Search Results (1,380)

In the context of the global shift toward sustainable energy systems and circular economy strategies, anaerobic digestion is a well-established biotechnology for the valorisation of organic residues, the production of biogas as a renewable energy carrier, and the generation of nutrient-rich digestate. This study aimed to evaluate the stability and methane yield of a two-stage co-digestion process using a substrate mixture developed based on the actual feedstock composition of a full-scale agricultural biogas plant. The daily feed mixture consisted of maize silage (8.2%), sugar beet pulp (4.9%), cellulose pulp (6.6%), distillery stillage (38.6%), corn syrup (6.4%), cattle slurry (22.5%) and sterilised animal by-products (12.8%). Digestate was recirculated separately as part of the reactor operation. Laboratory-scale experiments were conducted in a two-stage anaerobic digestion system operated at 42 °C and 50 °C. The physicochemical properties of the substrates and digestate were determined, biogas quantity and composition were monitored, and the microbial community structure was assessed using 16S rRNA gene amplicon sequencing. The process remained stable throughout the experimental period, with pH values ranging from 8.23 to 8.53, alkalinity between 2600 and 2940 mg CaCO₃/dm³, and a VFAs/alkalinity ratio of 0.17–0.93. Despite ammonium nitrogen concentrations reaching 4346 mg N-NH₄⁺/L, no clear concurrent reduction in gas or methane production was observed. Methane accounted for approximately 70–80% of the biogas produced. The overall specific methane yield reached 346.4 NL CH₄ kg⁻¹ VS added. 16S rRNA gene amplicon sequencing revealed a diverse microbial community containing taxa previously associated with hydrolysis, fermentation and syntrophic interactions, including Proteiniphilum and Syntrophaceticus. The results demonstrate stable process performance and methane production in this site-specific laboratory-scale case study based on the feedstock composition and process configuration of a full-scale agricultural biogas plant. Full article

Trace element contamination represents a persistent environmental issue, particularly in industrialized areas where anthropogenic emissions overlap with natural geochemical backgrounds. This study investigates the atmospheric deposition of trace elements in the Milazzo district (Italy), which is characterized by intense industrial activity. Pinus pinea L. needles were used as biomonitors to assess the spatial distribution and sources of trace elements, combined with lead isotopic analysis for source apportionment. Forty needle samples were analyzed by ICP-OES and ICP-MS for Ca, K, Mg, Na, P, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, V, Zn, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, while 25 samples were selected for Pb isotope ratio determination (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb). Multivariate statistical analyses identified source groups related to industrial and petrochemical emissions, vehicular traffic, crustal resuspension, and mixed combustion processes. Elevated concentrations of As, Cr, Mo, Ni, Pb, Sb, V, and Zn ranged from 16.6 μg g⁻¹ (Zn) to 0.09 μg g⁻¹ (Sb), with the following order of abundance: Zn > Cr > Ni > Pb > Mo > V > As > Sb; these elements were found near industrial facilities and urban areas. Enrichment Factor calculations indicated strong anthropogenic contributions to Cd, Cu, Mo, Sb, V, and Zn, with EF > 10, ranging from 10 (Cd) to 60 (Zn), whereas Al, Fe, and Ti exhibited EF values between 0.5 and 2, reflecting geogenic origins. Pb isotopic ratios (²⁰⁶Pb/²⁰⁷Pb = 1.153–1.192 and ²⁰⁸Pb/²⁰⁶Pb = 2.063–2.108) revealed mixing between industrial emissions and the local geological background, with limited influence from historical gasoline-derived Pb. This integrated geochemical and isotopic approach can effectively identify contamination sources in complex industrial environments. Full article

