Kerangas Research Articles

Diversity of Seedlings in the Kerangas Forest Kersik Luway Nature Reserve

The Extreme Kerangas Forest is an edapic type of kerangas forest dominated by a much higher quartz sand content than the soil. However, the vegetation in this area is still abundant and the species have their own criteria that are very distinctive and different from other forest types. This paper describes in detail the investigation of seedling variety in the extreme Kerangas Forest of the Kersik Luway Nature Reserve. The research focuses on sapling vegetation in a 1-hectare area of this unique forest type, which is distinguished by high quartz sand content in the soil. The study methodologies are thoroughly described, including the application of the sensus method. The investigation found 38,225 unique saplings representing 16 species from 13 different groups. The most common species were Tristania obovata, Ilex hypoglauca Laec, Podocarpus neriifolius D.Don, Ficus sp. and Calophyllum glaucum. These species thrive in the Kerangas forest's nutrient-poor, acidic soils. According to the report, conservation efforts should prioritize the preservation of these unique ecosystems as well as the rehabilitation of barren areas containing rare species. The severe Kerangas forest in the Nature Reserve is home to a broad assortment of species that have evolved to thrive in harsh environments.

Heath forest identification using remote sensing in the surrounding area of the new capital city of Indonesia

The construction of Indonesia’s new capital city, Nusantara, is envisioned as a forest city that heavily relies on biodiversity. One of the forest ecosystem types surrounding the Nusantara landscape is the heath forest ecosystem, also known as Kerangas. Heath forest is a rare and extreme habitat, thriving in nutrient-poor environments characterized by low pH, quartz sand soil, and podsol soil. However, there is still a lack of knowledge regarding the heath forest in East Kalimantan, particularly in the Nusantara region. This research aims to map the location and characteristics of the heath forest in the surrounding area of Nusantara, specifically in Penajam Paser Utara Regency and Kutai Kartanegara Regency, East Kalimantan. The creation of a tentative heath forest map requires four parameters: elevation, soil texture, NDVI, and a land cover map. Landsat 9 imagery was employed to conduct unsupervised classification and generate a land cover map. The Normalized Difference Vegetation Index (NDVI) was also applied as an image transformation. The parameters were then overlaid using Geographic Information System (GIS) with a binary model. The results indicate that the heath forest covers an area of 56,646 hectares, representing 23% of the total Nusantara area, while the non-heath forest covers 194,610 hectares. The heath forest tentative map aligns with the RePPProT (Regional Physical Planning Project for Transmigration) land system map. Kerangas forests exhibit unique vegetation types, characterized by stunted trees, shrubs, and various epiphytes. Due to the nutrient-poor soil conditions, the vegetation in heath forests is typically sparse and of low height.

Improving Simplicia of Kerangas Forest by Minimizing Microbial Content Under Ultraviolet Radiation Treatment

Kerangas forest is known as a source of traditional medicinal plants and thus potentially the source of simplicia. Medicinal plant preparations of simplicia are usually dried to meet water content standards (< 10%). However, in some cases the drying process carried out still does not eliminate the microbial content in the simplicia. This study aims to analyze the phytochemical compounds contained in three types of medicinal plant simplicia and the total microbial content by treatment with ultraviolet (UV) irradiation. The types of simplicia used were Baeckea frutescens leaves, Shorea balangeran bark and Vitex pubescens leaves (obtained from the kerangas forest). Before testing the total microbial content, simplicia first received UV irradiation. The first simplicia sample was not irradiated, while the next simplicia sample was given UV irradiation with a power of 60 watts and an irradiation time of 1, 2 and 4 h. The microbial content test used the total plate count method with the pour plate analysis technique. S. balangeran is unexposed species to microbes, even without UV irradiation. Radiation with a UV lamp for 1 h with a lamp power of 60 watts and a distance of the sample with a lamp of 30 cm effectively eliminates microbes in B. frutescens simplicia. Radiation for 4 h with a UV lamp of 60 watts and a sample distance of 30 cm was only able to eliminate the microbial content in V. pubescens simplicia. The results of this study indicate that S. balangeran has high potential to be developed as an antibacterial.

