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This study reconstructed historical monthly rainfall data at 24 observation stations in Sumatera, Indonesia, for 22 years (1879–1900) during the Dutch colonial era. The literature research was conducted in libraries in Indonesia and the Netherlands to collect meteorological data recorded in a series of Regenwaarnemingen in Nederlandsch-Indië, which have never been reconstructed or analyzed previously. The results showed that the six western coast stations (97°–103°E, 3°N–4°S) have abundant rainfall exceeding 3000 mm yr−1, and the 10 eastern coast stations and three stations east of the Barisan ridge obtained rainfall below 3050 mm yr−1. Abundant coastal rainfall appeared only along the western coast, but not in the eastern coast and east of the Barisan ridge. The El Niño events of 1888/89 had low impact on rainfall amounts during the dry season (May–October) at the six stations of the Southern Hemispheric climate type. A significant decrease in annual dry-season precipitation was observed in 1881, 1885, and 1896. When comparing monthly data for 1931–60 and 1971–2014 at the northernmost station Banda Aceh (5.5°N, 95.3°E) and the eastern coast station Bengkalis (1.5°N, 102.1°E), a noticeable decrease and increase occurred in June–December and January–May, respectively, throughout the last century. The recent El Niño events have resulted in a decline in rainfall and dry conditions in Sumatera, but the Indian Ocean dipole had much influence on the amount of rainfall in the late-nineteenth century.

Data assimilation (DA) is the overarching term for an ensemble of techniques to combine all possible information (models, observations, a priori data and statistics) to obtain the best possible estimate of the state of a system (Zhang & Moore, 2015). Data assimilation has its origins in meteorology and found its way into operational weather forecasting, oceanography and hydrology, but it is also a valuable technique for estimating variables related to crop growth (soil moisture, LAI (leaf area index), biomass, etc.) by combining models and observations of crop variables.

Tropical peat swamp forests that started to experience fires in the 1960s in Sumatra and in the 1980s in Kalimantan are now seriously degraded in many places in Indonesia. But from a longer perspective, we can see the tropical peat swamp forests’ resilience and adaptation. There have been several reports on how deep local knowledge has helped curb further degradation of these forests. Large-scale commercial logging had been undertaken in the Riau area in Sumatra in the 1860s; however, no serious peatland degradation and large-scale fires were reported until the end of the colonial era. Truly serious degradation started only in the middle of the 1980s when large-scale drainage systems were created to support the extensive cultivation of oil palm and timber plantations. Serious fires broke out in 1997, and in 2015 at the time of El Niño. Today only 18.4% of total peatlands in Indonesia are undisturbed natural peatland forests. We also find several initiatives to restore degraded peatlands. For one thing, the government has established the Peatland Restoration Agency (BRG) to coordinate the acceleration of peatland restoration and promote the welfare of local people in the peatland area. For another, international organizations, companies, nongovernment organizations, and local communities also have started their respective programs to rehabilitate the peatlands. Such developments can be interpreted as attempts at transformation, that is, the creation of a fundamentally new system in response to ecological, economic, or social (including political) conditions that render the existing system untenable. This volume intends to reshape the discussion on peatland degradation and regeneration with the ideas of vulnerability, resilience, adaptability and transformation, and deepen the understanding of degradation and regeneration.

Indonesia created a breakthrough in peatland management by establishing the Peatland Restoration Agency in early 2016 with the aim of restoring 2.67 million ha of degraded peatlands. This effort is intended to accelerate the recovery of peatlands and return of its hydrological functions after extensive damage by fire, drainage canals, and other external factors. This paper highlights the potential biomass and carbon resources in various land-use covers located in the Riau Biosphere Reserve. It discusses the results of restoration experiments conducted in severely degraded peatlands, and estimates carbon emission reductions in targeted priority areas. The total estimated emission reduction in natural forests was higher than in logged-over forests and disturbed forests: 207.36 CO2 Mg h−1, 161.48 CO2 Mg h−1, and 65.87 CO2 Mg h−1, respectively. The restoration of 2.3 million ha of targeted peatland ecosystems was estimated to have reduced carbon emissions by 98.77–153.53 Mt CO2e. The value of carbon from peatlands is considered important for maintaining ecological function while optimizing economic benefits. We have confirmed that above ground carbon storage can be restored even in severely degraded peatlands. Avoiding vegetation loss is an important aspect of restoration activity, but recovery of vegetation in degraded areas depends on below-ground carbon stocks, as these are indicative of fertile soils in various kinds of land cover and use.

