Global Warming Conditions Research Articles

Flood vulnerability analysis using geographic information system in the core zone of the Lore Lindu biosphere reserve, Indonesia

Floods are caused by the accumulation of several factors, such as global warming, climatological characteristics, hydrology, and physical conditions of an area. The purpose of this study was to map the level of flood vulnerability in the core zone of the Lore Lindu Biosphere Reserve using geographic information system (GIS) based spatial analysis with scoring and overlay. The research parameters consisted of rainfall, elevation, slope, soil type, land cover, and distance from the river. This research was conducted in the core zone divided into 13 subdistricts and 2 regencies. The results of the classification of flood vulnerability levels are divided into 4 (four) categories: not prone, low vulnerability, moderate vulnerability, and high vulnerability. The results of the analysis show that the core zone of the Lore Lindu biosphere reserve is dominated by a non-hazardous site with an area of 145,018’28 ha (67.23%), a low vulnerability zone of 65,430.10 ha (30.33%), a moderate vulnerability zone of 5,025.29 ha (2.33%), and a high vulnerability zone of 245.99 ha (0.11). Areas with a high level of vulnerability are at low elevations with flat to gentle slopes. Most land use is dominated by water, mining, and open land without vegetation and is located around rivers.

Vanadium Toxicity Is Altered by Global Warming Conditions in Sea Urchin Embryos: Metal Bioaccumulation, Cell Stress Response and Apoptosis.

In recent decades, the global vanadium (V) industry has been steadily growing, together with interest in the potential use of V compounds as therapeutics, leading to V release in the marine environment and making it an emerging pollutant. Since climate change can amplify the sensitivity of marine organisms already facing chemical contamination in coastal areas, here, for the first time, we investigated the combined impact of V and global warming conditions on the development of Paracentrotus lividus sea urchin embryos. Embryo-larval bioassays were carried out in embryos exposed for 24 and 48 h to sodium orthovanadate (Na3VO4) under conditions of near-future ocean warming projections (+3 °C, 21 °C) and of extreme warming at present-day marine heatwave conditions (+6 °C, 24 °C), compared to the control temperature (18 °C). We found that the concomitant exposure to V and higher temperature caused an increased percentage of malformations, impaired skeleton growth, the induction of heat shock protein (HSP)-mediated cell stress response and the activation of apoptosis. We also found a time- and temperature-dependent increase in V bioaccumulation, with a concomitant reduction in intracellular calcium ions (Ca2+). This work demonstrates that embryos' sensitivity to V pollution is increased under global warming conditions, highlighting the need for studies on multiple stressors.

The formation of a crop of fodder and semi-sugar beet under irrigation in conditions of global warming

Relevanse. To reduce the negative impact of drought on the production process of agrocenoses of field crops, the entire complex of agrotechnical and reclamation measures should be used to ensure increased drought resistance of crops in the structure of crop rotations for various purposes.The purpose of our research was to study the dynamics of the growth of the raw mass of root crops and the collection of dry matter by the periods of growth and development of fodder and semi-sugar beet at different moisture levels of the root layer of the soil.Material and methodology. The research was carried out in a specially built arid zone, which is a 3x20 m plot, isolated from soil moisture to a depth of 1.5 m by a clay castle along the periphery and a dense reinforced polyethylene film between the variants. The arid area was divided into four plots, each with an area of 15 m2 (3x5 m), in which a different level of moisture supply was maintained throughout the growing season. The variety of fodder beet Eckendorf yellow and semi–sugar beet – Semi-sugar pink variety were used as the object of research.Results. It has been established that at all values of humidity, the maximum accumulation of the raw mass of root crops in both varieties was noted in the second period of growth and development of plants, which lasts an average of 60 days and lasts from the beginning of closing of crops in rows to the beginning of opening in row spacing. Among the studied irrigation regimes, the option should be recognized as optimal, where during the growing season the relative humidity of the root layer at a depth of 1 m is maintained at the level of 70-75% of the WPV. With such moisture, the yield of root crops for fodder beet is 855 centners/ha, for semi-sugar beet – 679 centners/ha, and the collection of dry matter – 120.54 and 156.33 centners/ha, respectively. With a further increase in humidity to 75-80% of the FPV, the increase in yield and collection of dry matter per 1 ha of crops for both beet varieties is within the statistical error of the experiment, however, the cost of irrigation water for the formation of 1 q of dry matter increases by an average of 2.2 times, which negatively affects the cost of grown products. It has been proven that the optimal regime of soil moisture is provided by the irrigation scheme according to the periods of growth and development of plants 1 3 1; irrigation rate – 400 m3/ha, irrigation rate – 2000 m3/ha.

