Field Survey Research Articles

Differential response of subterranean microbiome to exogenous organic matter input in a cave ecosystem

As a recurrent climatic phenomenon in the context of climate change, extreme rainstorms induce vertical translocation of organic matter and increase moisture content in terrestrial ecosystems. However, it remains unclear whether heavy rainstorms can impact microbial communities in the deep biosphere by modulating organic matter input. In this study, we present findings on the different responses of bacterial and fungal communities in a subsurface cave to rainstorms and moisture variations through field surveys and microcosm experiments. During periods of rainstorms, the influx of dissolved organic matter (DOM) from soil overlying the cave into cave sediments significantly enhanced the correlation between core bacteria and environmental factors, particularly fluorescence spectral indices. The resource utilization of core bacteria was diminished, while the functional diversity of core fungi remained relatively unaltered. We also performed simulated experiments with restricted external DOM inputs, in which DOM content was observed to decrease and microbial diversity increase in response to artificially increased moisture content (MC). The niche breadth of core bacteria decreased and became more closely associated with DOM as the MC increased, while the niche breadth of core fungi remained predominantly unchanged. Compared to fungi, cave bacteria exhibited higher sensitivity towards variations in DOM. The core microbiome can efficiently utilize the available organic matter and participate in nitrogen- and sulfur-related metabolic processes. The study systematically revealed distinct microbial responses to rainstorm events, thereby providing valuable insights for future investigations into energy utilization within deep biospheres.

Optimizing aquatic weed management in Lake Ossa, Cameroon: Harnessing the power of biological control and real-time satellite monitoring

Salvinia, Salvinia molesta Mitchell (Salviniaceae) is a free-floating aquatic fern native to Brazil and considered one of the worst weeds in the world. When left unchecked, salvinia forms dense mats on the water surface, limiting sunlight penetration and altering water quality that disrupt ecosystem processes. In 2016, salvinia was first reported in Lake Ossa, Cameroon, and by summer 2021, had expanded to cover almost 49 % of the lake’s 4,000-hectare surface. A multinational team initiated a biological control and monitoring program, importing the salvinia weevil, Cyrtobagous salviniae Calder & Sands (Coleoptera: Curculionidae) from Louisiana, USA, in summer 2021. The objectives of this study were to: quantify the changes in salvinia cover and other floating vegetation, document the establishment and impact of the biological control program, and deliver a tool for near-real time monitoring of floating vegetation. We developed a satellite-based remote sensing application to document in near real-time the changes in coverage of floating vegetation. Using this tool, we quantified the reduction in the salvinia coverage by 80 % within three years of the release of the weevil. Field surveys in 2022 and 2023, demonstrated weevil establishment in the lake and widespread salvinia browning that was associated with weevil damage. Linear regressions of the percent cover of floating vegetation over time, demonstrated that after the weevil release, the rate of change decreased to −1.7 % per 60 days. Field monitoring and satellite imagery showed the establishment of a sedge (Oxycaryum sp., Cyperaceae) within the salvinia mat in late 2021. This secondary invasion slowed the reduction in coverage of floating vegetation from −1.7 % to −0.6 % per 60 days, and warrants further research. By late 2023, the revitalization of Lake Ossa restored fishing and transportation opportunities for the community, and also the comeback the emblematic African manatee. The success of the biological control of salvinia in Lake Ossa is not surprising due to its tropical conditions. However, it highlights the importance of early intervention and continuous monitoring. We propose that the integration of biological control and remote sensing technology is becoming more accessible and can be automated; therefore, a replicable model for future invasive weed programs around the world.

