Ecological Problems Research Articles

Innovative educational and research center for monitoring forest resources of Siberia based on laser and microwave aerospace imaging

The possibilities of creating an innovative educational and scientific center for monitoring forest resources in Siberia on the basis of the Department of Space Facilities and Technologies of the Siberian State University of Science and Technology named after Mikhail Fedorovich Reshetnev are discussed, with the aim of training highly qualified engineering personnel and conducting promising scientific research in the field of monitoring, modeling, forecasting and management of forest resources. Methodological solutions and algorithms for three-dimensional modeling of forest structure and dynamics based on laser scanning data, digital aerial and space photography are proposed. These methods contribute to operational monitoring and can significantly reduce the cost of monitoring the condition and use of forest resources over the vast territory of Siberia. Remote sensing data is presented in the form of a geotransformed database and digital photo map, compatible in formats with computer-aided design systems and with the main geographic information systems – ArcView, ArcINFO, MapINFO. The innovative monitoring center will be used for operational state control and monitoring of forest management, the state of forest lands, forest management and forest inventory, solving problems of ecology and environmental management, geoecology, formation of a forest resource inventory, aerospace methods for studying natural resources and territories, information technology. Solving these problems will allow for the training of highly qualified specialists. The center's specialists plan to create information technologies for remote sensing of natural objects with the aim of import substitution of foreign software products. The main scientific directions of the created center: development and research of methods for system analysis of large-scale multidimensional remote sensing data based on nonparametric decision-making algorithms and parallel computing technologies; testing hypotheses about the distributions of large-volume remote sensing data based on nonparametric nuclear-type pattern recognition algorithms; detection of compact groups of large-volume remote sensing data corresponding to unimodal fragments of the joint probability density of multivariate random variables.

CHARACTERISTICS OF YEAST BIOMASS FROM THE WASTES OF WINE PRODUCTION

Re-utilization of vinification wastes is actual ecological problems that needs to be solved. The current study was carried out to evaluate biochemical composition of biomass of wine sedimentary yeasts. According to obtained results, yeast sediments used in natural white and red wine making present a good source of protein as well, as of essential and immunoactive amino acids. The studied types of sediments possess antioxidant activity and activity of antioxidant enzymes catalase and superoxid dismutase, the values vary, depending on the type of wine. So, yeast sediments of wine production can be proposed for the further development of new technologies for the production of bioactive extracts with antioxidants properties.

Factors driving human–elephant conflict: statistical assessment of vulnerability and implications for wildlife conflict management in Sri Lanka

Human–elephant conflict (HEC) is a serious social–ecological problem in Sri Lanka’s elephant range regions, as between 200 and 400 elephants have been killed annually over the last years, and more than 1200 people have died from the consequences of elephant encounters within a decade. Crop foraging causes economic damage to farming households. The study aims to understand factors driving vulnerability to HEC among the population. Employing a cross-communal multi-item large-N field survey (N = 651), authors were able to describe living conditions and perceptions of Sri Lankan villagers affected by HEC. By running a multiple regression analysis with correlated variables, the study is able to correlate independent variables to vulnerability, namely socio-economic conditions, environmental change and land-use, and awareness. Furthermore, a vulnerability map has been created, identifying Puttalam, Anuradhapura, Kurunegala, Matale, and Polonnaruwa districts as conflict hotspots. Private electric fences as a widespread protection measure were found to have unintended negative side-effects to non-protected households. The findings suggest the urgent need to upscale public policies mitigating the consequences of HEC on affected populations by reducing overall vulnerability to environmental hazards, including human–wildlife conflict.

