Field Of Ecology Research Articles

Transient dispersion of settling gyrotactic microorganisms in an open channel flow

Dispersion of microorganisms is a key issue in bio-physics and has many applications in the fields of algae cultivation, biomass energy, and wetland ecology. However, there has been limited exploration of the effects of settling behavior and initial release conditions on the transient dispersion of gyrotactic microorganisms. This paper explores the transient dispersion of settling gyrotactic microorganisms in an open channel flow. The moment equations derived from the Smoluchowski equation are solved by the biorthogonal expansion method, and the results are compared with random walk simulations, showing good agreement. The time variations of concentration distribution, drift velocity, and dispersivity of settling gyrotactic microorganism suspension are explored in detail under typical initial release conditions. As illustrated and characterized, settlement weakens the gravitactic focusing of microorganisms near the free surface, leads to accumulation at the bottom, and increases the dispersivity; from a line source release, the relaxation time is shortest, and the microorganisms scatter fastest in the longitudinal direction, while the point source at the water surface leads to the most concentrated longitudinal distribution and the highest drift velocity; furthermore, the initial release condition assumes an important role in shaping the concentration distribution and drift velocity.

A dataset of soil organic carbon density of typical ecosystems in the arid areas of Northwest China from 2005 to 2020

The soil organic carbon pool is the largest and most active part of the terrestrial ecosystem carbon pool, and plays an important role in the global carbon cycle and global climate change. The arid region of northwest China is located in the hinterland of Eurasia, with extremely fragile ecosystems and extremely sensitive responses to climate change. It is a hot area that many scholars have paid attention to in recent years, and the estimation and spatial distribution characteristics of soil organic carbon storage have increasingly become one of the research focuses in this region. However, insufficient data sharing and the relative lack of measured data are important factors causing the uncertainty of the research results. Based on the long-term soil observation data collected from the ecological field stations of China Ecosystem Research Network (CERN) located in five provinces and regions of northwest China, the soil organic carbon density dataset of typical ecosystems in the arid region of Northwest China was calculated by organic carbon estimation model. This dataset contains the soil organic carbon density data of topsoil (0-20 cm) and soil profile of various long-term observation plots at 11 ecological field stations from 2005 to 2020, in order to provide valuable measured data for the estimation of soil carbon storage and the study of carbon cycle process in the arid area of northwest China.

Adaptation and Response in Drylands (ARID): Community Insights for Scoping a NASA Terrestrial Ecology Field Campaign in Drylands

Adaptation and Response in Drylands (ARID): Community Insights for Scoping a NASA Terrestrial Ecology Field Campaign in Drylands

A dataset of monthly potential evapotranspiration at ecological stations in arid central Asia from 2005 to 2020

The potential evapotranspiration represents the atmospheric evaporation capacity, which is an important indicator to measure the regional evaporation capacity, and also a key parameter to evaluate drought degree, the balance between supply and demand of water resources, and the water consumption of vegetation. Based on the meteorological data collected by 12 ecological field stations of Central Asia Ecosystem Monitoring Network and 11 ecological field stations of China Ecosystem Research Network in the arid region of Northwest China, and by using Penman-Monteith method recommended by FAO, the potential evapotranspiration was calculated from 2005 to 2020. This dataset has a long time series and covers a variety of ecosystem types. It can be used as basic data, model input data, simulation result verification data for drought research in Central Asia, and also provide data support for the research on the rational development and utilization of water resources, ecological environmental protection and other aspects in this region.

Development and Application of Surface-Enhanced Raman Scattering (SERS).

Since the discovery of the phenomenon of surface-enhanced Raman scattering (SERS), it has gradually become an important tool for the analysis of material compositions and structures. The applications of SERS have been expanded from the fields of environmental and materials science to biomedicine due to the extremely high sensitivity and non-destructiveness of SERS-based analytical technology that even allows single-molecule detection. This article provides a comprehensive overview of the surface-enhanced Raman scattering (SERS) phenomenon. The content is divided into several main sections: basic principles and the significance of Raman spectroscopy; historical advancements and technological progress in SERS; and various practical applications across different fields. We also discuss how electromagnetic fields contribute to the SERS effect, the role of chemical interactions in enhancing Raman signals, a modeling and computational approaches to understand and predict SERS effects.

