Sumatra Island Research Articles

A survey of the Sumatran Sparassidae (Araneae). 1. Two new Thelcticopis species

Two new species of Thelcticopis Karsch, 1884 are described from Sumatra Island, Indonesia, based on males: T. lizae sp. nov. and T. ketambe sp. nov. Detailed descriptions, digital photographs and a distributional map are provided. The distribution of Sumatran Thelcticopis is briefly discussed.

New or interesting species of gelechiid moths of the genus <i>Photodotis</i> Meyrick 1911 (Lepidoptera, Gelechiidae) from the island of Sumatra, Indonesia

Two new species of the gelechiid moth genus Photodotis Meyrick are described from Sumatra, Indonesia: P. ketambensis sp. n. and P. kedahensis sp. n. In addition, the species P. crockeri M. Omelko et N. Omelko and P. imperfecta M. Omelko et N. Omelko, both described earlier from Borneo Island, Eastern Malaysia, are recorded from Sumatra for the first time.

Association between long-term PM2.5 exposure and mortality on Sumatra Island: Indonesian Family Life Survey (IFLS) 2000-2014.

The concentration of PM2.5 (particulate matter with a diameter < 2.5µm) on Sumatra Island has increased, mainly because of forest and peatland fires, transportation, and industry. Biomass burning releases partially burned carbon into the atmosphere, resulting in a smoky haze containing PM2.5. Air quality has deteriorated quickly, and PM2.5 has become a major health hazard in Indonesia. Studies on long-term exposure to PM2.5 have indicated its associations with both morbidity and mortality. Here, we measured long-term (2000-2014) exposure to PM2.5 on the basis of satellite-derived aerosol optical depth measurements (1 × 1 km2) used to predict ground-level PM2.5 concentrations. Additionally, population data on Sumatra Island residents from the fourth wave of the Indonesian Family Life Survey (IFLS) were obtained. We investigated the association between long-term PM2.5 exposure and mortality with a retrospective cohort study design. A total of 2409 subjects aged ≥ 40years participated in the IFLS-3 beginning in November 2000, and we examined mortality outcomes until the IFLS-5 in September 2014. We used Cox regression models to calculate hazard ratios (HRs) of mortality associated with PM2.5 exposure. According to the adjusted model, the mortality HRs per 10µg/m3 increase in PM2.5 concentration were 1.10 (95% CI 1.03, 1.17) for all natural causes, 1.17 (95% CI 1.05, 1.25) for cardiovascular causes, and 1.19 (95% CI 1.04, 1.36) for respiratory causes. Long-term exposure to PM2.5 was associated with all-natural, cardiovascular, and respiratory mortality on Sumatra Island, where PM2.5 levels exceed the WHO and US-EPA air quality standards.

A survey of the Sumatran Ctenidae (Araneae). 4. A new species of Acantheis Thorell, 1891 with unique copulatory organs morphology

A new species, Acantheis kazantsevae sp. nov., is described from Sumatra Island (Indonesia) on the basis of both sexes. The male of the new species possesses unusual palp with a twisted tegular apophysis having two arms: a large boomerang-shaped anterior one and a posterior one with a deep cavity. Diagnosis, description and illustrations are provided. Systematic placement of the new species within Acantheis Thorell, 1891 is discussed.

Faktor-faktor yang Mempengaruhi Financial Distress pada Pemerintahan Provinsi di Sumatera

This research aims to examine the factors that influence financial distress in provincial governments in Sumatra in terms of the degree of decentralization, budgetary solvency ratio and growth ratio. The testing method uses a quantitative approach with secondary data on LHP obtained via the BPK RI website in 2018-2022. The population used includes all provinces on the island of Sumatra, totaling 10 provinces for the 2018-2022 fiscal year and each member of the population was taken as a sample using a saturated sampling technique, so that the observation units in this research were 50 samples. This research uses Eviews to analyze the data. The results of the research show that simultaneously there is a significant influence between the variables degree of decentralization, budgetary solvency ratio and growth ratio on financial distress in provincial governments in Sumatra, partially the degree of decentralization has a negative and significant influence on financial distress, while the budgetary solvency ratio has a positive and significant influence on financial distress and the growth ratio does not have a significant effect on financial distress in provincial governments in Sumatra during the 2018-2022 period.

