Peatland In Central Kalimantan Research Articles

Assessing the health impacts of peatland fires: a case study for Central Kalimantan, Indonesia

The conversion of Indonesian tropical peatlands has been associated with the recurring problems of peatland fires and smoke affecting humans and the environment. Yet, the local government and public in the affected areas have paid little attention to the impacts and costs of the poor air quality on human health. This study aims to analyse the long-term health impacts of the peat smoke exposure to the local populations. We applied the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the smoke dispersion and the associated PM2.5 concentrations of the resulted plumes from the fire hotspots in the deep and shallow peatlands in Central Kalimantan, Indonesia, that occurred during a 5-year period (2011–2015). We subsequently quantified the long-term health impacts of PM2.5 on the local people down to the village level based on the human health risk assessment approach. Our study shows that the average increase in the annual mean PM2.5 concentration due to peatland fires in Central Kalimantan was 26 μg/m3 which is more than twice the recommended value of the World Health Organisation Air Quality Guidelines. This increase in PM2.5 leads to increased occurrence of a range of air pollution–related diseases and premature mortality. The number of premature mortality cases can be estimated at 648 cases per year (26 mortality cases per 100,000 population) among others due to chronic respiratory, cardiovascular and lung cancer. Our results shed further light on the long-term health impacts of peatland fires in Indonesia and the importance of sustainable peatland management.

Fungal diversity and its functions in tropical peatlands as plant growth promoting microorganism or associated with green house emission

Peat land deterioration is global issue. Exploitation of peatland ecosystem, especially extreme drainage has caused severe environmental problem. Among other destruction of fresh water stock, emission of greenhouse gas in the form of carbon dioxide, methane, and nitrous oxide. The objective study was to assess the influence of land use type on fungal diversity and its activity which indirectly contribute plant growth promotion or associated with greenhouse emission from peatland in Central Kalimantan. Four land use types: Nearly-pristine peat swamp forest (n-PSF), Un-drained deforested peatlands (UDP), Drained deforested peatlands (DDP), and Degraded peatlands under agriculture (DPA) were evaluated representing the disturb and less disturb peatland ecosystem. The hydrolytic enzymes assessment, particularly those linking to polymeric substances mineralization, was conducted to estimate microbial activities which contribute to greenhouse gas emission. The result indicates that fungal diversity and its activities of less disturb peatland was quite distinctive from exploited areas, which implies that higher greenhouse gas emission in exploited areas. It is recommended that exploitation of peatland ecosystem should consider water regimes through managing oxic and anaerobic environment to limit greenhouse gas emission. The presence of IAA, phosphatase producing fungi could be important for genetic resources for the growth promotion in peatland ecosystem.

Dinamika Tinggi Muka Air Tanah Pada Lahan Gambut Yang Terbakar

Seasonal fluctuations of water table depth are very important regarding the sustainable peat management on tropical peatland. Water level depth can affect the greenhouse gases emissions and as the main indicator for peat fire risk management. Therefore, direct measurement of water level dynamics in the peat burning area is absolutely necessary. The research objective was studied the water level fluctuations on burning peatland in Central Kalimantan, Indonesia. Water level measurement performed manually in the field and ditch, every week from February to December 2014. Water level from February to December 2014 were -86.6 and -51.9 cm, on the ditch and field, respectively. Peat soil water level was strongly correlated to the variations of rainfall.

Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat

This study investigated spatial factors controlling CO2, CH4, and N2O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO2 flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH4 flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N2O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N2O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO2 flux was the highest in DF (241 mg C m−2 h−1) and was the lowest in DBL (94 mg C m−2 h−1), whereas CH4 flux was the highest in DBL (0.91 mg C m−2 h−1) and was the lowest in DF (0.01 mg C m−2 h−1), respectively. N2O flux was not significantly different among land uses. CO2 flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO2 flux to mitigate GWP through a rise in groundwater level and soil moisture in the region.

