Peat Swamp Research Articles

Diversity, Composition, Taxa Biomarkers, and Functional Genes of Fish Gut Microbes in Peat Swamp Forests and its Converted Areas in North Selangor, Malaysia

The aquatic organisms in peat swamp forests are under threat due to habitat degradation resulting from human activities. This study determines the fish gut microbes’ diversity, composition, taxa biomarkers, and functional genes in peat swamp forests and its converted areas in North Selangor, Malaysia. Three undisturbed and disturbed areas nearby the peat swamp forests were selected. First, the 16S amplicon metagenomic analysis was conducted to assess the composition and diversity of bacterial communities in fish gut contents from both areas. Then, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and Linear discriminant analysis Effect Size (LEfSe) were used to predict disease/pathogen related functional genes. This study revealed Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria as the predominant phyla in both studied areas. In contrast, bacterial community profiles of disturbed and undisturbed areas were slightly dissimilar. Metagenome predictions revealed that genes are related to metabolism, environmental information processing, genetic information processing, cellular processes, human diseases, and organismal systems. Further investigation revealed six potential biomarker genes, including chronic myeloid leukaemia in an undisturbed area, Vibrio cholerae infection, bladder cancer, pathogenic Escherichia coli infection, Staphylococcus aureus infection, and pertussis in disturbed areas. This study revealed that the fish gut microbiome could be used as an indicator in comparing the undisturbed and disturbed ecosystems.

Comparison of pulp sludge compost effectivity of three different decomposers to the growth of geronggang (Cratoxylon arborescens) seedlings

Pulp residue from liquid waste processing is suitable for compost materials, except for its high CN ratio so it needs composting to reduce the CN ratio. Geronggang is a native peat swamp species suitable for peat rehabilitation. The study aims to test pulp sludge compost quality enriched with three different decomposers to the growth of geronggang ( Cratoxylum arborescens ) seedlings. The sludge composting was incubated for a month using three species of decomposers, i.e., Phanerochaete chrysosporium (C); Penicillium citrinum and Penicillium oxalicum (CO); P. chrysosporium, P. citrinum and P. oxalicum (CCO). The compost is weighed and placed around the seedling's roots area with varies dosages equal to 2, 4, 6, 8, 10, 12, 14, and 16 ton ha -1 . The height and diameter of the seedlings were recorded for six months. Data was examined using ANOVA followed with DMRT at a 5% significance. The sludge compost in this study has CN ratio, Total N (%), P 2 O 5 (%) and K 2 O (%) about 40.22-44.5; 1.04-1.11; 1.05-1.13; 1.05-1.13, respectively. Statistically, the height increment of seedlings after the sludge compost application enriched with the CO was different from the CCO. However, the seedling's height rise was not statistically different at the dosages variation treatment. The raise of seedlings diameter after CO treatment at a dosage equal to 6 and 12 ton ha -1 was significantly different to the CCO at a dosage equal to 12 ton ha -1 . However, the rise of seedling's diameter was not significantly different at decomposers' variation treatment. The future study can be aimed to gain compost that meets the national standard.

Identification of Bird species in Wetlands around Siran Lake, Muara Kaman, Central Mahakam, East Kalimantan

The avifauna of tropical peat swamp forests in East Kalimantan has not been well documented because of the smallest peat area compared to central Kalimantan. The surveys were conducted using various methods in the Muara Siran peat swamp forests and surrounding areas of Lake Siran (heath forest and riparian) in East Kalimantan, Indonesia. These findings were recorded on a list of 80 bird species as well as in numerous noteworthy records. Wetlands are an essential habitat for many threatened and near-threatened bird species. We also discovered Gallinula tenebrosa in Siran Lake, a species that has not been seen in over a century. However, it has a wide distribution globally, including in Australia and the United States. In the peat swamp forest, we recorded Cymbirrhinchus macrurus and Ichtyophaga humilis, rare and widely distributed. We also found Dicrurus hottentotus and Dicrurus remifer, some species of Ferruginous Babbler, Trichastoma bicolor, and the White-necked Babbler, Stachyris leucotis. The Hook-billed bulbul Setornis criniger and the Sooty capped Babbler Malacopteron affinae are found in riparian forests. There are six species of woodpecker. Dryocopus javensis, Great Slaty Woodpecker, Mulleripicus pulverulentus, Meyglyptes tukki, Picus puniceus, and Sasia abnormis. Cuckoo-shrike Coracina striata and Pitta sordia were also discovered. Wetlands (peat swamp forest, heath forest, and riparian areas) should be better protected due to their importance to many species, particularly from destruction and loss of habitat caused by forest fires.