Termites are the major ecosystem service providers and contribute significantly to soil processes and nutrient cycling in tropical ecosystems. The ecological services provided by termites are often discredited due to their commonly-regarded status as pest in human-dominated landscapes, however. In order to understand the potential roles of termites in peatland ecosystems, termite samplings were conducted in abandoned degraded peatland and peatland cultivated with oil palm in Riau, Sumatra. Surveys found a total of six species of termite of the family Rhinotermitidae. (rhinotermitid) in study plots of disturbed lands. In particular, Coptotermes spp. are notorious pests to oil palm, and may also be a potential pest in indigenous tree replanting programs. Based on analysis of termite feeding groups and documentation of wood susceptibility to termite attack, this study provides a reference of tree species that must be avoided in indigenous tree replanting programs so that the trophic relations of termite populations are of most benefit to peatland soil biodiversity and thereby to resilient peatland ecosystems.

Ecological restoration of peatlands leads to the destruction of peatland ecosystems caused by human activities, whether intentional or not. As a result of the damage caused various kinds of problems such as land fires. Tanjung Leban Village is one of the villages with a fairly high rate of fire, especially in 2012, 2013, and 2015. Many burnt lands are left unused, which in turn becomes a fire-prone area due to the lack of control over the land. In response to this, it is necessary to carry out peatland ecological restoration activities in Tanjung Leban Village through revegetation activities. Implementation of activities with the mentoring method through village facilitators stationed in Tanjung Leban Village. The implementation process begins with socialization, which continues with group formation, procurement of seeds, land clearing, and planting. The implementation of this revegetation focuses on the participation of the community who are members of the Peat Care Community Group (MPG) in Tanjung Leban Village. This activity was carried out in the community area (group members) with an area of 14.7 ha and 14,381 plants. The number of plants is divided into 2 categories, namely natural wood species and fruit plants.

There is increasing interest in the use of unmanned aerial vehicles (UAVs) as cost-effective, high-resolution alternatives to satellites for the environmental monitoring of large areas. In this stu...

fires in Indonesia. About thirty percent of the total fires are spread in Central Kalimantan Province. Symptoms of climate change in the form of increasingly frequent weather and extreme climate phenomena support the severity of forest and land fires which results in increased release of air pollution gases. In 2015, the peak fire months had emitted a high concentration of air pollutant gasses and causes hazardous air pollution. This study aims to investigate the latest severe fire occurrence and haze conditions in Central Kalimantan. Hotspot data was from 2006 to 2017, visibility data were from four times of El Niño event, Particle Matter Size 10 (PM 10) data and Pollution Standard Index (PSI) was from very strong El Niño in 2015 comparison to La Niña in 2016/2017. The results showed that the top incidents occurred not only very strong in 2015 but also weak El Niño in 2006. The most of dense hotspots density in the last twelve years (> 50% of fires in the area) found in peatlands in Pulang Pisau, Palangka Raya and Kapuas. Palangka Raya's case, dangerous of APSI with PM10 concentrations of more than 500 µg m-3 occurred for 2 (two) months, from the end of August to the early of November 2015. The maximum peak concentration of PM10 is as high as 3000 μg m-3, which is higher than other fire years. Based on the data obtained, the haze was blanketed Palangka Raya was getting thicker at the end of October. As a result, visibility is decreasingly limited, only around 200 to 900 m during the peak season and air pollution-related-peat fire. Thus, this severe condition could rose multiple effects, which will exacerbate climate change, environmental sustainability and the livelihoods of thousands of peoples.

Central Kalimantan covers an area of 157,983 km2 with more than 2,000 km2 of tropical peatlands, which is one of the buffer regions of Indonesia's new capital government city. However, the sad story is the conversion of about one million hectares from peat swamp forests (PSF) to rice fields occurred in the mid-1990s, so called the Mega Rice Project (MRP). Since then, forest and peatland fires become an annual event due to high level of degradation under the climate change symptoms such the frequent of the El Niño event. In very strong El Niño of 2015, Indonesia has returned to the world spotlight in relation to the fires and the haze crisis. The most fire prone area was recorded in the iconic Tumbang Nusa, Pulang Pisau Regency and its adjecent areas. However, the thick haze had covered almost the entire province. There are the dis-adventages impact during more than two months. Therefore, this study was to investigate what are the causes and the impacts of this disaster at the site level. This research location was focuses on three regencies and one city namely Pulang Pisau, Kapuas, Katingan and Palangka City. The method was a Focus Group Discussion (FGD) with key figures representing eight clusters of village communities. This method is also supported by statistical, hotspots and spatial data for additional analysis. The result are only two villages with very high average of hotspot and eight with high average of hotspots in Pulang Pisau and Kapuas Regency. Further, the FGDs in seven villages showed that there were three main clusters that caused forest-land fires, namely natural factors, human factors and village policy / regulation factors. The villages study that were affected by the fire in 2015 showed there were three main impacts namely on people, environment and capital. This result is a foundation of cause-effect factor for further Root Cause Analysis to find out the options for fire prevention and management in climate change mitigation efforts. Keywords: Climate Change; El-Niño; Fires; Focus Group Discussion; Peatland