Understanding the formation of high-total-dissolved-solids (TDS) groundwater is essential for mine-water source identification, treatment, and resource utilization in arid and semi-arid coal mining areas. However, previous studies have commonly focused on individual aquifers and have not adequately explained the hydrochemical differentiation and evolutionary relationships within shallow-to-deep multi-aquifer systems. Taking the Xiaojihan Coal Mine in northern Shaanxi as a case study, 90 surface-water and groundwater samples were analyzed using self-organizing maps (SOM), hydrochemical diagrams, major-ion ratios, chlor-alkali indices, mineral saturation indices, X-ray diffraction data, and permeability-TDS relationships. SOM identified three hydrochemical units broadly corresponding to shallow surface water and groundwater from the Quaternary and Luohe formations, groundwater from the Anding Formation, and deep groundwater dominated by the Zhiluo and Yan’an formations. Their mean TDS concentrations increased from 348.69 to 1341.80 and 2510.00 mg/L, respectively. Groundwater evolved from low-TDS, HCO₃-Ca-dominated shallow water to high-TDS, SO₄-Ca/Na-rich deep water. Shallow groundwater was mainly controlled by carbonate and silicate weathering, whereas deep groundwater was increasingly affected by prolonged water-rock interaction, gypsum and anhydrite dissolution, pyrite oxidation, and reverse cation exchange. The increase in deep-groundwater TDS was primarily associated with the enrichment of SO₄²⁻, Na⁺ + K⁺, and Ca²⁺. Lower permeability with depth slowed groundwater circulation, prolonged residence time, and enhanced mineralization. XRD data confirmed the occurrence of exchange-active clay minerals, while saturation indices showed that carbonate minerals were generally near saturation to supersaturated, whereas gypsum, anhydrite, and halite remained undersaturated and retained dissolution potential. These findings clarify the shallow-to-deep evolution mechanism of high-TDS groundwater and provide a scientific basis for mine-water source identification and targeted management in arid and semi-arid coal mining areas. Full article

Extracting lithium from salt-lake brines boasts distinct advantages including low production cost, low energy consumption and low environmental risks, and will serve as a primary supply source of lithium salts in the future. This trend raises higher demands for the efficiency and cost-effectiveness of lithium extraction technologies. Nanofiltration (NF) membranes, renowned for their superior discrimination between monovalent and divalent ions, have been extensively utilized to obtain Li⁺ from Mg²⁺-rich saline brines. In this study, positively charged NF membranes aimed at Li⁺/Mg²⁺ fractionation were fabricated via surfactant-interlayer-assisted interfacial polymerization (SIAIP). Catechol (CA) and polyethyleneimine (PEI) were utilized to construct the CA/PEI interlayer, and oil-phase dodecyl phosphate (DDP) was used as an additive for interfacial polymerization (IP). The strongly bonded CA/PEI nanoaggregates improved interlayer stability and preserved the positive charge of the double-layer membrane. DDP adsorbed piperazine (PIP) at the two-phase interface through electrostatic interactions, accelerating PIP diffusion and forming a thick polyamide (PA) layer with uniform pores. The combination of CA/PEI interlayer and DDP synergistically enhanced size-sieving and Donnan effects. With MgCl₂ and LiCl rejections of 97.9% and 36.2% respectively, the optimized membrane shows superior selectivity for Li⁺ over Mg²⁺. Moreover, the membrane exhibited weak electrostatic screening and concentration polarization, showing excellent operational stability under varied Mg²⁺-Li⁺ ratios and feed concentrations. Full article