Sosialisasi Pencegahan Kebakaran di Lahan Gambut Daerah Bereng Bengkel Kota Palangka Raya

Peat is a type of soil that is formed from the accumulation of half-decaying plant debris, therefore, the content of organic matter is high. (Wikipedia, 2016). The fires of peatlands in Central Kalimantan in 2015 were very severe when compared to previous years. Almost all forests or land experience fires. Land fires do not only occur in forest areas but also within the city of Palangka Raya itself. This is not only triggered by the deliberate burning of land, but also due to natural factors (trees that dry out), strong winds, and also human negligence itself (such as removing cigarette butts in dry forest areas). As a result of extensive forest fires, resulting in smog and causing air pollution which inhibits air and land flight paths, making the prices of basic commodities in Palangka Raya move up. For this reason, it is necessary to hold awareness campaigns on fire prevention on peatlands to the community. In this socialization, information is given to the community about the causes of land fires, how to prevent and overcome them. Based on the results of the socialization, the community better understood the causes of land fires, prevention methods and how to overcome them, so that it was expected to prevent or unravel the occurrence of land fires in the coming years.

Assessment of Suitability of Tree Species for Bioenergy Production on Burned and Degraded Peatlands in Central Kalimantan, Indonesia

Large areas of deforested and degraded land, particularly degraded peatlands, need a viable long-term solution for restoration, ideally one that ensures energy security without compromising food security or biodiversity conversation. To address a knowledge gap on the most adaptive bioenergy crop(s) for degraded lands, this research project assessed the survival and growth performance of potential bioenergy crops to restore burned and degraded peatlands. Our methodology compared the bioenergy species with the potential to survive in extreme environments, i.e., gamal [Gliricidia sepium (Jacq.) Walp.], kaliandra (Calliandra calothyrsus Meissner), kemiri sunan [Reutealis trisperma (Blanco) Airy Shaw], and nyamplung (Calophyllum inophyllum L.). Observed parameters are plant survival rates, tree height, and circular stem growth. The experiment was conducted between March 2016 to February 2017 in a two-hectare demonstration plot on burned and degraded peatland in Buntoi village, Pulang Pisau, Central Kalimantan province. Using a split plot design, two treatments were given to each species, i.e., monoculture plantation and agroforestry (intercropped with Ananas comosus (L.) Merr.); with each treatment, the species were replicated on two separate plots. Results indicate that nyamplung is the most adoptable species followed by kemiri sunan, however both species performed very well under agroforestry treatment when compared with monoculture. Further study is needed to assess the productivity and associate biofuel yield.

Improving strategies for sustainability of short-term agricultural utilization on degraded peatlands in Central Kalimantan

Indonesia is the major contributor of peatland areas in the tropics; however, exploitation of peatlands for various needs with improper management such as illegal logging activities, conversion to plantations, and expansion of smallholder agriculture has caused peatland degradation. In Central Kalimantan Province, only 1.5 million ha (57%) of the total 2.6 million ha peatland is categorized as pristine peatlands forest and the remaining 1.1 million ha is categorized as degraded. Degraded peatland is a significant source of CO2 emissions as well as one such alternative for agricultural expansion. There is scientifically unfounded belief that drained peatland agriculture can be made “long-term sustainable”; therefore, the main idea is only short-term utilization of degraded peatlands for agriculture in a relatively sustainable manner, while effort for conservation and reforestation for long-term sustainable keeps going on. Prospective structural analysis was used to identify the most influential and sensitive variables to be influenced for determining the locally most crucial areas of improvement for enabling short-term agricultural utilization of degraded peatlands in a relatively sustainable manner. This method is a part of strategic foresight toolbox for scenario building process, which observes interrelation and influence among different variables in order to understand the most relevant factors for the development of a specific area. Based on the analysis, the strategies considered for enabling short-term agricultural utilization of degraded peatlands in a relatively sustainable manner include improvement in soil fertility and suitability for agriculture, infrastructure related to peatlands agriculture, institutional capacity, innovation technology and dissemination, farmer knowledge in sustainable peatlands agriculture, and plant productivity. Agricultural expansion implemented in connection with these improvements would enhance the welfare of farmers as well as maintain ecological systems.

Are peatland farming systems sustainable? Case study on assessing existing farming systems in the peatland of Central Kalimantan, Indonesia

Economically, peatland plays an important role since they can be reclaimed for agriculture. Shallow peat (<100 cm) can be used to grow food crops including vegetables. Peatland has also become attractive for development of large-scale oil palm and rubber plantations. However, peatland has a number of constraints in terms of greenhouse gas (GHG) emission, especially CO2 emissions in the degraded peatland. These arise from decomposition of peat. Common sense suggests three alternatives to manage GHG emissions from degraded peatland: conservation and restoration, natural recovery, and agricultural use. In this context, the challenge is to utilize degraded tropical peatland for agriculture while avoiding the negative impacts, and ensuring its environmental sustainability. This research attempts to contribute toward developing better management plans. Results of this study show that rice farming has highest sustainable score in degraded peatland. Rice farming secured a 52.14% sustainability score, while oil palm and rubber farming exhibited 47.55 and 47.67% sustainable scores, respectively. Therefore, rice farming can be considered as the first alternative for development of degraded peatland. Improved oil palm and rubber farming systems may also be subsequently considered if their sustainability can be improved.