Ecohydrological interactions in a boreal fen–swamp complex, Alberta, Canada

AbstractThe Western Boreal Plain (WBP) comprises a diverse array of wetland types; however, swamps are understudied in the WBP relative to other wetlands, despite their ubiquity. We apply an ecohydrological and GIS‐based research approach at a fen–swamp complex in the WBP to characterize the ecohydrological properties of the varying wetland types and relate these interactions to the hydrologic function of the watershed. In this study, we evaluate 3 years of hydrological monitoring data, with additional hydrochemical, vegetation and remote sensing data. In our analyses, we identified five land types: fen, flat peat swamp and peat margin swamp (peatlands), mineral swamp and upland. Flat peat swamp was distinguished from fen using Ducks Unlimited criteria, stating fens cannot have trees >10 m in height. Little difference in water table variability, groundwater connectivity, vegetation composition and water chemistry were found between flat peat swamp and fen, suggesting that for all practical purposes, they can be considered a single unit and tree height alone cannot be used to differentiate these peatland types. In contrast, peat margin swamps exhibited lower and more variable water tables and consistent downward hydraulic gradients and comprised a mixture of peatland and upland vegetation. Peat margin swamps, however, exhibited similar porewater pH, electrical conductivity and base cation concentrations as upland, flat peat swamp and fen, suggesting that they are well connected hydrologically. Peat margin swamps were also found to modulate subsurface water movement between fen and upland (via reduced transmissivity from lower water tables) and therefore act as distinct ecohydrological units.

A middle Eocene treefall pit and its filling: a microenvironmental study from the onset of a forest mire in the Geiseltal (Germany)

The treefall pit of a large tree at the base of the middle Eocene Mittelkohle has been studied in the former open-cast mine Neumark Nord of the Geiseltal Mining District. Above a light clastic soil, the sedimentation in the pit started with backfall and downwashed material grading upwards into pond deposits that filled the pit. This represents a high-resolution section equivalent in time to the initial peat-forming environment. Palynology revealed a striking difference between a fern-dominated herbaceous plant community below the pit and a pulse of washed-in fagaceous pollen (Tricolpopollenites liblarensis) at the base of the pit. This is overlain by an assemblage of woody taxa typical of a peat swamp forest associated with a number of tropical elements. Comparison with a nearby but undisturbed transition from underlying sediments to the seam confirms the ecotonal character of the parent plant of T. liblarensis, and suggests that Cupressaceae s.l., Nyssaceae and Myricaceae especially benefited from moisture and light in the clearing of the treefall pit. The transition from the underlying sediment to the lignite represents a sharp break in the sedimentary regime from clastic to purely organic material with a bounding surface colonised by large trees, most of them preserved as individual stumps, but including some fallen logs.

Prospective peat swamp water as growth medium for microalgal cultivation and kinetic study

Microalgae as source of renewable energy are very potential due to high biomass productivity and lipid content. The nutritious culture for microalgae cultivation, however, should be concerned to be affordable and feasible. Here, the utilization of peat swamp culture for microalgal cultivation was studied in comparison to the nutritious pure water. The effects of photoperiod and nitrogen sources on biomass were conducted as well. Compared to the commercial microalgae, the microalgae isolated from peat swamp showed excellent performance with the faster growth time of 10 days as well as higher biomass and its productivity of 1.72 g L−1 and 0.16 g L−1 d−1, respectively. Even for the commercial microalgae, the cultivation process using the peat swamp water led to increase in biomass by 17.2% and its productivity by 10% compared to that using the nutritious pure water. The proposed kinetic model with a modification to the modified Gompertz model showed an excellent prediction with the experimental data as R2 of 0.985 was obtained. The model could well envisage the initial biomass and lag phase compared to the original model. Hence, the model is deemed beneficial for the research development for implementation in high scale of microalgal cultivation.