Review: Diversity, structure, and community composition of Bornean heath forest with a focus on Brunei Darussalam

Abstract. Ikbal IM, Din HHM, Tuah WH, Jaafar SM, Ahmad N, Sukri RS. 2023. Review: Diversity, structure, and community composition of Bornean heath forest with a focus on Brunei Darussalam. Biodiversitas 24: 2814-2829. Tropical heath forests, a unique lowland forest ecosystem with high conservation value, are increasingly threatened by disturbances. Heath forests are characterized by trees of short stature and the presence of highly acidic, sandy soils with poor nutrient content. Bornean heath forests are widely studied for their diversity, structure, and community composition and are known to support endemics of high conservation value. Environmental factors and soil properties, such as topography, water availability, and nutrient status, are known to influence tree species diversity and forest structure of Bornean forests. However, factors influencing their community composition, including the role of seedling communities in influencing heath forest communities, are still not well understood. In particular, studies of tree diversity and community composition of heath forests in Brunei Darussalam have revealed high endemism and the presence of species with high conservation value. Anthropogenic threats to Bornean heath forests highlight the urgent need for an increased understanding of these forests and prioritization of their conservation. Increased insights into the ecological preferences of heath forest species are crucial for the successful restoration of degraded heath forests. The intact forest ecosystems of Brunei could provide opportunities for further ecological research on the plant communities found in these unique forests.

Short Communication: The potential of soil microbes in the three kerangas forest ecosystems on Belitung Island, Indonesia

Abstract. Oktavia D, Pratiwi SD, Pratiwi D, Kamaludin NN. 2023. Short Communication: The potential of soil microbes in the three kerangas forest ecosystems on Belitung Island, Indonesia. Biodiversitas 24: 1895-1899. The biogeochemical cycles on Earth are governed by living creatures, therefore the composition and activity of microbial communities are important ecological issues. In this study, we investigated the abundance of soil microbes randomly existing from the three types of kerangas forest ecosystems (Bukit Peramun, Cendil Kerangas Forest, and Gunung Lumut) in Belitung Island which belongs to the Geosites of Belitong UNESCO Global Geopark. In comparison to the Bukit Peramun and Hutan Cendil habitats, the populations of bacteria and fungus in the Gunung Lumut were greater at 3.11 x 1010 and 1.14 x 105 cfu g-1, respectively. In Gunung Lumut, there was a comparatively high population of soil bacteria. Gunung Lumut is a site where a variety of mosses have taken over and are overpowered by the terrain due to its high humidity and weathered rocks. Generally, under various conditions, a specific function is more likely to be carried out by soils with higher microbial populations. Understanding soil health and agricultural productivity depends on an understanding of the presence of soil bacteria in various types of kerangas forests. Our study aids the Geosites of the Belitong UNESCO World Geopark in ensuring a long-term sustainable ecosystem.

Diversity and ecology of Pteridophytes in Cendil heath forest and Gurok Beraye tropical rainforest, Belitung Island, Indonesia

Abstract. Priambudi AS, Chikmawati T, Sulistijorini, Fakhrurrozi Y. 2022. Diversity and ecology of Pteridophytes in Cendil heath forest and Gurok Beraye tropical rainforest, Belitung, Indonesia. Biodiversitas 23: 4775-4782. The tropical heath forest is a unique ecosystem type characterized by sandy and acidic soils with poor nutrients and water availability, making this ecosystem very vulnerable to disturbances. Yet, knowledge regarding the diversity and ecology of the biological elements of heath forests is still very limited, moreover, information on lesser-known plant groups, such as pteridophytes. Pteridophytes can be used as indicators of the quality of a forest ecosystem since they are cosmopolitan and have an excellent adaptation to various habitats. Belitung Island, Indonesia, is a region with a large proportion of tropical heath forest and small areas of tropical rainforest. There are only a few studies on comparison of the flora of the two ecosystem types on Belitung Island. This research aimed to compare the diversity and the ecology of pteridophytes that grow in the Cendil heath forest and the Gurok Beraye tropical rainforest, Belitung Island. The study used the cruise and the purposive sampling methods to record all pteridophytes within the sampling plots measuring 5 x 5 m alternately located on the right and left of line transects with a length of 50 meters each transect. Ecological data were calculated using the Important Value Index (IVI), Shannon-Wiener diversity index, Margalef richness index, Evenness index, Sorensen similarity index, Morisita distribution index, and Canonical Correspondence Analysis. The results showed that as many as 31 species of pteridophytes belonged to 14 families in the Cendil heath forest and Gurok Beraye tropical rainforest. The pteridophytes found in the Gurok Beraye tropical rainforest were higher (30 species) than that in the Cendil heath forest (9 species). There was high dominance of a few species in the Cendil heath forest due to the presence of three species with high IVI, namely Dicranopteris linearis, Palhinhaea cernua and Dicranopteris splendida. In contrast, pteridophytes in the Gurok Beraye tropical rainforest were evenly distributed with no high dominance species. Environmental parameters that affected the diversity and abundance of pteridophytes included temperature, light intensity, humidity, and altitude.