Forest fires in peatlands emit pollutants to the atmosphere, affecting public health. Though air quality data and epidemiology information are helpful in the management of the environment and public health, they are not always available. We aimed to reveal the utility of newspaper articles for estimating the public health concerns posed by air pollution. Using the database of a local newspaper, Riau Pos, in Riau Province of Sumatra, Indonesia, we have studied spatiotemporal correlations between publication frequency of newspaper articles mentioning search terms relevant to health issues and Fire Radiation Power (FRP) of peatland fires. FRP from one of the NASA satellite databases has been used as an index of air pollution caused by peatland fires. Visibility data for airport operation were also used as an index of particulate matter concentrations. The study regions are primarily the fire-prone Riau Province and nearby areas in the central area of Sumatra, Indonesia, from 2009 to 2018. Newspaper articles related to public health are found to be associated with FRP and visibility, or regional air pollution.

Biotic and abiotic factors control aboveground biomass (AGB) and the structure of forest ecosystems. This study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam. A data set of 173 1-ha plots from 52 locations in undisturbed old-growth forests was developed. The results indicate that basal area and AGB are closely correlated with annual precipitation, but not with annual temperature, evaporation or hours of sunshine. Basal area and AGB are positively correlated with trees > 30 cm DBH. Most areas surveyed (52.6%) in these old-growth forests had AGB of 100–200 Mg ha−1; 5.2% had AGB of 400–500 Mg ha−1, and 0.6% had AGB of > 800 Mg ha−1. Seventy percent of the areas surveyed had stand densities of 300–600 ind. ha−1, and 64% had basal areas of 20–40 m2 ha−1. Precipitation is an important factor influencing the AGB of old-growth, evergreen broadleaved forests in Vietnam. Disturbances causing the loss of large-diameter trees (e.g., > 100 cm DBH) affects AGB but may not seriously affect stand density.

Pemanfaatan lahan gambut dalam kegiatan pertanian, terutama untuk perkebunan menjadi sorotan akhir-akhir ini, akibat terjadinya kebakaran lahan gambut sebagai penyebab bencana asap selama 18 tahun di Indonesia. Tulisan ini bertujuan menguraikan persoalan penggunaan lahan gambut, kejadian kebakaran, dan restorasi lahan gambut dari perspektif sosial ekonomi. Telah dilakukan penelitian dengan pendekatan studi kasus di Desa Tanjung Leban, Kecamatan Bandar Laksamana, Kabupaten Bengkalis, Provinsi Riau. Pengumpulan data dilakukan dengan cara wawancara terstruktur dan mendalam, FGD, dan observasi partisipatif dengan cara tinggal bersama masyarakat. Dari data yang dikumpulkan, dapat dikatakan bahwa persoalan lahan untuk pertanian adalah kompleks, terutama persoalan kepemilikan lahan oleh orang luar Desa. Masyarakat pada umumnya latah melakukan budidaya tanaman sawit, namun sayangnya lahan selalu terbakar secara berulang. Kemudian ada upaya kegiatan restorasi gambut, sebagai usaha pemulihan lahan gambut terdegradasi akibat kekeringan dan kebakaran. Akan tetapi kegiatan restorasi tidak mudah dilakukan, dimana masyarakat merasakan bahwa restorasi adalah pilihan yang baik untuk menghindari kebakaran lahan gambut berulang, namun mereka mempertanyakan keuntungan ekonomi langsung dan kendala teknis seperti banjir yang mengganggu tanaman sawit yang dibudidayakan. Dari studi kasus ini tetap menyisakan pertanyaan upaya strategis apa yag dapat dilakukan dalam kegiatan restorasi gambut guna mendukung pengelolaan lahan yang berkelanjutan.

During the dry period of August–October 2015, a C-band Doppler weather radar of the BMKG station in a fire-prone peatland area, Palangka Raya, detected echoes with reflectivity values between − 19 and + 34 dBZ at a height below 2–3 km and a slant range of 100 km. The MERRA-2/NASA atmospheric reanalysis database is used to obtain the vertical profiles of refractive index and equivalent potential temperature of the air. The temporal variation of the radar image is due to the tropical diurnal cycle of planetary boundary layer formation, which is consistent with the results of the database analysis. The echo images are discussed in terms of Bragg scattering of microwaves at the top of the planetary boundary layer. Weather radar monitoring of the fire smoke layer-top images has a potential feasibility to support real-time management of peatland fires.