Effect of groundwater level fluctuation on soil respiration rate of tropical peatland in Central Kalimantan, Indonesia

ABSTRACTSoil respiration (SR) rate was measured at the burned land (BL), the cropland (CL), the forest land (FL) and the grassland (GL) of a tropical peatland in Central Kalimantan, Indonesia from 2002 to 2011 for the purpose of analysis with a relation to the drying and rewetting. The SR rate was fitted with groundwater level (GWL) to the equation of log(SR) = α – β × GWL using hierarchical Bayesian analysis where α and β were regression coefficients classified by GWL changing directions (drying, rewetting and fluctuating), water-filled pore space (WFPS) ranges in topsoil (low 0–0.54, intermediate 0.54–0.75 and high 0.75–1 m3 m−3), and land uses (BL, CL, FL and GL). SR rate (Mean ± SD, mg C m−2 h−1) was the significantly largest in the CL (333 ± 178) followed by GL (259 ± 151), FL (127 ± 69) and lastly BL (100 ± 90). In the CL, the significantly larger SR rate was found in the rewetting period than in the drying period in the high WFPS range. Also, the significantly steeper slope (β) in the rewetting period was obtained in the high WFPS range than in the drying period. These results suggested that the rewetting of peatland enhanced the SR rate rapidly in the CL, and that the further rise of GWL decreased the SR rate. In contrast, the SR rate in the rewetting period was significantly smaller than in the drying period in the BL in the high WFPS range, because the BL in the high WFPS range was flooded in most cases. The SR rate in the rewetting period was not significantly different from the drying period in the FL and GL. All of β were significant in the high WFPS range in all land uses, but not in the low–intermediate WFPS ranges, suggesting that GWL was not controlling factor of the SR rate when the GWL was deep due to the disconnection of capillary force under dry conditions. According to the results of correlation analysis of the α and β, the α was significantly correlated with relative humidity, soil temperature and soil pH, suggesting that the α was enhanced by dry condition, high soil temperature and neutralization of soil acidity, respectively. The β was significantly correlated with exchangeable Na+ and Mg2+ in the soil, but the reason was not clear. In conclusion, SR rate was enhanced by rising GWL with rewetting in the CL in the high WFPS ranges as well as by deepening GWL.

Ecosystem services from a degraded peatland of Central Kalimantan: implications for policy, planning, and management.

Increasingly, landscapes are managed for multiple objectives to balance social, economic, and environmental goals. The Ex-Mega Rice Project (EMRP) peatland in Central Kalimantan, Indonesia provides a timely example with globally significant development, carbon, and biodiversity concerns. To inform future policy, planning, and management in the EMRP, we quantified and mapped ecosystem service values, assessed their spatial interactions, and evaluated the potential provision of ecosystem services under future land-use scenarios. We focus on key policy-relevant regulating (carbon stocks and the potential for emissions reduction), provisioning (timber, crops from smallholder agriculture, palm oil), and supporting (biodiversity) services. We found that implementation of existing land-use plans has the potential to improve total ecosystem service provision. We identify a number of significant inefficiencies, trade-offs, and unintended outcomes that may arise. For example, the potential development of existing palm oil concessions over one-third of the region may shift smallholder agriculture into low-productivity regions and substantially impact carbon and biodiversity outcomes. While improved management of conservation zones may enhance the protection of carbon stocks, not all biodiversity features will be represented, and there will be a reduction in timber harvesting and agricultural production. This study highlights how ecosystem service analyses can be structured to better inform policy, planning, and management in globally significant but data-poor regions.