Digital health divide in Indonesia: evidence from national-level data

Abstract Indonesia is a country in south-east Asia with a diverse population and context underlined by its geographical condition as an archipelagic country. Due to closer proximity to the capital, the Western regions (e.g., provinces in Sumatra and Java islands) are relatively more developed than the central and eastern parts of Indonesia (e.g., Nusa Tenggara, Sulawesi, and Papua). In the last few years, the country started to embrace digital transformation for public services including the health sector. Accelerated by the COVID-19 pandemic, a proliferation of digital health services through for example the use of telehealth and health apps is now considered important to improve access and availability of health services, especially among marginalized and hard-to-reach populations. Nonetheless, the difference in access to information and technology infrastructure and services as well as in the level of digital literacy across different regions in Indonesia may perpetuate the existing inequity in access to health services. In 2022, data from the Indonesian Central Bureau of Statistics showed that the level of internet access in Indonesia’s capital Jakarta has reached 85%, while the level in the eastern part of Indonesia (i.e., Papua) is only 26%. Similarly, the level of internet access in the Western provinces tend to be higher than their Eastern counterparts. Additionally, a survey performed by the Ministry of Communication and Informatics to assess the level of digital literacy in Indonesia shows that 85% out of 10,000 respondents accessed the internet through smartphones. However, almost all respondents encounter problems when accessing the internet, especially regarding network quality which causes unstable and frequent connections disconnected. In addition, the level of digital literacy varies across different regions, with the Western region performing better than other regions (e.g., digital literacy index of 3.64 in Yogyakarta vs 3.55 in Papua in 2022).

A Langur from Sumatra

Abstract Researchers interested in the colonial provenance of European natural history collections find themselves currently in an ambiguous position. On one hand, there is a fast-growing amount of digital services that provide them with statistics, names and lists of objects that have been accumulated in former colonial areas and are now stored in natural history museums in the Global North. On the other hand, these digital collection services fail to provide researchers with archival information on historical collection contexts, local names and meanings of animals and plants, and the labour, knowledges, colonial infrastructure and (epistemic) violence that were necessary to move tens of millions of natural objects across the globe. By zooming in on the digital representation of a black-crested Sumatran langur collected on the island of Sumatra (Indonesia) in the 1830s, this short paper reflects on the impact of these data absences on the further development of large-scale data infrastructures in the field. Inspired by earlier problematization of the digital turn in collection-based biodiversity sciences, this paper argues for the more sustained use of archival evidence so as to rethink what it means to infrastructure ‘biodiversity heritage’ collections in a digital age.

Spatial Dynamics Of Tsunami Prone Areas In Kalianda Sub-District, South Lampung Regency

Kalianda Sub-District is one of the areas that is vulnerable to earthquakes and tsunamis because it is located on the west coast of Sumatra Island and the Sunda Strait has a potency from the eruption of Anak Krakatau Volcano. Increasing population growth also increases the risk of disaster impacts that are difficult to predict. This research aims to analyze the spatial dynamics of tsunami-prone areas in Kalianda District. This research uses multi-temporal land cover data, driving data on built-up land development factors, existing roads, slope, distance from the coastline, and distance from rivers. The method used is Cellular Automata Markov Chain which is used to model the development of built-up land, and the Berryman method for tsunami hazard analysis . Based on modeling results for 2031, the type of built land cover will experience a large increase. The tsunami danger level in Kalianda District is dominated by the low level covering an area of 4,741.80 ha, then the high level covering an area of 3,047.29 ha and the medium level covering an area of 1,243.66 ha. According to research results, the number of tsunami-prone areas increases every year. Therefore, we need to improve education and outreach to the public about tsunami dangers and effective evacuation procedures. The development and maintenance of evacuation support infrastructure, as well as the implementation of a reliable early warning system, are also very important to increasing community preparedness for tsunami disasters.

Budget Politics of Aceh Province’s Special Autonomy Fund for Poverty Alleviation

Fifteen years into the implementation of Aceh’s special autonomy, poverty still ranks Aceh the poorest province on the island of Sumatra. The high number and percentage of poverty are due to the budget allocation of the Special Autonomy Fund being allocated to other issues; the allocation of the Poverty Alleviation Special Autonomy Fund over the last five years has not been a priority in the development program in Aceh Province, poverty alleviation being the fourth priority after infrastructure, education and health. This research seeks to discover the factors that become obstacles and ineffectiveness of the Special Autonomy Fund Budget Politics in Poverty Alleviation in Aceh Province. This research uses a qualitative approach with a case study as a research strategy. This research uses three data collection techniques: First, documentation in the form of policy documents, papers, journals, or books from previous research. Second, in-depth interviews. Third, observation. Data analysis techniques used in qualitative research include transcribing interview results, data reduction, data analysis and interpretation. Aceh’s failed poverty alleviation was caused by the government’s failure to address its poverty. Factors contributing to poverty in Aceh’s poverty reduction include lack of poverty-related employment, inadequate government support, insufficient infrastructure and income related to prosperity, low human resource income, insufficient political participation, and corruption.

