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A comprehensive understanding of the impact of contaminants on organisms requires consideration of magnitude, duration, frequency, and life-history stage of exposure. Government guidelines provide a benchmark to evaluate exposure magnitude, but solely assessing magnitude does not consider duration and frequency of exposure. High-frequency sampling of data enables better integration of temporal patterns of potential environmental stressors and can inform research about habitat suitability. We develop and demonstrate an approach to examine temporal dynamics of abiotic conditions using high-frequency sampling data to assess water quality in the habitat of a Canadian federally listed endangered fish species, the Redside Dace (Clinostomus elongatus). Urban stressors, including chloride and non-point source pollutants, are considered contributing factors to the decline of Redside Dace in Canada. We collected and analyzed conductivity/chloride data from nine Redside Dace sites with varying degrees of upstream urbanization in the Greater Toronto Area to understand spatial and temporal variation in chloride exposure. Chloride loading in the region is largely driven by application of winter de-icing salt contributing to year-round elevated chloride concentrations. We highlight chloride patterns during critical early life stages of Redside Dace (spring spawning through summer; ‘non-salting season’), when sensitivity to stressors may be heightened. We assessed our data against the federal Canadian and American guidelines and found that at six out of nine sites, critical early life stages were exposed to chloride concentrations that exceeded the magnitude threshold of Canadian guidelines. We found instances of chronic duration threshold exceedance at six out of nine sites. Future research can leverage our approach to identify areas of concern where magnitude and duration thresholds are exceeded, and our results can be used to inform the duration of stressor exposure to critical life-history stages during ecologically relevant laboratory-based ecotoxicology studies. We emphasize that our approach can be used for any environmental parameter sampled with high frequency to better understand temporal regimes of ecological stressors.

In the fight against emerging pathogens, an important management strategy is to identify host refuges to prevent extinctions. Fungal pathogens (Batrachochytrium) are decimating amphibians around the world, but researchers have discovered that coastal amphibians living in high-salt water bodies can experience a refuge because the pathogens have lower survival outside the host in these conditions. This has led to the recommendation that managers should create disease refuges for amphibians by adding salt to water bodies. We review this literature and highlight that while some populations of coastal amphibians have evolved increased salt tolerance, most amphibian populations around the world have not. The relatively high concentrations of salt that are needed to kill the pathogens would cause widespread direct and indirect harm on amphibians and would kill most other aquatic taxa. Thus, intentionally salinizing freshwater habitats is a well-intentioned management strategy, but it is not a well-advised strategy.

Abstract Climate change elevates the threat of compound heat and drought events, with their ecological and socioeconomic impacts exacerbated by human ecosystem alterations such as eutrophication, salinization, and river engineering. Here, we study how multiple stressors produced an environmental disaster in a large European river, the Oder River, where a toxic bloom of the brackish-water planktonic haptophyte Prymnesium parvum (the “golden algae”) killed approximately 1000 metric tons of fish and most mussels and snails. We uncovered the complexity of this event using hydroclimatic data, remote sensing, cell counts, hydrochemical and toxin analyses, and genetics. After incubation in impounded upstream channels with drastically elevated concentrations of salts and nutrients, only a critical combination of chronic salt and nutrient pollution, acute high water temperatures, and low river discharge during a heatwave enabled the riverine mass proliferation of B-type P. parvum along a 500 km river section. The dramatic losses of large filter feeders and the spreading of vegetative cells and resting stages make the system more susceptible to new harmful algal blooms. Our findings show that global warming, water use intensification, and chronic ecosystem pollution could increase likelihood and severity of such compound ecoclimatic events, necessitating consideration in future impact models.

Abstract The agricultural sector faces challenges in managing water resources efficiently, particularly in arid regions dealing with water scarcity. To overcome water stress, treated wastewater (TWW) is increasingly utilized for irrigation purpose to conserve available freshwater resources. There are several critical aspects affecting the suitability of TWW for irrigation including salinity which can have detrimental effects on crop yield and soil health. Therefore, this study aimed to develop a novel approach for TWW salinity prediction using artificial intelligent (AI) ensembled machine learning approach. In this regard, several water quality parameters of the TWW samples were collected through field investigation from the irrigation zones in Al-Hassa, Saudi Arabia, which were later assessed in the lab. The assessment involved measuring Temperature (T), pH, Oxidation Reduction Potential (ORP), Electrical Conductivity (EC), Total Dissolved Solids (TDS), and Salinity, through an Internet of Things (IoT) based system integrated with a real-time monitoring and a multiprobe device. Based on the descriptive statistics of the data and correlation obtained through the Pearson matrix, the models were formed for predicting salinity by using the Hammerstein-Wiener Model (HWM) and Support Vector Regression (SVR). The models’ performance was evaluated using several statistical indices including correlation coefficient (R), coefficient of determination (R2), mean square error (MSE), and root mean square error (RMSE). The results revealed that the HWM-M3 model with its superior predictive capabilities achieved the best performance, with R2 values of 82% and 77% in both training and testing stages. This study demonstrates the effectiveness of AI-ensembled machine learning approach for accurate TWW salinity prediction, promoting the safe and efficient utilization of TWW for irrigation in water-stressed regions. The findings contribute to a growing body of research exploring AI applications for sustainable water management.

The aim of the study was to highlight morpho-physiological changes like plant height, spike characteristics and stomata features in wheat induced by salt stress. Seeds of wheat var. Alex were sown, in mezo-phyto-cosmos, in five repetitions, under six saline doses, 0, 15, 30, 45, 60, and 75 mM NaCl. The experiment was conducted under field conditions. The assessments including plant height, arista, and spike length were taken and evaluated at the end of the experiment. Adaxial stomatal imprints have been sampled and the stomata density (number of stomata/mm2) and their size were assessed under the microscope. Wheat morphological parameters were affected by the highest salinity dose. Plant height was significantly reduced in the 60 and 75 mM NaCl doses by 16% and 20%. The spike length showed a significant reduction only in the highest saline dose treatment. Arista length registered the highest value in the 15 mM NaCl treatment with 23% more compared to the control. Stomata density reported the highest value in the 15 mM NaCl treatment, significantly higher compared to the 0 mM NaCl dose. The highest salinity doses significantly reduced plant height and spike length. Arista length and stomata density showed similar patterns.

