.1 Mg DM ha^-1; 36.0 and 27.8 kg N ha^-1; and 13.37 and 8.32 kg N ha^-1 for plot 1 and 2 respectively. The higher N in the crop than that supplied by soil indicates that there are other sources of N for local rice grown in acid sulfate soil.

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Soil macro fauna have almost the same important role as soil microorganisms in affecting soil characteristics. However, data regarding the population and the biodiversity of soil macro fauna in Indonesia are still rare. The objective of this research is to determine the population and the biodiversity of soil macro fauna in various cropland types and soil depths.
The research was conducted at Bogor Agricultural University Field Experimental Station in Pasir Sarongge, Cipanas at four cropland types namely grass, citrus, cereals, and vegetables. In each cropland type, a hand sorting observation method was conducted at four different soil depths: 0-10 cm, 10-20 cm, 20-30 cm, and 30-40 cm. Each observation was replicated four times at different locations.
The total population of soil macro fauna in each cropland type were grass > cereals > vegetables > citrus. The populations were 3.64 × 10⁶ organisms ⁄ ha, 3.54 ×10⁶ organisms ⁄ ha, 3.28 × 10⁶ organisms ⁄ ha, and 3.17 × 10⁶ organisms ⁄ ha respectively. In all cropland types, the total population of soil macro fauna decreased with soil depth. The type of cropland had a significant effect on the biodiversity of soil macro fauna at all soil depths.
The biodiversity of soil macro fauna was vegetables > citrus > cereals > grass. The biodiversity in all cropland types decreased with soil depth. The population of earthworms and ants were affected significantly by soil depth in all cropland types, meanwhile the population of termites, centipedes, and beetles were affected by soil depth only in a certain cropland type.

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The rhizoplane microorganisms of Melastoma malabathricum, distributing throughout the acid sulfate and peat soils of South Kalimantan, Indonesia, were investigated, using a soft gel media of N-free Winogradsky’s mineral solution solidified with 0.3 % gellan gum. Two bacteria, Sphingomonas rosa EC-K013 and Burkholderia cepacia EC-K014 belonging to the subclasses of α- and β-Proteobacteria, respectively, emerged in the nitrogen-free medium. Inoculation of S. rosa EC-K013 in the M. malabathricum seedlings grown in N-free, 1⁄4 Hoagland’s No. 2 medium (pH 3.0) resulted in better growth of the seedlings. In the soft gel medium, EC-K013 also stimulated the growth of a root-associating fungus, tentatively identified as Nectria sp. and a nitrogen-fixer, Mesorhizobium sp., suggesting that S. rosa plays an important role in promotion of microfloral devlopment around the rhizosphere of some acidic soil-adapting plants.

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An initial study on the habitat distribution and diversity of plants as feed resources for mouse deer (Tragulus javanicus) and barking deer (Muntiacus muntjak) was conducted at Gunung Halimun National Park. The survey was carried out by visiting places where mouse deer and barking deer are usually seen, and collecting specimens of the plant species on which those animals feed. In Gunung Kendeng the mouse deer prefers forest habitats up to a height of 1,100 m asl, such as dense bush, rock crevices or tree hollows, dense tea plantations, and bush areas not far from rivers. Barking deer prefer forests up to a height of 1,100 m asl in Gunung Kendeng, but up to 1,600 m asl in Gunung Botol. Barking deer prefer dense bush on the forest edges. Results showed 50 plant species consisting of 22 families as possible feed resources for mouse deer and barking deer.

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Genetic Diversity of the Slow Loris (Nycticebus coucang) based on mitochondrial 12S rRNA genes. Research on the genetic diversity of the slow loris Nycticebus coucang (kukang) was conducted using DNA collected from the blood and tissue of 12 individuals collected from three locations (Sumedang and Jember in Java, and Lampung in Sumatra).
The mitochondrial 12S rRNA nucleotide sequences were determined to investigate the genetic diversity of this species. The regions were amplified by PCR using L1091 and H1478 primers. As a result of the 386bp sequence analysis, five haplotypes were found, two from Java and three from Sumatra.