JICA Partnership Project (JPP) “Restoration of Peatland Ecology and Livelihood Improvement through Rewetting and Revegetation toward the Prevention of Peat Fires” has been conducted in Tanjung Leban village, Riau province, Indonesia since 2017. Peatland restoration was attempted by encouraging villagers to manage water and ecosystem through weir construction and revegetation, respectively. The villagers aim for the coexistence of environmental restoration and livelihood improvement by planting native species suitable for peatland along with cash crop cultivation.

Most tropical forests outside protected areas have been or will be selectively logged because the timber industry is a main income-generating resource for many developing countries. Therefore, understanding the composition of commercial timber species and logging types is key for sustainable forest management in countries like Vietnam as they move toward fulfilling Reducing Emissions from Deforestation and Forest Degradation (REDD+) agreements. Seven 1-ha plots were surveyed in the Central Highland of Vietnam, and 18 commercial tree species from these plots, whose timber is widely used by local people for housing and furniture making and timber is easily sold at local markets for high prices, were analyzed. In total, 151 tree species with a diameter at breast height (DBH) of ≥ 10 cm were recorded. The 18 commercially valuable species assessed in this study accounted for 33.2% of all stems (total of 524 stems ha−1 for all species), 47.1% of basal area (total of 34.35 m2 ha−1 for all species), and 50.8% of aboveground biomass/AGB (total of 262.68 Mg ha−1 for all species). Practicing diameter-limit harvesting of all commercially valuable species with DBH of ≥ 40 cm, which is widely performed in Vietnam, will reduce the number of stems by 7%, basal area by 31.6%, and AGB by 38.2%. Because such harvesting practices cause severe ecological impacts on the remaining forest, logged forests may require > 40 years to recover the structure status of a pre-logged forest. In addition, the recovery of the 18 commercially valuable species may require a much longer time because they comprised 33.2% of stems. Permission for logging natural forests should be given in Vietnam to sustain lives of local communities, where logging has been prohibited. However, alternative harvesting systems, such as reduced-impact logging systems, should be considered. The systems selected must simultaneously generate economic returns for local people and respect the REDD+ agreements with regard to protecting biodiversity and reducing carbon emissions.

The intensive agricultural practices used in coffee plantations have profound impacts on invertebrate biodiversity. We surveyed termite diversity in the central highlands of Vietnam and evaluated it relative to the in situ ecological conditions of the coffee farms. Two survey sites were established at farms that were in place for 1 month and 1, 3, 5, and 25 years at the time of sampling. In addition, two models were tested: the diversity–resource relationship and the diversity–disturbance relationship. Our results demonstrated that the loss of termite diversity due to land perturbation in newly cultivated coffee farms may be as high as 86% compared with the nearest forested site. Only two feeding groups of termite (Group II and Group III) were present in the study sites. Termite composition of young and old farms was similar, but they only shared 48% similarity and differed significantly from the composition of the 1, 3, and 5 year old coffee farms. Understory vegetation cover and moisture content were positively associated with the occurrence of Group II and III termites but negatively associated with soil bulk density. Termite species richness did not increase linearly with the increased biomass production (plant litter) that is characteristic of old coffee farms. In contrast, termite species richness and occurrence were related to the intensity of farm management. Farms subjected to an intermediate level of management intensity due to annual crop cultivation recorded the highest diversity. Our study highlights the importance of annual crop cultivation to enhance termite diversity.

Forest ecosystems can modify the atmospheric CO2 through biomass accumulation mostly in tree stems with diameter at breast height (DBH) ≥ 10 cm. Aboveground biomass increment (ΔAGB), and changes in stand AGB, no. stems and basal area (BA) were calculated from mortality, recruitment, and growth data of tree stems in tropical evergreen broadleaved forest, Central Highland Vietnam. Data were derived from ten 1-ha permanent plots established in 2004, where all stems with DBH ≥ 10 cm were tagged, identified to species, and measured for DBH in 2004 and 2012. In an 8-year duration, the increment was 53 ± 10 stems ha–1, 7.8 ± 0.3 m2 ha–1 for BA and 86.0 ± 4.6 Mg ha–1 for AGB. The stem mortality rate was 0.9% year–1 and the stem recruitment rate was 2.2% year–1. Annual ΔAGB was 10.8 Mg ha–1 year–1, equaling to 5.4 Mg C ha–1 year–1. Of which, tree stems of 35–80 cm DBH classes accounted for 65%. The results indicated that the forest is in stage of carbon sequestration. Any disturbances causing death of 35–8...