Climate change elevates the threat of compound heat and drought events, with their ecological and socioeconomic impacts exacerbated by human ecosystem alterations such as eutrophication, salinization, and river engineering. Here, we study how multiple stressors produced an environmental disaster in a large European river, the Oder River, where a toxic bloom of the brackish-water planktonic haptophyte Prymnesium parvum (the "golden algae") killed approximately 1000 metric tons of fish and most mussels and snails. We uncovered the complexity of this event using hydroclimatic data, remote sensing, cell counts, hydrochemical and toxin analyses, and genetics. After incubation in impounded upstream channels with drastically elevated concentrations of salts and nutrients, only a critical combination of chronic salt and nutrient pollution, acute high water temperatures, and low river discharge during a heatwave enabled the riverine mass proliferation of B-type P. parvum along a 500 km river section. The dramatic losses of large filter feeders and the spreading of vegetative cells and resting stages make the system more susceptible to new harmful algal blooms. Our findings show that global warming, water use intensification, and chronic ecosystem pollution could increase likelihood and severity of such compound ecoclimatic events, necessitating consideration in future impact models. [ABSTRACT FROM AUTHOR]

Biodiversity intactness index (BII) was applied to monitor the deuteriation of diversity status of East Hammar marsh (EHM). Proposed bench mark list of 30 fish species existed in EHM after inundation in 2003 was initiated. Number of fish species recorded by previous authors varied between 22 to 44. In total, 35 non-native out of 52 total fish species recorded in EHM represent 67.1% of fish assemblage. Values of Shannon and wiener biodiversity index fluctuated between 1.89 & 2.9 and were positively related to an increase in salinity of EHM. As result of the increased salinity in EHM, a rise was detected in migratory marine species and an absence of freshwater native ones. Salinity fluctuation plays a major role in altering the composition of fish assemblage in EHM.The highest BII value observed at EHM was 103.57, and the lowest score was 52.07. The highest salinity value recorded was 16.1psu in EHM in August 2018. Salinity fluctuations in EHM play a major role in increasing or decreasing BII values through migration or immigration of marine fish species to or from the marsh to the Shatt al-Arab estuary. Consequently, an opposite relationship existed between BII values and marsh salinity. The fluctuation of freshwater discharge from the Shatt al-Arab River plays a major role in salinity changes in EHM. An indirect relation exists between the BII of EHM and discharge of the Shatt al-Arab River. Nonnative species tend to increase diversity value accompanied with an increase in the number of marine species. Negative relation existed between BII values and non-native species ratio in EHM. Establishing baseline BII data for fish assemblages in EHM is a vital step to create an intact reference mark. [ABSTRACT FROM AUTHOR]

This study examines the accumulation, distribution, and mobility of Potentially Toxic Elements (PTEs) in the sediments of a low‐lying coastal drainage network (Ravenna, Italy). The aim is to understand the geochemical processes occurring between drainage water and canal bed sediments and assess factors affecting and driving PTE distribution and enrichment in these environments. A geochemical database resulting from the analysis of 203 drainage sediment samples was analyzed using Principal Component Analysis and compared to undisturbed near‐surface sediment samples from the same depth and depositional environment. The results reveal PTEs exceeding national regulation limits. Distance from the sea, electrical conductivity of drainage water, and fertilizer use were identified as the main driving factors. The primary mechanisms for PTE precipitation (As, Co, Mo) and subsequent enrichment in the sediments is attributed to the absorption on Fe‐ and Mn‐oxyhydroxides (HFO and HMO), particularly in high salinity areas near the coast. While Cu, Zn, Pb, Cr, and V also have affinity for HFO and HMO, their adsorption efficiency decreases due to the competition with salt‐derived cations during ongoing salinization processes. Anthropogenic sources, including agriculture, hunting activities, traffic dust, and railways, contribute to the local abundance of other elements (Cr, Ni, Cu, Zn, Pb, and Sn). This paper's significant progress lies in assessing the concurrent interactions of chemical and physical processes that drive PTE distribution and accumulation in reclaimed low‐lying coastal plains. The findings are significant for assessing PTE accumulation risks and sediment toxicity in coastal areas affected by water salinization, drainage, and subsidence, providing valuable information to water management institutions globally. Plain Language Summary: This study investigates the presence of harmful substances called Potentially Toxic Elements (PTEs) in the sediment of the drainage canals in Ravenna's coastal area (Northern Italy). Researchers want to understand how these substances accumulate and spread in the sediment and what factors influence their distribution. They collected sediment samples from the bottom of the drainage canals and compared them to natural sediment samples. The results show that the PTE levels exceed the national and international limits. The distance from the sea, the water salinity, and the fertilizers are found to be the main factors affecting the distribution of PTEs. The researchers also discover that some PTEs (Arsenic, Cobalt, and Molybdenum) are absorbed by certain minerals in the sediment, especially in areas with high salinity close to the coast. However, other harmful elements, like copper, zinc, lead, chromium, and vanadium are not as strongly absorbed due to competition with salt‐related substances. The abundance of other elements like chromium, nickel, copper, zinc, lead, and tin come from human activities like agriculture, hunting, traffic, and railways. These findings are important for understanding the risks associated with these substances in the sediment, particularly in low‐lying coastal areas that have been reclaimed for human use. Key Points: First study on Potentially Toxic Elements (PTEs) enrichment in drainage canal sediments of reclaimed low‐lying coastal areaKey roles of (i) Fe‐ and Mn‐oxyhydroxides in PTE enrichments and (ii) salt‐derived cations in adsorption efficiencyDistance from the sea, salinity of drainage water, and use of fertilizers are the main factors affecting the distribution and enrichment of PTEs [ABSTRACT FROM AUTHOR]

Cotton is an important cash crop in Xinjiang, accounting for 90.2% of China's total production in 2022. However, natural factors such as drought, high soil salinity, and the constraints of perennial shallow tillage soil management practices limit the yield and efficiency of cotton production and sustainable agricultural development. Deep vertical rotary tillage facilitates the breaking up of soil solidification and promotes the salt leached by irrigation water. In order to investigate the improvement effect of deep vertical rotary tillage on heavily saline cotton fields in Southern Xinjiang of China, this study conducted a 2 a (2021-2022) field experiment with three deep vertical rotary tillage depths (DT20: deep vertical rotary tillage 20 cm, DT40: deep vertical rotary tillage 40 cm, DT60: deep vertical rotary tillage 60 cm), and alternate with conventional tillage (five-share plowing 20 cm CT20), and CT20 was set to be the two consecutive years of conventional tillage. Original soil samples from 0-60 cm were collected to determine the water-stable aggregates. Soil moisture, salinity, organic carbon, total nitrogen, total phosphorus and total potassium were defermined by samples under the drip irrigation tapes, wide rows and narrow rows of each treatment on the 3rd day after each irrigation. Cotton root samples were collected at 105 days after sowing in 2021 and at 103 days in 2022. The effects of different depths of deep vertical rotary tillage on soil physical properties, soil nutrient content, cotton root length density, boll weight, dry matter mass accumulation and seed cotton yield were investigated, and the effect of crop yield was quantified by structural equation modeling. The results showed that: 1) deep vertical rotary tillage was able to loosen the soil in the tillage layer to optimize the soil structure. DT60 treatment was able to significantly reduce the soil bulk density, the content of coarse aggregates (>2 mm), and silt and clay particle (<0.053 mm) in the tillage depth layer compared with DT20 and CT20 treatment, which led to a significant reduction in mean weight diameter and mean geometric diameter, and increased total soil porosity and the content of micro-aggregates (<0.25～ 0.053 mm), while DT60 treatment was unable to further improve the soil structure in the deep soil layer compared with DT40 treatment. 2) DT40 and DT60 treatments were able to significantly increase soil moisture from 0-40 cm soil layer and reduce soil salinity and pH value, whereas DT20 treatment was only able to reduce soil salinity from 0-20 cm soil layer, whereas DT60 treatment was able to significantly reduce soil salinity and pH value from 0-60 cm soil layer compared with DT40 treatment. The reduction of soil salinity promoted the accumulation of soil organic carbon in the 0-40 cm soil layer and soil total nitrogen in the 0-60 cm soil layer, but DT60 treatment was unable to significantly increase soil organic carbon and soil total nitrogen in the 0-20 cm soil layer compared with the DT40 treatment. 3) The analysis of the structural equation modeling showed that soil salinity was an indirect factor affecting the seed cotton yield, and the accumulation of cotton’s dry matter and the weight of cotton bolls were the direct factored. The reduction of soil salinity favors soil nutrient accumulation and cotton root growth, promoted nutrient transport and accumulation to the plant organ, and increased cotton dry matter accumulation and seed cotton yield. Therefore, DT60 treatment had the best effect of soil salinity reduction, and thus the effect of yield increase. Comprehensive analysis showed that the depth of 60 cm on deep vertical rotary tillage with conventional tillage alternating can realize the synergy of improving and increasing the yield and efficiency of the severe saline cotton fields in the Southern Xinjiang of China. [ABSTRACT FROM AUTHOR]