Ten tips from the Swiss Working Group on Sustainable Nephrology on how to go green in your dialysis unit.

The health-care system and particularly renal replacement therapy has a significant carbon footprint adding to global warming and extreme weather conditions. Improving sustainability has become the focus of national and international working groups. Many reviews underline the need for improvement of sustainability in nephrology, in particular dialysis, and provide recommendations on how to reduce waste, energy, and water consumption. However, how to implement these recommendations, and where to start, is not always clear. This paper summarizes discussions within the 'working group on sustainable nephrology' of the Swiss Society of Nephrology. We do not provide a detailed review of the topic but instead present a practical 10-point action plan to help health-care workers in nephrology make a start and improve the carbon footprint of their dialysis centres. We emphasize the importance of ongoing research, cooperation, and dialogue, and welcome additional ideas from the wider renal community.

Real-time emulation of future global warming reveals realistic impacts on the phenological response and quality deterioration in rice

Decreased production of crops due to climate change has been predicted scientifically. While climate-resilient crops are necessary to ensure food security and support sustainable agriculture, predicting crop growth under future global warming is challenging. Therefore, we aimed to assess the impact of realistic global warming conditions on rice cultivation. We developed a crop evaluation platform, the agro-environment (AE) emulator, which generates diverse environments by implementing the complexity of natural environmental fluctuations in customized, fully artificial lighting growth chambers. We confirmed that the environmental responsiveness of rice obtained in the fluctuation of artificial environments is similar to those exhibited in natural environments by validating our AE emulator using publicly available meteorological data from multiple years at the same location and multiple locations in the same year. Based on the representative concentration pathway, real-time emulation of severe global warming unveiled dramatic advances in the rice life cycle, accompanied by a 35% decrease in grain yield and an 85% increase in quality deterioration, which is higher than the recently reported projections. The transcriptome dynamism showed that increasing temperature and CO2 concentrations synergistically changed the expression of various genes and strengthened the induction of flowering, heat stress adaptation, and CO2 response genes. The predicted severe global warming greatly alters rice environmental adaptability and negatively impacts rice production. Our findings offer innovative applications of artificial environments and insights for enhancing varietal potential and cultivation methods in the future.

Impact of Drought in Northeastern Algeria: Comparative Study of the SPI and SPEI Índices

Purpose: The study aimed to evaluate drought trends in Annaba, Algeria, considering global warming and extreme weather, using quantitative indices for improved drought comprehension and prediction. Theoretical Framework:The study assesses changes in drought frequency and severity in the Annaba region of Algeria due to global warming and extreme weather conditions. It employs quantitative indices to enhance drought understanding and prediction. Methodology: The study analyzes temperature and precipitation data (1981-2021) from an Annaba weather station to assess drought characteristics.Standardized indices (SPI, SPEI) and extreme value analysis (Generalized Pareto Distribution) are used to quantify drought intensity, duration, and temperature impacts. Findings: Our analyses reveal a critical divergence in drought assessment tools. While stable monthly temperatures suggest a constant influence on evapotranspiration, the SPEI index (including temperature) indicates increasing drought compared to the precipitation-only SPI. This highlights the importance of considering temperature alongside precipitation for accurate drought assessment. Research Practical and Social Implication: This study emphasizes the significance of considering the interplay among temperature, precipitation, and evapotranspiration for better understanding and predicting drought changes in the Annaba region, Algeria. These insights are crucial for sustainable water resource management and climate change adaptation in the region. Originality/Value:This study distinguishes itself by its comprehensive analysis of long-term climate data to examine drought trends in a specific region (Annaba, Algeria) severely impacted by climate change. By comparing the effectiveness of two drought indices (SPEI and SPI), it offers valuable insights into how to improve drought assessments by considering the role of temperature in evapotranspiration. This research enriches the existing literature on drought management and climate change adaptation, providing a valuable case study for similar arid and semi-arid regions worldwide.