Understanding soil nutrients and stoichiometry across land-use types is essential for semiarid ecosystem management. We selected 130 sampling sites across four land-use types (dryland, paddy field, grassland, and forestland) in the Western Songnen Plain of China. We measured soil pH, nutrients (SOC, TN, TP, TK, and TS), trace elements (Mn, Zn, Cu, F, Se, and Cl), and oxides (MgO, CaO, Fe₂O₃, SiO₂, and TiO₂). One-way analysis of variance (ANOVA), Pearson correlation analysis, and redundancy analysis (RDA) were used to assess nutrient concentrations, stoichiometric ratios, and their environmental drivers. Our results showed that soils were generally alkaline, with the highest pH in grassland. Dryland had significantly higher SOC (12.47 g/kg), TN (1.05 g/kg), and TP (0.22 g/kg) than grassland (9.58, 0.79, and 0.19 g/kg, respectively). Forestland had the highest TK (23.18 g/kg). Most total nutrient concentrations were positively correlated with trace-element concentrations, except for TK. The C:N of paddy field (12.38) was significantly lower than those of grassland (14.24) and forestland (14.42), while both N:P (10.92) and N:K (0.13) were significantly higher than those in grassland (8.63, 0.11). The P:K of dryland (0.0137) was significantly higher than those in grassland (0.0108) and forestland soils (0.0106). RDA identified SOC and TP as common major factors associated with variation in nutrient stoichiometry, explaining 96.1%, 34.8%, 94.1%, and 93.2% of the variation in dryland, paddy field, grassland, and forestland, respectively. In addition, trace elements and oxides also explained the variation to varying degrees. This study provides a basis for sustainable land-use management in semiarid regions. Full article

Iron (Fe) is an essential micronutrient for plant growth, serving as a cofactor in chlorophyll synthesis, photosynthetic electron transport, and redox reactions. Both Fe deficiency and excess disrupt mineral nutrient homeostasis, but the ionomic and transcriptomic mechanisms underlying genotype-specific responses in potato remain elusive. We profiled the ionome and transcriptome of two potato genotypes, 05P and CI5, grown under Fe-deficient, Fe-sufficient and Fe-excess conditions represented by 1, 40.4 and 120 mg L⁻¹ FeNaEDTA, respectively. Ionomic analysis detected significant alterations in Fe, Mn, Zn, Ca, Mg, and Cu concentrations across roots, stems, and leaves, with the direction and magnitude of change varying by organ and genotype. Under Fe deficiency, CI5 showed steeper declines in root and stem Fe than 05P, while 05P retained higher leaf Fe, reflecting genotype-dependent patterns of shoot Fe distribution. Fe excess caused Fe accumulation in both genotypes, but coincided with Mn depletion in shoots, raising Fe/Mn ratios, consistent with potential antagonistic Fe–Mn interactions at the transport level. This pattern is consistent with potential antagonistic Fe–Mn interactions, although alternative mechanisms such as Mn uptake inhibition or dilution effects cannot be ruled out without direct experimental evidence. Transcriptome analysis showed organ-biased responses: Fe deficiency upregulated more genes in stems, whereas Fe excess triggered stronger transcriptional shifts in roots. No KEGG pathways remained significant after false discovery rate (FDR) correction, suggesting that genotype-dependent Fe-responsive divergence was not concentrated in a limited number of canonical KEGG pathways under the present analytical framework. Joint analysis of ionomic and transcriptomic data highlighted ferric-chelate reductase oxidase (FRO) and zinc-regulated transporter/iron-regulated transporter-like protein (IRT/ZIP) family members as genes associated with Fe reduction, divalent metal uptake, and Fe–Mn balance based on differential expression and orthology with functionally characterized Arabidopsis homologs. Comparative genomics showed that FRO and ZIP families have expanded in potato, with conserved domain architectures but divergent gene structures and promoter architectures, consistent with potential functional diversification related to metal transport. In conclusion, under Fe deficiency, genotype-dependent transcriptional divergence was most pronounced in stems, whereas under Fe excess it was more evident in roots, jointly maintaining systemic Fe–Mn homeostasis in potato. Full article

