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Shorea leprosula Miq is a Dipterocarps forest plantation that has the prospect of being developed because it is a fast-growing species with high economic value. Given its commercial importance, this study was conducted to analyze the effect of slope class and slope direction on growth. Data were collected using the census method on S.leprosula stands with a spacing of 2m x 2m and 4m x 8m. The direction of the slope is determined based on the configuration of the slope according to the cardinal directions, while the slope of the land is determined based on the classification of the slope class of the land. The results showed that the slope class, slope direction, and the interaction between factors had a significant effect on the growth of S.leprosula. The interaction between the slope class and the direction of the slope produces the highest average annual increment of diameter in the flat slope class with the direction of the slope facing north, which is 1.79 m / year while the highest annual increment of the total average height is in the very steep slope class with to the slope facing to the north at 0.82 m / year.

The use of local species for revegetation activities is expected to accelerate the natural regeneration to increase the biodiversity in restoration efforts of disturbed areas. This study used several parameters to observe the growth of 20-years old stand S. pinanga and S. platyclados, including diameter, total tree height, Mean Annual Increment (MAI), % of fruiting trees, Leaf Area Index (LAI), altitude, and slope. The study results were analyzed using one-way variance analysis (ANOVA) and Duncan test with a 95% confidence level. The results showed that S. platyclados significantly had a higher diameter (32.7 cm), height (19.1 m), and mean volume (0.43 m3) compared to S. pinanga. The growth of S. platyclados, which locally known as meranti bukit is strongly supported by conditions in Gunung Dahu Research Forest, which has an altitude of about 800 m.asl. On the other hand, S. pinanga, as lowland species, showed lower growth compared to S. platyclados.

Susilowati A, Rachmat HH, Elfiati D, Hidayat A, Hadi AN, Zaitunah A, Nainggolan D, Ginting IM. 2021. Floristic composition and diversity at Keruing (Dipterocarpus spp.) habitat in Tangkahan, Gunung Leuser National Park, Indonesia. Biodiversitas 22: 4448-4456. Dipterocarpus spp., or locally known as Keruing, is a wood-producing tree and has high economic value. Keruing also produces derivative products in oil and oleoresin, which are widely used as raw materials for medicines and perfumes. Keruing natural population has been severely declining caused by habitat alteration and also over exploitation. Therefore, information on the composition and diversity of the floristic community at their habitat is important as an initial step in designing conservation actions. This study aims to determine the floristic composition and diversity at the keruing habitat in the Tangkahan area, Gunung Leuser National Park (Gunung Leuser NP). A line transect has been used to establish a purposive sampling in particular forest areas where the population of the keruing is known to grow naturally. Four line transects, each with five nested plots, totaling 110 plots, were established to gather data at four growth stages. The results found 47 species at the seedling stage, 43 species at the sapling stage, 48 species at the pole stage and 65 species at the tree stage. There were three species of keruing in the research location, namely Dipterocarpus haseltii, Dipterocarpus costulatus and Dipterocarpus elongatus Korth with low IVI values ??at each stage. D. haseltii was only found at the seedling, pole and tree stage with IVI values ??of 0.32, 0.30, and 6.90, respectively. D. costulatus was only found at the tree level with an IVI value of 3.43, while D. elongatus found at the sapling and tree stage with an IVI of 0.30 and 3.42, respectively. The diversity index in the research location was in the medium category at the seedling, sapling, and pole levels with a value of 2.96, 2.86, and 2.92, respectively and was classified as high at the tree level with a value of 3.18. The evenness index (E') in all growth stages is high or evenly distributed with the value of E' > 0.75. The species diversity in research location classified into medium-high category although in each stage showing dynamic on species domination. Disturbed habitat due to illegal logging and land conversion caused a problem on keruing regeneration. Conservation efforts, including active monitoring keruing occurrence, ex-situ conservation, and artificial regeneration, are needed to avoid keruing from extinction.

Gunung Dahu Research Forest (GDRF) is a 250 ha tropical degraded land reforested by native dipterocarps species. The reforestation success was valued by evaluating the planted trees’ growth performance, their potential timber stock, natural regeneration capacity, soil improvement, biological interdependence, and environmental services. This scientific report used a combination of literature review and also primary data processing to describe the reforestation success within the area. A hilly species of Shorea platyclados showed the best growth performance with its average diameter and height of 43 cm and 23 m, respectively, with its mean diameter annual increment of 2.1 cm/year and the predicted standing stock at 220 m3/ha. Six Shorea species were identified to show their natural regeneration capacity and the occurrence of ectomycorrhizal fruiting bodies, predominantly by the genus Rusula, determined the establishment of biological interdependency at the site. Reforestation improved soil organic matters as revealed by high soil porosity (51.06–52.32%) and infiltration rate (120–155.33 mm/h). The reforested landscape also ensures a continuous water supply and provides an economic benefit for the community. Thus, planting native trees for reforesting degraded tropical landscapes is prospective and may deliver multiple benefits in an ecological and economic view.