An abrupt regime shift of bacterioplankton community from weak to strong thermal pollution in a subtropical bay.

Thermal pollution from the cooling system of the nuclear power plants greatly changes the environmental and the ecological conditions of the receiving marine water body, but we know little about their impact on the steady-state transition of marine bacterioplankton communities. In this study, we used high-throughput sequencing based on the 16S rRNA gene to investigate the impact of the thermal pollution on the bacterioplankton communities in a subtropical bay (the Daya Bay). We observed that thermal pollution from the cooling system of the nuclear power plant caused a pronounced thermal gradient ranging from 19.6°C to 24.12°C over the whole Daya Bay. A temperature difference of 4.5°C between the northern and southern parts of the bay led to a regime shift in the bacterioplankton community structure. In the three typical scenarios of regime shifts, the steady-state transition of bacterioplankton community structure in response to temperature increasing was more likely consistent with an abrupt regime shift rather than a smooth regime or a discontinuous regime model. Water temperature was a decisive factor on the regime shift of bacterioplankton community structure. High temperature significantly decreased bacterioplankton diversity and shifted its community compositions. Cyanobium and Synechococcus of Cyanobacteria, NS5 marine group of Bacteroidota, and Vibrio of Gammaproteobacteria were found that favored high temperature environments. Furthermore, the increased water temperature significantly altered the community assembly of bacterioplankton in Daya Bay, with a substantial decrease in the proportion of drift and others, and a marked increase in the proportion of homogeneous selection. In summary, we proposed that seawater temperature increasing induced by the thermal pollution resulted in an abrupt regime shift of bacterioplankton community in winter subtropical bay. Our research might broad our understanding of marine microbial ecology under future conditions of global warming.

Spatial and temporal characteristics of drought in the Mu Us Sandy Land based on the Standardized Precipitation Index

The environment of the Mu Us Sandy Land, northern Shaanxi, is fragile, so the temporal and spatial evolution of drought can provide a reference for ecological construction and agricultural production. Based on the daily precipitation data of five meteorological stations from 1967 to 2020, the spatial and temporal evolution characteristics of drought in the Mu Us Sandy Land of northern Shaanxi were analyzed using the methods Standardized Precipitation Index (SPI) and run-length theory. The results show that 1) the smaller the time scale, the higher the sensitivity of the SPI to primary precipitation. 2) The annual, summer, autumn, and winter SPI showed an upward and a wetting trend, and the fastest wetting speed is observed in summer, while spring showed an increasing trend of drought. 3) In the past 54 years, the duration, degree, and intensity of drought events at SPI-3 and SPI-12 scales in the Mu Us Sandy Land of northern Shaanxi showed an insignificant decreasing trend, but the decreasing rate at the SPI-12 scale was faster than that at the SPI-3 scale. The serious periods of drought are November 2018 to May 2019 and April 1999 to July 2021. 4) The duration of drought events at two timescales in each region showed a decreasing trend. The longest durations of drought were in Yulin and Jingbian; Shenmu and Dingbian are the regions with the fastest reduction rate of drought degree at the two scales. Hengshan shows rapid reduction of drought intensity at the two scales and also the region with large average drought intensity. These results are helpful in understanding and describing drought events for drought risk management under the condition of global warming.