Microbially induced calcium carbonate precipitation (MICP) is a promising biotechnology for environmental remediation; however, the high cost of conventional chemical-grade calcium sources limits its large-scale scalability. This study evaluated the feasibility of utilizing an aqueous extract of natural attapulgite clay as a sustainable, low-cost calcium source for MICP-mediated arsenic (As) immobilization in both aqueous and soil systems. Among the tested minerals, Baiyin attapulgite (group B) exhibited the highest calcium content (62,808.94 mg kg⁻¹) and minimal toxic metal impurities, providing a favorable chemical matrix for biomineralization. At an optimal solid-to-liquid ratio of 1:10, Lysinibacillus fusiformis LF and Enterococcus LZU-1 successfully induced calcite precipitation driven by the attapulgite extract. In batch aqueous remediation experiments (20 days), the attapulgite extract significantly enhanced As removal efficiency compared to the controls; As removal rates peaked at 66.4% for strain LZU-1 (with LZ1 extract) and 65.8% for strain LF (with group B extract), drastically outperforming the standard CaCl₂ groups (31.2–37.3%) and blank controls (21.8–24.5%). Concurrently, soil incubation experiments (30 days) demonstrated that the combined application of attapulgite and MICP bacteria reduced the highly bioavailable exchangeable As fraction from 0.115 to approximately 0.03 mg kg⁻¹, while effectively driving its transformation into more stable carbonate-bound and organic-bound fractions without causing secondary soil salinization. Morphological and mechanistic analyses revealed that, compared to the well-defined euhedral crystals in the CaCl₂ control, the precipitates mediated by the clay extract exhibited distinctly irregular, defect-rich rhombohedral structures. This structural disruption was governed by the natural matrix effect of attapulgite, which simultaneously supplied dissolved Ca²⁺ and provided an abundance of fine clay fragments, calcite micro-grains, and associated amorphous Fe/Al/Mn-bearing phases. These constituents acted as physical scaffolding and heterogeneous nucleation sites that became embedded in the growing CaCO₃ lattice, driving the formation of highly reactive, defect-rich clay-calcite-arsenic composite precipitates that efficiently encapsulated arsenate. Mantel analysis further revealed that the remediation efficiency was significantly correlated with key environmental variables including Ni, V, Ca. These findings highlight the dual-system potential of natural attapulgite as an inexpensive, eco-friendly calcium alternative for sustainable MICP-based remediation of As-contaminated water and agricultural soils. Full article

To elucidate the geochemical features of produced water in coalbed methane (CBM) wells of the Gujiao Block and their indicative significance for production, systematic testing of ion composition and total dissolved solids (TDS) of produced water from ten CBM wells was conducted through five discrete sampling campaigns over an 18-month period. Combined with production performance data, the spatiotemporal evolution patterns, controlling factors, and the response relationship with productivity were analyzed. The results show that the water chemistry type of produced water in the study area is mainly identified as the Na-HCO₃ type. The TDS averages 1716.62 mg/L. The hydrochemical characteristics are primarily controlled by water/rock interactions, with Na⁺ and K⁺ mainly derived from silicate mineral weathering and dissolution, coupled with cation exchange processes. The Na/Cl ratio suggests that halite dissolution contributes to both Na⁺ and Cl⁻, whereas the excess Na⁺ relative to Cl⁻ likely reflects cation exchange or dissolution of Na-bearing silicate minerals. As drainage proceeded, Na⁺ and K⁺ concentrations increased, Ca²⁺ decreased, Cl⁻ increased, and SO₄²⁻ first increased and then decreased. Spatially, TDS increases from north to south, with the central-southern region representing a stagnant groundwater zone. Productivity response analysis reveals that Na⁺, HCO₃⁻, and TDS all show a trend of initially slow increase followed by rapid increase with increasing gas production. A negative trend is observed between gas production and the concentrations of Cl⁻, Ca²⁺, Mg²⁺, and SO₄²⁻. The productivity response index for the Gujiao Block ranges from 3.75 to 42.43, with an average of 17.78. As the productivity response index increases, gas production initially decreases and then increases. The findings clarify the geochemical evolution mechanisms of produced water in the Gujiao Block, providing a scientific basis for productivity evaluation of CBM wells. Full article