EID AL-FITR INFLUENCES THE NUMBER OF TRAIN PASSENGERS ON THE SUMATRA ISLAND (CALENDAR VARIATIONS TIME SERIES MODEL)

The Train is one of the transportation options for land travel on the island of Sumatra because of its affordable cost, comfort, and fast mobility. The majority of the population of Sumatra Island who are Muslims influenced the sharp increase in the number of train passengers during Eid Al-Fitr due to the large number of residents who returned to their hometowns (Sumatra Island). The time of Eid Al-Fitr will change every year on the Gregorian calendar, but it is always the same if using the Hijri calendar. This study aims to predict the number of train passengers on the island of Sumatra based on calendar variations (Eid Al-Fitr). To overcome this calendar variation, time series modeling will be used with the addition of exogenous variables (ARIMAX). This model consists of a time series regression equation added with a time series model of the residual regression equation of an exogenous variable. The resulting model can forecast the number of train passengers in the next few months and find that Eid Al-Fitr affects the data. Every Eid Al-Fitr, there is an increase in the number of train passengers by 49 passengers. The model obtained is in the good category with MAPE in-sample of 18.12% and out-sample of 9.93%.

Problem-based learning with library e-resources to enhance student information literacy self-efficacy

PurposeThis study investigates the effectiveness of problem-based learning (PBL) in information literacy curricula using library e-resources to enhance information literacy self-efficacy (ILSE) of students in two universities in Indonesia, in Java Island (University A) and Sumatra Island (University B).Design/methodology/approachA comparison of the effectiveness of the approach in the two universities forms the focus of the study, which has adopted a single group quasi-experimental design which was conducted in one online teaching-learning session. The authors compared the pre-test and post-test scores of 65 library and information science (LIS) students from both universities.FindingsThe results show that the treatment enhanced ILSE effectively. After the treatment, University A students performed better than those at University B.Research limitations/implicationsThe factors which affected the success of PBL using library e-resources have not been identified in this study, a task for a future qualitative research study.Practical implicationsThis study will both inspire the use of library e-resources in learning activities and promote ILSE.Originality/valueIntegrating PBL with library e-resources provides opportunity to identify the advantages of library e-resources in supporting student ILSE, resulting a better learning achievement.

Four in one: An integrative taxonomic revision of the Microhyla berdmorei complex (Amphibia: Anura: Microhylidae) illustrates the tremendous amphibian diversity of Southeast Asia

Abstract Berdmore’s narrow-mouthed frog, Microhyla berdmorei (Blyth, 1856), is the largest member of the genus Microhyla and is distributed all over Southeast Asia, from Northeast India and southern China to Sumatra and Borneo in Indonesia. Here we demonstrate that M. berdmorei represents a complex of four species that are morphologically, acoustically, and genetically distinct from each other, and we implement taxonomic revisions. Phylogenetic analyses of three mitochondrial DNA (hereafter mtDNA, including COI, 12S, and 16S rRNA; 3119 bp) and one nuclear (BDNF; 716 bp) gene sequences are corroborated by phylogenomic analyses of 2700 ddRAD-seq loci (387,270 bp). All support that the M. berdmorei complex, which originates from the early Miocene (ca. 19.7 mya), consists of two clades that we date to the late Miocene (ca. 7.5 mya). The first clade, which regroups populations of large-sized individuals, is distributed in Indo-Burma and includes a lineage from Northeast India, Bangladesh, and Myanmar (M. berdmorei sensu stricto) and a lineage from West Malaysia, Thailand, Laos, Cambodia, and Vietnam (for which we propose to resurrect the species M. malcolmi Cochran, 1927). The second clade, which regroups populations of small-sized individuals, occurs in Sundaland and also includes two lineages for which we provide taxonomic descriptions on species rank. The first new species is widely distributed from Peninsular Malaysia to the islands of Borneo and Sumatra (described herein as M. sundaicasp. nov.), while the second one is restricted to the Malay Peninsula and occurs in extreme southern Thailand and adjacent Malaysia (M. peninsularissp. nov.). We further provide evidence for the synonymy of Callula natatrix Cope, 1867 with M. berdmorei sensu stricto, and M. fowleri Taylor, 1934 with M. malcolmi. Our study illustrates the high diversity of Southeast Asian amphibians, especially in the genus Microhyla, which presently totals 54 species.