Estimating the aboveground biomass of the Hulunbuir Grassland and exploring its spatial and temporal variations over the past ten years

In the past 10 years, extreme weather phenomena have increased, and global warming has markedly advanced; moreover, the intensity of human activity has gradually increased. These have an impact on the growth of global vegetation. Related studies have focused on the Tibetan Plateau and some northern provinces of China to estimate grassland AGB at a large scale but a low resolution. Hulunbuir Grassland is an important supplier of livestock products, and therefore, it is important to precisely map AGB and explore the response of Hulunbuir Grassland AGB to climate change and human activities at a high resolution to identify complex spatial details. In this study, we selected vegetation indices from Landsat 8 OLI and topographic indices and used multiple linear regression and machine learning algorithms to estimate the spatial distribution of AGB from 2013 to 2022. Then, we analyzed the correlations between AGB and cumulative precipitation and daily average temperature in summer and between population density and livestock density at the pixel level. Our results demonstrated that the RF model performed well, with an RMSE of 28.23 and R2 value of 0.74; the AGB was positively correlated with the cumulative precipitation in summer in 94.45 % of the area and negatively correlated with the daily average temperature in summer in 96.32 % of the area. We suggest that it is necessary to reduce grazing activities in future warm and drought years and to adjust sources of income to adapt to the decrease in AGB under global warming conditions. This study will provide reference for the countries or regions that depend on temperate grasslands for husbandry.

Mitigation of Vibrio coralliilyticus-induced coral bleaching through bacterial dysbiosis prevention by Ruegeria profundi.

Vibrio species are prevalent in ocean ecosystems, particularly Vibrio coralliilyticus, and pose a threat to corals and other marine organisms under global warming conditions. While microbiota manipulation is considered for coral disease management, understanding the role of commensal bacteria in stress resilience remains limited. Here, a single bacterial species (Ruegeria profundi) rather than a consortium of native was used to combat pathogenic V. coralliilyticus and protect corals from bleaching. R. profundi showed therapeutic activity in vivo, preventing a significant reduction in bacterial diversity in bleached corals. Notably, the structure of the bacterial community differed significantly among all the groups. In addition, compared with the bleached corals caused by V. coralliilyticus, the network analysis revealed that complex interactions and positive correlations in the bacterial community of the R. profundi protected non-bleached corals, indicating R. profundi's role in fostering synergistic associations. Many genera of bacteria significantly increased in abundance during V. coralliilyticus infection, including Vibrio, Alteromonas, Amphritea, and Nautella, contributing to the pathogenicity of the bacterial community. However, R. profundi effectively countered the proliferation of these genera, promoting potential probiotic Endozoicomonas and other taxa, while reducing the abundance of betaine lipids and the type VI section system of the bacterial community. These changes ultimately influenced the interactive relationships among symbionts and demonstrated that probiotic R. profundi intervention can modulate coral-associated bacterial community, alleviate pathogenic-induced dysbiosis, and preserve coral health. These findings elucidated the relationship between the behavior of the coral-associated bacterial community and the occurrence of pathological coral bleaching.IMPORTANCEChanges in the global climate and marine environment can influence coral host and pathogen repartition which refers to an increased likelihood of pathogen infection in hosts. The risk of Vibrio coralliilyticus-induced coral disease is significantly heightened, primarily due to its thermos-dependent expression of virulent and populations. This study investigates how coral-associated bacterial communities respond to bleaching induced by V. coralliilyticus. Our findings demonstrate that Ruegeria profundi exhibits clear evidence of defense against pathogenic bacterial infection, contributing to the maintenance of host health and symbiont homeostasis. This observation suggests that bacterial pathogens could cause dysbiosis in coral holobionts. Probiotic bacteria display an essential capability in restructuring and manipulating coral-associated bacterial communities. This restructuring effectively reduces bacterial community virulence and enhances the pathogenic resistance of holobionts. The study provides valuable insights into the correlation between the health status of corals and how coral-associated bacterial communities may respond to both pathogens and probiotics.