Decision tree learning with random forest models using agricultural and ecological field data incorporating multi-factor studies and covariate structure

Decision tree learning with random forest models using agricultural and ecological field data incorporating multi-factor studies and covariate structure

A dataset of acoustic measurements from soundscapes collected worldwide during the COVID-19 pandemic

Political responses to the COVID-19 pandemic led to changes in city soundscapes around the globe. From March to October 2020, a consortium of 261 contributors from 35 countries brought together by the Silent Cities project built a unique soundscape recordings collection to report on local acoustic changes in urban areas. We present this collection here, along with metadata including observational descriptions of the local areas from the contributors, open-source environmental data, open-source confinement levels and calculation of acoustic descriptors. We performed a technical validation of the dataset using statistical models run on a subset of manually annotated soundscapes. Results confirmed the large-scale usability of ecoacoustic indices and automatic sound event recognition in the Silent Cities soundscape collection. We expect this dataset to be useful for research in the multidisciplinary field of environmental sciences.

Exponential growth model of weevil populations: a didactic experiment for undergraduate course of Population Ecology

Exponential model for population growth (exponential model) is a foundation to evaluate population dynamics in Population Ecology field. Here, we used a didactic experiment to teach exponential model for an undergraduate course of Population Ecology. We built nine populations of weevils with three different initial population sizes: eight, 16, and 32 individuals with three replicates each. We provided equal food resource availability, and counted their population sizes weekly for 12 weeks. We estimated the intrinsic growth rate (i.e., r parameter), by trials and errors with an exponential model build in an Excel spreadsheet. The population growth rate (i.e., dN/dt parameter) was estimated using r values. Replicates with eight and 16 individuals reached the highest values of r and dN/dt, while replicates with 32 individuals reached the lowest values. Beyond of exponential model, two density dependency issues acting in populations were observed. First, in the lowest initial population sizes we observed the effect of demographic stochasticity acting in both r and dN/dt in one of the three populations. Second, we observed the intraspecific competition reducing r values in largest initial populations. Therefore, we highlight the importance of didactic experiment into learning exponential model in Population Ecology course, both for teaching and learning practices.

James O 'Connor's Ecological Thought and its Practical Enlightenment

James O 'Connor's ecological thought was born in the middle and late 20th century. By using the unique theory of double contradiction and double crisis of capitalism, James O 'Connor revealed the global ecological crisis caused by the development of capitalism, outlined a new model of ecological socialism, and tried to find a feasible path to solve the global ecological crisis. To mitigate the adverse effects of the ecological crisis on the capitalist world. James O 'Connor's ecological thought has been widely discussed by the academic community since it was put forward. Subsequently, many scholars in the field of ecology have analyzed and studied James O 'Connor's thought. Through the organic combination with the current actual situation and practical experience, they began to apply James O 'Connor's ecological thought to the management of ecological problems. The construction of ecological civilization in our country is also developing continuously, and O 'Connor's ecological thought has a very positive enlightening and instructive significance to the construction of ecological civilization in our country.

Exogenous Substances Used to Relieve Plants from Drought Stress and Their Associated Underlying Mechanisms.

Drought stress (DS) is one of the abiotic stresses that plants encounter commonly in nature, which affects their life, reduces agricultural output, and prevents crops from growing in certain areas. To enhance plant tolerance against DS, abundant exogenous substances (ESs) have been attempted and proven to be effective in helping plants relieve DS. Understanding the effect of each ES on alleviation of plant DS and mechanisms involved in the DS relieving process has become a research focus and hotspot that has drawn much attention in the field of botany, agronomy, and ecology. With an extensive and comprehensive review and summary of hundred publications, this paper groups various ESs based on their individual effects on alleviating plant/crop DS with details of the underlying mechanisms involved in the DS-relieving process of: (1) synthesizing more osmotic adjustment substances; (2) improving antioxidant pathways; (3) promoting photosynthesis; (4) improving plant nutritional status; and (5) regulating phytohormones. Moreover, a detailed discussion and perspective are given in terms of how to meet the challenges imposed by erratic and severe droughts in the agrosystem through using promising and effective ESs in the right way and at the right time.