Streptomyces acididurans sp. nov., isolated from peat swamp forest soil.

A novel actinomycete, designated strain KK5PA1T, was isolated from a soil sample collected from Kuan Kreng peat swamp forest, Nakhon Si Thammarat Province, Thailand. The morphological, chemotaxonomic and phylogenetic characteristics were consistent with its classification in the genus Streptomyces. Strain KK5PA1T was most closely related to Streptomyces bryophytorum NEAU-HZ10T (98.0 %) and Streptomyces guanduensis 701T (97.6 %). The G+C content of the genomic DNA was 72.3 mol%. Digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain KK5PA1T and those of S. bryophytorum DSM 42138T(25.1 and 79.1 %) and S. guanduensis DSM 41944T(25.1 and 79.7%) were below the thresholds of 70 and 96 % for prokaryotic conspecific assignation. Chemotaxonomic data revealed that strain KK5PA1T possessed MK-9(H6) and MK-9(H8) as the predominant menaquinones. It contained ll-diaminopimelic acid as the diagnostic diamino acid and galactose, glucose, mannose and ribose as whole-cell sugars. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, two unidentified aminolipids, five unidentified phospholipids and an unidentified lipid. The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and C16 : 0. On the basis of these genotypic and phenotypic data, it is proposed that strain KK5PA1T represents a novel species of the genus Streptomyces, for which the name Streptomyces acididurans sp. nov. is proposed. The type strain is strain KK5PA1T (=TBRC 13094T=NBRC 114802T).

Occurrence and probable source of chromium enrichment in Permian coals, South Africa

AbstractThe trace element data pool for South African coals is limited. However, certain elements are reported as occurring in considerably higher concentrations than global average values. These elements include chromium (Cr), as well as manganese (Mn), cobalt (Co), and molybdenum (Mo), with Cr showing the most consistent enrichment. The aim of this study was to investigate the occurrence of Cr in South African coals sampled from five coalfields, and to assess the possible source of Cr. A total of 21 run-of-mine (ROM) coal samples from the Waterberg, Soutpansberg, Witbank, Highveld, and the Nongoma Coalfields were obtained from active mines. Coal characterization, mineralogy, and geochemical data were compiled. The Cr values for the Waterberg (23 to 28 ppm), Soutpansberg (4.7 to 43 ppm), Witbank (24 to 37 ppm), and Highveld (33 to 37 ppm) coal samples are higher than those for the Nongoma coals (1.2 to 2.5 ppm), and, in nearly every case, higher than the Clarke value for hard coals (17 ppm). Correlation coefficients, density fractionation, and selective leaching were used to infer (indirect) modes of occurrence. A dominant silicate (clay) affinity was determined with Cr, as well as an organic affinity in the ROM samples. The Nongoma coals, with illite and no kaolinite, have extremely low Cr values. The other samples are enriched in kaolinite and also have a high Cr content. Chromium values as high as 67 ppm were reported for 1.4 RD float fraction samples, indicating a positive correlation with organic matter. A Cr - silicate association was observed following selective leaching. These results imply multiple modes of occurrence of Cr in the South African samples, in agreement with studies conducted globally. Chromium in the South African coals could have originated from the Bushveld Complex (approximately two billion years old), the largest Cr reserve in South Africa, which predates coal formation (approximately 299 to 252 million years ago) and is proximal to the coalfields. The Cr, seemingly not associated with chromite, may have been redistributed in the peat swamps during peat deposition, accumulating in the sediments and organic material. The Nongoma Coalfield is the farthest distance from the possible Bushveld Complex Cr source, and these samples are depleted in Cr.

RECORDS OF PRAYING MANTIDS (INSECTA: MANTODEA) FROM TWO AREAS OF CENTRAL KALIMANTAN, AND NOTES ON BORNEAN ODONTOMANTIS AND HIERODULA

Results are presented for a collection of praying mantids from two different habitats in Kalimantan Tengah: an area of peat-swamp forest and an area of hill forest. Forty-one specimens are recorded, representing 20 species; this is the first such collection to be recorded from Kalimantan after more than 70 years. Photographs are included for a number of species, concentrating on species which have not previously been illustrated. Some issues with the Bornean Odontomantis are highlighted and a key to Bornean species is provided. The status of O. micantula Beier, 1937 is clarified, the syntypes are located, and the species is illustrated; the synonymy of O. planiceps and O. javana is questioned. Some historical issues relating to Bornean members of Hierodula are reviewed; the synonymy of H. athene Rehn, 1909 and H. hybrida Burmeister, 1838 and H. venosa (Olivier, 1792) is considered doubtful. Issues with identification of H. venosa and H. vitrea (Stoll, 1813) leave their presence in Borneo questionable.