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The restoration and proper agricultural use of tropical peatlands require knowledge of the physical properties of peat soils. Several physical properties related to changes in the hydrological potential of peat soils as affected by agricultural development were investigated. Selected parameters obtained in selectively logged peat swamp forest were compared with those obtained in clear-cut and maize-cultivated peatlands. In all cases, changes in selected hydro-physical properties were evidently in the top 0-15 cm layer of peat soils, and as in developed sites the top layer of peat soils was subjected to more decomposition as shown by an increase in bulk density and a decrease in fiber content. Bulk density of the top 0-15 cm layer was on average 0.14, 0.29, and 0.19 kg dm^-3 in selectively logged peat swamp forest, clear-cut peatland and maize-cultivated peatland, respectively. Unrubbed fiber contents were on average 74, 35, and 58% volume basis, respectively. Water release potential, at low suction (high matrix potential), was significantly reduced in the top layer. Based on the three-parameter equation, reducing water release potential was attributed to decreasing the constant rate of water release (k_wr) and the maximum volume of water release (V_max). Values of k_wr and V_max in the top 0-15 cm layer of undeveloped site were 0.0346 cm^-1 and 47.69%, whilst in the clear-cut and maize-cultivated sites they were respectively 0,0135 cm^-1 and 44.03%, and 0.0363 cm^-1 and 41.50%. This three-parameter model of water release potential may further be developed to estimate available water for growing crops on peat soils at different water table heights. At high matrix potential there was more water volume over air volume of peat soils under developed sites compared with undeveloped sites. This implies that as a growing medium the quality of peat soils decreases with agricultural development. Based on correlation analysis, changes in selected hydro-physical properties of peat soils were significantly related to changes in bulk density and fiber contents, and so related to the progress of peat decay.

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We preliminarily investigated the correlation between productivity and the diversity of free-living nitrogen-fixing bacteria on the rhizoplane of local rice varieties, including Siam Unus, Siam Adil and Siam Pandak, all tolerable to acid-sulfate soil in South Kalimantan, Indonesia. The rhizobacteria of some unidentified weeds of native-grown in the acidic paddocks were also searched. Subsequently, sphingomonads, including Sphingomonas spp. and Sphingobium spp., are found as the most dominant rhizobacteria in local rice and also in weeds that are adapted to the strongly acidic wet soil. Other unique rhizobacteria are Alcaligenes spp. that powerfully neutralized their cultured media. To understand how the local variety of paddy rice can tolerate acid-sulfate soils with very low soil pH (2.5-3.5), studies of these acid-tolerant, root-associating, and often nitrogen-fixing, rhizospherous bacteria are likely to be important key factors.

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The chemical properties of peat pore water in the basin of the Sebangau River and Lahei district, Central Kalimantan, Indonesia, were studied with reference to data for the Cape Ochiishi and Furen Mires, in Eastern Hokkaido, Japan. We analyzed the major ions, pH, electrical conductivity (EC) and redox potential (Eh) of the peat pore water with reference to their vertical profiles. The mires exhibited different correlations between sulfate concentration and pH in peat pore water. A negative correlation between pH and sulfate concentration in the Paduran site implies that sulfuric acid produced by pyrite oxidation originating from the underlying sediment is contributing to pH. However, a positive correlation between pH and sulfate concentration was found in Lahei and the upper Sebangau sites. The present findings suggest that sulfuric acid production by pyrite oxidation is not the dominant acidification process of the peat pore water in the peat lands of the upper basin.