Estimating production of fine roots (diameter ≤ 2 mm) is significant important to understand carbon cycle of forest ecosystem as it may contributes up to 70% of total net primary production. The estimation of fine root production is left behind in many parts, especially in developing countries including Vietnam.

Based on mean rainfall data, Sarawak can be considered as having no very dry season. Rainfall analysis at 14 stations reveals that droughts rarely lasted more than a month in most parts of the Kemena and Tatau river basins in the period from 2006 to 2010. Monthly rainfall

Tropical peat swamp forests in Southeast Asia account for approximately 72% of global peatland. However, extensive forest exploitation following peat drainage for agricultural expansion has been leading to catastrophic peat fires. In this study, we compared the termite assemblage in burnt and unburnt peats in Sumatra, Indonesia. We also identified which taxonomic group is particularly resistant to fire disturbance and the traits that correlate with its persistence in fire-impacted peatlands. Overall, the termite species richness in fire-impacted peats was up to 40% lower than that of the total species found in peat swamp forests. Although the estimated species richness values in fire-impacted peats and peat swamp forests were not significantly different, fire changed termite community structure significantly. Only termites of the family Rhinotermitidae survived in the fire event, whereas members of the Termitidae that were reportedly resilient to fire and open habitats elsewhere disappeared during the fire events. The rhinotermitids found in the burnt sites were exclusively wood nesters. This suggests that the desiccation tolerance of termites in open habitat is not the simple underlying survival strategy, but tree branches and barks might have provided a refuge from heat during fire. The result also suggests that the high similarity in species composition in recently burnt peats and long burnt peats implies low species turnover. Thus, regardless of how much time had passed since the fire-impacted peats were abandoned or cultivated, the increase in habitat complexity did not favor colonization by the forest-dependent group.

Chestnuts have historical importance as a food source worldwide. Planting of chestnuts has focused on a few species, including Castanea dentata, Castanea sativa, Castanea mollissima, and Castanea crenata, although others species are also edible. Castanea species are members of the beech family (Fagaceae) and are native to tropical and temperate areas. In this study, the yield and nut quality of Castanopsis piriformis in natural forests of the Central Highlands of Vietnam were investigated to provide evidence that C. piriformis is worth growing as a food species. Data were collected from 12 plots of 50 m × 50 m size located in four altitude zones. Nuts were collected from three to five chestnut trees in each plot judged to be of typical sized based on diameter at breast height and crown diameter. Average dry yield of nuts was found to be elevation-dependent, being highest at 500–1000 m (1152 kg/ha/year), decreasing to 815 kg/ha/year below 500 m, and to 770 kg/ha/year at 1000–1500 m. The lowest yield was observed at above 1500 m (252 kg/ha/year). Protein and lipid contents in the kernels of C. piriformis chestnut were 4.4 and 0.1 %, respectively. Glucose accounted for 73.1 % and was significantly higher than that of commercially grown Castanopsis boisii chestnuts in Northern Vietnam. With the current price of 0.6 US$/kg nuts, collecting nuts growing in natural forest can bring at least 480 US$/ha/year to local people. These results indicate the possibility of growing and consuming C. piriformis chestnut as a crop to decrease poverty. However, governmental support is required for the sustainable development of C. piriformis.

Previous discussion about the factors of the expanding trend of abandoned cultivation had focused only on universal factors and lacked evaluation of the regionality of the phenomenon. This paper demonstrated the Toraja’s regional characteristics and the influence of cultural endemism on decision-making about abandoning cultivation by an observation-oriented approach. Based on a causal framework constructed by field observation and geospatial data generation, an adjustment for overt covariates using the multivariate logistic regression model to draw the causal effect from hidden covariates was examined in two rice terraces with different water systems, i.e. irrigated field and rain-fed field. The result of sub-group analysis revealed that decisions about abandoning cultivation in Toraja were greatly associated with disadvantageous factors for intensive farming, i.e. “number of adjacent fields” and “soil erosion” rather than advantageous factors, i.e. “area of field” and “distance to roads”. Moreover, the result of interaction analysis which controlled the effect of topography revealed the powerful effect of particular decision factors only in rain-fed rice terrace: the “distance to roads” factor’s fairly negative contribution on abandoning cultivation (Odds ratio = 9.94E - 01, P value = 2.03E - 11), as well as the “number of adjacent field” factor’s positive contribution on abandoning cultivation (Odds ratio = 1.13E+00, P value = 3.65E - 04). Given the evidence from the explanation of these results by customary laws and land inheritance system for each site, therefore, it could be concluded that the screening and detection of cultural endemism’s influence was achieved using the algorithm this paper proposes.