Efficiency of Built-up Land Use on the Socio-Economic Conditions of Cities: Case Study of Bandar Lampung City

Dynamic city development has an impact on land consumption levels, as an effort to increase city capacity, so this is not a sustainable option both socially and economically. As one of the provincial capitals on the island of Sumatra and the city closest to the island of Java, the city of Bandar Lampung certainly experiences the same demands regarding the use of built-up land. In identifying these conditions, this article uses a decoupling analysis method of built-up land area, population and local revenue. This research uses NDBI (Normalized Difference Built-Up Index) to describe built-up land, population and LGR (Local Government Revenue) to describe the social and economic conditions of Bandar Lampung City. The results of the NDBI analysis from 2014 to 2022 show that built-up land in Bandar Lampung City has reached 61.67%. In the same period, the city's population increased by an average of 6.01% and Bandar Lampung City's LGR increased by an average of 13.55% in 2022 amounting to IDR 645 billion. In the decoupling analysis of built-up land to population, Bandar Lampung City has an expansive negative decoupling category, so there are indications that the growth of built-up land is not adjusting to the number of residents to be accommodated. In the decoupling analysis of built-up land against PAD, the decoupling index falls into the Expansive coupling category, which means that built-up land and PAD have increased, but the growth of built-up land is higher than the PAD of Bandar Lampung City. In both conditions, it shows that population growth and local income of Bandar Lampung City is still below the growth of built-up land, so it is indicated that the growth of built-up land in Bandar Lampung City is less efficient.

Should developed regions bear more responsibility in addressing environmental issues? Insights from Indonesia's unequal regional development

Addressing environmental issues is inherently complex due to the fundamental question of who should bear the responsibility. While it is more prominent at the global level, this issue is also pertinent at a subnational level, such as in Indonesia, where significant disparities exist in economic development and environmental degradation across the archipelago. Our research intends to fill the gap by measuring environmental footprints in the country by accounting for the interregional trade between provinces. We integrate an Interregional Input-Output (IRIO) model developed by Indonesia's Central Bureau of Statistics with the national sectoral energy input dataset, the blue water consumption vector from EXIOBASE, and the national land use map, creating an Environmentally-Extended Interregional Input-Output (EE IRIO). The study revealed that Indonesia's carbon and water footprints are primarily consumed and produced on Java Island; meanwhile, the agricultural footprint is produced on Sumatra and Kalimantan Island but consumed significantly on Java Island. This result corresponds with Java Island's domination in terms of the economy and population. The study revealed that developed regions produce footprints directly and induce footprint generation in other areas through import demand, emphasizing the relevance of ‘common but differentiated responsibility’ in local development.

Language shift in Aceh: The sociolinguistic situation of post-conflict society

Aceh is a special autonomous province of Indonesia located on the northwest tip of Sumatra Island. Aceh had been in conflict with the Indonesian government for more than 3 decades before officially declaring peace in 2005. This study aims to shed light on the sociolinguistic situation in Aceh during the conflict and following the 2005 peace accord, as well as to provide a deeper understanding of the roots of Aceh’s rapid language shift. Based on focus groups with young people and young parents, as well as follow-up interviews with members of an earlier generation, the study revealed that the prolonged conflict between Aceh and Indonesia failed to lead to resistance. Instead of being a colonial language, Indonesian is an integral part of national identity. Even though there was still a stated pride and high level of ideological identification with Acehnese, a gradual shift away from Acehnese began during the conflict. Since the 1970s and 1980s, an emerging phenomenon of Indonesian intergenerational transmission has emerged. This linguistic phenomenon then became more and more common among Acehnese families in the 2000s and peaked after the tsunami and peace agreement. Prestige/modernity, education, and socioeconomic factors seem to be the primary drivers of the Acehnese-to-Indonesian language shift.

Development of a Prediction Model for Potential Forest and Land Fires using Machine Learning Algorithms Based on Patrol Data

Indonesia allocates 120 million hectares or 64% of its land area as forest areas. Indonesia's forests continue to experience deforestation; one of the causes is forest and land fires (karhutla). The government conducts forest and land fire prevention through integrated patrols with the Forest and Land Fire Prevention Patrol Information System (SIPP Karhutla) facility for patrol data management. However, the patrol data are still primarily used for data observation and simple spatial analysis in the spatial module. Patrol data has not been used for further forest and land fire prevention studies. Based on these problems, this research aims to build a prediction model of potential forest and land fires using SVM, Random Forest, and XGBoost algorithms and compare model performance to get the best model. The preprocessing stage uses the SMOTE-ENN method to handle data class imbalance, and the k-fold cross-validation stage and hyperparameter tuning use the random search method. The confusion matrix evaluation method to see the model performance in terms of accuracy is XGBoost (94.81%), Random Forest (90.23%), SVM-linear (79.58%), SVM-polynomial model (73.99%), SVM-rbf (74.26%), and SVM-sigmoid (35.04%). Therefore, the best prediction model is XGBoost (94.81%) with boosting technique. The results of this study have implications for helping early prevention of forest and land fires on the islands of Sumatra and Kalimantan.