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The shrinking of high-moor bogs around the globe has become an important problem, because these areas are ecologically valuable but very vulnerable to external impact. Sarobetsu Mire is a case in point. Its ecosystem is gradually losing its natural state because of human perturbations in the surrounding areas, which have caused water levels to decrease, and threaten to change the entire mire ecosystem. As a consequence, a new non-native fauna, Sasa sp., is growing rapidly and invading areas of natural species.
Previous research has shown that the quality and levels of the groundwater in the Sarobetsu Mire have a strong relationship with the surrounding vegetation, especially with the change of species, from sphagnum to Sasa sp. At Point E, where natural sphagnum still remains dominant and the groundwater levels are still high, less inorganic nutrients for plant growth are available. The WW and the NC points however, where sasa has already invaded, both have high nutrient contents. At point NC especially, an area suspected of being affected by external inflow from outside the mire, the high pH and high nutrient content of the water differs greatly to the natural condition of the Sarobetsu bog-mire. In this research we installed dams in the natural channel and found that by increasing the water level, mineralization by micro-organic activities can be restrained and the sasa growth can be minimized. It also showed that raising the water level could hinder growth of sasa brought about by mineralization from micro-organic activities, and enhanced by soil dryness and migration.

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Seasonal discharge measurements and water samplings were carried out at the upper reaches of the Sebangau River in Central Kalimantan, Indonesia. The samples were analyzed for chemical contents and total suspended solids, in order to clarify the relationship between river discharge (flux) and water chemistry. The river runs through tropical peat forest in Palangka Raya, Central Kalimantan. The Sebangau River flux was classified into dry season flux and rainy season flux by flow quantity. But water quality did not differ greatly between the two seasons. The great rainfall-retentiveness of tropical peat bogs may contribute to stability of the runoff load factor.

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Composition of meio- and macroinvertebrates associated with aquatic macrophytes was compared between acid waters in a peat swamp area of Central Kalimantan (CK) and neutral waters in West Java (WJ). Among the invertebrate assemblages, cladocerans and/or copepods dominated in both regions. On the other hand, relative abundances of chironomids and ostracods were significantly higher in CK and WJ, respectively. Eighteen taxa of oligochaetes were recorded from the regions, of which 14 ones belonged to the subfamily Naidinae of the family Tubificidae. The oligochaete composition was quite different between CK and WJ, in that Pristina species dominated in CK, while Stylaria fossularis dominated in WJ. WJ harbored more diverse oligochaetes than CK. The difference in oligochaete composition is related to water acidity.

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Mercury speciation was studied in the Cikaniki and Cidikit rivers, both of which have been contaminated by mercury as a consequence of gold mining. Sampling was carried out in October 2001 and in September 2002. It is well known that humic acid has the ability to bind metal ions, an environmentally important aspect because complex formation might change the toxicity and movement of mercury.
High concentrations of mercury were found in suspended particles at all sampling sites. Scanning Electro Microscope (SEM) images of suspended particles and elemental analysis data by X-Ray spectroscopy showed that the suspended particles were a clay-like mineral. Cationic and anionic species of mercury were also found in the water samples but at relatively low concentrations. Since the presence of humic acid was observed in the river water, the anionic species of mercury seemed to be a complex of mercury with humic acid. The total mercury concentration in the Cikaniki River was higher than the maximum tolerable concentration (0.002 mg ⁄ l) allowed for river water by Indonesian Government regulations. In the Cidikit River, the concentration of mercury was less than the maximum tolerable concentration for river water. Humic acid concentration was also measured to reveal the relationship between the distribution of mercury and humic acid; however, this relation is still unclear.
In the laboratory, the conditional stability constant and capacity of humic acid and mercury to form complex were estimated by Scatchard plot, at pH 6, using a 5 mg ⁄ l humic acid and mercury (II) solution in concentration range of 0-0.6 μM. The value of conditional stability constant between mercury (II) and humic acids is log K’= 6.5 at pH 6 and the complexing capacity of mercury (II) is 0.38 μM.