Enhancement of BaCeO3 OER performance by generating a nanohybrid with gCN for electrochemical water splitting

Significant research is currently performed on electrochemical water splitting to solve ecological problems and energy issues. Sustainable and eco-friendly energy systems prefer to generate cost-effective electrocatalyst material with higher stability and excellent electrocatalytic activity to speed up the oxygen evolution reaction (OER) process. The current study followed a hydrothermal approach to develop a barium cerium oxide nanohybrid with g-CN (BaCeO3/g-CN) as an electro-catalyst for an efficient OER process in 1.0 M KOH. Physical characteristics analyses confirmed the enhanced activity of the synthesized BaCeO3 (BCO) and BCO/g-CN nanohybrid materials. The evaluated increased performance may be ascribed to improved morphological characteristics and substantial surface area (212 m2 g−1). The nanocomposite as mentioned above (BCO/g-CN) exhibits significant potential for effective OER in electrochemical assessments due to its abundant active spots and accelerated charge transfer process. Further, the electro-catalytic activity of the composite is improved, as demonstrated by a reduced overpotential (η = 210 mV) with Tafel value (36 mV dec−1) in comparison to pristine BCO (η = 262 mV and 52 mV dec−1) for OER. The material exhibited a reduced charge transfer impedance (Rct = 0.7 Ω), confirmed by EIS analysis. It also demonstrated a substantial ECSA (electrochemical active surface area) of 237.5 cm2 as compared to the pure BCO (137.5 cm2) material. Moreover, electrocatalyst material durability for 30 h was assessed by a chronoamperometric study. Thus, BCO/g-CN exhibits a notable rise in electrochemical properties, suggesting that it is a viable candidate for prospective OER applications.

Anthropogenic effects on tropical cyclones near Western Europe

There is less consensus on whether human activities have significantly altered tropical cyclone (TC) statistics, given the relatively short duration of reliable observed records. Understanding and projecting TC frequency change is more challenging in certain coastal regions with lower TC activity yet high exposure, such as Western Europe. Here, we show, with large-ensemble simulations, that the observed increase in TC frequency near Western Europe from 1966 to 2020 is likely linked to the anthropogenic aerosol effect. Under a future scenario featuring regionally controlled aerosol emissions and substantially increased greenhouse gas concentrations (Shared Socioeconomic Pathway 5-85), our simulations show a potential decrease in TC frequency near Western Europe by the end of the 21st century. These contrasting trends in historical and future TC frequencies are primarily due to the rise for 1966–2020 and potentially subsequent fall for 2030–2100 in TC genesis frequency in the North Atlantic. The response of large-scale environmental conditions to anthropogenic forcing is found to be crucial in explaining the historical and future changes in TC frequency near Western Europe.

NOx precipitation and valorization driven by photocatalysis and adsorption over red soil

Nitrogen oxides (NOx) emissions can cause air pollution that is harmful to human health, even producing serious ecological problems. Whether it is diluted in the air or not, the management and valorization of NOx from industrial emissions have been constrained by technology and finance. This study shows that red soil can be used as a photocatalyst to convert NOx into soil nitrate nitrogen (NO3−-N) in the soil. The addition of zinc oxide (ZnO) and titanium dioxide (TiO2) onto the soil surface improves the photocatalytic precipitation efficiency of 1 ppm NO, approaching a removal efficiency of 77 % under ultraviolet (UV) light. The efficiency of red soil in precipitating NOx through adsorption exceeded that of photocatalysis at 100 ppm NOx (e.g. 16.02 % versus 7.70 % in 0.1-mm soil). Pot experiment reveals that the precipitated NO3−-N promoted biomass of water spinach (Ipomoea aquatica Forsk). Additionally, adding ZnO or TiO2 also affects mineral nutrition. This demonstration of converting air pollutants into available nitrogen (N) for plant growth not only provides a new perspective on treatment and valorization for NOx but also sheds light on the transport of N in the air-soil-plant path.

Simultaneous removal of CTRX and Cr(Ⅵ) by CQDs-doped bifunctional molecular imprinted BiOCl/Bi3NbO7 photocatalyst: The enhanced selective performance and charge separation abilities