Innovative earthquake resistant school building typologies for earthquake-hit areas of Nepal

The 2015 Gorkha earthquake in Nepal devastated over 50,000 classrooms across 14 rugged districts, many accessible only by foot trails. Rebuilding multi-hazard resilient school buildings in these remote areas posed unique challenges, including adherence to restrictive building codes, logistical hurdles in transporting modern construction materials and financial constraints. This study innovatively addressed these challenges by advocating for the utilisation of local materials and craftsmanship in line with the 'Build Back Better' initiative. Through a blend of literature review, field surveys, structural assessments, and stakeholder consultations, an overall framework of the research was prepared and is presented in this paper. This framework included an attribute-based approach for the selection of locally suitable construction materials, techniques and building types. Four novel multi-hazard resilient building prototypes are proposed, rigorously tested for compliance with Nepalese building codes using shaking table experiments and numerical simulations. By challenging conventional engineering norms, the findings of the findings of this study not only resulted in the development of pragmatic alternatives but also illustrated the significance of locally driven solutions for school infrastructure resilience, both in Nepal and also for regions worldwide where similar geographical and multi-hazard constraints are encountered.

Fire risk vulnerability and safety assessment of Farmgate area using fire risk index, Dhaka City and optimization of fire hydrant placement

This research addresses fire safety and assesses the vulnerability to fire hazards in the Farmgate area of Dhaka city employing Fire Risk Index (FRI) methodology. 16 key factors were identified from a comprehensive field survey for each building undergoing rigorous analysis for calculation of FRI value through weighting and scoring of each factor. The FRI values are divided into 5 grades of very high, high, moderate, low, and very low with a higher FRI value indicating better fire safety. The data analysis indicates that among all structures, 0.59 % exhibited a very high FRI, 5.35 % showed a high FRI, 17.24 % displayed a moderate FRI, 48.89 % had a low FRI, and 27.93 % had a very low FRI. Geographic Information System (GIS) tools were employed to spatially to optimize fire hydrant placement using data integration and strategic analysis in high-risk areas. By ensuring efficient resource utilization, this research aims to implement fire prevention approaches and serve as a foundational resource for stakeholders, including landowners, residents, and policymakers, to fortify risk awareness and improve overall fire safety protocols. Ultimately, this research aims to foster resilient urban environments, improving disaster preparedness not only in Dhaka but also in similar high-risk areas worldwide.

Occurrence, fate, and ecological risk of PAEs, PFASs, antibiotics in industrial, urban and rural WWTPs in Shaanxi Province, China

The wastewater treatment plants (WWTPs) were considered as a hub of transit from human activities as a source to the aquatic ecosystems as a sink of emerging contaminants (ECs). This study investigated the fate of phthalate esters (PAEs), per- and polyfluoroalkyl substances (PFASs) and antibiotics in the influent and effluent of WWTPs in industrial, urban and rural in Shaanxi province (China). The first most abundant monomer of these three types of ECs were the same in industrial, urban and rural WWTPs. The composition of PAEs in the influent of urban and rural WWTPs were quite different from that of industrial WWTPs. The removal efficiency of PAEs and PFASs in urban WWTPs were higher than those in rural and industrial WWTPs. The annual mass load of PFASs in rural WWTPs was lower than that in industrial and urban WWTPs. The risk quotient (RQ) of PAEs was high, with most of them exceeding 1. While the RQ of PFASs was low, exceeding 0.1 only in some industrial WWTPs. The frequency of high risk of total antibiotics in urban and rural WWTPs was higher than that in industrial WWTPs. This study provided field survey data and guidance to strengthen the management of ECs in the region.

Are they even there? How agri-environment schemes investments reach their target species in Dutch dairy-farmland, the case of meadow birds