The sustainable management of urban pruning residues is increasingly important for promoting circular bioeconomy practices and reducing green waste disposal. This study evaluated the composting potential of pruning biomass from 18 urban tree species (11 deciduous and 7 coniferous) and assessed the effects of biomass type and feedstock ratio on compost quality. Plant residues were composted with fresh cow manure using two compost ratios: V1 (700 g manure + 100 g plant biomass) and V2 (700 g manure + 700 g plant biomass). Compost quality was evaluated through pH, macroelement (N, P, K, Ca, Mg) and total microelement (Mn, Cu, and Zn) and heavy metal (Pb, Cd, and Ni) concentrations. The composting ratio was the primary factor controlling compost properties. V1 produced alkaline composts (pH 7.96–9.42) with higher nutrient concentrations, whereas V2 generated composts with pH values closer to neutrality (7.39–9.44). Increasing the proportion of plant biomass reduced macronutrient concentrations, with total N ranging from 2.23% in V1 to 0.72% in V2, and potassium decreasing by 50–80% relative to V1. In contrast, micronutrient concentrations increased in V2, reaching 1142.7 mg·kg⁻¹ Mn and 481.1 mg·kg⁻¹ Zn. Total heavy metal concentrations also increased with greater biomass incorporation, although values generally remained low; the highest Ni concentration (15.77 mg·kg⁻¹) was recorded in Paulownia tomentosa compost. Species-specific responses were observed for nutrient release and metal accumulation, highlighting differences between deciduous and coniferous feedstocks. The findings demonstrate that compost quality is primarily determined by the manure-to-biomass ratio, while tree species influence nutrient dynamics and trace element accumulation. Composts with higher manure proportions are suitable for nutrient enrichment and acidic soil amelioration, whereas biomass-rich composts provide enhanced micronutrient contents but require monitoring of heavy metal accumulation. Full article

This study presents a novel, low-temperature thermochemical activation process for the selective extraction of Cr and V from carbon steel EAF (CH1) and FeCr (CH2) slags at temperatures of up to 600 °C. Of the twelve reagents tested, NaOH was identified as the optimal alkaline agent for Cr activation at 500 °C, achieving extraction yields of 61.6% for CH1 (slag-to-reagent ratio of 12:8 g) and 80.6% for CH2 (ratio of 12:16 g). KOH at 400 °C was the most effective reagent for V extraction, yielding 89.4% for CH1 and 54.5% for CH2. Maximum metal concentrations were achieved after only five minutes of leaching at 60 °C. The process exhibits high selectivity; primary matrix components (Fe, Si, Al, Ca, Mg) either do not leach or only leach in negligible amounts. Iron forms insoluble oxides, and calcium converts into stable calcite, while magnesium is bound in the form of hydrotalcite specifically in the CH2 slag leaching residue. The CaCO₃ content was proven to be a crucial parameter determining the activation efficiency and effective transformation of Fe-Cr-V phases. This procedure enables the recovery of clean Cr and V leachates, while the residual mineral-rich fraction offers potential for various industrial applications in a closed-loop slag recycling process. Full article

The Lower Cambrian Yurtus Formation along the northwestern margin of the Tarim Basin has commonly been regarded as a regionally developed marine source-rock interval. However, the formation features strong internal source-rock heterogeneity, and the paleogeographic mechanism governing its thin organic-poor intervals remains to be further clarified, which constrains a more comprehensive understanding and evaluation of the Yurtus Formation. This study integrated whole-well source-rock geochemical data with major- and trace-element records from Well K1 in the Keping area to evaluate the geochemical background of the Yurtus Formation, its contrast with adjacent strata, and the internal differentiation of a thin and organic-poor interval at 5269–5274 m. The whole-well dataset of analytical results shows that the deep Yurtus-related section occurs within an overall low-TOC and low-S2 background. The 5269–5274 m interval is represented by only approximately 5 m of source-rock-bearing strata and is compositionally distinct from the adjacent carbonate-dominated strata. Compared with the adjacent intervals, the target interval has higher mean Al, Si, K, Ti, Fe, V, Cr, Zr, Rb, Sr, and U values, but lower Ca and Mg values. Elemental profiles and ratio data further define three first-order meter-scale geochemical subunits: an upper carbonate-rich subunit with high Ca and Ca/Al values, a middle aluminosilicate-rich subunit with higher Al, Si, K, Ti, and Fe values, and a lower chemically enriched subunit marked by elevated V, Cr, U, Sr, P/Ti, Sr/Ca, V/Cr, and S/Fe values. Mo enrichment is weak, and the available Mo–U and Mo/Al evidence does not support a definitive interpretation of persistent euxinic conditions. Therefore, the lower subunit is interpreted as recording relatively stronger reducing and chemically reactive conditions rather than a stable euxinic water column. Elevated P/Ti in the lower subunit is treated as phosphorus enrichment associated with redox-sensitive chemical fixation and/or early diagenetic redistribution, rather than as direct evidence for increased primary productivity alone. Regional comparison with published Yurtus sections and wells indicates that the thin, low-TOC, and compositionally differentiated interval in Well K1 represents a local expression of source-rock heterogeneity. The results suggest that slope-break-related paleogeographic differentiation controlled accommodation, sediment supply, hydrodynamic disturbance, preservation efficiency, and early diagenetic modification, thereby governing the heterogeneous development of the Yurtus Formation along the northwestern Tarim margin. Full article