As a commonly used additive in breeding industry, the complex pollutants and metabolites formed by antibiotics and heavy metals in aquaculture wastewater have the characteristics of strong persistence, refractory degradation and easy accumulation, and exist in the environment and human body for a long time, which caused seriously ecological, environmental and health problems. Their effective removal studies are very essential. In this paper, a CQDs-doped bifunctional molecular imprinted BiOCl/Bi3NbO7 heterojunction photocatalyst (CQDs-MIP-BNO) was fabricated and the micromorphology along with photoelectric characteristics were explored by SEM, XRD, FTIR, XPS, UV-Vis and PL analysis. The photocatalytic performance experiments implied that 10 % doping of CQDs showed the highest selectivity and photocatalytic activity for the 94 % removal rate of Ceftriaxone Sodium (CTRX) and 80 % of Cr (VI) within 45 min. On this basis, a photocatalytic reactor loaded with the as-synthesized bifunctional catalyst through a sponge mesh covered with CS/PVA film was set up and the actual operation potential was further explored. The results showed that the enhanced removal performance of this bifunctional photocatalyst for CTRX and Cr(VI) made it feasible to efficiently remove one or more low-concentration, high-toxicity antibiotics and heavy-metal pollutants from the water column to validate the utility of combining molecular imprinting and photocatalytic technologies for the treatment of aquaculture wastewater.

Saline–Alkali Soil Reclamation Contributes to Soil Health Improvement in China

Soil salinization is a significant threat to soil health, especially to the agricultural ecosystem; it reduces vegetation biomass, destroys ecosystem diversity, and limits land use efficiency. This area of investigation has garnered extensive attention in China, especially in the arid and semi-arid areas, totaling 7.66 × 106 ha. A variety of theoretical research and technology developments have contributed to soil water and salt regulation and the screening of salt-tolerant varieties to improve nutrient utilization efficiency and microbial control and reduce ecological problems due to saline-based obstacles. These techniques can be classified into physical treatments, chemical treatments, biological treatments, and combined treatments; these different measures are all aimed at primarily solving saline–alkali stress. In general, the improvement and utilization of saline–alkali soil contribute to soil health improvement, concentrating on high-quality development, food security, ecological security, cultivated land protection, and agricultural upgrading. However, the risks of various technologies in the practical production process should be highlighted; green and healthy measures are still expected to be applied to saline–alkali land.

Improving the efficiency of combined displacement of ultra-viscous oil from the reservoir by carbon dioxide and coolant

Currently, in the world practice, special attention is paid to the processing of carbon dioxide in the aspect of obtaining it at the field itself, which reduces the cost of the technology of gas capture and injection into the well, because it is important for Russia due to the remoteness of the main part of oil fi elds. Realization of the gas method of oil feedstock extraction increases its efficiency several times taking into account the elimination of the ecological problem of utilization of carbon dioxide formed on a large scale industrially, with the growth of qualitative parameters of extracted commercial oil feedstock, taking into account the relatively small cost of carbon dioxide, the ability to recycle, as well as the use at any stage of fi eld operation. It is obvious that the increase of efficiency of technologies of carbon dioxide influence on the formation mass in complex with a thermal agent for super viscous oil feedstock requires an integrated approach in terms of methodical and empirical studies of regime parameters, applied technological processes and materials. On the basis of systematization of known theoretical data, results of empirical studies and their industrial approbation the authors recommend an algorithm for research of the problem. The article presents empirical substantiation of the ability to increase the effi ciency of exploitation of carbonate deposit of super viscous oil at great depth through the impact of thermal agent and carbon dioxide through the inclusion of the matrix component of the reservoir mass in more mobile development. It is shown that it is possible to incorporate the oil-saturated matrix by means of increasing the mobility of carbon dioxide when the temperature in the reservoir rises, the high degree of solubility of extra-viscous oil there and the additive drop in its dynamic viscosity. The data of empirical studies lead to the conclusion that the level of heating of the deposit and the volume of carbon dioxide supplied serve as optimizable factors, with a rational combination of which can increase the effectiveness of their influence.