Emergent marsh and open water have been identified as alternate stable states in tidal marshes with large, relative differences in hydrogeomorphic conditions. In the Florida coastal Everglades, concern has been raised regarding the loss of non-tidal, coastal peat marsh via dieback of emergent vegetation and peat collapse. To aid in the identification of alternate stable states, our objective was to characterize the variability of hydrogeomorphic and biologic conditions using a field survey and long-term monitoring of hydrologic and geomorphic conditions across a range of vegetated (emergent, submerged) and unvegetated (open water) communities, which we refer to as "ecosystem states," in a non-tidal, brackish peat marsh of the coastal Everglades. Results show (1) linear relationships among field-surveyed geomorphic, hydrologic, and biologic variables, with a 35-cm mean difference in soil surface elevation between emergent and open water states, (2) an overall decline in soil elevation in the submerged state that was related to cumulative dry days, and (3) a 2× increase in porewater salinity during the dry season in the emergent state that was also related to the number of dry days. Coupled with findings from previous experiments, we propose a conceptual model that describes how seasonal hydrologic variability may lead to ecosystem state transitions between emergent and open water alternate states. Since vegetative states are only moderately salt tolerant, as sea-level rise pushes the saltwater front inland, the importance of continued progress on Everglades restoration projects, with an aim to increase the volume of freshwater being delivered to coastal wetlands, is the primary management intervention available to mitigate salinization and slow ecosystem state shifts in non-tidal, brackish peat marshes. [ABSTRACT FROM AUTHOR]

The response of microbiomes to salinity has been clarified in different geographic scales or ecosystems. However, how soil microbial community structure and interaction respond to salinity across wide salinity range and climatic region is still unclearly resolved. To address this issue, we examined the microbial community's composition in saline soils from two climatic regions (coastal wetland and arid desert). Our research confirms that soil salinity had a negative effect on soil nutrient content. Salinity decreased the relative abundance of bacteria, but increased archaea abundance, leading to the shifts from bacteria dominant community to archaea dominant community. Low-water medium-salinity soil (LWMS) had the most complex archaeal community network, whereas for bacteria, the most complex bacterial community network was observed in low-water high-salinity soils (LWHS). Key microbial taxa differed in three salinity gradients. Salinity, soil water content, pH, total nitrogen (TN), and soil organic carbon (SOC) were the main driving factors for the composition of archaeal and bacterial community. Salinity directly affected archaeal community, but indirectly influenced bacteria community through SOC; pH affected archaeal community indirectly through TN, but directly affected bacterial community. Our study suggests that soil salinity dramatically influences diversity, composition, and interactions within the microbial community. [ABSTRACT FROM AUTHOR]

Soil salinization has damaged the soil biological environment and chemical structure, resulting in a decline in soil quality and crop yields, which has caused harm to the ecological environment and human health, and severely hindered the development of the economy. In this experiment, using the 'Ningdan 33' maize seeds as materials, the maize was treated with histidine and salt stress (100 mM NaCl), and photosynthesis, photosynthetic enzyme activity, relative expression of photosynthetic genes of maize were measured. The anatomical structure of the leaves was also observed. The study explored the impact of exogenous histidine treatment on the photosynthesis of maize under salt stress. When the concentration of histidine sprayed on the leaves was 0.5 mM, it had the best effect on promoting photosynthesis in maize under salt stress. 0.5 mM histidine significantly improved the photosynthetic performance (PN, gs, E, Chl a/Chl b) of maize under salt stress, significantly improved photosynthesis efficiency (Fv/Fm, ΔF/F'm, qP were significantly increased. NPQ was significantly decreased), significantly increased the activity of photosynthetic enzymes (PEPC, NADP-ME, PPDK, Rubisco) and the relative expression of photosynthetic genes (ZmPEPC, ZmNADP-ME, ZmPPDK, ZmRCA), increased the length of the vascular bundle in the cross-section of the leaf, played a certain protective role on the vascular bundle, and improved the efficiency of material transportation under salt stress. Based on the above analysis, 0.5 mM histidine can significantly improve the tolerance of maize under salt stress, which has great application value for planting maize in saline environments. [ABSTRACT FROM AUTHOR]

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The island of Krk in Primorje-Gorski Kotar County, Croatia, is also called the Golden Island because of its favorable geographical location, the diversity of natural and urban landscapes, the beauty of the coast and the sea, the wealth of tangible and intangible heritage, and especially because of the opportunities for living and working. During the last century and in this century, urban landscapes have been exposed to dramatic changes that transformed old castles or former smaller settlements of the local population into tourist centers and desirable places for permanent or temporary residence. A significant part of their complex structure is the cultural and historical heritage, within which the island's park heritage has so far been insufficiently recognized and valued. Therefore, this paper examines forty selected public park spaces in the area of all local self-government units of the island of Krk in the context of urban transformations and climate change. It is concluded that the island's park heritage has often been created as a result of urban transformations in which, despite being exposed to constant changes, it is mostly preserved, but that recently, new elements of this heritage are emerging. A new challenge is the threat of the consequences of climate change—increasingly frequent and long-lasting droughts, extreme precipitation and flash floods, stormy winds, rising sea level and salinization, which further emphasizes the need to preserve the park heritage of the island of Krk in the context of resistance to climate change. [ABSTRACT FROM AUTHOR]