Exploring New Horizons for Wine Grapes: Modulating Functional Effects by Varying Harvest Timing and Solar Exposure.

Grenache (GN) and Cabernet Sauvignon (CS) are two traditional red grape varieties widely cultivated in the Mediterranean area and both late-ripening cultivars, which makes them less sensitive to global warming conditions and more stable to harvest timing. Although different studies have evaluated the final antioxidant properties of grapes and pomaces, few studies have explored the effect of sun exposure and harvest on the nutritional and antioxidant properties of these products. This study investigates the control of sunlight and ripening as tools to tailor nutritional and antioxidant properties of grape juices (GJ) and their byproducts (pomace GP). The compositional analysis showed no significant (p ≥ 0.05) differences associated to either harvesting timing or exposure to sunlight for either of the two studied varieties. However, differences (p ≤ 0.05) were observed between varieties of protein and total dietary fibre (TDF). CS protein content ranged from 0.52 to 3.88 (g 100 g-1) in GJ and from 1.0 to 1.32 (g 100 g-1) in GP; meanwhile, GN had higher protein values in GJ (from 2.11 to 4.77 g 100 g-1) and GP (from 5.11 to 6.75 g 100 g-1). The opposite behaviour was observed in TDF; CS grape had higher values for juice (from 11.43 to 19.53 g 100 g-1) and pomace (from 42.20 to 65.80 g 100 g-1) than GN (from 11.43 to 17.22 g 100 g-1 in juice and from 25.90 to 54.0 g 100 g-1 in pomace). The total phenolic content (TP) in GP was 100 times higher than in the juices and showed a much less pronounced evolution compared to the GJ during the harvesting time. GN TP values ranged from 5835 to 8772 mg GAE 100 g-1; meanwhile, CS values ranged from 7637 to 9040 mg GAE 100 g-1. A significant (p ≤ 0.05) correlation between the TP total antioxidant capacity (TAC) results was observed, regardless of variety, harvesting time, and sunlight exposure. These findings show how the control of different factors can contribute to obtain modified grape-derived products from conventional varieties beyond the wine market.

Carbon farming as a future strategy for climate change: A literature review

Background: This research aims to know about carbon farming and strategies for storing carbon in the soil. Methods: The research method used is qualitative data analysis where this method describes the research conducted by the author by collecting data from scientific journals, books, and research journals. Finding: Respiration plants absorb carbon dioxide and give off oxygen. However, the balance of plants and humans/animals is now disturbed along with the massive and excessive use of fossil fuels. The result is global warming and uncomfortable conditions and health risks to humans and the planet globally. We are currently paying attention to how carbon dioxide is present in the air due to pollution and industrial waste. Various ways are done, including reducing the consumption of petroleum or fossil fuels. Instead of decreasing, the consumption of fossil fuels has not decreased but has increased along with the pace of industrialization in developing countries. Carbon farming is one method that can be a solution, with the principle that problems are solutions. Conclusion: Many strategies for storing carbon in the soil that we already know. As carbon is absorbed by the soil, the health of the soil will improve so that the health of plants will also increase and yields will increase.

Post-halite gypsum pseudomorphs with evidence of challenging climatic conditions and diagenetic replacement: a study from the southwest of Kağızman Basin (Eastern Anatolia, Türkiye)

The study area is about the evaporitic-dominated Middle Miocene sequence situated in the southwest of the Kağızman Basin in Eastern Anatolia. The aim of this study is to investigate the formation conditions and diagenetic development of pseudomorph gypsum formed after halite. Pseudomorph gypsum formations are intriguing geological features found in terrestrial deposits. These formations are replaced by primary halite crystals during the very early phases of diagenesis, giving the appearance of halite crystals but being composed of gypsum. The development of these pseudomorphs is indicative of specific paleoenvironmental conditions. The fact that these gypsum pseudomorphs are found in shallow depths of the lake and are well-preserved, smooth-surfaced, and varying in size suggests that they were the result of intense evaporation and rapid fluctuations in the water and pH level. This evaporation likely led to a decrease in the lake level and changes in the concentration of saltwater over time. The correlation coefficient relationships and element concentration values of these gypsums show that these elements are both continental in origin and subject to microbial influence. These pseudomorph gypsum and the clastic materials (transported by fluvial activity) that were interbedded gave important insights into the hot, long-drought, and low-humidity climate of the era and adapted to the Middle Miocene global warming conditions.