Influence of species functional strategy on leaf stoichiometric responses to fertilizer in a Bornean heath forest

Abstract The distribution of Bornean heath forest on white sand soils is believed to be due to element limitation and soil acidity. To determine the impact of both element limitation and soil acidity on tropical heath forest, we established a soil fertilization experiment to investigate the impact that increased soil N availability and reduced soil pH (using lime/CaCO3) had on a range of elements in tree leaves. We hypothesized that alterations in soil resource availability would cause changes in the tree leaf N:P ratio and concentrations of other elements and these changes would be influenced by species' functional strategies. The experiment was carried out in a Bornean heath forest on infertile soil over a 2‐year period. We selected 10 common tree species, spanning acquisitive to conservative strategies and tested whether tree species functional strategies influenced tree leaf elemental concentrations after the fertilization. Leaf N:P ratios showed considerable differences among co‐occurring species. Overall, we found that soil N addition treatments increased leaf N concentration, although leaf N:P ratios were not affected. Changes in leaf Al, Fe and S concentrations were correlated with species functional strategy: conservative species showed a greater increase in leaf Fe compared with acquisitive species, whereas acquisitive species showed a greater increase in leaf Al but a decrease in leaf S compared with conservative species. Synthesis. We show that soil elements uptake differs between acquisitive and conservative species and that acquisitive species may not take up soil elemental resources more effectively than conservative species. We suggest that the greater Fe acquisition by conservative species, in comparison to acquisitive species, might be due to a stress tolerance strategy. The overall increase in leaf N showed that, in this nutrient‐poor forest, N is a fundamental requirement irrespective of species functional strategies. Given the increased leaf Al and Fe concentration after liming, we also suggest that these elements are important, and possibly limiting (Fe), in this heath forest.

Floristic composition and species diversity in three habitat types of heath forest in Belitung Island, Indonesia

Oktavia D, Pratiwi SD, Munawaroh S, Hikmat A, Hilwan I. 2021. Floristic composition and species diversity in three habitat types of heath forest in Belitung Island, Indonesia. Biodiversitas 22: 5555-5563. Exploring plant diversity, structure, and composition of vegetation in forest ecosystems is necessary for understanding the mechanism of species coexistence and forest dynamics, moreover in a unique and vulnerable ecosystem such as tropical heath forest (kerangas). We investigated the composition and structure of vegetation of heath forests in East Belitung, Indonesia in three habitat types, namely primary heath forest (rimba), secondary heath forest (bebak), and grassland (padang). Vegetation analysis was conducted using the combination of transect and plot method to calculate the importance value index (IVI) for all species and biodiversity indicators for each habitat type. We recorded 157, 135, and 31 species in rimba, bebak, and padang, respectively. The top three dominant families of species found were Myrtaceae, Clusiaceae, and Euphorbiaceae. In rimba, Syzygium lepidocarpa had the highest IVI for seedlings, Calophyllum lanigerum had the highest IVI for saplings, and Schima walichii had the highest IVI for trees. In bebak, Guioa pleuropteris had the highest IVI for seedlings, Garcinia hombroniana had the highest IVI for saplings, and Schima walichii had the highest IVI for trees. In padang, Fimbristylis sp. had the highest IVI for seedlings, while Leptospermum flavescens had the highest IVI for saplings and trees. Some pioneer species were found such as Rhodomyrtus tomentosa, Rhodamnia cinerea, Syzygium buxifolium. We also found two carnivorous plants Drosera burmannii and Nepenthes gracilis in padang, indicating that this habitat type is poor in nutrients in the soils. We suggested that the presence of species composition in the three habitat types of heath forest is an essential plant resource to be conserved and sustainably utilized. Establishing reserve areas to protect natural habitat and biodiversity is encouraged to provide proper ecosystem function for the people and nature.

