Local Environmental Conditions Research Articles

IoT Applications in Agriculture: Enhancing Crop Yield in Vietnam

Purpose: To aim of the study was to analyze the IoT applications in agriculture: enhancing crop yield in Vietnam Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: IoT applications in agriculture have significantly enhanced crop yield in Vietnam. Through sensors and IoT devices, farmers monitor soil conditions like moisture, temperature, and humidity in real-time. This data-driven approach optimizes irrigation and fertilization, minimizing waste and maximizing resource efficiency. Studies show that smart farming techniques using IoT lead to higher crop yields by ensuring optimal growth conditions and timely pest and disease management. Remote monitoring also improves farm management, reducing labor costs and promoting sustainable practices through precise resource management. Unique Contribution to Theory, Practice and Policy: Technology acceptance model (TAM) & diffusion of innovations theory& resource-based view (RBV) may be used to anchor future studies on IoT applications in agriculture: enhancing crop yield in Vietnam. Encourage the adaptation and customization of IoT solutions to suit local farming practices and environmental conditions across different regions of Vietnam. Implement policies that incentivize the adoption of IoT technologies in agriculture, particularly among smallholder farmers.

Fine‐grained sediment production by endolithic sponges on Caribbean coral reefs

AbstractEndolithic sponges are key players in carbonate cycling on coral reef systems. While their bioerosion of reef framework is relatively well studied, their role in biogenic sediment generation is poorly understood. In this study, the sedimentary attributes and production rates of eight Caribbean endolithic sponge species were characterized. The findings revealed notable species‐specific variations in sediment production rates (range: 1.0–6.3 kg CaCO3 m−2 yr−1), alongside consistency in sediment characteristics (modal sizes ranging from 39 to 48 μm). The species‐specific rates were used to explore reef‐scale variations in sponge‐derived sediment generation across 50 reef sites in the Mexican Caribbean. Significant between‐site variability was observed, with estimated annual sediment production ranging from < 0.01 to 0.84 kg m−2 of reef. Production was primarily driven by sponge abundance, with discernible spatial variations in the contributions of different species, which could be related to variability in local environmental conditions. The rapidity at which these sediment producers can utilize dead coral substrates, coupled with their positive response to the changing marine environment, highlights the growing importance of these sponges in modern degraded Caribbean reef systems.

Vegetation resistance to increasing aridity when crossing thresholds depends on local environmental conditions in global drylands

The crossing of aridity thresholds triggers abrupt changes in multiple functional and structural ecosystem attributes across global drylands. While we understand the consequences associated with aridity thresholds, the key factors influencing dryland vegetation resistance when crossing them remain unclear. Here, we used field observations from 58 dryland sites across five continents and satellite remote sensing data (2000-2022) to show that plant richness, soil moisture dynamics and texture, and bare soil fraction are important variables contributing to vegetation resistance. Additionally, drought history (frequency and magnitude of past droughts) is important in interaction with plant richness and soil texture. Interestingly, plant species richness was negatively related to vegetation resistance, except in areas with higher drought history and in grasslands. Our results highlight that vegetation resistance depends on local environmental conditions. Enhancing our understanding of the factors important for vegetation resistance is an important step towards dryland conservation efforts and sustainable management strategies.

Manipulation of photosensory and circadian signaling restricts phenotypic plasticity in response to changing environmental conditions in Arabidopsis

Plants exploit phenotypic plasticity to adapt their growth and development to prevailing environmental conditions. Interpretation of light and temperature signals is aided by the circadian system, which provides a temporal context. Phenotypic plasticity provides a selective and competitive advantage in nature but is obstructive during large-scale, intensive agricultural practices since economically important traits (including vegetative growth and flowering time) can vary widely depending on local environmental conditions. This prevents accurate prediction of harvesting times and produces a variable crop. In this study, we sought to restrict phenotypic plasticity and circadian regulation by manipulating signaling systems that govern plants’ responses to environmental signals. Mathematical modeling of plant growth and development predicted reduced plant responses to changing environments when circadian and light signaling pathways were manipulated. We tested this prediction by utilizing a constitutively active allele of the plant photoreceptor phytochrome B, along with disruption of the circadian system via mutation of EARLY FLOWERING3. We found that these manipulations produced plants that are less responsive to light and temperature cues and thus fail to anticipate dawn. These engineered plants have uniform vegetative growth and flowering time, demonstrating how phenotypic plasticity can be limited while maintaining plant productivity. This has significant implications for future agriculture in both open fields and controlled environments.