Late Holocene ENSO-related fire impact on vegetation, nutrient status and carbon accumulation of peatlands in Jambi, Sumatra, Indonesia

Peat fires in Indonesia are predominantly anthropogenic and intensified by El Niño Southern Oscillation (ENSO)-related droughts. In recent decades, peat fires, which typically occurred in degraded areas (partially/entirely deforested peatlands), released massive amounts of carbon by burning the peat swamp vegetation and peat substrate. However, it could also influence atmospheric nutrient deposition, have a fertilizing effect on peatlands, and enhance their productivity. Little is known about how ENSO-related peat fires would affect the vegetation in times of little or no human impact. It is also unclear whether in the past such an ash-fertilization effect also occurred in the long term and how fires affected peatland carbon sequestration, which is one of their important ecosystem services. In order to understand this, we examine the fire regime, vegetation composition, nutrient status and carbon (C) accumulation rates of the Air Hitam and Sungai Buluh peatlands in Jambi, Sumatra, Indonesia during the Holocene. The results suggest that increased ENSO frequency and magnitude in the Late Holocene increased the fire occurrence and severity in both sites. During times of little human influence, those fires had little effect on peatland vegetation composition. The coincidence of more frequent fires, a nutrient enrichment and an increased carbon accumulation rate in the Late Holocene suggest that ash-fertilization might have also played a role in the recent past. Thus, low-severity fires could potentially enhance the peatlands' capacity to accumulate carbon if the water table is sufficiently high.

Design and Built a Prototype Kit for Fire Detection in a Peat Swamp Forest: A Preliminary Results

Peat forest fire detectors need to be developed immediately due to the frequency of peat forest fires in Malaysia during the summer is very high. This can affect the life in the forest and the health of the surrounding population. Among them is the Ayer Hitam Muar Forest Reserve, Johor which is almost 50,000 acres in size and experiences fires every year. However, fire monitoring management methods still need to be improved in terms of speed, accuracy and systematic channeling fire alerts. Apart from location and area factors, the main challenge of the early fire detection process is the lack of manpower to monitor and notify fires. The conventional method through patrols and phone calls from farmers who see a fire is less effective because of the delay in the notification received by the authorities. Initially, the work of identifying the location of the fire and measuring the signal strength of the telco service in the Forest Reserve was done with the help of rangers from the Muar district forestry department. This article proposes a prototype for detecting peat forest fires capable of monitoring and sending early fire notifications using a smartphone. The prototype uses an ESP32 microcontroller, GSM/GPRS modem and industry-standard sensors incluing smoke, temperature, humidity and motion detectors. A total of five prototype units were developed as sensor nodes (SN) 1 to 5 with unique IDs that can send information to UTHM web servers simultaneously. Data from each SN is displayed in real-time while notifications of smoke detection and motion alerts are sent to the authorities via the Telegram application. Solar panels are used as a source of electricity supply while the authorities can access information via smartphones. This prototype was tested to see its stability and operational accuracy while the data obtained were recorded. The developed system can help the authorities detect fires at an early stage and the location of the fire can be known based on the SN information received on the smartphone screen.