Impacts of invasive Acacias on ion deposition in a coastal Bornean tropical heath forest

ABSTRACT The uncontrolled invasive spread of exotic Acacias is a growing concern for many tropical ecosystems, particularly due to their negative impact upon nutrient cycling. Studies investigating the effects of Acacia invasion on nutrient cycling have focused on litterfall and litter decomposition, although its impact on ion deposition in tropical ecosystems is less understood. We quantified and compared the rates of ion deposition (Ca2+, Mg2+, NH4 +, NO3 −) between Acacia-invaded and non-invaded tropical heath (Kerangas) forest sites in Brunei Darussalam, Southeast Asia. Ion exchange resin (IER) sampler, IER ring and IER bags were used to determine ion depositions via throughfall, in soils and in stream water respectively. Throughfall in Acacia-invaded heath forest sites recorded significantly higher NH4 + and Ca2+ depositions but lower Mg2+ than non-invaded, intact sites. For ion deposition in soil, all depths recorded significantly higher Ca2+ (except for 0 cm depth), Mg2+ and NH4 + depositions, but significantly lower NO3 − depositions, in Acacia-invaded sites. Ion deposition in stream water showed significant monthly variations, with Acacia-invaded sites recording significantly higher Mg2+ depositions in June, August and September 2015 but lower NH4 + depositions in June, July and September, lower NO3 − and Ca2+ depositions in June and September than non-invaded heath forest sites. Overall, these findings demonstrate that ion deposition via throughfall, in soil and in stream water were all affected by Acacia invasion, thus confirming the influence of alien invasive Acacias on nutrient cycling of tropical heath forests.

KEANEKARAGAMAN JENIS BURUNG DIURNAL DI HUTAN JAJAU KECAMATAN MENTEBAH KABUPATEN KAPUAS HULU KALIMANTAN BARAT

Mentabah sub-district is one of the territories in Kapuas Hulu, the province of West Borneo. The width is about 781,26 km² with enormous potential for biodiversity. One of them is Jajau forest. The local people called it Jajau Forest that also known as Kerangas forest. The purpose of this research is to collect data about the diversity of Diurnal species in Jajau Forest in Mentabah sub-district, Kapuas Hulu, the province of West borneo. IPA ((Index Point Abundance) is used in this research that placed purposively. The result of this research shows that there are 111 birds species could be indetified with 938 birds include 39 families. This research showh that the variety of birds in this are is so high, it is 4.4221.Keywords: diversity of birds, Jajau Forest, Mentebah District

Post-fire impacts on tree diversity in coastal heath forests of Brunei Darussalam

The adverse impacts of fires on the diversity of native plants in forest ecosystems are well documented. Tree diversity was studied in coastal heath (Kerangas) forests of Brunei Darussalam, Northwest Borneo after fire events. Eight 20 x 20 m plots were set up in once-burnt (3 plots), twice-burnt (3 plots) and unburnt heath forests (2 plots). All trees (live and dead) with stem diameters of 1 cm and above were censused, and measures of percentage canopy openness and soil variables (pH, gravimetric water and organic matter content, and concentrations of total nitrogen and phosphorus) were determined. Soil pH, gravimetric water content and total nitrogen and phosphorus concentrations, and canopy openness were significantly higher in the burnt plots. Stem diameters were significantly higher in the unburnt heath forests, with mostly Acacia species recording smaller stem sizes (&lt;10 cm dbh). Tree species richness and diversity were significantly lower in the once-burnt plots than in unburnt, intact heath forest plots indicating substantial loss of native tree diversity in fire-affected habitats. Tree community compositions of the once-burnt plots were dominated by invasive Acacia mangium. This study highlights the negative impact of fire on native tree diversity, soil properties and canopy openness of these coastal Kerangas forests, and further provides preliminary evidence that fire events have facilitated the successful establishment of invasive Acacia species.