Soil organic matter (SOM) is a crucial component of soil, through which physical, chemical, and biological characteristics interact in a local context. Within the forest category, the conversion of natural forests to monoculture plantations has raised concerns in Indonesia over the loss of soil functions, similar to conversion to agriculture. In natural forests, SOM can accumulate as part of a closed nutrient cycle with minimal nutrient losses; in plantation forestry, SOM decline and recovery can alternate over time, associated with larger nutrient losses. We reviewed existing studies to quantify how shifts from natural forests to short-rotation plantation forests (SRPF) affect SOM dynamics, soil nutrient contents, and soil-borne pathogens that cause disease. The review combines descriptive and quantitative methods (meta-analysis). The results show that conversion affects the soil C balance, soil structure and water balance, soil nutrient balance, and soil-borne diseases. Contributing factors include the reduced diversity of plant and rhizosphere communities, lower annual litter production, more uniform litter quality, and nutrient removal at the harvest cycle. Conversion from natural to plantation forest conditions also increases plant disease incidence by changing biological control mechanisms.

The benefits of revegetation provided by the successful growth of planted vegetations. This paper described a successful initiative on the revegetation of tropical degraded land using native trees. More than 250 hectares of intact landscape in Gunung Dahu, West Java—Indonesia have been successfully revegetated using 32 Dipterocarp species. The success of this 20-years-old revegetated landscape was revealed by timber volume, natural regeneration, soil characteristics, ectomycorrhiza occurrence, and ecotourism potential. The results showed that the average diameter and height were varied from 12–43 cm and 10–23 m; diameter mean annual increment were at 0.6–2.1 cm year−1; standing stock per hectares were at 10–220.84 m3 ha−1. The variations might be caused by different planted species, spacing distance, and planting technique. The natural regeneration success was observed by the offspring’s occurrence from six Shorea species and supported by mycorrhiza fruiting bodies predominantly by the genus Rusula. Planted trees also improved the availability of organic materials to the soils, as described by the good total soil porosity (51.06–52.32%) and infiltration rate (120–15,533 mm hour−1) at the site. The landscape also provided springs with continuous water supply and allowed tourists to experience the serenity of the tropical forest. Hence, revegetation using a native tree is prospective and proven to deliver a wider benefit in the ecological, economic, and social aspect.

One of the rehabilitation efforts undertaken by the Forest Research and Development Center in Bogor was to establish a mixed meranti(Dipterocarp) forest in the Gunung Dahu Research Forest, Bogor - West Java. The rehabilitation activities adopted several planting techniques, including total and line planting, used several types of red meranti (Shorea spp.). The purpose of this study was to assess the success of rehabilitation effort by analyzing the growth performance of Shorea leprosula and Shorea selanicastands in which applying total and line planting techniques. Diameter and height, as well as environmental factors such as soil texture, average litter thickness, slope, the average thickness of topsoil, and canopy density, were plant growth parameters that were observed. Growth data analysis was performed using ANOVA and followed by Duncan's test. The results showed that planting techniques affected the diameter growth. The highest growth rate was found in S. selanicaspecies with line planting techniques with the average diameter and height increment was 1.13 cm/year and 0.78 cm/year. Line planting techniques also scored the highest value of basal area and stand volumes, 0.06 m2 and 0.64 m3per year for S. leprosulaand 0.06 m2and 0.66 m3per year for S. selanica.

Susilowati A, Rachmat HH, Elfiati D, Hasibuan MH. 2019. The composition and diversity of plant species in pasak bumi’s (Eurycoma longifolia) habitat in Batang Lubu Sutam forest, North Sumatra, Indonesia. Biodiversitas 20: 413-418. Pasak bumi (Eurycoma longifolia Jack) is one of the most popular medicinal plants in Indonesia. Currently, E. longifolia is being over-exploited due to its potential and popularity as herbal medicine and its high value in the market. Therefore, the study on the population structure of the species and habitat characterization is required to ensure successfulness of conservation of this species. The study was carried out in lowland forest, located in Limited Production Forest within the Register Number 40, situated administratively in Papaso Village, Sub-District of Batang Lubu Sutam-Padang Lawas, North Sumatra, Indonesia. Batang Lubu Sutam forest is known as a source of pasak bumi material in North Sumatra. Every year tons of pasak bumi are collected from this forest and exported to Malaysia and surrounding countries. Due to illegal harvesting for its roots, pasak bumi has been seriously depleted in some areas in Batang Lubu Sutam forest. Therefore, current data on its population are needed for conservation effort of Batang Lubu Sutam's pasak bumi. The objectives of this study were to assess the structure of forest where pasak bumi grows and to determine the correct management for sustainability the future stocks. Vegetation analysis was carried out purposively in four transect belts, each consisting of five quadrats or plots. The results showed that the Importance Value Index of pasak bumi at seedling, sapling, pole and tree stages was 21.26%, 9.147%, 0, and 0 respectively. The Shannon Diversity Index (H) ranged between 3.050 and 3.220 and was inside its common value distribution. The evenness index was high, more than 0.85, at all stages of plant growth. The disappearance of pasak bumi at pole and tree stages indicates threatening condition for the sustainability of pasak bumi in the study sites because of excessive harvesting.