Antibacterial and Antifungal Activity of Galam (Melaleuca cajuputi subsp. Cumingiana (Turcz.) Barlow) Extract against E. coli bacteria and C. albicans fungi

Galam (Melaleuca cajuputi subsp. Cumingiana (Turcz.) Barlow) is a peat swamp forest plant. This plant is used to treat respiratory diseases, colitis, sore throat, itchy skin, diarrhea, and dizziness. This study aimed to analyze the antibacterial and antifungal activity of the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow flowers and fruit against Escherichia coli and Candida albicans bacteria. This research is a pretest-posttest research with control group design and consists of 3 stages of research. The first stage is the phytochemical screening test, the second stage determines the minimum inhibitory concentration (MIC) and the third determines the minimum bactericidal concentration (MBC). The results showed that the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow flowers and fruit contained terpenoids, flavonoids, phenols, saponins, quinones, steroids, tannins, while alkaloid compounds only found in the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow fruit. The MIC and MBC values ​​of M. cajuputi subsp. Cumingiana (Turcz.) Barlow flower methanol extract against E. coli were 1.67 and 2.083 mg/mL, respectively, while the MIC and MBC values ​​of the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow flower against C. albicans were 3.125 and 25 mg/mL. The MIC and MBC values ​​of the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow fruit against E. coli have same value were 3.334 mg/mL, while the MIC and MBC values ​​of the methanol extract of M. cajuputi subsp. Cumingiana (Turcz.) Barlow fruit against C. albicans were 3.125 and 12.5 mg/mL, respectively.
 Keywords: Galam antibacterial, antifungal, Escherichia coli, Candida albicans

Biotic and abiotic drivers of dispersion dynamics in a large-bodied tropical vertebrate, the Western Bornean orangutan.

Understanding of animal responses to dynamic resource landscapes is based largely on research on temperate species with small body sizes and fast life histories. We studied a large, tropical mammal with an extremely slow life history, the Western Bornean orangutan (Pongo pygmaeus wurmbii), across a heterogeneous natural landscape encompassing seven distinct forest types. Our goals were to characterize fluctuations in abundance, test hypotheses regarding the relationship between dispersion dynamics and resource availability, and evaluate how movement patterns are influenced by abiotic conditions. We surveyed abundance in Gunung Palung National Park, West Kalimantan, Indonesia, for 99 consecutive months and simultaneously recorded weather data and assessed fruit availability. We developed a Bayesian hierarchical distance sampling model to estimate population dispersion and assess the roles of fruit availability, rainfall, and temperature in driving movement patterns across this heterogeneous landscape. Orangutan abundance varied dramatically over space and time. Each forest type was important in sustaining more than 40% of the total orangutans on site during at least one month, as animals moved to track asynchronies in fruiting phenology. We conclude that landscape-level movements buffer orangutans against fruit scarcity, peat swamps are crucial fallback habitats, and orangutans' use of high elevation forests is strongly dependent on abiotic conditions. Our results show that orangutans can periodically occupy putative-sink habitats and be virtually absent for extended periods from habitats that are vitally important in sustaining their population, highlighting the need for long-term studies and potential risks in interpreting occurrence or abundance measures as indicators of habitat importance.

Establishment of Cell Lines from Slender Walking Catfish Clarias nieuhofii (Valenciennes, 1840)

The slender walking catfish (Clarias nieuhofii Valenciennes, 1840) is a freshwater fish found in the ecosystems within the peat swamp forests of South-East Asian countries, including Thailand. In this study, a new testis fibroblast-like (FLT) and ovary epithelial-like (ELO) cells derived from C. nieuhofii (Valenciennes, 1840) was established. The optimal number of both cells was determined, and the optimal starting concentration of both cells is approximately 105 cellsžml-1. The FLT and ELO can grow best at 28 °C in DMEM supplemented with 20, 15, and 10 % fetal bovine serum (FBS). Chromosome analysis revealed that the typical diploid chromosome number was 66 (2n) in C. nieuhofii (Valenciennes, 1840). In both males and females, the elementary number of chromosomes (NF; the number of chromosome arms) was 98. No heteromorphic chromosome was observed. Four types of chromosomes were found in this species, including 14 metacentric, 20 submetacentric, 2 acrocentric, and 30 telocentric chromosomes. The FLT and ELO cells were maintained up to 6 months with more than 20 passages successfully cryopreserved and thawed. HIGHLIGHTS Two new fibroblast-like cell from testis and epithelium-like cell from ovary, derived from slender walking catfish Clarias nieuhofii (Valenciennes, 1840) have been successfully established by explant outgrowth technique Indicated the optimal cell density, fetal bovine serum and types of culture media for growing of both cells Chromosome analysis revealed that the typical diploid chromosome number is 66 (2n) in Clarias nieuhofii (Valenciennes, 1840) GRAPHICAL ABSTRACT

