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Summary: The first year in a tree's life is characterized by distinct morphological changes, requiring constant adjustments of the hydraulic system. Despite their importance for the natural regeneration of forests and future vegetation composition, little has been known about the hydraulics of tree seedlings.At different times across the first growing season, we analysed xylem area‐specific (Kshoot_Axyl) and leaf area‐specific (Kshoot_L) shoot hydraulic conductance, as well as embolism resistance of three temperate conifer trees, two angiosperm trees and one angiosperm shrub, and related findings to cell osmotic parameters and xylem anatomical traits.Over the first 10 wk after germination, Kshoot_Axyl and Kshoot_L sharply decreased, then remained stable until the end of the growing season. Embolism resistance was remarkably low in the youngest stages but, coupled with an increase in cell wall reinforcement, significantly increased towards autumn. Contemporaneously, water potential at turgor loss and osmotic potential at saturation decreased.Independent of lineage, species and growth form, the transition from primary to secondary xylem resulted in a less efficient but increasingly more embolism‐resistant hydraulic system, enabling stable water supply under increasing risk for low water potentials. [ABSTRACT FROM AUTHOR]

Summary: Both mistletoes and their hosts are challenged by increasing drought, highlighting the necessity of understanding their comparative hydraulic properties. The high transpiration of mistletoes requires efficient water transport, while high xylem tensions demand strong embolism resistance, representing a hydraulic paradox.This study, conducted across four environments with different aridity indices in Yunnan, China, examined the xylem traits of 119 mistletoe–host species pairs.Mistletoes showed lower water use efficiency, indicating a more aggressive water use. They also showed lower hydraulic efficiency (lower vessel diameter and theoretical hydraulic conductivity) but higher safety (lower vulnerability index and higher conduit wall reinforcement, vessel grouping index, and wood density) compared with their hosts, supporting the trade‐off between efficiency and safety. Environmental variation across sites significantly affected xylem trait comparisons between mistletoes and hosts. Additionally, the xylem traits of mistletoes were strongly influenced by host water supply efficiency. The overall xylem trait relationships in mistletoes and hosts were different.These findings stress the impact of host and site on the hydraulic traits of mistletoes, and suggest that mistletoes may achieve high transpiration by maintaining high stomatal conductance under low water potentials. This study illuminates the distinctive adaptation strategies of mistletoes due to their parasitic lifestyle. [ABSTRACT FROM AUTHOR]

Summary Grasses are exceptionally productive, yet their hydraulic adaptation is paradoxical. Among C3 grasses, a high photosynthetic rate (Aarea) may depend on higher vein density (Dv) and hydraulic conductance (Kleaf). However, the higher Dv of C4 grasses suggests a hydraulic surplus, given their reduced need for high Kleaf resulting from lower stomatal conductance (gs). Combining hydraulic and photosynthetic physiological data for diverse common garden C3 and C4 species with data for 332 species from the published literature, and mechanistic modeling, we validated a framework for linkages of photosynthesis with hydraulic transport, anatomy, and adaptation to aridity. C3 and C4 grasses had similar Kleaf in our common garden, but C4 grasses had higher Kleaf than C3 species in our meta‐analysis. Variation in Kleaf depended on outside‐xylem pathways. C4 grasses have high Kleaf : gs, which modeling shows is essential to achieve their photosynthetic advantage. Across C3 grasses, higher Aarea was associated with higher Kleaf, and adaptation to aridity, whereas for C4 species, adaptation to aridity was associated with higher Kleaf : gs. These associations are consistent with adaptation for stress avoidance. Hydraulic traits are a critical element of evolutionary and ecological success in C3 and C4 grasses and are crucial avenues for crop design and ecological forecasting. [ABSTRACT FROM AUTHOR]