Runoff recharge increases during the wet season in arid inland river basins; however, solute inputs along river courses, evaporite salt dissolution, and leaching from saline sediments may still substantially modify the chemical composition of surface waters. To identify the sources of major ions, hydrochemical controlling processes, and salt-enriched river reaches during the wet season in the Cele River Basin, 107 surface water samples were collected from the mainstream of the Cele River and five major tributaries in August 2025. Field and laboratory analyses were conducted for pH, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), and major ions, including Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄²⁻, and HCO₃⁻. Piper diagrams, Gibbs diagrams, ionic ratios, Spearman correlation analysis, and principal component analysis (PCA) were used to characterize the major-ion composition, hydrochemical facies, and controlling factors. The results show that the surface waters were generally weakly alkaline, with pH values ranging from 7.42 to 8.46. TDS and EC exhibited pronounced spatial heterogeneity, with higher salinity levels in the Buzang River, the Cele River mainstream, and the Uluk Say River, and relatively lower mineralization in the Bostan River and Nur River. SO₄²⁻ and Cl⁻ dominated the anionic composition, together accounting for 80.3% of total anions, whereas Ca²⁺ + Mg²⁺ and Na⁺ + K⁺ jointly controlled the cationic composition, accounting for 57.3% and 42.7% of total cations, respectively. The Piper diagram indicated that the Cl·SO₄–Na·Ca type was the dominant hydrochemical facies, accounting for 67.3%, suggesting a pronounced sulfate–chloride salt-enrichment signature during the wet season. Evidence from Gibbs diagrams, ionic end-member ratios, and PCA further indicates that the hydrochemical composition is primarily constrained by rock weathering and jointly influenced by sulfate and chloride salt dissolution, evaporation–concentration processes, and leaching from saline sediments. These processes reflect the coexistence of runoff dilution and salt reloading during the wet season. The Buzang River, Cele River mainstream, and Uluk Say River should be prioritized for continuous water-quality monitoring and salinity-risk early warning, while TDS, EC, Na⁺, Cl⁻, and SO₄²⁻ can serve as core indicators for diagnosing wet-season water–salt processes and tracking water-quality baselines. This study identifies the key salt-enriched reaches, major ion sources, and hydrochemical control mechanisms of surface waters in the Cele River Basin during the wet season, providing a scientific basis for water-quality protection, oasis agricultural water regulation, and sustainable water–salt management in arid inland river basins. Full article