Agri-environmental schemes (AES) implemented by farmer collectives for meadow bird protection in The Netherlands create complex landscape mosaics due to the variability of options and combinations farmers use. We propose a method to simplify this complexity, using the number of meadow birds potentially benefiting as the measure of success, and evaluate how AES combinations affect management success as a function of monetary investments. Between 2016-2022, we conducted field surveys to measure the density and distribution of Black-tailed Godwits across three land-use types: AES, site-protected areas, and intensive agriculture. AES fields were categorized into nest protection, inundation, delayed mowing, and herb-rich grasslands. We analysed the relationship between these managements, the area they cover, and godwit numbers, while also examining land area and subsidies. Intensive agriculture covered 74.3% of the area but hosted only 23.2% of the godwit population at low densities (0.063 godwits/ha). In contrast, protected areas (6.2% of the area) and AES fields (19.5%) supported 24.7% and 52.1% of the population at higher densities (0.48 and 0.46 godwits/ha, respectively). Among AES types, delayed mowing and herb-rich grasslands showed the highest godwit densities (0.66 and 1.25 godwits/ha, respectively) covering smaller areas (6% and 1.1%). These AES types pay the highest subsidies, while nest protection, covering 10.5% of the area with lower godwit densities, pays the lowest. Although AES fields hosted about half of the godwit population, area-wise the focus remained on nest protection, and with intensive agriculture dominated the landscape. This may limit effectiveness at a population level, calling for re-evaluating conservation priorities and funding.

Functional traits of macrobenthos substantially indicated habitat change from the invasive saltmarsh to introduced mangrove

Mangrove afforestation is usually thought to be beneficial to mitigate the degradation and loss of mangroves. In Southern China, planting mangroves with the introduced Sonneratia apetala is also supportive to remove the invasive Spartina alterniflora. However, the influence of mangrove afforestation dominated by introduced species on macrobenthos, a vital joint of energy flow and nutrient cycling in mangroves, remains unclear. We explored the linkage between the functional traits of macrobenthos and the physicochemical properties of sediments in a coastal continuum including the mudflat (MF), exotic Spartina alterniflora saltmarsh (SL), natural Avicennia marina forest (AM), and introduced S. apetala afforestation (SA) via a seasonal field survey. After removing the S. alterniflora invaded into mudflat via S. apetala afforestation, the sediment C/N ratio decreased compared to that of natural forest, while the concentrations of microphytobenthic chlorophyll-a increased. The macrobenthic inhabiting mode shifted from epifaunal to infaunal as well. The biomass and density of microbenthic community decreased along MF, SL, AM, and SA. SL had greater C/N ratio and smaller functional richness (FR) than MF. AM was characterized by similar functional diversities, and pH value and salinity of sediment to those of MF, and greater microphytobenthic chlorophyll-a was found in AM. Compared to AM, the introduced S. apetala substantially engineered the habitat due to its flourishing above-ground pneumatophore system which caused faster deposition process, subsequently changed the resource utilization strategies of macrobenthos considerably. Overall, the use of Sonneratia afforestation on Spartina removal could not replace the contribution of natural Avicennia forest with respect to the functional traits of macrobenthos. Careful consideration on ecosystem functionalities would be indispensable for conducting saltmarsh eradication and mangrove afforestation in the future.

A drone-based population survey of Delacour's langur (Trachypithecus delacouri) in the karst forests of northern Vietnam

The Critically Endangered Delacour's langur (Trachypithecus delacouri) is presently found only in a few isolated karst areas in northern Vietnam, where conducting field surveys has proven challenging due to the difficult terrain. Accurate population estimates from a scientifically sound method are needed to inform management of the species. From October to December 2022, we used a drone equipped with optical and thermal cameras to survey the species in Kim Bang Forest, a critical site for the species. We estimated langur abundance from the resulting point count data using N-mixture models including abiotic and biotic variables. We also compared the effectiveness and efficiency of the drone method with two commonly used ground-based methods. The drone survey recorded 16 groups with 104 individuals. We estimated a density of 0.87 groups per km2 and a population of 25 groups and 175 individuals. This estimate is 80–113 % higher than previous ground-based estimates, attributed primarily to the higher area coverage by the drone survey. The estimate reaffirms the conservation importance of Kim Bang Forest for the species. The modelling also indicated that Delacour's langur abundance was correlated negatively with Assamese macaque Macaca assamensis presence and positively with vegetation productivity. Other variables (elevation, terrain ruggedness and distance to forest edge) were much less important in explaining langur abundance. Compared to the ground-based methods, the drone approach proved effective and resource-efficient for surveying Delacour's langurs. We recommend the drone method for future Delacour's langur surveys, with potential applicability to other arboreal mammals in difficult-to-access karst forests.