How human activities affect and reduce ecological sensitivity under climate change: Case study of the Yangtze River Economic Belt, China

Ecological sensitivity (ES) shows the adaptability of ecosystem. As anthropogenic activities and climatic change intensify, they affect ES individually and interactively. Thus, clarifying the effects of anthropogenic activities and climatic change on ES, and grading them to improve them, is beneficial for improving the ecological resilience and sustainable development of the region. However, few studies focus on the effects of climate-anthropogenic interactions on ES. According to data from 130 cities in the Yangtze River Economic Belt (YREB), this study constructs index systems of ES, anthropogenic activities and climate change. And response surface methodology (RSM) is utilized to analyze the effects of factors acting alone and interacting on ES, as well as the ecological improvement paths under different climatic condition. The results manifest that: (1) From years 2001–2021, the ES of the YREB fluctuates in time, increasing by 2.2%, due to declining biological abundance and water network density. Spatially, it displays a spatial distribution of “high in the north and low in the south.” In 2021, the percentages of cities in the YREB with relatively high and high sensitivity reach nearly 50%. (2) Among the climatic and anthropogenic factors, the proportions of cities where urbanization, advanced industrial structure, precipitation and temperature factors individually significantly affected ES is 67.7%, 63.1%, 56.2% and 54.6%, respectively, suggesting that all these factors have a significant impact on ES in most of the YREB. The proportion of negative interaction effects in the significant interaction between anthropogenic and climatic factors is 78.6%, indicating that most of the climatic factors have an inverse role in the anthropogenic effect on ES. (3) Improvement paths for areas with high sensitivity (27 cities) are found by RSM. A total of 24 cities can reduce ES by harmonizing anthropogenic factors under different climatic conditions. Meanwhile, 17 cities should take targeted measures in the light of climate change. This study proposes relevant recommendations for zoning governance, which is expected to provide enlightening opinions for the field of regional ecological governance. Meanwhile, it provides ideas for the in-depth application of RSM in the ecological field.

Unsettling extractivism: Indigeneity, race, and disruptive emplacements

AbstractDrawing inspiration from new work across the fields of political ecology, plantation and abolition studies, critical Indigenous studies, and racial capitalism, this Introduction to a special issue of The Journal of Latin American and Caribbean Anthropology locates extraction within an account of property as a system of racialized exploitation. Aware of the risks of a cosmopolitics that romanticizes non‐Western value systems as largely untouched by extractivism, in this Introduction and in the articles themselves, we center the question of how Indigenous communities and others navigate extractivism in places and landscapes that have been deeply impacted and partly transformed by resource mining, agrarian monoculture, and deforestation. In voicing demands not subordinated by a materialist and secular language of resource exploitation, these accounts invite a less deterministic account of “our” late capitalist present. We contend that just as extraction is not monolithic, neither are its refusals, resistances, and alternatives.

Estimating taxonomic and functional structure along a tropical estuary: linking metabolic traits and aspects of ecosystem functioning.

Microbial life forms are among the most ubiquitous on Earth, yet many remain understudied in Caribbean estuaries. We report on the prokaryote community composition of the Urabá Estuary in the Colombian Caribbean using 16S rRNA gene-transcript sequencing. We also assessed potential functional diversity through 38 metabolic traits inferred from 16S rRNA gene data. Water samples were collected from six sampling stations at two depths with contrasting light-penetration conditions along an approximately 100 km transect in the Gulf of Urabá in December 2019. Non-metric multidimensional scaling analysis grouped the samples into two distinct clusters along the transect and between depths. The primary variables influencing the prokaryote community composition were the sampling station, depth, salinity, and dissolved oxygen levels. Twenty percent of genera (i.e., 58 out 285) account for 95% of the differences between groups along the transect and among depths. All of the 38 metabolic traits studied showed some significant relationship with the tested environmental variables, especially salinity and except with temperature. Another non-metric multidimensional scaling analysis, based on community-weighted mean of traits, also grouped the samples in two clusters along the transect and over depth. Biodiversity facets, such as richness, evenness, and redundancy, indicated that environmental variations-stemming from river discharges-introduce an imbalance in functional diversity between surface prokaryote communities closer to the estuary's head and bottom communities closer to the ocean. Our research broadens the use of 16S rRNA gene transcripts beyond mere taxonomic assignments, furthering the field of trait-based prokaryote community ecology in transitional aquatic ecosystems.IMPORTANCEThe resilience of a dynamic ecosystem is directly tied to the ability of its microbes to navigate environmental gradients. This study delves into the changes in prokaryote community composition and functional diversity within the Urabá Estuary (Colombian Caribbean) for the first time. We integrate data from 16S rRNA gene transcripts (taxonomic and functional) with environmental variability to gain an understanding of this under-researched ecosystem using a multi-faceted macroecological framework. We found that significant shifts in prokaryote composition and in primary changes in functional diversity were influenced by physical-chemical fluctuations across the estuary's environmental gradient. Furthermore, we identified a potential disparity in functional diversity. Near-surface communities closer to the estuary's head exhibited differences compared to deeper communities situated farther away. Our research serves as a roadmap for posing new inquiries about the potential functional diversity of prokaryote communities in highly dynamic ecosystems, pushing forward the domain of multi-trait-based prokaryote community ecology.