Riverine environments host diverse microbial communities, exhibiting distinctive assemblies at both microscopic and macroscopic levels. Despite the complexity of microbial life in rivers, the underlying factors that shape the community structure across different compartments remain elusive. Herein, we characterized microbial community composition of biofilm and planktonic (water column) compartments in five naturally saline inland streams and a freshwater stream to examine changes in microbial communities following salinization via sequencing of the microbial 16S rRNA gene. Significant differences in specific conductivity, oxidation–reduction potential, dissolved oxygen, and pH among the sampled streams were measured, as were significant differences in the microbial community composition between the planktonic and biofilm. The bacterial families Bacillaceae, Vicinamibacterceae, and Micrococcaceae were significantly more abundant in the biofilm compartment, while Methylophilaceae, Alcaligenaceae, Spirosomaceae, Burkholderiaceae, and Comamonadaceae were more abundant in the planktonic compartment. In addition, salinity (based on specific conductivity) influenced the microbial community composition in both compartments, with higher sensitivity of the planktonic compartment. Increases in the bacterial families Shewanellaceae, Marinomonadaceae, and Saccharospirillaceae or loss of Anaeromyxobacteraceae could be indicative of increased salinity within inland streams. Our results suggest that monitoring of microbial assemblages of freshwater ecosystems could be used as early warning signs of increased salinization levels. [ABSTRACT FROM AUTHOR]

Stream ecosystem functioning is often impaired by warming and salinization, but the joint effect of both environmental stressors on key processes such as leaf litter decomposition is virtually unknown, particularly in the tropics. We experimentally explored how increased water temperature (26, 29 and 32°C) and salinity (no salt addition, 0.1, 1.0 and 10 g l−1 NaCl added) affected the rates of total, microbial and detritivore-mediated decomposition, in stream microcosms containing leaf litter of Ficus insipida and larvae of Chironomus sp. collected from tropical streams. Effects of temperature were strong and consistent with previous findings: it promoted microbial decomposition and reduced decomposition mediated by detritivores, which showed greater feeding activity at 26°C. Salinity was negatively correlated with microbial decomposition at 32°C; it also had a negative influence on detritivore-mediated decomposition, which was nevertheless non-significant due to the high detritivore mortality at higher salinities. Notably, total decomposition was reduced with the joint presence of both factors (32°C and salt addition treatments, compared to 26°C and no salt addition), indicating the existence of additive effects and highlighting the relevance of multiple-stressor contexts when assessing the consequences of global change on stream ecosystems. [ABSTRACT FROM AUTHOR]

This study employed meta-heuristic clustering algorithms to determine the source and mechanism of groundwater salinization in Quebec's Saguenay-Lac-Saint-Jean (SLSJ) region, utilizing hydrogeochemical (38 inorganic constituents, including minor, major, and trace elements) and isotopic data (δ18O and δ2H). A total of 382 groundwater and precipitation samples were examined. Among the meta-heuristic algorithms, Artificial Bee Colony K-Means (ABCKM), Differential Evolution K-Means (DEKM), Harmony Search K-Means (HSKM), Particle Swarm Optimization K-Means (PSOKM), and Genetic K-Means (GKM) were used and investigated, and finally, PSOKM displayed superior performance and was chosen for further investigation. Analysis of diverse plots and hydrogeochemical modeling unveiled the impact of the Laflamme Sea invasion on groundwater chemistry. PSOKM1, PSOKM4, and PSOKM5 exhibited notable carbonate and silicate dissolution, with PSOKM4 demonstrating predominant carbonate dissolution. Cation exchange was identified through binary plots and Chloro Alkaline Index (CAI), with reverse cation exchange predominantly observed in most PSOKM4 samples, while positive values suggested direct cation exchange in other clusters. Spatial dynamics analysis using HFE-D indicated that salinization occurs as groundwater flows through crystalline bedrock aquifers, resulting in a transition from HCO3− dominance in PSOKM4 to Cl− dominance in the remaining clusters. Interaction between groundwater and rock along this path facilitated a transformation towards a Na-Cl end-member. The closely aligned stable isotopes with the Global Meteoric Water Line (GMWL) indicated a blend of meteoric water and seawater as the groundwater source. [ABSTRACT FROM AUTHOR]

Background: Salinity, exacerbated by rising sea levels, is a critical environmental cue affecting freshwater ecosystems. Predicting ecosystem structure in response to such changes and their implications for the geographical distribution of arthropod disease vectors requires further insights into the plasticity and adaptability of lower trophic level species in freshwater systems. Our study investigated whether populations of the mosquito Culex pipiens, typically considered sensitive to salt, have adapted due to gradual exposure. Methods: Mesocosm experiments were conducted to evaluate responses in life history traits to increasing levels of salinity in three populations along a gradient perpendicular to the North Sea coast. Salt concentrations up to the brackish–marine transition zone (8 g/l chloride) were used, upon which no survival was expected. To determine how this process affects oviposition, a colonization experiment was performed by exposing the coastal population to the same concentrations. Results: While concentrations up to the currently described median lethal dose (LD50) (4 g/l) were surprisingly favored during egg laying, even the treatment with the highest salt concentration was incidentally colonized. Differences in development rates among populations were observed, but the influence of salinity was evident only at 4 g/l and higher, resulting in only a 1-day delay. Mortality rates were lower than expected, reaching only 20% for coastal and inland populations and 41% for the intermediate population at the highest salinity. Sex ratios remained unaffected across the tested range. Conclusions: The high tolerance to salinity for all key life history parameters across populations suggests that Cx. pipiens is unlikely to shift its distribution in the foreseeable future, with potential implications for the disease risk of associated pathogens. [ABSTRACT FROM AUTHOR]

The regular hydrochemical monitoring of groundwater in the Mila basin over an extended period has provided valuable insights into the origin of dissolved salts and the hydrogeochemical processes controlling water salinization. The data reveals that the shallow Karst aquifer shows an increase in TDS of 162 mg L−1 while the thermal carbonate aquifer that is also used for drinking water supply exhibits an increase of 178 mg L−1. Additionally, significant temperature variations are recorded at the surface in the shallow aquifers and the waters are carbogaseous. Analysis of dissolved major and minor elements has identified several processes influencing the chemical composition namely: dissolution of evaporitic minerals, reduction of sulphates, congruent and incongruent carbonates' dissolution, dedolomitization and silicates' weathering. The hydrogeochemical and geothermometric results show a mixing of saline thermal water with recharge water of meteoric origin. Two main geothermal fields have been identified, a partially evolved water reservoir and a water reservoir whose fluid interacts with sulphuric acid (H2S) of magmatic origin. These hot waters that are characterized by a strong hydrothermal alteration do ascend through faults and fractures and contribute to the contamination of shallower aquifers. Understanding the geothermometry and the hydrogeochemistry of waters is crucial for managing and protecting the quality of groundwater resources in the Mila basin, in order to ensure sustainable water supply for the region. A conceptual model for groundwater circulation and mineralization acquisition has been established to further enhance understanding in this regard. [ABSTRACT FROM AUTHOR]