Rare Pleurotus species with veiled basidiomata from the Neotropics: neotypification of Pleurotus magnificus and epityfication of Pleurotus rickii

Knowledge of Pleurotus in Brazil dates back to the 19th century, when European mycologists studied and described numerous Neotropical taxa. Some of these long-described species remain poorly known, mostly due to the lack of recent records, detailed morphological descriptions, and molecular data. During field surveys in Southeast and Southern Brazil, specimens of two rare Pleurotus species with veiled basidiomata, i.e. P. magnificus and P. rickii, were collected. These species are recorded for the first time in the state of Santa Catarina, Brazil, and P. magnificus for the first time in the states of Minas Gerais, Paraná and São Paulo. Updated and detailed morphological descriptions are provided. DNA sequences of the ITS and nLSU molecular markers were obtained for both species, and phylogenetic analyses were conducted to explore their relationships within Pleurotus. A neotype is designated for P. magnificus, and a lectotype and epitype are designated for P. rickii.

Ecosystem Structure and Function in the Sea Area of Zhongjieshan Islands Based on Ecopath Model

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; the energy structure of the marine ecosystem was divided into 21 functional groups, and its nutrient structure, energy flow, and total system characteristics were analyzed. The results show that the credibility of the model is 0.414, which is at a medium level. The trophic level of each functional group of the ecosystem in the sea area of Zhongjieshan Islands was 1–3.48, the energy flow structure of the system was mainly concentrated in the first five grades, and the trophic level was relatively simple, with the average energy transfer efficiency of the system being 8.11%, the energy flow range being 2.81–13.04%, the energy transfer efficiency of the primary producers of the system being 7.25%, and the energy conversion efficiency of the system debris being 9.12%. The total system throughput was 2125.96 t·km−2; The analysis of the overall characteristics of the ecosystem showed that the system connectance index and the system omnivory index were 0.45 and 0.24, respectively, while the Finn’s cycling index was 8.24, the Finn’s mean path length of the system was 2.72, and the total primary production/total respiration was 1.71. In this study, the marine ecosystem model of the sea area of the Zhongjieshan Islands was studied to understand the trophic structure and ecosystem status of the sea area, which is conducive to the sustainable utilization and scientific management of fishery resources in the sea area.

Long-Term Cumulative Effect of Management Decisions on Forest Structure and Biodiversity in Hemiboreal Forests

We evaluated the long-term impacts of various forest management practices on the structure and biodiversity of Estonian hemiboreal forests, a unique ecological transition zone between temperate and boreal forests, found primarily in regions with cold winters and moderately warm summers, such as the northern parts of Europe, Asia, and North America. The study examined 150 plots across stands of different ages (65–177 years), including commercial forests and Natura 2000 habitat 9010* “Western Taiga”. These plots varied in stand origin—multi-aged (trees of varying ages) versus even-aged (uniform tree ages), management history—historical (practices before the 1990s) and recent (post-1990s practices), and conservation status—protected forests (e.g., Natura 2000 areas) and commercial forests focused on timber production. Data on forest structure, including canopy tree diameters, deadwood volumes, and species richness, were collected alongside detailed field surveys of vascular plants and bryophytes. Management histories were assessed using historical maps and records. Statistical analyses, including General Linear Mixed Models (GLMMs), Multi-Response Permutation Procedures (MRPP), and Indicator Species Analysis (ISA), were used to evaluate the effects of origin, management history, and conservation status on forest structure and species composition. Results indicated that multi-aged origin forests had significantly higher canopy tree diameters and deadwood volumes compared to even-aged origin stands, highlighting the benefits of varied-age management for structural diversity. Historically managed forests showed increased tree species richness, but lower deadwood volumes, suggesting a biodiversity–structure trade-off. Recent management, however, negatively impacted both deadwood volume and understory diversity, reflecting short-term forestry consequences. Protected areas exhibited higher deadwood volumes and bryophyte richness compared to commercial forests, indicating a small yet persistent effect of conservation strategies in sustaining forest complexity and biodiversity. Indicator species analysis identified specific vascular plants and bryophytes as markers of long-term management impacts. These findings highlight the ecological significance of integrating historical legacies and conservation priorities into modern management to support forest resilience and biodiversity.