Effect of plant-mediated oxygen supply and drainage on greenhouse gas emission from a tropical peatland in Central Kalimantan, Indonesia

To evaluate the hypothesis that plant-mediated oxygen supplies decrease methane (CH4) production and total global warming potential (GWP) in a tropical peatland, the authors compared the fluxes and dissolved concentrations of greenhouse gases [GHGs; CH4, carbon dioxide (CO2) and nitrous oxide (N2O)] and dissolved oxygen (DO) at multiple peatland ecosystems in Central Kalimantan, Indonesia. Study ecosystems included tropical peat swamp forest and degraded peatland areas that were burned and/or drained during the rainy season. CH4 fluxes were significantly influenced by land use and drainage, which were highest in the flooded burnt sites (5.75 ± 6.66 mg C m−2 h−1) followed by the flooded forest sites (1.37 ± 2.03 mg C m−2 h−1), the drained burnt site (0.220 ± 0.143 mg C m−2 h−1), and the drained forest site (0.0084 ± 0.0321 mg C m−2 h−1). Dissolved CH4 concentrations were also significantly affected by land use and drainage, which were highest in the flooded burnt sites (124 ± 84 μmol L−1) followed by the drained burnt site (45.2 ± 29.8 μmol L−1), the flooded forest sites (1.15 ± 1.38 μmol L−1) and the drained forest site (0.860 ± 0.819 μmol L−1). DO concentrations were influenced by land use only, which were significantly higher in the forest sites (6.9 ± 5.6 μmol L−1) compared to the burnt sites (4.0 ± 2.9 μmol L−1). These results suggest that CH4 produced in the peat might be oxidized by plant-mediated oxygen supply in the forest sites. CO2 fluxes were significantly higher in the drained forest site (340 ± 250 mg C m−2 h−1 with a water table level of −20 to −60 cm) than in the drained burnt site (108 ± 115 mg C m−2 h−1 with a water table level of −15 to +10 cm). Dissolved CO2 concentrations were 0.6–3.5 mmol L−1, also highest in the drained forest site. These results suggested enhanced CO2 emission by aerobic peat decomposition and plant respiration in the drained forest site. N2O fluxes ranged from −2.4 to −8.7 μg N m−2 h−1 in the flooded sites and from 3.4 to 8.1 μg N m−2 h−1 in the drained sites. The negative N2O fluxes might be caused by N2O consumption by denitrification under flooded conditions. Dissolved N2O concentrations were 0.005–0.22 μmol L−1 but occurred at < 0.01 μmol L−1 in most cases. GWP was mainly determined by CO2 flux, with the highest levels in the drained forest site. Despite having almost the same CO2 flux, GWP in the flooded burnt sites was 20% higher than that in the flooded forest sites due to the large CH4 emission (not significant). N2O fluxes made little contribution to GWP.

Development of the Dayak Ngaju Community Forest in the Forest and Peatland Area, Central Kalimantan, Indonesia

Peat swamp forests are one type of swamp forest that is specific and fragile ecosystems. In order peatland forest ecosystem formed thousands of years, no damage then peatland management should be done wisely by considering the social, economic and cultural as well as ecological functions that peat swamp forest conservation can be guaranteed. This perspective is directly correlated with the paradigm of sustainable forest management. The paradigm explains that the use of natural resources based on the moral ethics that human and nonhuman components are subject to utilization with respect moral and responsible for human rights in addition to the biotic community, and abiotic that still exist and thrive naturally, so it does not compromise the use of the integrity, stability and beauty ecosystem. Dayak Ngaju who resided in forest and peatland in Central Kalimantan have noble values and local wisdom to the development of community forests in forest areas and peatlands. Moral behavior is implemented through the cultural norms carried by generations to support the success of the planting. This study tries to explore the values contained in the Dayak Ngaju cultural norms for development of comunity forests. Dayak Ngaju community forest development start of cultivation. To ensure the success of planting, Dayak Ngaju very concerned about forest site selection will be opened with a consideration of the physical condition of the land,, which is given by the sign of the animals, and natural phenomena. Each activity in the development of community forests, ranging from land clearing, burning, planting, maintenance and harvesting time very concerned about governance. Dayak Ngaju people do in community forest development activities of mutual cooperation, better known as handep, namely employment with other farmers when working back breaking new ground. Based on the structure and composition of the forest vegetation of the people belonging to the community forest is not purely dominated by rubber sap its main results, and based on the diversity of species diversity in the types being classified with the value 2.4336. Estimated revenue generated from private forest landowners in the region of ex PLG Central Kalimantan in 2010 was Rp.31,898,257.67/ha/year. Key word: dayak ngaju, handep, structure and vegetation composition, and diversity.