Background: Soil salinization has a major impact on crop production and it is expected to increase in area in the coming years. In this scenario, exploring the potential of halophytes and their plant-associated microbiomes as to increase phytoremediation strategies represents a suitable and sustainable strategy. Methods: We conducted a microcosm experiment with the halophyte Atriplex nummularia, cultivating it in two contrasting soils (clay and sandy) at distinct levels of salinity (0, 10 and 20 mS/cm). After 109 days, we assessed its growth and bacteriome composition, through 16S rRNA gene sequencing of the leaf and root endospheres, as well as rhizosphere. Results: A. nummularia showed increased growth under salinity levels of up to 20 mS/cm in both soils. Salinity and soil type had an effect in determining the rhizosphere bacterial communities of A. nummularia, with a stronger signal in the sandy soil. Most interestingly, no differences were found in endophytic bacterial communities, suggesting a strong buffering effect of the plant physiology, even though this halophyte accumulates NaCl. Last, functional prediction based on a subset of differentially abundant taxa in the rhizosphere revealed an increase in plant-growth promotion and salinity tolerance traits in higher salinity, indicating simultaneous selection by salinity and A. nummularia under stress. Conclusion: Collectively, these results provide valuable insights into halophyte-associated bacteria, advancing our understanding of this complex system with potential application in phytoremediation strategies for saline soils. [ABSTRACT FROM AUTHOR]

Present study deals with water quality (WQ) assessment season-wise ionic concentration in the Mewat district of Haryana, India. A total of 36 groundwater samples were collected, 12 each for the pre-monsoon, monsoon, and post-monsoon seasons of 2016, to know the status of WQ for drinking and irrigation purposes. Piper, Durov, and Gibbs plots were used to find out the water type and the factors controlling the chemistry of groundwater, respectively. Piper diagram reveals that Ca-Cl and mixed Ca–Mg-C1 typed water during the pre-monsoon, monsoon, and post monsoon season's where- Na-Cl water type indicates salinity problem. Gibb's plot depicted that the weathering of rocks is the major reason behind the ionic chemistry of the groundwater. Water Quality Index (WQI) has been calculated to know the overall WQ based on physico-chemical parameters estimated for this study. It was found that Na+ concentration was dominant among cations and Cl- among anions. Moreover, irrigation indices (KR, RSC, P.I, Cl–/HCO3–,SAR, and Na%) represent that majority of the groundwater samples during pre-monsoon (PRM) season were suitable for agricultural purposes but in monsoon (MON) and post monsoon (POM) season majority of samples lie in an unsuitable zone. The groundwater in the study region presents a high risk of salinization. Using the baseline data generated through this work, there is an immediate need for carrying out a detailed study to address the groundwater issues, understand salinity mechanisms, expansion of salinization in the fresh water aquifers and to suggest suitable management and remedial measures. Extension of this work is being carried out in the form of a purpose driven study under the National Hydrology Project aided by the World Bank. [ABSTRACT FROM AUTHOR]

The invasion process and the persistence of invasive species across environments can be explained by their tolerance to stressors, such as salinization. Urochloa arrecta (Poaceae) exhibits high invasive potential and has already established in various natural and artificial aquatic ecosystems. Here, we experimentally evaluate the effects of water salinity on the traits of three exotic populations of U. arrecta derived from naturally occurring populations across a salinity gradient. Specifically, we measured the difference in the number and perimeter of intercellular spaces for individuals from the different populations across three experimental treatments of salinity. Our results demonstrate that high water salinity levels affected anatomical traits in all populations. However, the traits of freshwater populations were the more significantly impacted by increasing salinity compared with populations sampled from naturally higher occurring salinity. Populations of U. arrecta established in places with certain degree of salinity can be more resistance to salt increases compared with populations established in freshwater habitats that are more distant geographically. However, the resistance of freshwater populations to certain high salinity levels suggests that these populations may exhibit rapid adaptation and to survive under some degree of salinity, demonstrating the species' high resilience across various environments. [ABSTRACT FROM AUTHOR]

Human activities and climate change cause abiotic factors to fluctuate through time, sometimes passing thresholds for organismal reproduction and survival. Multiple stressors can independently or interactively impact organisms; however, few studies have examined how they interact when they overlap spatially but occur asynchronously. Fluctuations in salinity have been found in freshwater habitats worldwide. Meanwhile, heatwaves have become more frequent and extreme. High salinity pulses and heatwaves are often decoupled in time but can still collectively impact freshwater zooplankton. The time intervals between them, during which population growth and community recovery could happen, can influence combined effects, but no one has examined these effects. We conducted a mesocosm experiment to examine how different recovery times (0‐, 3‐, 6‐week) between salt treatment and heatwave exposure influence their combined effects. We hypothesized that antagonistic effects would appear when having short recovery time, because previous study found that similar species were affected by the two stressors, but effects would become additive with longer recovery time since fully recovered communities would respond to heatwave similar to undisturbed communities. Our findings showed that, when combined, the two‐stressor joint impacts changed from antagonistic to additive with increased recovery time between stressors. Surprisingly, full compositional recovery was not achieved despite a recovery period that was long enough for population growth, suggesting legacy effects from earlier treatment. The recovery was mainly driven by small organisms, such as rotifers and small cladocerans. As a result, communities recovering from previous salt exposure responded differently to heatwaves than undisturbed communities, leading to similar zooplankton communities regardless of the recovery time between stressors. Our research bolsters the understanding and management of multiple‐stressor issues by revealing that prior exposure to one stressor has long‐lasting impacts on community recovery that can lead to unexpected joint effects of multiple stressors. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study aimed to evaluate the effect of nanoclay (NC), zeolite (Z), biochar (B), municipal waste compost (MWC), and farmyard manure (FYM) at two application levels of 1% and 3% (w/w) on the saturated hydraulic conductivity (KS) and sodification process of a calcareous soil under leaching by waters with different electrical conductivity (EC) and sodium absorption ratio (SAR) values. Columns containing control and amended soils were washed in three separate experiments using 20 pore volumes of three solutions classified in C3S1, C4S3, and C4S4 classes. The incorporation of the amendments led to a significant decrease in soil sodification because of decreasing exchangeable sodium and increasing exchangeable calcium. The exchangeable sodium percentage (ESP) of soils after leaching by solutions C3S1, C4S3, and C4S4 varied in the ranges of 1.80–5.79%, 2.78–7.85%, and 3.66–15.6%, respectively. The highest and lowest ESP values were obtained for control and 3% FYM treatment, respectively. For each leaching solution, the KS was significantly higher in the control compared to the amended soils (P ≤ 0.05). The lowest value of KS was obtained for the 3% B treatment. Furthermore, KS values increased with an increase in SAR of water. This was likely due to the simultaneous increase in EC and concentration of divalent cations (calcium and magnesium). The most effective amendments in controlling soil sodification were FYM, B, and MWC at the application level of 3%.Highlights: Farmyard manure and nanoclay showed the most efficiency in controlling soil pH. Nanoclay was the most efficient amendment in controlling soil salinity. The most effective amendment in controlling soil sodification was farmyard manure. Saturated hydraulic conductivity increased with the increase in SAR of water. Saturated hydraulic conductivity was higher in control than in amended soils. [ABSTRACT FROM AUTHOR]