Carbon dots-doped melamine–formaldehyde microsphere as a dual functional material for sensing and adsorption of oxytetracycline

The abuse of oxytetracycline (OTC) leaves serious environmental residues and triggers accumulation in organisms, constituting a threat to human health. Constructing an effective platform based on dual-functional materials for monitoring and removing OTC residues is a preferable solution. Herein, we proposed a novel composite material by doping carbon dots (CDs) into melamine–formaldehyde microsphere (MFM) through a one-pot method and named CDs@MFM, which inherited the fluorescence property of CDs and porous structure of MFM simultaneously. CDs@MFM demonstrated dual functions for the detection and removal of OTC concurrently within a few minutes, with its performance compared in detail with bare CDs and MFM as controls. By virtue of the pre-enrichment effect attributed to its porous structure, CDs@MFM exhibited a lower detection limit for OTC than bare CDs (0.027 mg/L vs 0.067 mg/L) and a higher adsorption capacity than MFM (73.01 mg/g vs 68.76 mg/g) resulting from more affiliated functional groups available for OTC provided by the CDs. Overall, CDs@MFM has proven to be an efficient and convenient candidate capable of monitoring and removing OTC synchronously, and this work offers an avenue for the design of dual-functional materials in the field of environmental science.

Ultra-sensitive DNA detection with single-base mismatch resolution using a tapered thin-diameter photonic crystal fiber interferometer

A tapered thin-diameter photonic crystal fiber interferometer (TTD-PCFI) biosensor is proposed and demonstrated for DNA hybridization detection with an ultra-low limit of detection (LoD) and high specificity. The TTD-PCFI is fabricated by arc-discharged melting and adiabatic tapering, with a lower loss and stronger evanescent optical field. The fabricated TTD-PCFI with a diameter of 8.63 µm achieves a high refractive index sensitivity of 3842.5 nm/RIU. DNA hybridization detection of concentration ranging from 1 fM to 1 pM is achieved, with a sensitivity of 632 pm/lg(fM). The measured LoD is as low as 410 aM. Single-base mismatch detection of 25-base target single-stranded DNA is also achieved. The proposed label-free DNA biosensor has the advantages of the ultra-low LoD, high specificity, and real-time detection, which has great application prospects in the fields of disease diagnosis, microbial detection, and environmental science.

Spatial patterning and species coexistence: A case study using concentric circular vegetation patches in saline land

Spatial patterns in plant community structures within stressed ecosystems have drawn much attention in the field of ecology. However, the mechanisms underlying spatial formation and its impact on species coexistence and diversity remain controversial. In this study, we investigated concentric circular vegetation patches in coastal saline land, and analysed the spatial patterning of plant communities and associated soil physicochemical properties. Thereafter, we tested how the soil conditioned by plant communities from different locations within the vegetation patches influence the species growth and inter-specific competition. Our results show soil salinity enlarges in a centrifugal manner in horizontal direction in all patches. Soil salinity decreased and species diversity increased along with the increase of patch size. In addition, we found significant shifts in both the composition of plant communities and in soil physicochemical properties from outer to center. The results indicate that the pioneer species Suaeda salsa facilitated the subsequent species. However Suaeda salsa was inhibited and became inferior competitor in the soil conditioned by the subsequent species. We infer that the less-visible spatial patterns of soil physicochemical properties at small scales create ecological niches for specialized species, allowing them to coexist but not mix. We suggest that a trade-off between tolerance to salt stress and competitive ability under ameliorated conditions may underlie mechanisms of pattern formation in small scale. Our findings lend support to the idea that soil stress constraints community assembly and triggers spatial patterns, which, in turn, buffer the stress on plant communities and enhance species diversity.