Canal blocking strategies for hydrological restoration of degraded tropical peatlands in Central Kalimantan, Indonesia

In the 1990s the Government of Indonesia decided to develop one million hectares of peatlands for agriculture in Central Kalimantan on the Island of Borneo. The construction of thousands of kilometres of canals resulted in over-drainage and targets for agricultural production failed. Abandoned, the area has been subject to severe forest and peat fires. Restoration of degraded peatlands normally starts with restoring the water table to rewet the surface in order to control fire and to initiate reforestation. Canal blocking strategies are a potential means for accomplishing this. In a test plot in the Northern part of Block C of the former Mega Rice Project (MRP), a series of dams were constructed and (ground)water tables and subsidence rates were monitored to assess the effects of dam construction on peatland hydrology. The resulting higher water tables did not completely compensate for the negative effects of increased subsidence near the canals. The canals, which are “eating” themselves into the peatland, create depressions in the peatland surface leading to interception of overland- and interflow and increased risk of overtopping of dams during extreme rainfall events. The lessons learned are being used to improve blocking strategies and dam design. The changes in peatland topography caused by drainage, however, need to be better understood in order to further refine strategies for hydrological restoration of degraded peatlands in Indonesia.

Seed rain into a degraded tropical peatland in Central Kalimantan, Indonesia

Forested tropical peatlands in Southeast Asia are important as global carbon stores and for biodiversity conservation yet are being rapidly converted to agriculture or degraded into fire-prone non-forest vegetation. Although large areas have been abandoned, there is little evidence for the subsequent recovery of forest. As part of a study of forest degradation and recovery, we assessed seed rain into an area of non-forest regrowth in degraded tropical peatland in the former Mega Rice Project: an abandoned attempt to convert 1 million hectares of tropical peatland for rice production in Central Kalimantan, Indonesia. Fifty seed traps were placed in the open and fifty under trees. Seeds were collected every 15 ± 3 days for 1 year. Seed rain and foreign seed rain (species different from the tree over the trap) was higher for traps under trees (1127.8 seeds and 465.0 seeds m−2 y−1 respectively) than for traps in the open (95.2 seeds m−2 y−1). Foreign seed rain consisted largely of species that also grow in mature forest, but was dominated by a few abundant wind-dispersed species (particularly from the woody liana, Uncaria elliptica, and the tree, Combretocarpus rotundatus) and the majority of animal-dispersed foreign seeds were found under trees. While seed rain both in the open and under trees appears sufficient for the development of woody plant cover, diversity will be limited in the early stages of succession. We recommend enrichment planting with species that would have been present before forest destruction but are not represented in the current seed rain.

Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells

Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects. It was found that 50 mg/L HA showed cytotoxicity, which we considered to be mediated by apoptosis through the mitochondrial pathway because of an increase in the expression of caspases 6 and 9 in response to HA administration. In addition, this cytotoxicity was enhanced when cells in this experimental system were exposed to oxidative stress, while it was decreased by the addition of vitamin C. Thus, we conclude that the apoptosis induced by HA depends upon oxidative stress. Furthermore, an iron chelator, DFO, showed a tendency to decrease HA-induced cytotoxicity, suggesting that iron may potentially mediate HA-induced oxidative stress. In conclusion, long-term consumption of HA-rich water obtained from our study area may cause damage to endothelial cells and subsequent chronic health problems.

Nitrous oxide emission derived from soil organic matter decomposition from tropical agricultural peat soil in central Kalimantan, Indonesia

Our previous research showed large amounts of nitrous oxide (N2O) emission (>200 kg N ha−1 year−1) from agricultural peat soil. In this study, we investigated the factors influencing relatively large N2O fluxes and the source of nitrogen (N) substrate for N2O in a tropical peatland in central Kalimantan, Indonesia. Using a static chamber method, N2O and carbon dioxide (CO2) fluxes were measured in three conventionally cultivated croplands (conventional), an unplanted and unfertilized bare treatment (bare) in each cropland, and unfertilized grassland over a three-year period. Based on the difference in N2O emission from two treatments, contribution of the N source for N2O was calculated. Nitrous oxide concentrations at five depths (5–80 cm) were also measured for calculating net N2O production in soil. Annual N fertilizer application rates in the croplands ranged from 472 to 1607 kg N ha−1 year−1. There were no significant differences in between N2O fluxes in the two treatments at each site. Annual N2O emission in conventional and bare treatments varied from 10.9 to 698 and 6.55 to 858 kg N ha−1 year−1, respectively. However, there was also no significant difference between annual N2O emissions in the two treatments at each site. This suggests most of the emitted N2O was derived from the decomposition of peat. There were significant positive correlations between N2O and CO2 fluxes in bare treatment in two croplands where N2O flux was higher than at another cropland. Nitrous oxide concentration distribution in soil measured in the conventional treatment showed that N2O was mainly produced in the surface soil down to 15 cm in the soil. The logarithmic value of the ratio of N2O flux and nitrate concentration was positively correlated with water filled pore space (WEPS). These results suggest that large N2O emission in agricultural tropical peatland was caused by denitrification with high decomposition of peat. In addition, N2O was mainly produced by denitrification at high range of WFPS in surface soil.