In the steppe zone of the Southern Ural region (Russia, Republic of Bashkortostan), an abrupt change in the hydrological regime due to drainage melioration triggered alteration of the set of soil properties, potentially leading to soil degradation. Drainage of the Berkazan-Kamysh nature area resulted in a development of a number of adverse effects, of which the major ones included mineralization of peat organic matter and soil salinization as strong as the formation of meadow solonchaks entirely devoid of vegetation. As illustrated by the example of the Serek-Kul' nature area, rewetting after drainage has not triggered degradation of the soils and appears to be the most effective practice in restoration of bog ecosystems. [ABSTRACT FROM AUTHOR]

Salinized soil is an important reserved arable land resource in China. The management and utilization of salinized soil can safeguard the current size of arable land and a stable grain yield. Salt accumulation will lead to the deterioration of soil properties, destroy soil production potential and damage soil ecological functions, which in turn will threaten global water and soil resources and food security, and affect sustainable socio-economic development. Microorganisms are important components of salinized soil. Microbial remediation is an important research tool in improving salinized soil and is key to realizing sustainable development of agriculture and the ecosystem. Knowledge about the impact of salinization on soil properties and measures using microorganisms in remediation of salinized soil has grown over time. However, the mechanisms governing these impacts and the ecological principles for microbial remediation are scarce. Thus, it is imperative to summarize the effects of salinization on soil physical, chemical, and microbial properties, and then review the related mechanisms of halophilic and halotolerant microorganisms in salinized soil remediation via direct and indirect pathways. The stability, persistence, and safety of the microbial remediation effect is also highlighted in this review to further promote the application of microbial remediation in salinized soil. The objective of this review is to provide reference and theoretical support for the improvement and utilization of salinized soil. [ABSTRACT FROM AUTHOR]

To investigate the hydrogeochemical characteristics of shallow groundwater and evaluate groundwater salinization state in Cangzhou, China, two sampling campaigns have been conducted. In summer, 33 groundwater samples, 3 seawater samples and 5 river water samples were collected. In winter, 22 groundwater samples were collected. The hydrochemical type was determined by the Piper diagram. Evolutionmechanisms of groundwater were analyzed by the Gibbs diagram. The trend of de-salinization or salinization of groundwater was determined by the hydrochemical facies evolution diagram. The groundwater salinization grade was evaluated by both the seawater intrusion groundwater quality index (GQISWI) and the attribute recognition model based on entropy weight (ARMEW). The Piper diagram shows that Na+ is the dominant cation and Cl- is the dominant anion in shallowgroundwater, and the groundwater in this area is mainly of Cl-Na type followed by Cl-Ca·Mg type. The evaporation-crystallization process has significant influence on the evolution of saline groundwater. In summer, most brackish groundwater exhibit compositions of the freshening stage with direct cation exchange, and most saline groundwater is mainly at the seawater intrusion stage with reverse cation exchange. In winter, compared to the summer season, more groundwater samples in the middle of study area exhibit intrusion trend, and without obvious Na-HCO3 facies. In summer, values of GQISWI range from 20.47 to 75.38 with an average of 59.31. The GQISWI gradually increases from east to west, denoting the degree of groundwater salinization is alleviated from coast to inland. In winter, values of GQISWI range from 54.47 to 79.09 with an average of 66.00, slightly higher than that in summer. The proportion of no salinization (Grade I), minor salinization (Grade II) and serious salinization (Grade III) of groundwater samples in Cangzhou identified by ARMEW is 3.0%, 21.2% and 75.8% in summer, respectively. In winter, the proportion is 9.1% for Grade II and 90.9% for Grade III. The GQISWI index shows the largest area of Grade II, and ARMEW presents the largest area of Grade III in both seasons. Compared with GQISWI index, ARMEW model gives more conservative evaluation results of groundwater salinization. The results provide useful information on the groundwater salinization status for the local area, and help for the management of groundwater resources in Cangzhou. [ABSTRACT FROM AUTHOR]

Freshwater salinization increasingly threatens river ecosystems in arid regions. In situ studies on effects of salinity on freshwater communities are still scarce, especially in largely understudied areas of Africa. To compare macroinvertebrate communities in differing salinity levels, we conducted a confluence-based study in the Draa River basin in Morocco by focusing on two tributaries and their joint downstream sections, in the immediate vicinity of three confluences. Our study revealed that α-diversity differed only minimal. Although only around five taxa comprised over 90% of specimens per section, the more saline sections exhibited proportionally more salt-tolerant generalist species. There was lower β-diversity between the downstream section and each tributary compared to between tributaries, indicating a mixed community after the confluence. The trait profile of the saline El Mellah displayed more resistance and resilience traits to disturbances than the less saline Iriri. Furthermore, low water flow reduced the abundance of sensitive taxa. Overall, we observed minimal differences in macroinvertebrate community composition, due to low γ-diversity in the basin. However, the confluence-based study design remains valuable for investigating effects of specific stressors on ecosystems by excluding large-scale geographic patterns, as compared sites are close and therefore share the same climate, geology, and altitude. [ABSTRACT FROM AUTHOR]

Daphnia spinulata Birabén, 1917 is an endemic cladoceran species, frequent in the zooplankton communities of the shallow lakes of the Pampean region of Argentina. These lakes have varying salinity levels and, being located in agricultural areas, are frequently subject to pesticide pollution. This study aimed to determine the effects of the herbicide glyphosate (Panzer Gold®) in combination with different salinity levels on the biological parameters of D. spinulata and its recovery ability after a short exposure. Three types of assays were performed: an acute toxicity test, a chronic assessment to determine survival, growth and reproduction, and recovery assays under optimal salinity conditions (1 g L−1). The LC50-48 h of glyphosate was 7.5 mg L−1 (CL 3.15 to 11.72). Longevity and the number of offspring and clutches were significantly reduced due to the combined exposure of glyphosate and increased salinity. The timing of the first offspring did not recover after glyphosate exposure. Our results reveal that D. spinulata is sensitive to the herbicide Panzer Gold® at concentrations well below those indicated in the safety data sheet of this commercial formulation, which causes stronger negative effects in conditions of higher salinity. Further research is needed to shed light on the sensitivity of this cladoceran to glyphosate and its variability under other interactive stress factors. [ABSTRACT FROM AUTHOR]