Photosynthetic Responses of Invasive Acacia mangium and Co-Existing Native Heath Forest Species to Elevated Temperature and CO2 Concentrations

ABSTRACT The impacts of climate change, in particular via elevated temperature and atmospheric CO2 concentrations, cause differential photosynthetic responses between native and invasive alien plants, often resulting in varying magnitudes of plant growth and productivity. This study investigated variations in photosynthetic responses of an invasive alien Acacia species and two successional groups of tropical heath forest species: early secondary (Bucha nania arborescens and Dillenia suffruticosa) and secondary (Calophyllum inophyllum and Ploiarium alternifolium) groups at elevated temperature (25 to 30°C) and CO2 levels (400 to 700 ppm). Invasive A. mangium appears better adapted to higher temperature and CO2. High temperature improved CO2 assimilation of A. mangium compared to heath species, which was attributed to increased transpiration rate and stomatal conductance but decreased water-use efficiency. Photosynthetic responses showed no differences in early secondary species at elevated temperature and CO2 but invasive A. mangium and P. alternifolium were stimulated by elevated CO2. The greater maximum net photosynthesis of A. mangium coincided with lower light compensation point and electron transport rate for RuBP regeneration, to a certain extent. Findings provide insights into possible underlying ecophysiological mechanisms contributing to the invasion success of Acacias in degraded tropical heath forests in response to future climate change.

Impact of soil nitrogen availability and pH on tropical heath forest organic matter decomposition and decomposer activity

Decomposition is a key process for rain forest nutrient cycling, and this may be altered by the increasing rate of deposition of reactive nitrogen on rain forests. Tropical heath forests are characterised by slow litter decomposition rates due to low quality litter, along with acidic soil pH and low availability of soil nitrogen (N). To investigate whether soil N or pH is most important in regulating tropical heath forest organic matter decomposition, we used a factorial N and CaCO3 addition experiment, and measured wood and leaf litter decomposition rates and mesofaunal activity (using bait-lamina sticks and numbers of worm casts). Our heath forest site in the Kabili-Sepilok Forest Reserve (Sabah, Malaysia) had a decomposition rate (calculated using standard tea material) comparable to that of temperate forest soils. Overall, the experimental modification of both soil pH and available N had weak effects on decomposition rates, although different materials responded differently to the experimental treatments. There was a clear, but transient, increase in number of worm casts in the CaCO3 and N + CaCO3 treatment. Although we obtained some evidence that low soil acidity reduced decomposer activity, it may take longer than one year for the decomposer community, and associated processes, to be influenced by the experimentally altered edaphic conditions.

ROLE OF INTERPERSONAL VILLAGE PARTNERS IN SUPPORTING THE DEVELOPMENT OF GEOPARK BELITONG

The purpose of the study: Inter-Village Cooperation (IVC) is a mandate of Law no. 6 of 2014 regarding Village, and it has an important role in supporting the development of the Geopark Area. Geopark area has potential fishery products that can be managed with IVC in East Belitung Regency to encourage its development. This study aims to identify the potential of economic resources to be managed by IVC that can support the development of Belitung Geopark.&#x0D; Methodology: This study is qualitative research in which the location case set based on the needs and can support the development of Geopark Belitong. The data were obtained from 10 people including village officers, community leaders, and small-medium village business entrepreneurs.&#x0D; Main Findings: The results show the Belitung Geopark consists of 5 tourist destination areas (Open Pit Nam Salu, Kerangas Forest, Batu Pulas/Keran island, Burung Mandi Geopark, and Gunung Lumut) with potential commodity with different infrastructure according to its conditions. Besides, Fishery products are also the most potential commodity in Belitong Geopark. Also, there are some activities that can be collaborated in the field of security, development of local transportation for tourism, souvenir shops (galleries) that managed by the Joint Village-Owned Enterprises to promote geopark area. Commodities processing that can be developed is coffee, pepper, sapu-sapu tea, pasak bumi herbs, Kerangas Forest screen printing-shirts, seafood products, Mengguru shrimp paste, rattan handicraft, Kater miniature, and Krakap Batu herbs.&#x0D; Implication: This study is useful to provide literature about potential economic resources in Belitong Geopark.&#x0D; Novelty/Originality: This study takes place in the Belitong Geopark area that there is still no research investigating potential economic resources in the Belitong Geopark area.

KEANEKARAGAMAN JENIS MAMALIA DIURNAL DI BEBERAPA TIPE HUTAN PADA AREAL IUPHHK-HT PT. HUTAN KETAPANG INDUSTRI KABUPATEN KETAPANG