Determination of occurrence of atmospheric blockings over the Caspian Sea region in winters of 1959–2022, and influence of them on the ice regime of the Northern Caspian Sea

The ice regime of the Caspian Sea has pronounced influence on the heat and moisture exchange of the reservoir with the atmosphere, the state of the ecosystem, as well as human marine activities, including shipping, fishing, construction of hydraulic structures, etc. Consequently, the development of existing ideas about the causes of changes in the characteristics of the ice regime of such water bodies is actual and socially significant problem of limnology, hydrometeorology, ecology, and navigation. This study was aimed at determination the frequency of occurrence of atmospheric blockings over the Caspian region with standings longer 5 days in winter period of 1959–2022, and investigation of influence of them on the ice regime in the Northern area of the Sea. The following information and data were used: changes in hourly mean values of atmospheric pressure at the sea level, geopotential of isobaric surfaces 850, 500 and 300 hPa, presented in the ERA5 reanalysis; and observational data on air temperature and ice cover from hydrometeorological stations located in the Caspian region of Kazakhstan and Russia. It has been established that in the winter during a long standing of atmospheric blockings the mean daily air temperatures noticeably drop. The values of all the studied characteristics of every atmospheric blocking which occurred in 1959–2022 were estimated as well the influence of them on the ice regime in the North of the Caspian Sea was analyzed. The relationship between a decrease in the frequency of atmospheric blockings (AB), sums of negative air temperatures on its coasts, and the ice cover thickness in the corresponding areas of coastal waters has been revealed in the region. The longer the total AB duration, the lower is the air temperature, and the ice thickness in February is larger.

Enhanced mechanical properties and tribological performance of anodic oxide coating by using thermal power plant waste material

Numerous researchers have dedicated their efforts to exploring the utilization of industrial waste, specifically fly ash (FA), as a reinforcement for developing economical composites and minimizing ecological pollution problems. FA consists of multiple phases, including quartz (SiO2) and mullite (3Al2O3·2SiO2), which can significantly enhance the mechanical properties of materials. In tribological applications, incorporating FA into surface coatings can offer a cost-effective alternative to enhance surface properties. Meanwhile, the usage of FA and its difference from other commercial ceramics (e.g., SiO2) is still unknown. Thus, the present study aims to clarify the role of FA and factors that contribute to improving mechanical properties and tribological performance with commercial SiO2 as a comparison using electrochemical anodization. The growth mechanism was investigated by varying the anodizing times while maintaining a constant (100 g/L FA) in the electrolyte for the first phase. Meanwhile, the mechanical and tribological properties of different reinforcement content (0, 10, 50, and 100 g/L) were determined for the second phase. Then, evaluations were conducted on the surface morphology, chemical composition, surface hardness, and tribological properties. The results revealed that growth of oxide coating was initiated within the first 5–10 min by forming the barrier layer. Pores began to appear visibly after 30 min of anodizing time, while the complete formation of porous anodic oxide coating was achieved at 60-min with pores dimension (width: 30.75 ± 14.45 μm and depth: 13.4 ± 6.43 μm). Interestingly, 100 g/L of FA-reinforced anodic oxide coating demonstrated lower surface roughness (4.08 ± 0.41 μm), higher surface hardness (444.4 ± 8.63 HV), lowest coefficient of friction (COF) (0.46), and low wear rate (reduction almost 31.8 %) compared to 100 g/L of commercial SiO2 reinforced anodic oxide coating. The electrophoretic deposition effect, combined with the quartz (SiO2) and mullite (3Al2O3·2SiO2) phase structure, enhances mechanical properties and tribological performance.

Using the model of closed-loop economy in certain branches of the agro-industrial complex