Deficit Irrigation as an Effective Way to Increase Potato Water Use Efficiency in Northern China: A Meta-Analysis

Water scarcity poses a significant threat to the sustainable production of crops in Northern China. Despite this, the effect of water management practices, such as deficit irrigation, on the yield and WUE of potatoes has been rarely explored. Based on the meta-analysis of field experiment data, this study evaluated the influence of deficit irrigation on potato yield, evapotranspiration (ET), water use efficiency (WUE) and irrigation water use efficiency (IWUE) under variable soil types, water-saving ratio, irrigation methods, soil organic carbon (SOC) content, and fertilizer rate in Northern China. Here, we determined that potato WUE and IWUE were significantly increased by 10.0 and 31.6%, respectively, under deficit irrigation, while ET was significantly decreased by 26.3% compared to full irrigation. Conclusively, deficit irrigation significantly reduced potato yields by 16.4% compared to full irrigation. Furthermore, SOC content played a vital role in improving the WUE and alleviating potato yield losses under deficit irrigation. Our study suggested that maximum WUE with lower potato yield losses under deficit irrigation can be achieved in the Central Plains region of China or in yellow loam soil, brown soil, and meadow soil under alternate root-zone irrigation when the water-saving ratio was less than 45% and fertilizer application rates were 300 kg N ha−1, >240 kg P2O5 ha−1, and 181–300 kg K2O ha−1. Overall, these findings highlight the need for a comprehensive understanding of various agricultural management practices and local environmental conditions to optimize the benefits of deficit irrigation in potato-growing regions across Northern China.

Human-Environment Interactions Shape Mosquito Seasonal Population Dynamics.

Mosquito species, including the Asian tiger mosquito, can transmit disease-causing pathogens such as dengue, Zika, and chikungunya, with their population dynamics influenced by a variety of factors including climate shifts, human activity, and local environmental conditions. Understanding these dynamics is vital for effective control measures. Our study, conducted in Jardí Botanic Marimurtra from May to November 2021, monitored Ae. albopictus activity using BG-Traps and investigated larval control effects. We employed Generalized Linear Mixed Models to analyze variables like weather, human presence, and larvicidal control on adult mosquito abundance. Adults of Ae. albopictus exhibited a seasonal pattern influenced by temperature but with bimodal peaks linked to cumulative rainfall. Proximity to stagnant water and visitor influx directly affected mosquito captures. Additionally, the effectiveness of larvicide treatments depended on interactions between preceding rainfall levels and treatment timing. Our research emphasizes the significance of studying vector ecology at local scales to enhance the efficacy of control programs and address the escalating burden of vector-borne diseases. Considering the impacts of extreme weather events and climate shifts is essential for the development of robust vector control strategies. Furthermore, our distinct findings serve as a prime illustration of utilizing statistical modeling to gain mechanistic insights into ecological patterns and processes.

Modelling and mapping carbon capture potential of farmed blue mussels in the Baltic Sea region

This study applies a regional Dynamic Energy Budget (DEB) model, enhanced to include biocalcification processes, to evaluate the carbon capture potential of farmed blue mussels (Mytilus edulis/trossulus) in the Baltic Sea. The research emphasises the long-term capture of carbon associated with shell formation, crucial for mitigating global warming effects. The model was built using a comprehensive pan-Baltic dataset that includes information on mussel growth, filtration and biodeposition rates, and nutrient content. The study also examined salinity, temperature, and chlorophyll a as key environmental factors influencing carbon capture in farmed mussels. Our findings revealed significant spatial and temporal variability in carbon dynamics under current and future environmental conditions. The tested future predictions are grounded in current scientific understanding and projections of climate change effects on the Baltic Sea. Notably, the outer Baltic Sea subbasins exhibited the highest carbon capture capacity with an average of 55 t (in the present scenario) and 65 t (under future environmental conditions) of carbon sequestrated per farm (0.25 ha) over a cultivation cycle – 17 months. Salinity was the main driver of predicted regional changes in carbon capture, while temperature and chlorophyll a had more pronounced local effects. This research advances our understanding of the role low trophic aquaculture plays in mitigating climate change. It highlights the importance of developing location-specific strategies for mussel farming that consider both local and regional environmental conditions. The results contribute to the wider discourse on sustainable aquaculture development and environmental conservation.