Biampullisna, a new genus for “Teulisna” uniplaga Hampson (Lepidoptera: Erebidae: Arctiinae: Lithosiini)

A new genus Biampullisna gen. n. is erected to solely include “Teulisna” uniplaga Hampson, 1894 widely distributed in Mainland Southeast Asia, South China (Hainan Island) and the islands of Borneo and Sumatra. A new combination is introduced: Biampullisna uniplaga (Hampson, 1894), comb. n. Adults, as well as male and female genitalia of the type species of the new genus and similar taxa are illustrated.

Pengaruh Investasi, Human Capital, Kesenjangan Sosial, dan Pertumbuhan Ekonomi terhadap Kesempatan Kerja di Pulau Sumatera

This research aims to examine the influence of investment, human capital, social inequality and economic development on job prospects on the island of Sumatra. Associative quantitative research is used as an investigative approach. Secondary statistical data originating from the Central Statistics Agency (BPS) includes information regarding investment, human development index, Gross Regional Domestic Product (GRDP), Gini index, and job opportunity levels from 2018 to 2022. The results of this research show that simultaneously and partial investment factors, human capital, socio-economic disparities have a positive influence on employment opportunities on the island of Sumatra. Investment, human capital, social inequality and economic growth contribute 86.9% to the variation in employment opportunities.

The Ship is Laden with Rice and Salt: A Comparison of Two Sailing Models on an Early 17th Century Trade Route Between Java and Sumatra

Abstract Archaeological and historical sailing modeling has become an increasingly productive field of study in the twenty-first century. The research has largely concentrated on methodological development, yet comparisons between models have so far been lacking. In this paper we juxtapose two directed sailing models, Digital Navigator and qtVlm, on a route from East Java to South Sumatra. In the early seventeenth century, the former was a major producer and exporter of rice and salt, while especially Jambi, Indonesia, on the island of Sumatra, had become dependent on imports due to cash-cropping of black pepper. Our simulation results show the optimal sailing season on this route falls between May and September, and that La Niña events somewhat affect the length of this time window. During favorable winds both models produce quite similar routes. In adverse winds there is more variation between the models and the temporal frequency of wind data has more marked effects on routing. The models’ sailing durations match fairly well to the one measured from the Selden Map of China, but the simulated optimized routes tend to take more direct open sea routes than the coast-hugging route on the map. This implies that other factors such as ease of navigation played a more significant role in route selection than mere efficiency. Furthermore, a comparison to the production schedules of rice and salt in the Gresik region shows that products from the same summer’s harvests would have been available for export to Sumatra.

Molecular identification of Nemacheilus sp. from Bangka Island, Indonesia Based on the Cytochrome C oxidase Subunit I (COI) Gene

Abstract Nemacheilus is a genus of stone loaches native to Asia. There are 13 species of the genus Nemacheilus that can be found in western Indonesia, from 44 species that exist in Asia. During our expedition to Bangka Island, which took place between the 20th and the 25th of January 2023, we discovered 15 live specimens of Nemacheilus sp. These specimens were collected using a fish trap in the Bencah River, Bangka Island, Indonesia. We identified Nemacheilus sp based molecular analysis by using the DNA Barcoding method based on the Cytochrome C oxidase Subunit I (COI) gene. DNA barcoding is a solution to provide accurate, fast, and automatable identification of species and species discovery. Based aon the COI gene, Nemacheilus sp. Nemacheilus from Bangka Island is genetically closest to Nemacheilus pfeifferae, which is found in Sumatra. Sumatra and Bangka Island have a history of river connection before the maximum glacial phase II. However, based on the similarity of DNA base pairs, these two species are only 90% similar. This indicates that the genetic difference between these two species is 10%, which is far below the threshold for what is considered to be an identical species, which is under 3%. Therefore, we hypothesize that the Nemacheilus that was found on the island of Bangka is not the species known as Nemacheilus pfeifferae, but rather another species. Since the data for this other species are not yet available in Genbank, we are referring to it as Nemacheilus sp. Bangka for the time being.