From agricultural production to domestic consumption of products, the food industry produces huge amounts of waste every year, which leads to contamination of soil, water and air. Waste created upon processing agricultural raw materials and using axillary materials, such as additives, certain chemical components, fuel and so on, enhances an impact of the food chain on the environment leading to depletion of natural resources. In the last few years, production branches of economy, including the agro-industrial complex, have made attempts to maintain the balance between their impact on the environment, the use of resources, well-being of the population and economic benefits. This trend stimulates the intensive development of the theory of circular (cyclic) economy or closed-loop economy and facilitates a search for methods of its realization in the real economic system. The paper summarizes the main specific features typical of circular economy: strengthened control of supply of limited natural resources and maintenance of the stable balance of renewable resources; optimization of consumption processes by development and use of products, components and materials that correspond to the highest level of their reuse; detection and prevention of negative external effects of current production activities to increase efficiency of the economic and ecological systems. With that, despite the fact that the concept of circular economy was formulated several decades ago, its comprehensive definition is still a subject of discussions. Ambiguity of the existing definitions shows that the concept of closed-loop economy has different meaning for stakeholders. The paper examines several aspects of using elements of closed-loop economy in certain branches of the agro-industrial complex, including the meat industry. A special attention in this work is given to the introduction of modern technologies and equipment for efficient processing of waste from crop husbandry, animal husbandry and meat production to include it into the economic turnover. In addition, ecological problems arising in the course of activities of enterprises of the food and processing industries are examined and the possibilities of solving these problems by introduction of the model of circular economy have been established. Risks and barriers preventing transition of Russia to the model of circular economy have been revealed. The authors propose measures and directions of scientific research aimed at the development and introduction of elements of closed-loop economy in the meat sub-complex, including related branches of the agro-industrial complex.

Reduced seagrass resilience due to environmental and anthropogenic effects may lead to future die-off events in Florida Bay

Coastal systems often depend on foundation species such as seagrasses that are supported by self-facilitation. Seagrass meadows, however, are threatened worldwide due to climate change and local human impact, disrupting self-facilitation leading to system instability. Florida Bay is a large seagrass dominated coastal ecosystem that suffered from multiple seagrass mortality events over the last half century driven by hypoxia, high water temperatures, hypersalinity, and high biological oxygen demand. These conditions reduce the amount of photosynthetically-derived oxygen in the plant causing sulphide intrusion into meristematic tissues. Using a bay-wide sampling design and long-term monitoring trends of seagrass condition, we investigated the current state of the meadows, sediment characteristics (e.g., organic matter, sulphide, nutrients) and discuss how climate stressors interact with plant and sediment oxygen dynamics. Our survey revealed that at sites where seagrass had been previously denuded by die-off, the dominant seagrass Thalassia testudinum had not recovered, while the pioneering seagrass Halodule wrightii recolonized the impacted areas. Organic matter and sulphide levels were higher at the impacted sites, apparently a persistent characteristic of the formerly dense T. testudinum meadows in central and western Florida Bay. These sediment conditions promote sulphide intrusion of T. testudinum belowground tissue under anoxic conditions. Plant oxidation initially buffers sulphide intrusion, but disruption of this oxidation mechanism due to changing environmental conditions results in widespread mortality and seagrass community collapse. Climate change cannot be fully mitigated by local management, however, attempts can be made to control critical salinity and oxygen levels by increasing freshwater input, reducing hypersalinity and aiming to keep the internal seagrass oxidation feedback intact. Our study shows that the Florida Bay seagrass ecosystem is still recovering four years post die-off and continues to be susceptible to future climate change and system degradation.

Analysis of Urbanization-Induced Land Subsidence in the City of Recife (Brazil) Using Persistent Scatterer SAR Interferometry

The article addresses anthropogenic and geological conditions related to the development of soil subsidence in the western zone of Recife (Brazil). Over the past 50 years, human activity has intensified in areas previously affected by soft soils (clay, silt, and sandstone) resulting in subsidence due to additional loads (landfills and constructions). The duration of the settlement process can be significantly influenced by the specific characteristics of the soil composition and geological conditions of the location. This work presents, for the first time, accurate InSAR time series maps that describe the spatial pattern and temporal evolution of the settlement, as well as the correlation with the geological profile, and validation with Global Navigation Satellite System (GNSS) data. Persistent Scatterer Interferometry (PS-InSAR) was employed in the analysis of Single Look Complex (SLC) images generated by 100 ascending COSMO-SkyMed (CSK) and 65 PAZ (32 ascending, and 33 descending) from the X-band, along with 135 descending Sentinel-1 (S1) acquisitions from the C-band. These data were acquired over the period from 2011 to 2023. The occurrence of subsidence was identified in several locations within the western region, with the most significant displacement rates observed in the northern, central, and southern areas. In the northern region, the displacement rates were estimated to be approximately −20 mm/year, with the Várzea and Caxangá neighborhoods exhibiting the highest rates. In the central region, the displacement rates were estimated to be approximately −15 mm/year, with the Engenho do Meio, Cordeiro, Torrões, and San Martin neighborhoods exhibiting the highest rates. Finally, in the southern region, the displacement rates were estimated to be up to −25 mm/year, with the Caçote, Ibura, and Ipsep neighborhoods exhibiting the highest rates. Additionally, east–west movements were observed, with velocities reaching up to −7 mm/year toward the west. These movements are related to the lowering of the land. The study highlights that anthropogenic effects in the western zone of Recife contribute to the region’s vulnerability to soil subsidence.