Sonochemical deposition of gold nano-shells on suspended polymeric spheres

Metal nanoparticles have drawn great interest due to their unique properties for applications in the fields of catalysis, biomedicine and environmental science depending on the architecture of the metal nanoparticle composites. Amongst different designing routes, the chemical template deposition offers great flexibility in terms of the template selection and interfacial interactions, giving rise to controllable designs. In order to control over nanoparticle size distribution and deposition efficiency, a sonochemical approach has been systematically followed in this study. Key parameters of the ultrasound-assisted deposition procedures during the seeding step to synthesise gold nanoparticle-coated poly(styrene) beads were investigated. The impact of the solution pH and the ultrasonic frequency on the template deposition was examined at 139, 300, 500 and 1000 kHz. The results, monitored by transmission electron spectroscopic imaging, show that the highest gold deposition was achieved at 300 kHz, revealing the mechanistic details of the nucleation-crystal growth behaviour as a function of ultrasonic frequency and reaction time. In addition, the concentration ratio between gold ions and poly(styrene) beads was varied. The highest deposition coverage and smallest particle size were reached at 0.05 mM and 2.5 mg, respectively. The proposed mechanism of the MNPs formation and deposition behaviour were then discussed based on the tested parameters.

Investigating fish reproduction phenology and essential habitats by identifying the main spatio-temporal patterns of fish distribution

Abstract Fish spawning phenology is a major concern for conservation and fisheries management. New intensive data sources, such as GPS-based tracking data and high-resolution catch declaration data, are becoming increasingly available in the field of marine ecology. These data benefit from high spatiotemporal resolution and open new research avenues for investigating the interannual variability in fish phenology. In this paper, we demonstrate how an integrated species distribution model informed by commercial catch data combined with spatiotemporal dimension reduction methods known as empirical orthogonal functions (EOFs) can be used to synthesize spatiotemporal signals in fish reproduction phenology. Specifically, we address the following questions: (1) Can we identify seasonal spatial patterns that can be interpreted in terms of reproductive phenology and essential habitats? (2) Can we identify changes in reproductive phenology over time? (3) Are these changes related to environmental drivers? The analysis illustrates the reproductive phenology of three key commercial species in the Bay of Biscay (sole, hake, and sea bass). The EOF analysis emphasized strong seasonal spatiotemporal patterns that correspond to reproduction patterns and feeding patterns. Based on this methodology, we identified seasonal variations in the timing of reproduction, and we related these variations to sea surface temperature, a key driver of fish reproduction.

Emissions from Ethiopian clinker-producing cement factories and their impact on community well-being

In the realm of cement production, clinker-producing factories emerge as both energy and material-intensive entities, emitting a substantial array of primary pollutants into the environment compared to their non-clinker-producing counterparts. This study investigates the emissions from clinker-producing cement factories in Ethiopia and their impact on community well-being. We specifically focus on particulate matter (PM2.5 and PM10) and gaseous emissions (CO2, N2O, SO2) measured at various units within the cement factories and nearby residential areas. The study area includes major industry players such as Derba Cement plant, National Cement Share Company, Mugher Cement Enterprise, Ethio Cement P.L.C, Dangote Cement plant, Habesha Cement, and Pioneers Cement Share Company. The pollutants were measured using standard instruments, including the portable Aeroqual Series-500 Gas Sensor (S-500) for both particulate matters and gases, with sampling conducted from August 1, 2021, to January 30, 2022. We analyzed the potential health impacts of these emissions, particularly respiratory diseases, among different age groups. The findings underscore the urgent need for regulatory measures to mitigate cement particulate emissions and protect community health. Our study provides valuable insights into the environmental and health risks associated with clinker-producing cement factories in Ethiopia, contributing to the broader field of environmental science.

الإنسان وبيئة الوسيط الرقمي: تأثير مواقع التواصل الاجتماعي على طرق تفكير وتعبير الإنسان

This paper seeks, using the interpretive philosophical approach, to look into the issue of the impact of digital media on human life and ways of thinking and expression. This paper aims to analyze this issue interpretatively and link it to historical transformations in the field of media ecology in order to adopt a forward-looking view instead of a numerical analysis of the available information. The issue, as this paper sees it, lacks the philosophical dimension to discuss the characteristics of social media and link changes that these social media have brought on humans with changes that humans have brought on various concepts such as culture, thought, and society. This paper concluded that social media are a different revolution in communication media. It changed the procedures of the communication process, bringing the margin groups into the position of the elites and returning the elites to a position that is close to the position of the margin groups. The margins have become the agent that determines the ways of building new social relationships and carries out the process of transforming from traditional relationships to digital relationships. Thus, concepts change and are shaped by a different perception (the margin group). By carefully reading the characteristics of three social media (Twitter, Facebook, and WhatsApp), three common characteristics and features emerged that shaped and influenced their users: openness, permanence and continuity, and changing concepts.