ВЛИЯНИЕ ТРЕНДА СКОРОСТИ ВЕТРА НА ПРОДОЛЖИТЕЛЬНОСТЬ ПЕРИОДА ТЕРМИЧЕСКОГО КОМФОРТА НА ЕВРОПЕЙСКОЙ ЧАСТИ РОССИИ В ПОСЛЕДНИЕ ДЕСЯТИЛЕТИЯ

The combination of the parameters of temperature, humidity, and wind conditions of surface air, solar radiation fluxes, human metabolism under various modes of physical exertion and clothing properties characterize the thermal comfort. Under conditions of global warming, the climate characteristics that affect the quality of life, health, and well-being of people, in particular, the length of thermal comfort periods, are changing. Bioclimatic indices that determine the thermal comfort conditions depend not only on temperature changes, but also on humidity and wind speed trends. When comparing the results of the calculations of the thermal comfort period length with the use of air temperature observations and major bioclimatic indices, the authors have revealed a significant difference in the effect of changes in average wind speed on the length of the thermal comfort period in different regions of European Russia.

Current status and prognosis of Raphidiopsis raciborskii distribution in Bulgaria as part of the southeastern region of Europe

The cyanobacterial species Raphidiopsis raciborskii (Wołoszyńska) Aguilera et al. has a high invasiveness potential, which in less than a century leads to its cosmopolitan spread. In the temperate climate of Europe, R. raciborskii has been reported in many countries, but there is still a lack of detailed information about the current status of its distribution in lakes of Bulgaria, as a part of the southeastern range of its spread in Europe. We investigated the distribution of the species using data on the phytoplankton of 122 lakes surveyed during 13-years period (2009–2022). The species was found in 33 lakes (up to 324 m asl), and 14 new localities were registered during the studied period. The results reveal that the number of lakes with the presence of R. raciborskii (27 % of all research lakes) and its contribution to the total phytoplankton biomass, has increased significantly over the last decade. The species has successfully adapted and dominated the phytoplankton in 9 lakes, forming a bloom in 8 of them. The dominant position of R. raciborskii causes loss of species and functional diversity of phytoplankton and displaces the native bloom-forming cyanobacteria.Lakes with and without the species were compared based on the available data on bioclimatic and local environmental variables. Statistically significant differences were established with respect to water transparency, conductivity, maximum depth and maximum air temperature in the warmest month. Species distribution models (SDMs) were used to identify lakes in high risk of future invasion by R. raciborskii. The results of the SDMs implementation confirmed the high maximum air temperature and low water transparency to be important predictors of the occurrence of R. raciborskii in freshwater lakes in Bulgaria. In the areas with high summer temperatures the most suitable for R. raciborskii development were found to be shallow polymictic or medium deep lakes with small surface area and low water transparency. In areas with a suitable climate, the large, deep reservoirs with high transparency as well as macrophyte dominated lakes have a low probability of occurrence of R. raciborskii. Future colonization of lakes above 500 m asl (but most likely below 700 m asl) is also possible, especially in the conditions of global warming. SDMs account for climatic and biogeographic differences of lakes and could help in elucidating the underlying factors that control the occurrence and adaptation of R. raciborskii in a given area.