Assessing the risk of groundwater contamination is of crucial importance for the management of water resources, particularly in arid regions such as Menzel Habib (south-eastern Tunisia). The aim of this research is to create and validate artificial intelligence models based on the original DRASTIC vulnerability methodology to explain groundwater salinization risk (GSR). To this end, several algorithms, such as artificial neural networks (ANN), support vector regression (SVR), and multiple linear regression (MLR), were applied to the Menzel Habib aquifer system. The results obtained indicate that the DRASTIC Vulnerability Index (VI) ranges from 91 to 141 and is classified into two categories: low and moderate vulnerability. However, the correlation between groundwater total dissolved solids (TDS) and the Vulnerability Index is relatively weak (r < 0.5). Indeed, the original DRASTIC index needs some improvements. To improve it, some adjustments are required, notably by incorporating the TDS-groundwater salinization risk (GSR) indicator. The seven parameters of the original DRASTIC model were used as inputs for the artificial intelligence models, while the GSR values were used as outputs. Performance indicators, such as the correlation coefficient (r) and the Willmott Agreement Index (d), showed that the ANN model outperformed the SVR and MLR models. Indeed, during the training phase, the ANN model obtained r values equal to 0.89 and d values of 0.4, demonstrating the superiority, robustness, and accuracy of ANN-based methodologies over the original DRASTIC model. The findings could provide valuable information to guide management of groundwater contamination risks, especially in arid regions. [ABSTRACT FROM AUTHOR]

The degradation of freshwater systems by salt pollution is a threat to global freshwater resources. Salinization is commonly identified by increased specific conductance (conductivity), a proxy for salt concentrations. However, conductivity fails to account for the diversity of salts entering freshwaters and the potential implications this has on microbial communities and functions. We tested 4 types of salt pollution—MgCl2, MgSO4, NaCl, and Na2SO4—on bacterial taxonomic and functional α‐, β‐diversity of communities originating from streams in two distinct localities (Nebraska [NE] and Ohio [OH], USA). Community responses depended on the site of origin, with NE and OH exhibiting more pronounced decreases in community diversity in response to Na2SO4 and MgCl2 than other salt amendments. A closer examination of taxonomic and functional diversity metrics suggests that core features of communities are more resistant to induced salt stress and that marginal features at both a population and functional level are more likely to exhibit significant structural shifts based on salt specificity. The lack of uniformity in community response highlights the need to consider the compositional complexities of salinization to accurately identify the ecological consequences of instances of salt pollution. [ABSTRACT FROM AUTHOR]

Human activity is increasing salt concentrations in freshwaters worldwide, but effects of freshwater salinity gradients on biogeochemical cycling are less understood than in saline, brackish, or marine environments. Using controlled microcosm experiments, we characterized (1) short-term (one to five days) biogeochemical responses and (2) water column metabolism along a freshwater salinity gradient of multiple salt types. After one day, microcosms were oxic (4.48–7.40 mg O2 L−1) but became hypoxic (1.20–3.31 mg L−1) by day five. After one day in oxic conditions, microbial respiration in magnesium-, sodium-, and sea salt-based salinity treatments showed a subsidy-stress response, with respiration increasing by over 100% as salinity increased from 30 to 350–800 µS cm−1. Conversely, respiration consistently increased along a calcium-based salinity gradient, peaking at 1500 µS cm−1. By day five, an inverse subsidy-stress response was observed with elevated respiration at upper or lower ends of the gradient except for the magnesium treatment, which had the lowest respiration at the highest salinity. Calcium- and magnesium-based salinity treatments also caused considerable changes in phosphorus concentrations and C:P and N:P. In a separate experiment, microbial respiration and water column primary production also displayed subsidy-stress responses, but imbalances in effect sizes caused consistently declining net community production with increasing salinity. Collectively, our results establish that short-term exposure to different salt ion concentrations can enhance freshwater biogeochemical cycling at relatively low concentrations and alter resource stoichiometry. Furthermore, the nature of effects of freshwater salinization may also change with oxygen availability. [ABSTRACT FROM AUTHOR]

The aim of the study was to highlight morpho-physiological changes like plant height, spike characteristics and stomata features in wheat induced by salt stress. Seeds of wheat var. Alex were sown, in mezo-phyto-cosmos, in five repetitions, under six saline doses, 0, 15, 30, 45, 60, and 75 mM NaCl. The experiment was conducted under field conditions. The assessments including plant height, arista, and spike length were taken and evaluated at the end of the experiment. Adaxial stomatal imprints have been sampled and the stomata density (number of stomata/mm2) and their size were assessed under the microscope. Wheat morphological parameters were affected by the highest salinity dose. Plant height was significantly reduced in the 60 and 75 mM NaCl doses by 16% and 20%. The spike length showed a significant reduction only in the highest saline dose treatment. Arista length registered the highest value in the 15 mM NaCl treatment with 23% more compared to the control. Stomata density reported the highest value in the 15 mM NaCl treatment, significantly higher compared to the 0 mM NaCl dose. The highest salinity doses significantly reduced plant height and spike length. Arista length and stomata density showed similar patterns. [ABSTRACT FROM AUTHOR]

This study determined the effects of salt stress (NaCl) and alkali stress (Na2CO3) on the growth and physiology of Amorpha fruticosa seedlings. The results showed that salt and alkali stress inhibited the growth of root, stem and leaf, but the appropriate concentration of salt and alkali stress could stimulate root elongation. Salt stress and alkali stress resulted in the decrease of photosynthetic capacity of seedlings. The degree of Na+ absorption by the roots is relatively low, and a large amount of Na+ absorbed into the body is separated in the stem and total petiole. The concentration K+, Ca2+ and Mg2+ in diverse plant organs significantly changed under both stresses while concentration of K+, Ca2+ and Mg2+ in leaflets did not change significantly. In addition, accumulation of Cl- under salt stress was not obvious. Soluble sugar accumulation in roots and lobules remarkably increased under both stresses. The distribution of soluble sugar in each vegetative organ was changed. The absorption of degree of harmful ions was relatively low, and more harmful ions were accumulated in the stem and total petiole. This was the response strategy of the seedlings to adapt to salt and alkali stress and it provides a theoretical basis for planting Amorpha fruticosa in areas with relatively low salinization degree. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Ecological zonation in coastal forests is driven by sea level rise and storm‐surge events. Mature trees that can survive moderately saline conditions show signs of stress when soil salinity increases above its tolerance levels. As leaf burn, foliar damage, and defoliation reduce tree canopy cover, light gaps form within the crown. At the forest‐marsh edge, canopy cover loss is most severe; trunks of dead trees without canopies form “ghost forests.” Canopy thinning and light from the edge alter conditions for understory vegetation, promoting the growth of shrubs and facilitating establishment and spread of invasive species that were previously limited by light competition. In this research, we present an analysis of illuminance and temperature in a coastal forest transitioning to a salt marsh. Light sensors above the ground surface were used to measure light attenuation of trees and understory vegetation and to observe the effect of reduced canopies at the forest‐marsh edge. Farther from the marsh, where salinity is lower and trees are healthy, dense canopies attenuate light. We estimate that during the growing season, tree canopies intercept 50% of illuminance on average. Closer to the marsh, canopy thinning, and tree death allow greater light penetration from above, as well as from the adjacent marsh. These illuminance values are further increased by light penetration from the forest‐marsh edge (edge effect). Here, higher illuminance may permit Phragmites australis expansion. At intermediate locations, trees intercept between 32% and 49% of light and the understory shrub Morella cerifera intercepts a further 45% of penetrating light based on comparisons of illuminance above and below shrub canopies. Light penetration from the edge can also be felt. The presence of M. cerifera reduces the air temperature close to the soil surface, creating a cooler summer microclimate. The tree health state is reflected in the canopy size. The canopy patterns and the edge effect are responsible for light availability distribution along forest‐marsh gradients, consequently affecting the understory vegetation biomass. We conclude that during forest retreat driven by sea level rise, tree dieback increases light availability favoring the temporary encroachment of Ph. australis and M. cerifera in the understory.