Keanekaragaman Jenis Herpetofauna (Ordo Squamata) di Kawasan Hutan Rawa Gambut Tropis Mangsang-Kepayang, Sumatera Selatan

Herpetofauna is a group of fauna consisting of amphibians and reptiles. The Squamata Order is one of the Reptiles that has the highest number of species. The Mangsang-Kepayang tropical peat swamp forest area of South Sumatra kepayang is one of the key biodiversity on the island of Sumatra. The diversity of herpetofauna can be used as a parameter of the balance and quality of the area where it lives. The problem raised in this study is how is the diversity of herpetofauna species (order Squamata) in the area of the tropical peat swamp forest of Mangsang-Kepayang, South Sumatra? Based on the problems that arise, then this study aims at the diversity of herpetofauna species (order Squamata) in the area of tropical peat swamp forest in Mangsang-Kepayang, South Sumatra. Sampling along the Boyong-Code River from upstream to downstream uses a combination of several methods, namely VES (Visual Encounter Survey), Time Search, and Road Cruising. The results obtained are 7 species of members of the Suborder Lacertilia (lizards) and 2 species of members of the Suborder Serpentes (snakes). Based on these results it can be seen that the area of Mangsang-Kepayang tropical peat swamp forest in South Sumatra is a suitable habitat for Squamata Order members.

Physicochemical Properties as Driver of Odonata Diversity in Oil Palm Waterways

Large-scale oil palm agriculture has caused deforestation in the tropics, but also degrades stream water quality and reduces aquatic biodiversity. Though the outcomes of industrial-scale oil palm plantations for biodiversity have been explored extensively, the consequences of small-scale oil palm agriculture for freshwater macroinvertebrate fauna are poorly understood. Here, we explored the impacts of small-scale oil palm agriculture on aerial adult Odonata (the dragonflies and damselflies), which, due to their inherent sensitivity to habitat degradation, represent useful indicators of wider ecosystem health. We surveyed riparian corridors of man-made waterways in natural habitats converted into agricultural lands in both peat swamp and mangrove forest, comprising a total of 60 sampling units across a region of Peninsular Malaysia where such small-scale agricultural practices are widespread. We hypothesized that physicochemical water quality of oil palm waterways together with riparian vegetation influence Odonata species richness and composition. Our results revealed that Odonata species richness increased with dissolved oxygen, water temperature and vegetation cover, but decreased with water level, pH, and total dissolved solids. Species composition was influenced by both dissolved oxygen and pH. The present study provides valuable insights into the effects of small-scale oil palm agriculture for water quality of associated aquatic habitats, and subsequent responses of adult Odonata. Therefore, smallholders should reduce the use of chemical pesticides and fertilizers to improve the conservation value of oil palm waterways for both Odonata and aquatic fauna more generally, in order to be certified as biodiversity-friendly agriculture.

Effectiveness of Bacteria Isolated from Peat Swamp Forests to Control Rice Dirty Panicle Fungi in Thailand

Rice dirty panicle disease is one of the most important problems in Thailand. The fungal pathogens were reported to be many species including Curvularia lunata, Bipolaris oryzae, Fusarium incarnatum, Sarocladium oryzae, Trichoconis padwickii and Cercospora oryzae. Biological control is an alternative method for controlling this disease and reducing the application of fungicides. Therefore, this study aimed to evaluate the antagonistic potential of bacteria isolated from peat swamp forests in Thailand. A total of 513 bacterial isolates were collected and screened in the laboratory using the dual culture method. The results revealed that three of the 513 bacterial strains (IBK-4, IBK-8 and IBK-5) were highly inhibitory to the fungal pathogens including C. lunata, B. oryzae and F. incarnatum. These three strains were identified as Bacillus (IBK-4 and IBK-8) and Brevibacillus (IBK-5) based on 16S rRNA sequencing. Then, these three strains were evaluated on a susceptible rice variety by inoculation with three fungal pathogens. The results indicated that Bacillus strain IBK-8 had the highest efficiency to control the disease development as observed in the disease severity and index. The results of this study indicated that bacterial strains from peat swamp forests have the potential to be antagonistic to plant pathogens.