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We investigated the growth and life span of floating leaves in Victoria amazonica (Poepp.) Sowerby, growing in a shallow pond of the Bogor Botanical Gardens, West Java, Indonesia. In the pond, five plants were selected and the diameter of each leaf was measured at two-day intervals for two weeks to detect the fate of each individual leaf. A visual inspection of any lost (decayed) areas was also conducted at each observation date to evaluate the percentage of decayed leaf area. Leaf life span was estimated from the time interval for the emergence of new leaves, provided that the number of leaves per plant was constant. It was shown that the maximum value in leaf diameter was 2.35 m (4.34 m² in area) with a mean value of 1.6-1.7 m. Each plant was composed of 10-15 floating leaves and while the total leaf area per plant differed considerably (minimum value 12.1-17.2 m², maximum value 27.6-31.2 m²), the minimum and maximum values in time interval for new leaf emergence and in leaf life span were quite similar (2.78 and 2.88 days and 30.8 and 39.7 days, respectively) among the five plants observed. Specific leaf weight (mg·cm^-2) was 7-9 for young leaves and 10-12 for mature leaves, respectively.

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In this study, in order to monitor seasonality function in peat swamp forests by remotely sensed data; we attempted to predict the hydroperiod and phenology of a peat swamp forest in Central Kalimantan using multi-temporal TERRA-MODIS data. We developed a niche method to compress the monthly NDVI images of a one-year period into four seasonal NDVI images. The four seasonal periods were discriminated by using the degree and aspect of the local groundwater levels. Five phenology types, i.e., Dry-philous, Dry-phobous, Wet-philous, Wet-phobous, and Mixed phenology, were classified from the seasonal fluctuation in NDVI values. Water-deficit stress of vegetation during the dry season in the Dry-phobous forest phenology type, and the water-flooding stress of vegetation during the wet season in the Wet-phobous forest phenology type were indicated. The strong effect of the hydroperiod on the forest phenology of peat swamp forests is clarified.

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The Dayak people in Central Kalimantan, traditionally consumed local vegetable, either collected from the wild or traditionally cultivated. Unfortunately, many of the traditional vegetables are approaching extinction, even in their local market. This research is intended to conserve the traditional vegetable by collecting nutritional data and cultural information about the vegetable.
Nineteen traditional Dayak vegetables were observed in local markets and in wild areas. Taxonomic identification revealed that the vegetables were Passiflora foetida L. (kemot), Diplazium esculentum (Retz). SW. (bajey fern), Spondias pinnata (L.f.) Kurtz (kedondong leaves), Neptunia oleracea Lour (malu-malu leaves), Manihot esculenta Crantz (cassava leaves). Vigna unguiculata (L.) Walp. (talak leaves), Etlingera elatiar (Jack) R.M. Smith (potok shoots, red and green cultivar), Calamus sp. (rotan shoots), Nauclea sp. (Taya leaves), Momordica charantia L. (paria leaves), Gymnopetalum cochinense Kurz (kanjat), Solanum torvum Swartz. (segau fruit), Colocasia esculenta (L.) Schott (sulur keladi shoots), Stenochlaena palutris (Burm.)Bedd. (kalakai leaves; red and white cultivar), lotus shoots (pucuk teratai), and Cnesmone javanica Blume (lampinak leaves).
Nutrient analysis revealed that red kalakai (wild fern) has the potential nutrient value. It has a high amount of Fe (41.53 ppm), Cu (4.52 ppm), vitamin C (15.41 mg ⁄ 100g), protein (2.36%), β-carotene (66.99 ppm), and folic acid (11.30 ppm). Other iron-rich vegetables were sulur keladi (49.25 ppm) and bajey (44.6 ppm). While other vitamin C-rich vegetables were paria leaves (18.34 mg ⁄ 100 g wb), and bajaj fern (22.05 mg ⁄ 100g w.b). Sulur keladi and bajey were also rich in folic acid. They had 16 and 6.3 ppm of folic acid respectively. The β-carotene content in bajey was 74.04 ppm while taya was 77.41 ppm.

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