Mangroves are an important ecosystem that provides valuable social, economic, and environmental services. Indonesia has placed mangroves on its national priority agenda in an important effort to sustainably manage this ecosystem and achieve national climate commitments. However, mangrove management is faced with complex challenges encompassing social, ecological, and economic issues. In order to achieve the government’s commitments and targets regarding mangrove restoration and conservation, an in-depth study on and critical review of mangrove management in Indonesia was conducted herein. This work aimed to provide a comprehensive analysis of the challenges and strategic recommendations for sustainable mangrove management in Indonesia. SWOT analysis was carried out to understand the strengths, weaknesses, opportunities, and threats related to mangrove management in Indonesia. To address these gaps, we reviewed the existing policies, current rehabilitation practices, environmental challenges, and research and technology implementations in the field. We found that strategies on mangrove ecosystem protection, such as improving the function and value of mangrove forests, integrating mangrove ecosystem management, strengthening political commitments and law enforcement, involving all stakeholders (especially coastal communities), and advancing research and innovations, are crucial for sustainable mangrove management and to support the national blue carbon agenda.

Kapur (Dryobalanops aromatica) is an important dipterocarp species currently classified as vulnerable by the IUCN Red List Threatened Species. Science-based conservation and restoration efforts are needed, which can be supported by new genomic data generated from new technologies, including MinION Oxford Nanopore Technology (ONT). ONT allows affordable long-read DNA sequencing, but this technology is still rarely applied to native Indonesian forest trees. Therefore, this study aimed to generate whole genome datasets through ONT and use part of these data to construct the draft of the chloroplast genome and analyze the universal DNA barcode-based genetic relationships for D. aromatica. The method included DNA isolation, library preparation, sequencing, bioinformatics analysis, and phylogenetic tree construction. Results showed that the DNA sequencing of D. aromatica resulted in 1.55 Gb of long-read DNA sequences from which a partial chloroplast genome (148,856 bp) was successfully constructed. The genetic relationship was analyzed using two selected DNA barcodes (rbcL and matK), and its combination showed that species of the genus Dryobalanops had a close relationship as indicated by adjacent branches between species. The phylogenetic tree of matK and the combination of the matK and rbcL genes showed that D. aromatica was closely related to Dryobalanops rappa, whereas the rbcL gene showed group separation between D. aromatica and D. rappa. Therefore, a combination of the matK and rbcL genes is recommended for future use in the phylogenetic or phylogenomic analysis of D. aromatica.

Susilowati A, Rachmat HH, Elfiati D, Kholibrina CR, Kusuma YS, Siregar H. 2019. Population structure of Cotylelobium melanoxylon within vegetation community in Bona Lumban Forest, Central Tapanuli, North Sumatra, Indonesia. Biodiversitas 20: 1681-1687. In many forests stand, Cotylelobium melanoxylon is hard to find in the wild at present day because its bark has been intensively harvested for traditional alcoholic drink and sold by kilogram in traditional market in North Sumatra and Riau. This activity has put the species into serious threats of their existence in their natural habitat. We conducted study to determine the population structure of the species at seedling to tree stage in Bona Lumban Forest, Central Tapanuli. We used purposive sampling by making line transect at forest area where C. melanoxylon naturally grow. There were four transects with each transect consisted of five plots in which nested plots were established to record data at four growth stages, resulting in 80 plots in total. The result showed that the Important Value Index (IVI) for C. melanoxylon were 66.33, 17.65, 11.82, 12.90; Diversity Index (H) were 2.9, 1.90,2.88, 2.53 and 12.90, Index of evenness (E) were 0.844, 0.534, 0.85, 0.935 and the Index of Richness (R) were 5.71, 7.13, 5.37, 3.67 for the stage tree, pole, sapling, and seedlings, respectively This result demonstrates that C. melanoxylon still grows naturally in Bona Lumban at all stages from tree to seedling. However, there might be a problem in its natural regeneration as there is big difference of its high IVI at tree stage compared to IVI value for its younger stages. The regeneration status of C. melanoxylon was also classified into fair. This might be generated from the condition that the existing mature trees remaining were no longer productive and healthy due to excessive harvesting for its bark.

Shorea divided into four groups: Shorea Red Meranti, White Meranti, Yellow Meranti and Balau. In the past, conservation was not an important issue as this groups were common and abundant. However, Sumatran rain forest were cleared and converted at annual rate of 500.000 Ha with the most extensive in the Province of Riau where had lost 63% between 1985 and 2009. This study conducted to determine the potency and availability of most valuable tropical Shorea dipterocarps in Riau Province. Lines transect and point count methods used to determine the presence any of the Shorea species in the designated remnants area. Leaves samples for morphological identification collected for further taxonomic identification. Data analysis for mapping conducted by overlying the secondary and primary data source. The result showed that the patchy remnants forests in Riau still conserve at least of around 22 Shorea species, included 14 species those of Shorea Red Meranti, 1species Shorea White Meranti, 4 species Shorea Yellow Meranti, and 3 species of Shorea Balau. However, in average the numbers of individual found for each of the species was low with uncomplete occurrence of the life stage in several spots, showing the fragility of local species loss and extinction.