Biomass estimation model for peat swamp forest ecosystem using light detection and ranging

Peat swamp forest plays a very important role in absorbing and storing large amounts of terrestrial carbon, both above ground and in the soil. There has been a lot of research on the estimation of the amount of biomass above the ground, but a little on peat swamp ecosystems using light detection and ranging (LiDAR) technology, especially in Indonesia. The purpose of this study is to build a biomass estimation model based on LiDAR data. This technology can obtain information about the structure and characteristics of any vegetation in detail and in real time. Data was obtained from the East Kotawaringin Regency, Central Kalimantan. Biomass field was generated from the available allometry, and Point cloud of LiDAR was extracted into canopy cover (CC), and data on tree height, using the FRCI and local maxima (LM) method, respectively. The CC and tree height data were then used as independent variables in building the regression model. The best-fitted model was obtained after the scoring and ranking of several regression forms such as linear, quadratic, power, exponential and logarithmic. This research concluded that the quadratic regression model, with R2 of 72.16 % and root mean square error (RMSE) of 0.0003% is the best-fitted estimation model (BK). Finally, the biomass value from the models was 244.510 tons/ha.

Growth responses of light demanding and shade tolerant peat swamp forest saplings to elevated CO2

Aim: To determine the growth responses of two peat swamp forest species, Shorea platycarpa, a shade-tolerant slow-growing species and Macaranga pruinosa, a light-demanding fast-growing species under elevated atmospheric CO2 concentration. Methodology: The saplings of both species were grown in a shade house at ambient (400±50 µmol mol-1) and in an open roof ventilation greenhouse at elevated atmospheric CO2 concentration 800±50 µmol mol-1 for seven months. The temperature in both environments ranged between 25-33°C with 55–60% sunlight transmittance and the saplings were thoroughly watered twice a day. Plants growth measurements were estimated at frequent intervals. Saplings biomass characteristics were examined using destructive methods after seven months of treatment and non-destructive method was used for determination of leaf area. Results: Elevated CO2 enhanced all the growth characteristics in M. pruinosa with a significant increase was observed particularly on both height and diameter relative growth rate and biomass characteristics. The height relative growth rate and leaf area were significantly reduced under elevated CO2 in S. platycarpa but did not affect the shoot or root diameter and biomass significantly. A positive correlation (r =0.77, p>0.05) between stem biomass and basal diameter for plants under elevated CO2 was recorded for M. pruinosa, but not in S. platycarpa. Both species showed negative correlation (S. platycarpa; r = -0.53, M. pruinosa; r = -0.46, p>0.05) between stem growth and stem biomass at elevated CO2. Interpretation: These results unveiled profound effects of elevated CO2 on the growth of light-demanding species M. pruinosa, while shade-tolerant species S. platycarpa was not relatively affected by elevated CO2. This underscored the necessity to analyse different species performance to elevated CO2, thereby improving the ability to predict tropical swamp forest ecosystem responses to rising CO2.

Status of Sumatran Tiger in the Berbak-Sembilang landscape (2020)

Monitoring the status of the Critically Endangered Sumatran Tiger Panthera tigris sumatrae is a key component for assessing the effectiveness of conservation interventions, and thus informing and adapting strategic planning for the remaining 600 Sumatran Tigers on the island. The Berbak-Sembilang National Park is an integral part of the priority Berbak-Sembilang Tiger Conservation Landscape, in a unique habitat of mixed peat and freshwater swamp in eastern Sumatra. Our camera trap survey covered both the Berbak and Sembilang Tiger Core Areas (BTCA, STCA) over a period of 10 years, with surveys undertaken in 2010, 2015, 2018–2019. The most recent population density estimates (BTCA 1.33 adults/100 km2, 95% CI 0.82–1.91 with 19 adults; and STCA 0.56 adults/100 km2, 95% CI 0.45–0.89 with five adults) confirmed a small but stable population. A landscape level management approach is a priority for tiger population recovery, consolidating ground-based protection and establishing a well-maintained fire management system with reforestation of affected areas along with multi-stakeholder engagement and partnerships. The study also recommends extending the BTCA to include the primary swamp forest in the north of the national park, based on evidence from camera trap surveys.