Sharks and Rays of Northern Australia’s Roper River, with a Range Extension for the Threatened Speartooth Shark Glyphis glyphis

Northern Australia is considered a ‘lifeboat’ region for globally threatened shark and ray species (elasmobranchs), although much of the region is understudied. The Roper River in the Northern Territory’s Gulf of Carpentaria has been inadequately surveyed, with most elasmobranch data gained opportunistically through freshwater fish surveys. This study aimed to report the occurrence of elasmobranch species in the Roper River through targeted field surveys conducted between 2016 and 2024 and to review data from other sources. Four euryhaline species were recorded, comprising two sharks, a sawfish, and a stingray. Records of the globally Vulnerable speartooth shark (Glyphis glyphis) represented a significant range extension and the documentation of a new reproductive population. Records of the Critically Endangered largetooth sawfish (Pristis pristis) extended almost 400 km upstream, highlighting extensive use of the river system. A predominantly marine species, the Critically Endangered giant guitarfish (Glaucostegus typus) was observed in brackish estuarine waters, approximately 15 km upstream from the river mouth. Further research is required to develop a more thorough understanding of abundance, life history, and population connectivity for these species in this river system. Given the documentation of threatened species, the potential impacts of fisheries, water allocations, and climate change require assessment.

Rural Settlement Dynamics in a Rapidly Urbanizing Landscape: Insights from Satellite Remote Sensing and Archaeological Field Surveys in Zanzibar, Tanzania

ABSTRACT In Africa, rapid urbanization covers archaeological sites and limits the utility of traditional archaeological field survey methods. This is not only a crisis for archaeological heritage conservation, but it also distinctly impacts anthropological understandings of African urban trajectories since much evidence for precolonial urbanism lies within areas of rapid expansion. However, high-resolution multitemporal satellite data may facilitate reconstructions of urban growth in African cities, enabling archaeological surveys to target undeveloped areas for prospection within the interstices of modern urban development. This paper describes an application of satellite remote sensing for archaeological prospection within the rapidly urbanizing hinterland of Zanzibar Stone Town, a UNESCO World Heritage site. Survey results reveal settlement trajectories around the city over the last millennium, drawing attention to the role of rural agricultural land as a factor in the emergence of precolonial urbanism and the continued significance of rural places as urbanization progressed into the Colonial era.

Monitoring Dissolved Organic Carbon Concentration and Flux in the Qiantang Riverine System Using Sentinel-2 Satellite Images

Real-time monitoring of riverine-dissolved organic carbon (DOC) and its controlling factors is critical for formulating strategies regarding the river basin and marginal seas pollution prevention and control. In this study, we established a linear regression formulation that relates the permanganate index (CODMn) to the DOC concentration based on in situ measurements collected on five field surveys in 2023–2024. This regression formulation was used on a large number of data collected from automatic monitoring stations in the Qiantang River area to construct a daily quasi-in situ database of DOC concentration. By combining the quasi-in situ DOC data and Sentinel-2 measurements, an enhanced algorithm for empirical DOC estimation was developed (R2 = 0.66) using the extreme gradient boosting (XGBoost) method and its spatial and temporal variations in the Qiantang River were analyzed from 2016 to 2023. Spatially, the main stream of the Qiantang River exhibited an overall decreasing and increasing trend influenced by population density, economic development, and pollutant discharge in the basin area, and the temporal distribution of DOC was controlled by meteorological conditions. The DOC contents had the highest in summer, primarily due to high rainfall and leaching. The inter-annual variation in DOC concentration was influenced by the total annual runoff volumes, with a minimum level of 2.24 mg L−1 in 2023 and a maximum level of 2.45 mg L−1 in 2019. The monthly DOC fluxes ranged from 6.3 to 13.8 × 104 t, with the highest values coinciding with the maximum river discharge volumes in June and July. The DOC levels in the Qiantang River remained relatively high in recent years (2016–2023). This study enables the concerned stakeholders and researchers to better understand carbon transportation and its dynamics in the Qiantang River and its coastal areas.