ABSTRACT Functional redundancy is considered a pivotal mechanism for maintaining the adaptability of species by preventing the loss of key functions in response to dehydration. However, we still lack a comprehensive understanding of the redundancy of leaf hydraulic systems along aridity gradients. Here, photosynthesis (An), stomatal conductance (gs) and leaf hydraulic conductance (Kleaf) during dehydration were measured in 20 woody species from a range of aridity index (AI) conditions and growing in a common garden to quantify stomatal redundancy (SR), the extent of stomatal opening beyond the optimum required for maximum photosynthesis (Amax), leaf hydraulic redundancy (HR), and the extent of leaf hydraulic conductance (Kleaf) beyond the optimum required for maximum gs (gs‐max). The findings revealed that species from arid habitats tended to have higher SRs but lower HRs than did species from humid habitats. The relatively high SR in arid species arose from relatively high gs‐max values. The relatively low HR arose from the relatively high Kleaf value at a 5% reduction in gs‐max (Kleaf‐gs). Our results suggest that greater stomatal redundancy and lower hydraulic redundancy prevent the loss of photosynthesis and water transportation, respectively, and thus might be the key adaptive mechanisms for plants to adapt to drought conditions. [ABSTRACT FROM AUTHOR]

Hydraulic conductivity of conifer sapwood varies greatly between and within annual rings due to varying dimensions and numbers of tracheids, lumina and bordered pits, complex relationships and non-linearities. Existing laboratory methods are too tedious and expensive for large scale studies for instance of genetics, tree improvement and silvicultural practices, and their spatial resolution is not enough for information on seasonal weather effects which may reflect vulnerability to drought. The article presents a set of integrated models estimating radial variations in hydraulic conductivity at the tracheid level, at 25 µm resolution. A rationalised model was designed for the organisation of tracheids and the water transport through lumina and bordered pits. Within this, pressure drops at flow along lumina and at passages of pits are estimated and integrated to provide local estimates of lumen and xylem conductivities with same radial resolution. The estimated lumen conductivities varied from maximum 0.030 m2/(s·MPa) in earlywood to minimum 0.001 m2/(s·MPa) in latewood. Estimated pressure drops on pit passages reduce these values with about 80 and 90 % into xylem conductivities of 0.006 and 0.0001 m2/(s·MPa) in same earlywood and latewood. Sample means of modelled trunk xylem conductivities were correlated with data from laboratory analyses, resulting in R2 > 0.50. [ABSTRACT FROM AUTHOR]

Functional traits like hydraulic conductivity and vulnerability to cavitation are increasingly important due to climate change. In conifers, water is transported through lumina of tracheids connected via bordered pits, which severely limit xylem conductivity by causing large pressure drops related to their number, dimensions and structure. According to literature, numbers and dimensions of pits correlate positively with tracheid and lumen dimensions. This reflects variations from earlywood to latewood and between rings formed under different grow conditions, contributing to major conductivity variations. The wider aim of the work is to estimate such conductivity variations in trunkwood from measurement data on radial and axial variations of tracheid dimensions. This requires several integrated models, including models estimating numbers and dimensions of pits. The article presents such models developed on data from 27 Norway spruce trees representing different sites, clones and growth rates. Measured and estimated variations of tracheid, lumen and pit properties within and between rings are illustrated, indicating on average about one third smaller and fewer pits in latewood than in earlywood tracheids, and variations in numbers and areas of pits per unit volume of xylem which may be interesting also in fields like wood drying and impregnation. [ABSTRACT FROM AUTHOR]

Numerical modeling of the recovery of moisture by injecting warm air in the unsaturated zone in a 100 m × 100 m plot of agricultural land in Kuwait, a country located in an arid environment, was conducted to provide "proof of concept" of the technique. If technically and economically feasible, it will be a potential additional source of water that could be exploited for farming activities and other uses. The COMSOL software was used to develop the model and, based on the results of the scenario runs, the effects of different hydraulic and operational parameters, including that of well spacing, on moisture recovery were assessed. In general, the results suggested that the recovery should increase with the increase in the hydraulic conductivity of the unsaturated zone, the amount of heat input, and the pressure differential between the unsaturated zone and the well head. Within the period examined (0 to 11 days), the recovery decreases with the increase in the soil moisture content, possibly due to the fall in relative permeability to moisture‐rich air with the increased water contents in the pore spaces, although the effects may change over a longer period as water contents decrease with moisture recovery. The moisture recovery from the unsaturated zone through the injection of warm air appears to be a feasible proposition from this study that should be demonstrated through a pilot scale experiment in the field. [ABSTRACT FROM AUTHOR]