Interactive effects of soils, local environmental conditions and herbivores on secondary chemicals in tallow tree

Abstract Plants produce secondary chemicals that may vary along with latitude due to changing abiotic and biotic stress gradients and local environmental conditions. Teasing apart the individual and combined effects of these different abiotic, such as soil nutrients, and biotic factors, such as soil biota and herbivores, on secondary chemicals is critical for understanding plant responses to changing environments. We conducted an experiment at different latitudes in China, using tallow tree (Triadica sebifera) seedlings sourced from a population at 31° N. These seedlings were cultivated in gardens located at low, middle and high latitudes, with either local soil or soil from the original seed collection site (origin soil). The seedlings were exposed to natural levels of aboveground herbivores or had them excluded. Plant secondary chemicals (both foliar and root), aboveground herbivores and soil characteristics were measured. Results showed that most leaf and root secondary metabolites depended on the interaction of the experimental site and soil type. Leaf and root phenolic and tannin concentrations were higher at the middle latitude site, especially in the origin soil. Root and foliar flavonoid concentrations increased when aboveground herbivores were excluded. Microbial communities depended strongly on soil treatment. The different responses of tannins versus flavonoids suggest that these two chemical classes differ in their responses to the varying abiotic and biotic factors in these sites along latitudes. Taken together, our results emphasize the importance of considering the interactive effects of local environmental conditions, soil properties and herbivory in regulating plant chemical defenses.

Clutchesof the Cat-eye snakes genus Leptodeiraspp. (SERPENTES: Dipsadidae), with a bibliographic review and new reports for Panama

The reproduction of Neotropical snakes, such as those of the genus Leptodeira, varies widely influenced by climatic factors, with species ranging from strictly seasonal to continuous reproductive patterns. Recent research reveals significant variability in reproductive cycles, determined by local environmental conditions such as temperature and precipitation. Nesting behaviors remain poorly understood, and snakes use diverse environments, from natural shelters to communal nests of other species. Within the family Dipsadidae, species such as L. maculataand L. punctatademonstrate correlations between female body size (SVL) and clutch size, reflecting adaptive strategies to maximize reproductive success in diverse ecological contexts. Field work in Panama provided new insights, documenting egg-laying and gravid individuals of species such as L. rhombiferaand L. ornata, highlighting further research to elucidate the reproductive dynamics and ecological adaptations particular to each. species. Analytical approaches including Pearson and Spearman correlationsandcluster analysis reveal distinct patterns in clutch size relative to female size, underscoring species adaptations and variability within the genus

Evidence of environmental niche separation between threatened mobulid rays in Aotearoa New Zealand: Insights from species distribution modelling

AbstractAimMobulid rays are a group of threatened batoid fishes susceptible to population decline from targeted fisheries and accidental capture. Spatial distributions of mobulid rays remain poorly known. Prior studies found commonalities between favourable environments and prey among various mobulid species, yet most were conducted in tropical waters. To explore the habitat use and distribution of mobulid rays in a temperate environment we model the habitat suitability of two mobulid rays (Mobula mobular and Mobula birostris) in Aotearoa New Zealand using fisheries and citizen science occurrence data spanning almost two decades.LocationNortheastern coast of Aotearoa, New Zealand.MethodsBoosted Regression Tree models were used to predict the annual habitat suitability and favourable environmental conditions of the two species based on available sightings records in conjunction with high resolution (1 km2) environmental data.ResultsThe sympatric study species had contrasting habitat requirements. We found a separation in their spatial distribution defined by the 200 m isobath – the onshore extent for M. birostris and the offshore extent for M. mobular. While there were only subtle variations in relative habitat suitability for M. mobular over the study period, M. birostris exhibited greater interannual variability. Despite differing interannual patterns, spatial separation, as a function of environmental properties, persisted regardless of the year.Main ConclusionsOur results suggest that associations between mobulid species may differ from tropical regions due to regional adaptations to prey availability or local environmental conditions unique to colder and more productive temperate waters. Our findings highlight the importance of multi‐species surveys and the inclusion of temporal variability in support of separate species‐specific management plans to account for differing stressors impacting each species.