Educational Inequality and Household Dynamics in India: Exploring the Role of Caste Capital

The article uses caste capital as a conceptual tool to analyze educational inequalities by looking at the household-level differences and school differentiation among different caste groups in eastern Uttar Pradesh, India. Caste capital is the social, cultural, and economic assets associated with the hierarchical ranking of a group, which privileged groups could utilize to take advantage of disprivileged others. This includes an informed and conscious effort to create a cultural environment that values and prioritizes education for social and economic advancement. Based on a field survey at the household level, the findings indicate a strong connection between caste, household type, and school choice. The pattern of educational inequality becomes evident whereby individuals from higher caste backgrounds with more affluent households tend to have better educational opportunities. The findings show how caste hierarchy intersects with school choice, creating a hierarchy of educational opportunities producing and reproducing educational inequalities.

New records and an updated list of reptiles from Thanh Hoa Province, Vietnam

Thanh Hoa Province is located in North Central Vietnam and the Province contains a large area of 393,361.33 hectares of natural forest. A complexity of landforms has given this Province a high level of biodiversity potential. However, the reptile fauna of Thanh Hoa Province is still underestimated. Previous studies documented 111 species of reptiles from this Province. As a result of our field surveys in Pu Luong and Xuan Lien Nature Reserves, we report five species of reptiles for the first time from Thanh Hoa Province, Vietnam, namely Plestiodon tamdaoensis, Scincella devorator (Scincidae), Elaphe taeniura, Pareas macularius and Pseudoxenodon macrops (Colubridae), with novel data about morphological characteristics. In addition, we provide an updated checklist of 116 species of reptiles from Thanh Hoa Province. The reptile fauna of Thanh Hoa Province also contains a number of species of conservation concern: 22 species listed in the Red Data Book of Vietnam, 22 species listed in the IUCN Red List, 18 species listed in the Vietnam Governmental Decree No. 84; and 21 species listed in CITES appendices.

Seismic performance assessment of structural systems in the aftermath of the 2023 Kahramanmaraş earthquakes: Observations and fragility analyses

This article evaluates how different reinforced concrete (RC) building systems in Türkiye behaved during the extreme 2023 Kahramanmaraş earthquakes. The analysis relies on a comprehensive field survey covering 242 RC buildings across various heavily affected locations. Most surveyed buildings were low- and mid-rise RC moment frames and frame-wall (hybrid) systems, with RC wall construction being less commonly observed. Both RC frame and hybrid buildings exhibited several common deficiencies, resulting in significant structural and non-structural damage due to high drift demands. The performance of RC wall construction varied, with some buildings sustaining severe damage while others remained largely unaffected. An analysis of structural plans revealed that RC wall buildings with adequate wall amounts demonstrated exceptional performance, while those with inadequate amounts of walls experienced severe damage. In addition, fragility analyses using simplified models based on surveyed buildings reinforced these findings. The analyses suggested that RC frame and hybrid systems were insufficient in ensuring life safety during the earthquakes. Conversely, properly designed RC wall buildings are expected to perform well. This alignment between field observations and fragility analyses underscores the reliability of the study’s findings and emphasizes the effectiveness of RC wall construction in mitigating seismic risks and protecting life and property.