Determination of the amount of carbon stored in Indonesian peatlands

Extensive peatlands in Indonesia are a major store of carbon. Deforestation, conversion to other land uses, especially plantations of oil palm and pulpwood trees, and recurrent fires have recently caused the release of large amounts of this carbon to the atmosphere. If these large emissions from degrading peatlands are taken into account Indonesia is one of the largest emitters of CO 2 worldwide. To improve estimates of the amount of carbon stored in Indonesian peatlands we applied 3D modelling based on the combined analysis of satellite imagery (Landsat ETM+, SRTM) and 750 in situ peat thickness measurements. We demonstrate that SRTM radar data can be used to determine the extent and topography of the dome shaped surface of a selection of peatlands in Central Kalimantan, South Sumatra and West Papua. A strong correlation was obtained between the convex peat dome surface and the underlying mineral ground, which was used to calculate the peat volume and carbon store. Conservatively, we estimate that at least 55 ± 10 Gt of carbon are stored in Indonesia's peatlands. This amount is higher than previous results published because it takes into account the biconvex nature of the tropical peatlands. With this huge carbon storage and the current rate of degradation the tropical peatlands of Indonesia have the power to negatively influence the global climate.

Requirement for particular seed‐borne fungi for seed germination and seedling growth of Xyris complanata, a pioneer monocot in topsoil‐lost tropical peatland in Central Kalimantan, Indonesia

AbstractHawaii yellow‐eyed grass (Xyris complanata: Xyridaceae) inhabits infertile, acidic peat soil in the rainy tropical zone in Southeast Asia. This monocot plant produces a large number of dormant seeds in order to make a large deposit to seed bank in the soil. Under laboratory conditions, surface‐sterilized X. complanata seeds are rarely able to germinate on sterilized peat moss bed; they require inoculation with either seed epiphytic or soil fungi to facilitate active seed germination. In the present study, three different genera of seed epiphytic fungi were isolated, and two common fungal genera, Fusarium sp. (strain R‐1) and Penicillium sp. (strain Y‐1), were found to promote seed germination of X. complanata. In sterile peat moss beds, the germination‐stimulating fungi also showed growth‐promoting effects on X. complanata seedlings. These results suggest that the seed germination‐promoting fungi likely function as genuine partners for X. complanata in tropical open peat lands.

Microclimate Conditions of the Developed Peatland in Central Kalimantan

Microclimate Conditions of the Developed Peatland in Central Kalimantan

Peat–water interrelationships in a tropical peatland ecosystem in Southeast Asia

Abstract Interrelationships between peat and water were studied using a hydropedological modelling approach for adjacent relatively intact and degraded peatland in Central Kalimantan, Indonesia. The easy to observe degree of peat humification provided good guidance for the assignment of more difficult to measure saturated hydraulic conductivities to the acrotelm–catotelm hydrological system. Ideally, to prevent subsidence and fire, groundwater levels should be maintained between 40 cm below and 100 cm above the peat surface. Calculated groundwater levels for different years and for different months within a single year showed that these levels can drop deeper than the critical threshold of 40 cm below the peat surface whilst flooding of more than 100 cm above the surface was also observed. In July 1997, a dry El Nino year, areas for which deep groundwater levels were calculated coincided with areas that were on fire as detected from radar images. The relatively intact peatland showed resilience towards disturbance of its hydrological integrity whereas the degraded peatland was susceptible to fire. Hydropedological modelling identified areas with good restoration potential based on predicted flooding depth and duration. Groundwater level prediction maps can be used in fire hazard warning systems as well as in land utilization and restoration planning. These maps are also attractive tools to move from the dominant uni-sectoral approach in peatland resource management toward a much more promising multi-sectoral approach involving various forestry, agriculture and environment agencies. It is demonstrated that the combination of hydrology and pedology is essential for wise use of valuable but threatened tropical peatland ecosystems.