Assessing the effects of long-term mining exploitation on a lacustrine system from the arid region of the Atacama Desert, Chile

Over the last century, the Atacama Desert has been exploited due to the mineral resources in this environment. These anthropogenic effects have primarily been linked to the development of the mining industry, the impact of which remains uncertain. Here, we use high-resolution geochemical characterization and magnetic properties analysis from the sedimentary core of Inka Coya Lake, located in the Atacama Desert, to assess the anthropogenic impact in this metallogenic region. The geochemistry and magnetic properties changed with core depth. Elements, such as Cu, Ni, and Zn, increased during the lake's most recent period.Additionally, an increase in mass magnetic susceptibility (χ) and a decrease in magnetic susceptibility depending on the frequency (χfd%) may be attributed to fine iron oxide grains originating from industrial and urban sources. Moreover, indices of pollution classified the sediment of Inka Coya Lake as slightly polluted and strongly polluted with Ni, and Cu, respectively. This could reflect a period of pollution caused by the increase in the production of copper sulfide. These results highlight the possible impact of mining activities in the hyper-arid core of the Atacama Desert, which affects surrounding areas through dispersive processes, even reaching high altitudes, and provides a scientific basis for the prevention of environmental pollution from mining and the protection of the sediment and water source in the Atacama Desert.

Isolation by environment and its consequences for range shifts with global change: Landscape genomics of the invasive plant common tansy.

Invasive species are a growing global economic and ecological problem. However, it is not well understood how environmental factors mediate invasive range expansion. In this study, we investigated the recent and rapid range expansion of common tansy across environmental gradients in Minnesota, USA. We densely sampled individuals across the expanding range and performed reduced representation sequencing to generate a dataset of 3071 polymorphic loci for 176 individuals. We used non-spatial and spatially explicit analyses to determine the relative influences of geographic distance and environmental variation on patterns of genomic variation. We found no evidence for isolation by distance but strong evidence for isolation by environment, indicating that environmental factors may have modulated patterns of range expansion. Land use classification and soils were particularly important variables related to population structure although they operated on different spatial scales; land use classification was related to broad-scale patterns and soils were related to fine-scale patterns. All analyses indicated a distinctive genetic cluster in the most recently invaded portion of the range. Individuals from the far northwestern range margin were separated from the remainder of the range by reduced migration, which was associated with environmental resistance. This portion of the range was invaded primarily in the last 15 years. Ecological niche models also indicated that this cluster was associated with the expansion of the niche. While invasion is often assumed to be primarily influenced by dispersal limitation, our results suggest that ongoing invasion and range shifts with climate change may be strongly affected by environmental heterogeneity.

The Use of Methane from Landfill Gas to Generate Energy and its Management at the Plant as a Way to Reduce Climate Change

In the era of consumerism, increasing amounts of waste constitute an ecological and logistical problem. Waste landfills are increasingly installing degassing installations and obtaining landfill gas containing methane as a renewable energy source. The work aims to analyse the production and management of energy at a selected waste landfill operating a cogeneration unit. The role of landfill gas, its production amount, composition and use in cogeneration units to produce energy were analysed. The biogas produced is used to produce electricity and heat at the analysed waste treatment plant. The research showed the extraction and energy use of biogas in the amount of 916,876 m3 per year, which produced 1,558 MWh of electricity and 1,589 MWh of heat in cogeneration. The electricity produced is a power source for the enterprise and its infrastructure, and the surplus is sent to the power grid. However, 34% of the heat is used for the plant's needs. The remaining part can be used in ORC systems (Organic Rankine Cycle). The tests showed that the total efficiency of energy production is 85.80%, with the availability index of the cogeneration unit amounting to 0.95. The energetic use of landfill gas containing methane is an optimal solution from an energy and environmental perspective to limit climate change.