Mammals are wild animals that are often considered as pests by the community, even though the existence of mammals has an important role in the preservation of forest ecosystem as soil fertilizers, pollinators, seed dispersers, and biological bugs control. Forest is habitat for flora and fauna, but now the forests in Kalimantan are starting to be degraded caused by land clearing of plantations, illegal logging and infrastructure development. Forest degradation is very influential on forest cover, especially mammals. Land clearing by plantation companies has an impact on the survival of animals and vegetation in the plantation area. Food sources and shelter for mammals is reduced. That makes mammals move to habitats that are good vegetation and ecosystems. This study aims to record the diurnal mammal species and find out the diversity of species of mammals diumal in several forest types in the IUPHHK-HT area of PT. Hutan Ketapang Industri district Ketapang. This research was conducted on 25 February 2019 until 23 March 2019 to obtain data on species of mammals diumal in a number of forest types in the IUPHHK-HT area of PT. Hutan Ketapang Industri district Ketapang. The results of this study are expected to provide data and information on the types of diurnal mammals and the diversity of diurnal mammal species in several forest types in the IUPHHK-HT area of PT. Hutan Ketapang Industri district Ketapang The results of observations in five habitat types were found as many as 8 species belonging to 6 families. In Kerangas forest 2 species were found with 7 individuals, Peat Swamp forest was found 5 species with 15 individuals, Lowland Dipterocarpa forest was found 7 species with 19 individuals, Riparian forest was found 3 species with 9 individuals. and Open Wetlands / Flood Plains are found 3 species with a number of individuals 11.Keywords: Mammals Diumal, Diversity, Five Habitat Types

Analisis Vegetasi Hutan Kerangas Di Arboterum Nyaru Menteng Kalimantan Tengah

&lt;p&gt;Environmental management in the Nyaru Menteng Arboretum Conservation area especially for the Kerangas forest has not been done much. This research was conducted to determine the analysis of vegetation in the Kerangas forest in the Arboretum conservation area. This research is expected to get the value of vegetation and important value index in the Kerangas forest, based on the results of the study there are 23 types of vegetation found at seedling level, 24 types of vegetation found at sapling level, 14 types of vegetation found on poles, 13 types of vegetation found at tree. &lt;em&gt;Blumeodendron tokbrai&lt;/em&gt; vegetation has the highest value with a NIP value of 18,047 at the seedling level. Vegetation type &lt;em&gt;Litsea sp.&lt;/em&gt; Has the highest value with a NIP value of 18,159 at the stake level. The vegetation type &lt;em&gt;Syzygium lineatum&lt;/em&gt;, has the highest value with a NIP value of 44,584 at the pole level. Vegetation type &lt;em&gt;Cratoxylon glaucum&lt;/em&gt;, has the highest value with a NIP value of 48,656 at the tree level.&lt;/p&gt;

Effects of Acacia invasion on leaf litter nutrient and soil properties of coastal Kerangas forests in Brunei Darussalam

Exotic Acacia were introduced to Brunei Darussalam in the 1990s for plantation forestry and land rehabilitation but are now regarded as invasive. We assessed the effects of Acacia on litter nutrient composition and soil physicochemical properties of Brunei’s coastal Kerangas (heath) forests. Soil and litter samples were collected from ten 20 x 20 m plots in Acacia-invaded Kerangas forests (IKF) and ten uninvaded (UKF) plots. Soil samples were analyzed for pH, gravimetric water content and nutrient concentrations whereas litter samples were analyzed for total nutrients only. We recorded significantly higher concentrations of litter total N and P in the IKF than the UKF plots. In contrast, no significant differences were detected in soil properties, except for topsoil available P and subsoil exchangeable Ca which were both lower in the IKF plots. A significant positive correlation was detected between litter N and topsoil N in the IKF plots. We suggest that the fairly recent timescale of Acacia invasion (&lt; 25 years) of the IKF sites resulted in the lack of significant increase of soil nutrients. In conclusion, Acacia invasion into Brunei’s forests can potentially alter both leaf litter and soil physicochemical properties of Kerangas forests, in particular affecting nutrient availability. This alteration of ecosystem may further enhance the invasion success of Acacia, making restoration attempts more challenging.