Data-driven probabilistic definition of the low energy conformational states of protein residues.

Protein dynamics and related conformational changes are essential for their function but difficult to characterise and interpret. Amino acids in a protein behave according to their local energy landscape, which is determined by their local structural context and environmental conditions. The lowest energy state for a given residue can correspond to sharply defined conformations, e.g.in a stable helix, or can cover a wide range of conformations, e.g.in intrinsically disordered regions. A good definition of such low energy states is therefore important to describe the behaviour of a residue and how it changes with its environment. We propose a data-driven probabilistic definition of six low energy conformational states typically accessible for amino acid residues in proteins. This definition is based on solution NMR information of 1322 proteins through a combined analysis of structure ensembles with interpreted chemical shifts. We further introduce a conformational state variability parameter that captures, based on an ensemble of protein structures from molecular dynamics or other methods, how often a residue moves between these conformational states. The approach enables a different perspective on the local conformational behaviour of proteins that is complementary to their static interpretation from single structure models.

Effects of vineyard inter‐row management on soil physical properties and organic carbon in Central European vineyards

AbstractThe intensity and frequency of inter‐row management in vineyards are highly diverse and depend on local environmental conditions and the wine grower's attitude and experience. Reasons for different management include water conservation, weed and pest control, biological activity promotion and soil fertility and biodiversity preservation. We studied different soil cover management in 16 paired vineyards located at eight sites in the Leithaberg and Carnuntum regions of eastern Austria. To this end, we compared inter‐rows with medium intensity (Periodically Mechanically Disturbed) and low intensity (Permanent Green Cover). We investigated the effects of these different management intensities on soil organic carbon, bulk density, saturated and unsaturated hydraulic conductivity, pore size distribution and percolation stability in the upper soil layer from 3 to 8 cm. Soil organic carbon and percolation stability were significantly higher and soil bulk density was significantly lower in vineyards with permanent green cover. No significant differences were observed for saturated hydraulic conductivity, pore size distribution and plant available water. This may be attributed to a minor effect as a result of the time lag of up to 2 years since the last tillage. Regression analysis to predict plant‐available water for local vineyard soils also showed that texture, total organic carbon and bulk density were suitable predictor variables. These results suggest that both investigated inter‐row management systems support a good soil structure for winegrowers. Organic carbon content and parameters interacting with organic carbon may still be improved with permanent vegetation cover systems; however, the positive effects on plant available water are limited.

CHALLENGES OF FASCIOLOSIS SPREADING IN CATTLE IN UKRAINE IN 2021-2023

The paper presents a comparative analysis of the epizootic process of cattle Fasciolosis dynamics in Ukraine from 2021 to 2023. The data are broken down by region. The risk zones are determined, and the territory of Ukraine is conditionally divided into dangerous, threatened, and temporarily not-dangerous areas. Grazing ruminants' helminths are common worldwide and harm cattle productivity and food security. The concern that climate change can increase the frequency and intensity of helminth infections has been growing. In Ukraine, this concern stems from case reports and theoretical life-cycle models, which allow us to assess the impact of climate change on helminth epidemiology. We believe that this study is the first attempt to investigate geographic and climatic trends in cattle helminth infections spreading by region. In the total of 474209 conducted tests, 6967 cases had positive results, and the average infection rate of cattle with Fasciola from 2021 to 2023 was 1.5 % in the regions with mild climate. Fasciolosis infection spread depends on the elevation of the farm and agricultural region. The studies show that meteorological changes can significantly contribute to understanding the impact of climate on infectious disease dynamics. If local environmental conditions are taken into account, the impact of climate change on disease dynamics can be clearer on a local scale. We recommend developing a strategy for extensive sample selection across Ukraine to monitor changes in helminthic disease risk and inform on adaptation strategies to increase productivity and protect the health of the cattle.