Size‐based indicators of unexploited deep‐sea community in the Colombian Caribbean Sea

AbstractComposition, size distribution, structure, and function of deep‐sea marine communities must be understood before they are impacted by anthropogenic effects. The deep‐sea ecosystem of the Colombian Caribbean Sea is unexploited with no fishing activity ever registered. We quantified the current state of the marine community using body size distribution (size‐spectra), size‐based indicators, minimum length (LMIN), maximum length (LMAX), average length (Lmean), standard deviation of length (LSD), 10th and 90th percentiles of the length distribution, Shannon–Wiener diversity (H′), and Pielou's evenness (J′) to generate a baseline of potential ecological indicators that contribute to management and conservation of the Colombian bento‐demersal community of deep‐sea marine ecosystem. Sampling was in the Colombian Caribbean Sea at 58 stations during four samplings in August and December 2009, 21 stations in March and May 2010, and 45 stations from August to December 2020, using the swept area method, at depths of 200–550 m. Catches included >50% families and species of fish, followed by 27 families (30%) and 33 and species (37%) of crustaceans. Chondrichthyes included 14% families and 9–11% species. Cephalopods included 2–3% families and 1–4% species. Size‐spectra analysis confirmed expected values for unexploited communities in three sampling years for teleostei, crustacea, and whole community.

Microbially induced calcium carbonate precipitation to combat desertification: A field application experiment

Combating desertification and recovering vegetation can help resolve global ecological problems. Microbially induced calcium carbonate precipitation is a natural and widespread phenomenon that has been a green and efficient approach for environmental issues. However, long-term field experiments are lacking and microbially induced calcium carbonate precipitation biological routes for desert restoration is unclear. Therefore, we investigated soil wind erosion resistance and soil characteristics via mixed methodology involving field and laboratory experiments and revealed the biological route. Our objective was to evaluate sand fixation efficiency and clarify the biological route. Results demonstrated that (1) microbially induced calcium carbonate precipitation produced sand cement, increased soil hardness, and changed soil characteristics. (2) Compared with CK, 25%, 50% and 75% treatments (MICP treatment from low to high concentration) reduced soil loss by 34.93%, 31.62% and 51.93%, respectively, and wind erosion decreased by 69.09%–77.27% at highest wind speed. (3) The 75% treatment had the greatest effect on wind erosion resistance. (4) Microbial activity changes the mechanism of wind erosion which meteorological effects change from direct to indirect after treatment. These results can address challenges and overcome the natural disadvantages of microbially induced calcium carbonate precipitation and contribute to technologies for combating desertification using soil microbial approaches.

Prediction of long-term changes of weak diurnal stratification in shallow lakes using artificial neural networks

ABSTRACT Thermal stratification plays a key role in lakes' ecosystems. In contrast to deep lakes, the thermal structure of shallow polymictic lakes is characterized by a weak stratification with an apparent diurnal cycle. Long-term changes in stratification are governed by climate change and anthropogenic effects such as water level regulation. We developed a simple and robust model system consisting of an energy balance model to estimate depth-averaged water temperatures and an artificial neural network (ANN) model to predict stratification with high temporal resolution. One novelty of our approach is that instead of directly estimating water temperatures at different depths, we simulated the potential energy anomaly index, the indicator of stratification's strength. The ANN-based model's performance was assessed against a physical-based one-dimensional model (General Ocean Turbulence Model) by modeling a 40-year-long period from 1981 to 2020. The new model accurately predicts a shallow lake's weak stratification and its diurnal cycle. Besides, the model proved reliable on longer time scales, capturing the effect of climate change, anthropogenic water level regulation, and their synergistic interaction on the change of stratification's intensity and duration.