The high demand for unmanned aerial systems (UASs) reflects the notable impact that these systems have had on the remote sensing field in recent years. Such systems can be used to discover new findings and develop strategic plans in related scientific fields. In this work, a case study is performed to describe a novel approach that uses a UAS with two different sensors and assesses the possibility of monitoring peatland in a small area of a plantation forest in West Kalimantan, Indonesia. First, a multicopter drone with an onboard camera was used to collect aerial images of the study area. The structure from motion (SfM) method was implemented to generate a mosaic image. A digital surface model (DSM) and digital terrain model (DTM) were used to compute a canopy height model (CHM) and explore the vegetation height. Second, a multicopter drone combined with a thermal infrared camera (Zenmuse-XT) was utilized to collect both spatial and temporal thermal data from the study area. The temperature is an important factor that controls the oxidation of tropical peats by microorganisms, root respiration, the soil water content, and so forth. In turn, these processes can alter the greenhouse gas (GHG) flux in the area. Using principal component analysis (PCA), the thermal data were processed to visualize the thermal characteristics of the study site, and the PCA successfully extracted different feature areas. The trends in the thermal information clearly show the differences among land cover types, and the heating and cooling of the peat varies throughout the study area. This study shows the potential for using UAS thermal remote sensing to interpret the characteristics of thermal trends in peatland environments, and the proposed method can be used to guide strategical approaches for monitoring the peatlands in Indonesia.

Tropical peatlands in Indonesia have been disturbed over decades and are a source of carbon dioxide (CO2) into the atmosphere by peat respiration and peatland fire. With a portable solar spectrometer, we have performed measurements of column-averaged CO2 dry-air molar mixing ratios, XCO2, in Palangka Raya, Indonesia, and quantify the emission dynamics of the peatland with use of the data for weather, fire hotspot, ground water table, local airport operation visibility and weather radar images. Total emission of CO2 from surface and underground peat fires as well as from peatland ecosystem is evaluated by day-to-day variability of XCO2. We found that the peatland fire and the net ecosystem CO2 exchange contributed with the same order of magnitude to the CO2 emission during the non-El Niño Southern Oscillation year of July 2014-August 2015.

Tropical peatland, which dominantly distributes in Indonesia and Malaysia, has experienced recurring fires in the last few decades. Constraining the enhancement ratios and emission factors of gas and particulate matter emitted by the wildfires is necessary to evaluate their environmental and climatic impacts. We analyzed continuous observation data at Pekanbaru in Indonesia and Muar in Malaysia to investigate the emissions of gas and particulate matter. The enhancement ratios of particulate matter to carbon monoxide (PM10/CO) of wildfires in Riau province in June 2013 and February–March 2014 were analyzed. The PM10/CO ratios of peatland burning plumes ranged from 77 to 97 μg mg−1 for the event in June 2013, whereas the corresponding value was 127 μg mg−1 in February–March 2014. These enhancement ratios were translated to the emission factors of particulate matter using previous data on the emission factors of CO, assuming that secondary formation was ignorable. The estimated emission factors for PM10 were 13 ± 2 g kg−1 (2013) and 19 ± 2 g kg−1 (2014). These values are comparable to those reported by recent field observations in Indonesia and Malaysia (17.3 ± 6.0 to 34.4 ± 18.8 g kg−1). The estimated emission factors from both the present study and recent field work are consistently higher than that used in the current emission inventory, which suggests that it should be updated. A caveat for this analysis is possible influence of secondary formation, which will still be needed to be investigated in future studies. NRF (Natl Research Foundation, S’pore) Published version

The rapid development of the Vietnamese coffee industry caused widespread deforestation, land degradation, desertification, and soil and water degradation in the late 1990s. However, little is known about the impact of intensification of coffee farming on arthropod diversity in Vietnamese coffee agroecosystems. We conducted an in-depth study of the termite presence in five land-uses along a gradient of increased land-use intensity in the Central Highlands of Vietnam: mixed deciduous forest (MF), secondary forest (SF), planted pine forest (PF), rubber plantation (RP), and coffee plantations (CP). The estimated number of termite species decreased along the land-use gradient. In coffee agroecosystems, the termite species richness was 20–50 % lower than that of the forested areas and monoculture rubber plantation. In terms of beta diversity, the termite faunal composition in CP was significantly separated from those of the other land-uses, in which the similarity was only 28.67 %. Litter depth, canopy cover, and wood basal area were positively associated with the termite communities present in MF and SF, whereas the termite community in PF was positively associated with soil bulk density, leaf litter, and understory vegetation. The ecological characteristics in RP and CP appeared to be negatively associated with wood basal area, leaf litter, and understory vegetation where well represented by Ancistrotermes pakistanicus (Ahmad). The sites also supported a few soil-feeding termites [e.g., Dicuspiditermes garthwaitei (Gardner), Pericapritermes latignathus (Holmgren), and Pseudocapritermes sinensis Ping and Xu in RP; only D. garthwaitei in CP].