Machine Learning based Forest Fire Prediction: A Comparative Approach

Wildfires are among the world's most pressing issues, and they are getting more prevalent as global warming and other environmental conditions deteriorate. These wildfires might be caused by humans or by natural causes. Wildfires are one of the factors contributing to the extinction of rare flora and wildlife that serve to maintain our planet's ecological balance. In this paper, a comparative analysis of various machine learning classifier models for predicting forest fires was undertaken using two separate datasets. The suggested system's processing is dependent on a few characteristics such as temperature, humidity, oxygen, and wind. Several machine learning classification techniques, including logistic regression, support vector classifier, decision tree, k neighbors and random forest, were used in this study. For further optimization of the model, K-fold cross validation method and hyperparameter tuning were implemented. The system reveals Support Vector Machine as the best strategy for the forest fire dataset, with 96.88% accuracy. Random Forest method was found to be the best for the Cortez and Morais dataset, with 90.24% accuracy.

Numerical simulation for vibration-induced settlement and permanent deformation accumulation in permafrost subgrades of the Qinghai-Tibet Railway

Train-induced vibrations critically influence permafrost subgrade deformation. This study used ABAQUS secondary development to establish a finite element model of vibration-induced settlement for permafrost subgrades in the Qinghai-Tibet Railway (QTR) based on a cumulative plastic strain model. A numerical simulation method for cumulative vibration-induced settlement prediction considering seasonality, vibration frequency, train types, and global warming was proposed. The scientificity of the simulation was verified by monitoring data. Then, the influences of embankment height, ice-rich permafrost thickness, and initial mean annual ground temperature (MAGT) of the site on cumulative vibration-induced settlement and permanent deformation accumulation in permafrost subgrades were analysed. The study further quantitatively evaluated cumulative dynamic and static deformation in the DK1136 section under various global warming conditions. The results indicate that cumulative vibration-induced settlement primarily occurs near the ice-rich permafrost layer and is significantly influenced by ground temperature. Permanent deformation accumulation increases with increasing embankment height, ice-rich permafrost thickness and initial MAGT of the site. Permanent deformation accumulation primarily results from thaw consolidation of the permafrost layer, with vibration-induced settlement contributing approximately 20 %. For permafrost regions, an optimal railway embankment height of 3–3.5 m and effective mitigation of settlement issues involve lowering the ground temperature and the embankment weight. These findings provide essential insights for subgrade challenges in permafrost regions.

Evolutionary radiation and microbial community dynamics shape the thermal tolerance of Fungiidae in the southern South China Sea.

Fungiidae have shown increased thermal adaptability in coral reef ecosystems under global warming. This study analyzes the evolutionary divergence and microbial communities of Fungiidae in the Sanjiao Reef of the southern South China Sea and explores the impact of coral evolution radiation and microbial dynamics on the heat tolerance of Fungiidae. The results found that Cycloseris was an ancient branch of Fungiidae, dating back approximately 147.8953 Mya, and Fungiidae differentiated into two ancestral clades (clades I and II) before 107.0312 Ma. Fungiidae exhibited specific symbioses with the Cladocopium C27 sub-clade. Notably, the Cladocopium C1 sub-clade has a high relative abundance in clade I, whereas the heat-tolerant Cladocopium C40 and C3u sub-clades subdominante in clade II. Regarding bacterial communities, Cycloseris costulata, the earliest divergent species, had higher bacterial β-diversity, while the latest divergent species, Lithophyllon scabra, displayed lower bacterial α-diversity and higher community stability. Beneficial bacteria dominante Fungiidae's bacterial community (54%). The co-occurrence network revealed that microbial networks in clade II exhibited lower complexity and greater resilience than those in clade I. Our study highlights that host evolutionary radiation and microbial communities shaped Fungiidae's thermal tolerance. The variability in subdominant Symbiodiniaceae populations may contribute to interspecific differences in thermal tolerance along the evolutionary branches of Fungiidae. The presence of abundant beneficial bacteria may further enhance the thermal ability of the Fungiidae. Furthermore, the later divergent species of Fungiidae have stronger heat tolerance, possibly driven by the increased regulation ability of the host on the bacterial community, greater microbial community stability, and interaction network resistance.IMPORTANCECoral reefs are facing significant threats due to global warming. The heat tolerance of coral holobionts depends on both the coral host and its microbiome. However, the association between coral evolutionary radiation and interspecific differences in microbial communities remains unclear. In this study, we investigated the role of evolutionary radiation and microbial community dynamics in shaping the thermal acclimation potential of Fungiidae in the Sanjiao Reef of the southern South China Sea. The study's results suggest that evolutionary radiation enhances the thermal tolerance of Fungiidae. Fungiidae species that have diverged more recently have exhibited a higher presence of heat-tolerant Symbiodiniaceae taxa, more stable bacterial communities, and a robust and resilient microbial interaction network, improving the thermal adaptability of Fungiidae. In summary, this study provides new insights into the thermal adaptation patterns of corals under global warming conditions.