Background/Objectives: This study aimed to compare the effects of two distinct dietary protein sources, soybean meal (SBM, 454 g CP/kg dry matter [DM]) and fermented protein source (FPS, 635 g CP/kg DM), on milk yield (MY), milk quality traits, and serum biochemistry in crossbred dairy cows. Methods: This study employed a randomized complete block design with four groups (n = 6 per group): Control (120 g/kg SBM), FPS30 (30 g/kg FPS and 75 g/kg SBM), FPS40 (40 g/kg FPS and 60 g/kg SBM), and FPS50 (50 g/kg FPS and 45 g/kg SBM). Results: After 66 days (21-day adaptation period and 45-day feeding trial), DM intake, milk protein content, and milk density did not differ significantly across groups. However, MYs were significantly higher in the FPS50 group (p = 0.043). Additionally, milk fat (p = 0.021), DM (p = 0.013), solids-non-fat (SNF, p = 0.047), and lactose content (p = 0.007) were significantly higher in the FPS groups. Although serum biochemistry did not differ across groups on day 0, blood urea nitrogen (BUN, p = 0.044) and serum Ca (p = 0.041), P (p = 0.039), and Mg (p = 0.041) concentrations were significantly lower in the FPS groups on day 66. Moreover, FPS intake correlated positively with MY (R = 0.680), milk DM (R = 0.706), fat (R = 0.665), SNF (R = 0.566), lactose content (R = 0.653), and fat-to-protein ratio (R = 0.507) and negatively with milk density (R = −0.429) and mineral content (R = −0.271). Conclusions: These findings indicate that FPS is effective in increasing productivity and improving/maintaining milk quality traits in cows fed diets substituting specific amounts of SBM with FPS. The induced reduction in BUN can be interpreted as increased protein utilization. Full article

Catchment characteristics significantly influence water composition in pristine mountain lakes, receiving similar atmospheric deposition. We analysed these relationships for 20 subalpine and alpine catchment–lake systems in the High Tatra Mountains (Slovakia), using a comprehensive new dataset of detailed catchment characteristics and mean water chemistry from 2021 to 2024. Redundancy analysis indicated that catchment characteristics explained 47% of the spatial variability in lake hydrochemistry. The most influential parameters were land cover (20%), terrain slope (11%), lake-to-catchment area ratio (8%), and bedrock geology (8%). Cation concentrations were dominated by Ca²⁺, while anions were dominated by HCO₃⁻. Concentrations of Na⁺, K⁺, Cl⁻, dissolved organic carbon (DOC), and total organic nitrogen (TON) were higher, while NO₃⁻ was lower, in lakes with greater soil and vegetation cover in catchments. Concentrations of Na⁺, K⁺, Mg²⁺, Ca²⁺, HCO₃⁻, Cl⁻, SO₄²⁻, silicon (Si), and DOC decreased with increasing altitude, whereas Na⁺, K⁺, SO₄²⁻, NO₃⁻, NH₄⁺, and Si increased with catchment slope. Catchment bedrock geology affected K⁺, SO₄²⁻, and Si concentrations in lake water. More than 50% of the observed variability remained unexplained, indicating that additional climatic and hydrological drivers may influence lake hydrochemistry and represent important directions for future research. Full article

Efficient rooting is essential for the propagation of grape rootstocks. This study aimed to identify an effective rooting formulation for hardwood cuttings and to investigate its underlying physiological and molecular mechanisms. Seven grape rootstocks were treated with indole-3-butyric acid (IBA) combined with melatonin (MLT) or citric acid (CA), with IBA plus naphthaleneacetic acid (NAA) and water serving as controls. Rooting performance was comprehensively evaluated using morphological traits, physiological characteristics, endogenous hormone contents, and transcriptome analysis. Among all treatments, 400 mg/L IBA combined with 1.2 mM MLT exhibited the best rooting performance. This treatment significantly enhanced root activity, soluble sugar, and soluble protein contents. It also increased IAA and GA₃ levels and improved the IAA/ABA and GA₃/ABA ratios compared with the controls. Transcriptome analysis of ‘110R’ revealed that MLT-responsive genes were mainly enriched in plant–pathogen interaction, hormone signal transduction, and MAPK signaling pathways. Transcription factor families including MYB, ERF, and NAC were identified as potential regulators. Collectively, these findings demonstrate that IBA–MLT combined application promotes rooting by regulating physiological metabolism, hormone balance, and gene expression, providing a theoretical basis for improving grape propagation efficiency. Full article