The combine impact of stock market, international investment and clean energy consumption on ecological footprint in emerging countries

Purpose Emerging nations strive to diminish their ecological impact to meet net-zero targets, yet encounter formidable hurdles in curbing their environmental footprint. This purpose necessitated the study into impact of stock market, renewable energy and international investment on the ecological footprint in emerging countries from 1990 to 2020. Design/methodology/approach The study used augmented mean group (AMG) estimator, cointegration and heterogenous panel causality approach. Findings Results from the AMG show that renewable energy consumption reduces environmental pollution in most countries except Mexico. The study disclosed that stock market capitalization decreases ecological footprint in emerging countries. Using both the Kao and Pedroni cointegration methods, the study affirms the existence of stable equilibrium relationship in the long term. The causality test concluded a bidirectional relationship between stock market and ecological footprint and a unidirectional link between international investment, clean energy and ecological footprint. Research limitations/implications The research is limited to only emerging countries. Therefore, future research should examine the environmental impacts of renewable energy consumption in different countries and regions, taking into account the local environmental conditions, policies and practices. This would help to identify the best practices and standards for minimizing the ecological footprint of renewable energy technologies and maximizing their benefits for environmental sustainability. Practical implications The study found that stock market capitalization reduces ecological footprint in Brazil, China, Turkey and India. To foster a culture of sustainability in stock market development impact, academic policies should emphasize the integration of environmental education across disciplines. By promoting awareness of the ecological consequences of stock market activities, societies can cultivate a mindset that values responsible economic practices. This, in turn, can lead to informed decision-making at individual and institutional levels. Social implications First, since the study found that clean energy reduces ecological footprint, advocating for utilization of clean energy sources could be a key priority in emerging countries. Governments should incentivize the development and adoption of renewable energy technologies, such as wind and solar power, by providing subsidies and tax benefits. Furthermore, increasing awareness among residents about the benefits of clean energy and promoting its utilization in both residential and commercial environments can expedite the transition to a more environmentally friendly energy combination. Originality/value First, it pioneers an exploration into the interplay between stock market capitalization, international investment, clean energy and ecological footprint in emerging countries. Secondary unlike, unlike prior research, this study uses methodologies that account for cross-sectional dependencies and a unique characteristic specific to each country. In addition, by using common correlated effects mean group, AMG, cointegration and causality procedures, this study distinctly isolates and analyzes empirical findings for each country, leading to policy-oriented outcomes.

Storing CO2 while strengthening concrete by carbonating its cement in suspension

Cement is a key constituent of concrete and offers a large sequestration potential of carbon dioxide (CO2). However, current concrete carbonation approaches are hindered by low CO2 capture efficiency and high energy consumption, often resulting in weakened concrete. Here, we conceptually develop and experimentally explore a carbonation approach that resorts to injecting CO2 into a cement suspension subsequently used to manufacture concrete, turning the carbonation reaction into an aqueous ionic reaction with a very fast kinetics compared to traditional diffusion-controlled approaches. This approach achieves a CO2 sequestration efficiency of up to 45% and maintains an uncompromised concrete strength. The study shows that the CO2 injection rate influences the polymorph selectivity of mineralized calcium carbonate (CaCO3) depending on the local environmental conditions and impacts the strength of concrete. The technological simplicity of the proposed approach enables a reduced carbon footprint and promising prospects for industrial implementation.