Agarwood trade has been growing rapidly due to its active ingredients composed of volatile substances, which are widely used in the cosmetics and pharmaceuticals. However, the formation time of agarwood in nature is quite long and little is known about its formation agents and mechanisms in planted Aquilaria crassna trees. In this study, biological, chemical and mechanical treatments were applied to 5-, 8-, and 11-year-old A. crassna plantations in north central, Vietnam. Agarwood samples were collected at 1 and 2 years after treatment. Oil content (Oc) in dry wood of A. crassna and sesquiterpene content in extracted oil were analyzed using hydrodistillation method and gas chromatography–mass spectrometry. The results indicated that 1 year after treatment, control (no treatment) and mechanical treatment (nails hammered to tree stems) had highest Oc (0.061–0.079 %) but lowest sesquiterpene content (2.1–7.1 %). Chemical treatment (mixture of acid sulfuric and sodium methyl bisulfate) had lowest Oc (0.038–0.039 %) but highest sesquiterpene content (15.8–20.8 %). While, 1 year after treatment biological treatments had Oc of 0.050–0.077 % and sesquiterpene content of 2.4–11.1 %. Two years after treatment, control still had lowest sesquiterpene content (3.2–7.0 %), while highest content (13.9–44.2 %) belonged to biological treatment (a mixture of fungi Phialophora spp. and Fusarium spp.). There was a total of 56 sesquiterpenes found in extracted oil from wood samples in biological treatments, which included eight highly commercially-valuable sesquiterpenes on international trade. Biological treatment with a mixture of fungi P. spp. and F. spp. should be encouraged to apply to 11-year-old A. crassna plantation, which resulted in highest sesquiterpene content (44.2 %).

Net primary production (NPP) is an important index for evaluating the patterns, processes, and dynamics of carbon cycling in forest ecosystems. In this study, we estimated the NPP in a warm-temperate old-growth evergreen broad-leaved forest in southwestern Japan. The estimation was based on four compartments: aboveground stand increment (ΔM), aboveground litterfall (Lf), fine-root production (Fr), and coarse root increment (ΔCr). The data for ΔM and ΔCr were collected from a permanent 200 × 200 m2 plot over a 4-year interval, while Lf and Fr were collected over a 1-year interval. The NPP was 4.65 g m−2 day−1, of which ΔM accounted for 25.2 %, Lf accounted for 38.7 %, Fr accounted for 33.4 %, and the remaining 2.7 % was attributed to ΔCr. There was a significant regression between aboveground litterfall and fine-root production (R 2 = 0.65, P

Peatlands have experienced large scale changes due to extensive deforestation for logging, conversion to agro-industrial plantations, and frequent peat fires. The adverse effects of peat fires can lead to long-term impacts on invertebrate biodiversity in the peatland ecosystem. Although the impact of fire on termite diversity in tropical grasslands and savannas has been the focus of increased attention in recent years, little is known about the effects of peat fires on termite assemblages. In this review, we present available information about the impact of human use of peatlands on termite assemblages in the Indo-Malayan region. By synthesizing the currently available studies conducted in temperate and tropical savanna systems, we highlight the need for studies of the relationship between termites and fire-impacted tropical peatlands. We consider the ecological and biological scenarios in fire-impacted peatland that are likely to shape termite assemblages, and we discuss traits of the surviving genera (i.e., Coptotermes, Schedorhinotermes, and Parrhinotermes) that may contribute to their success in the harsh post-fire peatland environment (e.g., colony fusion, colony breeding structure, subsidiary nests, and colony migration). Knowledge of these strategies is crucial for understanding the evolutionary adaptation process of termites. This review also aims to stimulate further research in using termite ecosystem services to restore the fertility of degraded fire-impacted peatlands.