IntroductionSalinity negatively affects maize productivity. However, calcium lignosulfonate (CLS) could improve soil properties and maize productivity.MethodsIn this study, we evaluated the effects of CLS application on soil chemical properties, plant physiology and grain quality of maize under salinity stress. Thus, this experiment was conducted using three CLS application rates, CLS0, CLS5, and CLS10, corresponding to 0%, 5%, and 10% of soil mass, for three irrigation water salinity (WS) levels WS0.5, WS2.5, and WS5.5 corresponding to 0.5 and 2.5 and 5.5 dS/m, respectively.Results and discussionResults show that the WS0.5 × CLS10 combination increased potassium (K 0.167 g/kg), and calcium (Ca, 0.39 g/kg) values while reducing the sodium (Na, 0.23 g/kg) content in soil. However, the treatment WS5.5 × CLS0 decreased K (0.120 g/kg), and Ca (0.15 g/kg) values while increasing Na (0.75 g/kg) content in soil. The root activity was larger in WS0.5 × CLS10 than in WS5.5 × CLS0, as the former combination enlarged K and Ca contents in the root while the latter decreased their values. The leaf glutamine synthetase (953.9 µmol/(g.h)) and nitrate reductase (40.39 µg/(g.h)) were higher in WS0.5 × CLS10 than in WS5.5 × CLS0 at 573.4 µmol/(g.h) and 20.76 µg/(g.h), leading to the improvement in cell progression cycle, as revealed by lower malonaldehyde level (6.57 µmol/g). The K and Ca contents in the leaf (881, 278 mg/plant), stem (1314, 731 mg/plant), and grains (1330, 1117 mg/plant) were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 at (146, 21 mg/plant), (201, 159 mg/plant) and (206, 157 mg/plant), respectively. Therefore, the maize was more resistance to salt stress under the CLS10 level, as a 7.34% decline in yield was noticed when salinity surpassed the threshold value (5.96 dS/m). The protein (13.6 %) and starch (89.2 %) contents were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 (6.1 %) and (67.0 %), respectively. This study reveals that CLS addition can alleviate the adverse impacts of salinity on soil quality and maize productivity. Thus, CLS application could be used as an effective soil amendment when irrigating with saline water for sustainable maize production.

The scale of land pollution with oil waste necessitates the use of economical and effective methods of recultivation. Phytoremediation is one of the simplest methods, but it has a number of limitations, so additional preparation of the territory is often required before it is carried out. Preliminary electrical preparation and subsequent seeding of special phytoremediants are of interest. Passing a constant electric current through the soil volume under a low voltage removes toxicants from deep soil layers even with flooding. In addition, it reduces pollutant content in the upper layer, where the plants root system is located, which creates more favorable conditions for phytoremediants. Adequately selected types of plants will ensure additional soil cleaning, improve its structure and air exchange. The results of two research directions are presented. Experiments on the study of plant resistance to oil-contaminated soil substrate allowed establishing contamination thresholds at which it is advisable to sow a particular species, and to choose optimal phytoremediants. The study of the oil-containing soil cleaning in a monocathodocentric electrochemical installation with the fixation of main characteristics (oil products concentration, soil temperature, volt-ampere characteristics) allows us to develop technical measures to prepare territories for phytoremediation taking into account the relief features.

Taihu Lake, the third largest freshwater lake in China, has experienced rapid salinization in the past decades; however, little is known about the impact of sodium (Na) on ion exchange in the lake environment. To explore the potential effect of increased Na on the migration of base cations (Ca and Mg) and resulting redistribution between the water and sediment, we used the adsorption-exchange experiment, MINTEQ modeling to explore the cation exchange induced by high Na input, and its impact on the redistribution of Ca and Mg in Taihu different media. The results indicated that exchanged quantity of Ca and Mg increased with time, and the exchange process reached 90% during 0–4 h and reached equilibrium after 24 h under 100 mg/L Na (the maximum Na concentration in Taihu sediment pore water). Our MINTEQ modeled result indicated that the exchanged quantity of Ca and Mg increased with the increasing Na concentration, with Ca being preferably exchanged over Mg at the same Na concentration. The MINTEQ model further predicted that, in the Taihu lake environment, the exchange adsorption would reach the equilibrium at the concentration of 6000 mg/L Na, with exchanged Ca2+ and Mg2+ accounting for 47% and 55% of the total exchangeable Ca and Mg in the sediment, respectively. Although current Na-induced exchange in the Taihu lake has been far from the equilibrium, the MINTEQ result confirmed the existence of this reaction and predicted the potential redistribution of base cations or Ca/Mg ratio in the lake sediment and water phase with further Na increase. Furthermore, our field observations not only confirmed the existence of Na-induced cation exchange in this lake environment but also were generally in agreement with our experimental and modeled results. The increased salinization-induced ion exchange would alter the re-distribution of base cations and the resulting potential ecosystem consequences should be given close attention in this large freshwater lake. [ABSTRACT FROM AUTHOR]

One of the crucial challenges of our time is climate change. The consequences of rising sea levels and drought greatly impact water resources, potentially worsening seawater intrusion. Characterizing coastal aquifers is an essential step in devising strategies to address these phenomena. Seawater intrusion poses a critical socio-economic and environmental issue in the coastal plain of Muravera, southeastern Sardinia (Italy). This coastal plain is an important agricultural area in Sardinia, and the health of the crops is compromised by the increasing salinization of shallow groundwater. To enhance our understanding of the hydrogeological conceptual model, which is essential for a sustainable resource management system, hydrogeological investigations were conducted and complemented by the chemical and multi-isotopic analyses of groundwater. The main objectives of this study were to identify groundwater recharge areas, understand salinization mechanisms and trace the evolution of water chemistry. Within this framework, a monthly survey monitoring piezometric level and electrical conductivity was carried out for one year. This survey was integrated with chemical and isotope analyses, including δ18OH2O and δ2HH2O, δ11B, δ18OSO4, δ34SSO4, and 87Sr/86Sr. Hydrochemistry analysis results revealed the occurrence of seawater–freshwater mixing, extending up to 4 km inland. H2O isotope analysis confirmed the mixing processes and indicated the meteoric origin of recharge waters for both shallow and semi-confined aquifers. The strontium isotopes ratio facilitated the identification of four main groundwater flow paths, confirmed by the SIAR model. The results of this combined hydrogeological–geochemical–isotopic survey provide essential elements for the future implementation of an integrated and sustainable management system. These findings enable interventions to slow the process of seawater intrusion and meet the economic needs for the development of local communities. [ABSTRACT FROM AUTHOR]