Global Invasion of Thrips parvispinus (Karny) (Thysanoptera: Thripidae) Across Three Continents Associated With Its One Haplotype

ABSTRACTThrips parvispinus (Karny) is an exotic pest that has invaded many regions around the world in the last three decades. It was first detected in Florida in 2020 on ornamental plants (Hoya and Anthurium) in greenhouses and subsequently on ornamental plants in residential landscapes (Gardenia) in 2021. However, its first report on open vegetable field crops (Capsicum) in Florida was in 2022. We conducted field surveys and genetic analysis to answer three questions: (1) Is the population of T. parvispinus that invaded Florida the same as the one that has spread globally in the last few decades? (2) Is the host expansion to Capsicum in Florida a new population or the extension of the existing population reported on ornamental plants? and (3) What are the native and invaded distribution ranges of T. parvispinus? We analysed the genetic variation in the mitochondrial gene cytochrome oxidase I (COI) to address these questions. The global genetic diversity analysis of T. parvispinus revealed 18 haplotypes (populations) worldwide based on available data, but only one population (Hap1) invaded three continents: Africa, Europe, and North America. Based on available data, the highest haplotype diversity was observed in India, suggesting India may be part of the presumed native range (South and Southeast Asian countries) of T. parvispinus. Our survey of retail plant stores across 10 Florida counties indicated that plant trade is the source of T. parvispinus in open vegetable field crops and ornamental landscape plants. The outcome of this study will assist with regulatory and management decisions of T. parvispinus in Florida and elsewhere.

Field survey for assessing seawater reverse osmosis (SWRO) applications on very small islands in Indonesia

Very small islands in Indonesia face challenges in accessing clean water due to limited space for building water resource facilities, such as reservoirs. Most of the time, the inhabitants of these islands rely on rainwater and wells, which are not sustainable sources due to drought seasons and seawater intrusion. To address this issue, Seawater Reverse Osmosis (SWRO) can be implemented in these areas where seawater is abundant. However, there may be obstacles when applying SWRO systems in such environments. This study aimed to assess the capabilities of SWRO facilities, and the obstacles involved in evaluating clean water access on very small islands. We used a combination of structured questionnaires, interviews, and direct observations on two small islands in Indonesia, Belakang Padang Island and Labu Island. On Belakang Padang Island, we interviewed the water resource manager in October 2022 and March 2023 and surveyed 61 households in the Tanjung Sari subdistrict in October 2022. On Labu Island, we interviewed the staff of the SWRO system and surveyed 35 coastal households in September 2023. On both islands, the government improved residents’ access to clean water by constructing SWRO facilities in 2016 on Belakang Padang Island and in 2021 on Labu Island. However, on Belakang Padang Island, the system was not operational when we visited on March 15, 2023. The main obstacles were slow bureaucratic processes for repairs and maintaining the operation of SWRO facilities. These problems need to be addressed before expanding the implementation of this system to other very small islands in Indonesia.

Determining the optimal time window to detect emerald ash borer damage for effective management.

The emerald ash borer (EAB) is an invasive pest of global concern. Accurate detection of EAB is crucial for effective management. Traditional field surveys fail to meet large-scale monitoring requirements. Remote sensing methods offer a potential solution, but the phenological decline of ash trees may obscure the remote sensing features for detecting EAB. Therefore, determining the timing of leaf abscission caused by EAB before phenology is crucial for effective detection. We collected time-series data of Leaf Area Index (LAI), leaf sizes, and hyperspectral images of damaged ash trees throughout the growing season to determine the optimal detecting time window for EAB detection using field surveys or remote sensing techniques. Significant differences in LAI and leaf size were observed throughout the growing season among ash trees with different EAB infestation degrees, providing a basis for small-scale field surveys. However, in May and June, the hyperspectral reflectance showed no variation. The difference began to appear in July and became apparent from August to October. By October, severely EAB-infested ash trees had almost completely defoliated. Machine learning classification results showed that accuracies after July were higher than before July. After July, the highest classification accuracy reached 100%, while the highest accuracy before July was only 88.57%. Selecting the optimal monitoring time significantly enhanced detection accuracy. The optimal period for field surveys is from May to November, whereas for remote sensing it is from August to October. Identifying the optimal months enables us to achieve more efficient decision-making and management. © 2024 Society of Chemical Industry.