Environmental quality of the Paraim River springs, far south of Piauí

The small flows of runoff give rise to water bodies which, through their multiple uses, contribute to satisfying the basic vital needs of animals, plants and ecosystems. Spring areas play an important role in maintaining the environmental quality of the basin. To this end, it is essential that these areas have an effective conservation policy. The aim of this study was to determine the environmental quality of the Paraim River's spring areas, emphasizing the physical-chemical and biological quality of the water and characterizing local environmental conditions through macroscopic assessment. Visits were made to seven of the Paraim River's perennial springs and the macroscopic assessment made it possible to identify the impacts observed in the springs and permanent preservation areas, access conditions, proximity to rural centers and types of use of the springs. The physical-chemical and microbiological parameters of the water were assessed and compared with Resolution 357/2005 of the National Environment Council (CONAMA) and the Water Quality Index (IQA). The macroscopic assessment of the springs showed that 57.1% of the springs were rated as "excellent" or "good" and only one spring was rated as "very bad". Determining the WQI of the springs resulted in values varying between 59 and 86 in the dry season and between 56 and 89 in the rainy season. This shows that all the springs evaluated had satisfactory WQIs ("good" or "excellent"). The assessment of water quality made it possible to observe the relationship between the quality parameters, as well as their influence on the macroscopic characteristics of the springs. In this way, the information obtained indicates that, despite the good quality of the water, the assessment of the environmental situation of the springs warns of the need for future strategies aimed at planning for land use and environmental management of micro-watersheds.

Sezonowa i przestrzenna zmienność jakości wody w systemie jezior Lumina-Rosu w delcie Dunaju w Rumunii

The main aim of the present scientific paper is to assess water quality of the surface water of various lakes located in the Lumina-Rosu interdistributary depression, Danube Delta, Romania. As specific objectives, the paper considered to spot the main potential sources of contamination and their environmental impacts on aquatic ecosystems. Equally, the purpose of the article is to emphasize the importance of monitoring the water quality of the Danube Delta, for preserving these unique natural water resources and their ecosystem services (fresh water, biodiversity, flood control, recreation, nutrient cycling, fishing and other traditional activities, ecotourism). Surface water samples collected from several control sections situated on the main tributaries and canals, as well as from lakes were investigated physically (To - C, EC - μS/cm, TDS - mg/L, turbidity - NTU units, TSS - mg/L) and chemically (pH - units, DO - mg/L, N-NO2- - mg/L, N-NO3- - mg/L, P-PO43-- mg/L, Chla - mg/L, SiO2 - mg/L, TOC - mg/L, SO42- - mg/L, S2- - mg/L, H2S - mg/L and synthetic detergents - mg/L). Generally, the hydro-physical-chemical characteristics and water quality assessment of the surface waters of the lakes manifest the combined effect of both processes occurred in the catchment (weathering, sediment supply and transport), as well as the in situ lake processes (photosynthesis, sediment mixing, biogeochemical cycling, evaporation, eutrophication, productivity changes). Overall, the physical and chemical characteristics of the sampling sites investigated at high waters of the Danube are quite similar to those measured at low waters. The differences that mainly occurred within the lakes are more related to the limnological variables and the local environmental conditions. Anyway, a significant seasonal variation was noticed in the lakes, during the dry period, when different physical and chemical characteristics appeared to be influenced by high air temperature, lack of precipitation, low water level regime, low dissolved oxygen level regime, all related to climate change effects etc. Moreover, the anthropogenic factor that left its mark on some physical-chemical characteristics of water should not be omitted either. However, the results obtained within this study did not show such alarming values as might have dangerous effects on the investigated aquatic environments. The water quality information within this case study may be used for improving the understanding of the water quality issues and to better coordinate and plan for future monitoring activities in and around the Danube Delta environment. The results will contribute to updating the existing database with relevant information for a sustainable future of the Danube Delta and in similar areas that are subjected to such environmental challenges.

Bottom-up effects drive the dynamic of an Antarctic seabird predator-prey system.