Influence of weather conditions on the dynamics of summer phytoplankton in the Kuibyshev reservoir

Based on observation data in the summer of 2019 and 2021, an assessment was made of changes in abiotic characteristics and chlorophyll (Chl) content in the Kuibyshev Reservoir. Regular observations were carried out at the outlet section of the reservoir (Zhigulevsky hydroelectric complex) under conditions of complete mixing of water masses. The main goal of the study is to assess the influence of abiotic factors on the chlorophyll content and the mass development of cyanobacteria. It has been established that the main influencing factors are thermal regime and weather conditions. 2019 is characterized as “cold”. The total number of days with water temperatures above 22 °C was only 11. The degree of favorability was low (23 °C ˃ t ˃ 22 °C). 2021 characterized as “warm”. The total number of days with water temperatures above 22 °C was 72. The degree of favorability varied widely: from low (23 °C ˃ t ˃ 22 °C) to extreme high (t ˃ 26 °C). The most favorable year for the mass development of cyanobacteria was 2021, when the Chl content over the summer period was 7.2 μg/dm3. The least favorable year was 2019, when the Chl content was 1.4 μg/dm3. Seasonally, the temperature optimum was observed annually in July. The Chl content in July 2021 was 12.6 μg/dm3, and in July 2019 – 1.8 μg/dm3. Significant variability in chlorophyll content is due to synoptic cyclicity and changing weather conditions. The established influence of thermal regime and weather conditions on the content of chlorophyll suggests that in conditions of global warming, the process of mass development of cyanobacteria is expected to intensify, which will negatively affect the ecological state and water quality of the Kuibyshev Reservoir.

Влияние погодных условий на процесс массового развития цианобактерий в Куйбышевском водохранилище

According to observation data in the summer period 2016-2021. The interannual variability of weather conditions, water temperature and chlorophyll (Chl) content in the Kuibyshev Reservoir was considered. Regular observations were carried out at the outlet section of the reservoir (Zhigulevsky hydroelectric complex) under conditions of complete mixing of water masses. It has been established that the main factors influencing the process of mass development of cyanobacteria (MDC) are thermal regime and weather conditions. With increasing water temperature, the interval and degree of favorable activity of cyanobacteria increases. Over a 6-year period, the average interval was 44 days, the largest was 72 days, and the smallest was 11 days. The degree of favorability varied widely: from low (23 °С ˃ t ˃ 22 °С) to extreme high (t ˃ 26 °С). The most favorable years for the MRC process were 2016 and 2021, when the Chl content during the summer period was 6.2 and 7.2 μg/dm3, respectively. The least favorable years were 2017 and 2019, when the Chl content during the summer period was 0.6 and 1.4 μg/dm3, respectively. Seasonally, the temperature optimum was observed annually in July. The Chl content in July 2021 was 12.6 μg/dm3, and in the cold July 2017 – 0.7 μg/dm3. Significant variability of the MRC process is due to synoptic cyclicity and changing weather conditions. The established influence of thermal regime and weather conditions on the content of chlorophyll suggests that in conditions of global warming, the process of mass development of cyanobacteria is expected to intensify, which will negatively affect the ecological state and water quality of the Kuibyshev Reservoir.