SUMMARY This is the first study on carbon stock estimation in the tropical evergreen broadleaf forests in Central Highland, Vietnam. As result of selective logging and shifting cultivation, remaining forests are silviculturally classified to five categories by governmental standard basing on standing volume (V), including very poor forest (V ≤ 10 m3/ha), poor forest (10 300 m3/ha). Carbon stock of four pools including big trees (diameter at breast height/dbh ≥ 5 cm), short vegetation layer (dbh < 5 cm), necromass, and soil was measured by using 150 plots of 50 m × 50 m each. Soil carbon stock was assessed from soil samples taken to 30 cm depth. The results indicated total carbon stock increased from 75 tons C/ha in very poor forest to 199 tons C/ha in medium forest, and to 255 tons C/ha in very rich forest. Carbon stock in necromass was significant different (ANOVA; F(4,145) = 61.70, p < 0.001) amo...

Ba Vi National Park (BNP) is known as one of the first parks established in Vietnam and has been well pre served against human disturbances. A study was conducted to understand altitudinal changes and aspect differences of species diversity and stand structure in evergreen broadleaf forest in BNP. Twenty plots (40 m x 50 m), distributing between 130 and 1,195 m above sea level were used for stem census, which were equally established in both eastern and western aspects. All stems with diameter at breast height (DBH) ≥ 10 cm were identified to species and measured for DBH. Results indicated significant linear relationships between elevation and basal area (G), top canopy height, species density, Shannon diversity index, and E venness. Elevation zone of > 1,000 m above sea level had highest species density, Shannon diversity index, Evenness, stem density, G, and top canopy height, which were significant higher than that in 500 - 1,000 m and < 500 m elevational zones. Species compo sition in BNP was different between eastern aspect and western aspect, and both aspects shared 86 species in total 219 species found. While, stand structure and species diversity were not significant different between two aspects.

Agroforestry has been practiced for a long time in Vietnam. In this study, the cost - benefit was analyzed in four agroforestry systems, which have been widely established in north mountainous provinces with Star Anise ( Illicium verum ) + t ea (IT), bead tree ( Melia azedarach ) + cassava (MC), Acacia hybrid + cassava (AC) and Acacia mangium + maize (AM). A questionnaire was used to obtain information on (1) Inputs , which included costs for seeds/seedlings, fertil izers, pesticides, and labor costs, and (2) Incomes , which included benefits from selling fruits, leaves, corns, and timbers. The results indicated that IT had the highest economic benefit (6,527 US$ ha - 1 y - 1 ), followed by MC (2,905 US$ ha - 1 y - 1 ), AC (1,043 US$ ha - 1 y - 1 ), and AM (870 US$ ha - 1 y - 1 ), respectively. However, even with such economic benefits, these agroforestry models could not be established across all mountainous regions because of site specific ecological requirements of tree species and crops. In addition, unstable market and fluctuating price of agroforestry product s is a big concern leading to un sustainability of these agroforestry systems. It is recommended that

Fire has become a common feature in tropical drained peatlands, and it may have detrimental impacts on the overall biodiversity of the forest ecosystem. We investigated the effect of fire on termite and ant assemblages and the importance of remnant forest in restoring species diversity in fire-impacted tropical peat swamp forests. The species loss of both termites and ants was as high as 50% in some fire-impacted peats compared to remnant forests, but in most cases the species richness for termites and ants was statistically equal along the land uses surveyed. However, a pronounced difference in functional group composition of termites was detected. In particular, sites close to remnant forests contained two additional termite feeding groups so that they shared a similar composition structure with remnant forests but were significantly different from sites distant from remnant forests. In general, ants were resilient to fire, and the similarity index showed a high degree of similarity among ant communities in all land uses surveyed. The Shannon diversity index for termites and ants decreased with increasing distance from the remnant forests and level of ecological degradation. Peat vegetation variables and ecological degradation were important in shaping termite and ant communities in the tropical peatlands, but their relative importance was not significant in fire-impacted peats regardless of distance from the remnant forests. This study highlights the importance of remnant forests as a biodiversity repository and natural buffer that can enhance species diversity and recolonization of forest-adapted species.

Synthetic aperture radar (SAR) backscatter amplitude image data have proven useful in estimating soil moisture levels and in approximating areas of water inundation over large regions. Based on the pattern of seasonal change in the backscatter coefficient at each image pixel, this study classified a variety of crop fields in Northeast Thailand according to their hydrological characteristics. L-band horizontal-transmit horizontal-receive (HH) polarization images from advanced land observing satellite phased array type L-band synthetic aperture radar (ALOS-PALSAR) at six dates from January to December over the rainy season (May to November) in 2007 were used. Fifteen clusters of pixels were generated using the k-means method, with five variables obtained by taking the difference between the backscatter coefficient for the dry season (January) and the other five dates, effectively removing effects of soil surface roughness. As a result, a detailed spatial distribution of hydrological characteristics that acc...