Understanding how populations respond to variability in environmental conditions and interspecific interactions is one of the biggest challenges of population ecology, particularly in the context of global change. Although many studies have investigated population responses to climate change, very few have explicitly integrated interspecific relationships when studying these responses. In this study, we aimed to understand the combined effects of interspecific interactions and environmental conditions on the demographic parameters of a prey-predator system of three sympatric seabird populations breeding in Antarctica: the south polar skua (Catharacta maccormicki) and its two main preys during the breeding season, the Adélie penguin (Pygoscelis adeliae) and the emperor penguin (Aptenodytes forsteri). We built a two-species integrated population model (IPM) with 31 years of capture-recapture and count data and provided a framework that made it possible to estimate the demographic parameters and abundance of a predator-prey system in a context where capture-recapture data were not available for one species. Our results showed that predator-prey interactions and local environmental conditions differentially affected south polar skuas depending on their breeding state of the previous year. Concerning prey-predator relationships, the number of Adélie penguin breeding pairs showed a positive effect on south polar skua survival and breeding probability, and the number of emperor penguin dead chicks showed a positive effect on the breeding success of south polar skuas. In contrast, there was no evidence for an effect of the number of south polar skuas on the demography of Adélie penguins. We also found an important impact of sea ice conditions on both the dynamics of south polar skuas and Adélie penguins. Our results suggest that this prey-predator system is mostly driven by bottom-up processes and local environmental conditions.

Acoustic phenology of tropical resident birds differs between native forest species and parkland colonizer species

Most birds are characterized by a seasonal phenology closely adapted to local climatic conditions, even in tropical habitats where climatic seasonality is slight. In order to better understand the phenologies of resident tropical birds, and how phenology may differ among species at the same site, we used ~70 000 hours of audio recordings collected continuously for two years at four recording stations in Singapore and nine custom‐made machine learning classifiers to determine the vocal phenology of a panel of nine resident bird species. We detected distinct seasonality in vocal activity in some species but not others. Native forest species sang seasonally. In contrast, species which have had breeding populations in Singapore only for the last few decades exhibited seemingly aseasonal or unpredictable song activity throughout the year. Urbanization and habitat modification over the last 100 years have altered the composition of species in Singapore, which appears to have influenced phenological dynamics in the avian community. It is unclear what is driving the differences in phenology between these two groups of species, but it may be due to either differences in seasonal availability of preferred foods, or because newly established populations may require decades to adjust to local environmental conditions. Our results highlight the ways that anthropogenic habitat modification may disrupt phenological cycles in tropical regions in addition to altering the species community.

Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration

The surface chemistry of pyrrhotites from intact particles directly collected from asteroid (162173) Ryugu was investigated by micro-Raman spectroscopy. The Raman peak characteristic to pyrrhotite was observed at around 115 cm−1 in Ryugu pyrrhotites, similar to freshly cleaved surfaces of terrestrial pyrrhotites. Additional Raman bands centered at around 220, 275, and 313 cm−1 with broadened features were also detected from the Ryugu pyrrhotites. The set of Raman bands at 220 and 275 cm−1 was assigned to typical Fe-S stretching vibrations of ν2 (225 cm−1) and ν1 (275 cm−1). These bands are not clearly observed in bulk crystals of pyrrhotite but appear in its nanoparticulate phase. These bands are ordinarily seen in amorphous monosulfides that formed under low oxygen fugacity (fO2) conditions in nature, indicating that the structural alteration of pyrrhotite surfaces occurred heterogeneously on the nanoscale under low fO2 conditions. Further, the Raman band at 313 cm−1 was attributed to a characteristic tetrahedral bonding of Fe(III) in the lattice of FeII1-3xFeIII1-2xS, followed by the local breakdown of the crystal lattice structures from planar bonding with Fe(II). In addition, some areas of the Ryugu pyrrhotite grains showed corroded structures with iridescence. Furthermore, assemblages of magnetite particles were also preferentially observed on small areas of the likely-dissolved pyrrhotite crystals in phyllosilicate matrices. These characteristic features in the Raman spectra and in corroded structures of Ryugu pyrrhotites record changes in the local environmental conditions via aqueous alteration. The corrosion of pyrrhotite crystals followed by the preferential formation of magnetite particles by asteroidal water is the likely product of dissolution of Fe(II) from the pyrrhotite surface and its oxidative precipitation in microchemical environments on the Ryugu parent body.