Tree diversity and forest composition of a Bornean heath forest, Indonesia

Heath Forest on Borneo is a forest type mostly found between the transitions from the peat-swamp forests in lowlands to the Dipterocarp Forest in hillier areas. Heath forest soil structure is characterized by a dominant sand layer with a thin organic horizon on top. Tropical Heath Forest has been understudied and undervalued for many years, considered as a low-diversity habitat due to a nutrient-poor sandy soil, unable to aggregate and bind nutrients, resulting in stunted, low canopy forest. Despite its reputation, our research in the KHDTK Mungku Baru(it is a Forest Area with Special Purpose (KHDTK)) in southern Central Kalimantan is revealing heath forest of remarkably high quality, with large trees, high canopy and high biodiversity, including important endemic and emblematic flora and fauna species. Fourteen 30 m x 30 m nested plots were established, where all the trees ≥ 10 cm diameter breast height (DBH) were identified and measured. Additional 5 x 5m and 2 x2 m nested plots were used to define the micro-habitat and soil composition, determining the pH, organic layer depth, water moisture, and canopy cover. A total of 1,007 trees were recorded, representing 87 species in 58 genus and 40 families. Soil layers exhibited visual differences and analysis of soil composition was used to define 2 sub-habitat types of Heath Forest, named as Black sand Heath Forest (BHF) and White sand heath forest (WHF). Significant differences were found on peat/organic layer depth (BHF 26.4 cm; WHF 6.1 cm) and soil moisture (BHF 18.3 %; WHF 11.1 %). Independent analysis for the tree community compositions was done for each sub-habitat type. Few differences were found between sub-habitat types on DBH (BHF 18.9 ± 11.7 cm; WHF 18.6 ± 9.7 cm) and tree height (BHF 18.9 ±5.5 m; WHF 17.9 ± 5.4 m). Tree species composition analysis reveals in both cases a high species richness, with no differences in distribution (Simpson’s Diversity Index BHF=0.96; WHF=0.95) but significant differences in species abundance (Fisher’s alpha index BHF=23.74; WHF=18.01). BHF is a more homogeneous sub-habitat type, dominated by species belonging to Dipterocarpaceae (19.5 %), Myrtaceae (19.2 %) and Sapotaceae (13 %) families, whereas WHF is largely dominated by Dipterocarpaceae species (43.4 %) including Dipterocarpus borneensis and Shorea teysmanniana. The preliminary results of this study indicate that the Central Kalimantan’s Heath Forest presents high tree species diversity with high conservation value, with potentially 2 different sub-habitat types characterized by their soil and tree composition. This highlights the importance of protecting this rare and understudied habitat in the context of Borneo biodiversity conservation.

Soil characteristics influence species composition and forest structure differentially among tree size classes in a Bornean heath forest

Whilst several studies have shown that edaphic variability influences species composition in nutrient-poor tropical forests, the determinants of local species distributions and, in particular, how these change from younger to mature individuals in such forests are still under debate, and have been poorly explored in tropical heath forests that are among the least fertile tropical forest ecosystems. We investigated the influence of soil fertility and topography on a Bornean heath forest species composition, α-, β-diversity and tree size structure among size classes by recording all trees ≥1 cm DBH in 16 forest plots totalling 0.36 ha. Tree species distributions generally followed gradients in available Al and soil depth; α- and β-diversity were linked to soil depth, and to some extent also to pH and the H:Al ratio. In contrast, forest structural attributes (basal area and stem density) were negatively correlated with both available and total P and a wider suite of soil nutrients, although trees ≥10 cm DBH were positively correlated with total P. Our study shows that heath forest species distribution, richness and structure is related to both edaphic and topographic characteristics and that soil acidity might have a strong influence in shaping these forests’ features. Among size classes, small trees are less influenced by soil and topography, whereas the sensitivity to these variables increases with tree size. We thus highlight that multiple edaphic factors influence different aspects of tropical forest structure, including different tree life stages, and species composition.

Study of Odonata Diversity in Kerangas Forest Sukadamai Village and Punai Beach Simpang Pesak, Belitung Timur

Belitung is known as the biggest tin mining in Indonesia. Besides that, Belitung also has a lot of biological resources, that is Odonata (dragonfly). The research was conducted in June 2018 by exploration in Belitung, particularly in Punai beach and Kerangas forest (ex-tin mining) area. There is found 17 type of dragonfly such as Ichtinogomphus decoratus., Macrogomphus sp., Orthetrum sabina., Nannophya pygmaea., Neurothemis fluctuans., Rhodothemis rufa., Rhyothemis phyllis., Urothnemis signata., Pseudagrion coomansi., Ceriagrion cerinorubellum., Acisoma panorpoides., Brachydiplax chalybea., Diplacodes nebulosa., Orthetrum pruinosum., Agriocnemis femina., Agriocnemis pygmaea., and Ischnura senegalensis. All species were conducted to find out the diversity using Shannon-Wiener index and resulting 2,77 index.