Summary The anatomical reorganization required for C4 photosynthesis should also impact plant hydraulics. Most C4 plants possess large bundle sheath cells and high vein density, which should also lead to higher leaf capacitance and hydraulic conductance (Kleaf). Paradoxically, the C4 pathway reduces water demand and increases water use efficiency, creating a potential mismatch between supply capacity and demand in C4 plant water relations. Here, we use phylogenetic analyses, physiological measurements, and models to examine the reorganization of hydraulics in closely related C4 and C3 grasses. The evolution of C4 disrupts the expected positive correlation between maximal assimilation rate (Amax) and Kleaf, decoupling a canonical relationship between hydraulics and photosynthesis generally observed in vascular plants. Evolutionarily young C4 lineages have higher Kleaf, capacitance, turgor loss point, and lower stomatal conductance than their C3 relatives. By contrast, species from older C4 lineages show decreased Kleaf and capacitance. The decline of Kleaf through the evolution of C4 lineages was likely controlled by the reduction in outside‐xylem hydraulic conductance, for example the reorganization of leaf intercellular airspace. These results indicate that, over time, C4 plants have evolved to optimize hydraulic investments while maintaining the anatomical requirements for the C4 carbon‐concentrating mechanism. [ABSTRACT FROM AUTHOR]

Leaf area to sapwood area ratio (AL/AS) influences carbon sequestration, community composition, and ecosystem functioning in terrestrial vegetation and is closely related to leaf economics and hydraulics. However, critical predictors of AL/AS are not well understood. We compiled an AL/AS data set with 1612 species‐site combinations (1137 species from 285 sites worldwide) from our field experiments and published literature. We found the global mean AL/AS to be 0.63 m2 cm−2, with its variation largely driven by growing‐season precipitation (Pgs), which accounted for 18% of the variation in AL/AS. Species in tropical rainforests exhibited the highest AL/AS (0.82 m2 cm−2), whereas desert species showed the lowest AL/AS (0.16 m2 cm−2). Soil factors such as soil nitrogen and soil organic carbon exhibited positive effects on AL/AS, whereas soil pH was negatively correlated with AL/AS. Tree density accounted for 7% of the variation in AL/AS. All biotic and abiotic predictors collectively explained up to 45% of the variation in AL/AS. Additionally, AL/AS was positively correlated to the net primary productivity (NPP) of the ecosystem. Our study provides insights into the driving factors of AL/AS at the global scale and highlights the importance of AL/AS in ecosystem productivity. Given that Pgs is the most critical driver of AL/AS, alterations in global precipitation belts, particularly seasonal precipitation, may induce changes in plant leaf area on the branches. Summary statement: In this study, we assessed global patterns and key predictors of leaf area to sapwood area ratio (AL/AS) and underscored the significance of growing‐season precipitation, soil pH, and tree density in influencing AL/AS variation and its impact on plant primary productivity. [ABSTRACT FROM AUTHOR]

Plants differ widely in how soil drying affects stomatal conductance (gs) and leaf water potential (ψleaf), and in the underlying physiological controls. Efforts to breed crops for drought resilience would benefit from a better understanding of these mechanisms and their diversity. We grew 12 diverse genotypes of common bean (Phaseolus vulgaris L.) and four of tepary bean (P. acutifolius; a highly drought resilient species) in the field under irrigation and post‐flowering drought, and quantified responses of gs and ψleaf, and their controls (soil water potential [ψsoil], evaporative demand [Δw] and plant hydraulic conductance [K]). We hypothesised that (i) common beans would be more "isohydric" (i.e., exhibit strong stomatal closure in drought, minimising ψleaf decline) than tepary beans, and that genotypes with larger ψleaf decline (more "anisohydric") would exhibit (ii) smaller increases in Δw, due to less suppression of evaporative cooling by stomatal closure and hence less canopy warming, but (iii) larger K declines due to ψleaf decline. Contrary to our hypotheses, we found that half of the common bean genotypes were similarly anisohydric to most tepary beans; canopy temperature was cooler in isohydric genotypes leading to smaller increases in Δw in drought; and that stomatal closure and K decline were similar in isohydric and anisohydric genotypes. gs and ψleaf were virtually insensitive to drought in one tepary genotype (G40068). Our results highlight the potential importance of non‐stomatal mechanisms for leaf cooling, and the variability in drought resilience traits among closely related crop legumes. Summary statement: We grew 16 genotypes of common and tepary bean in the field and found that, although genotypes fell neatly into archetypally "isohydric" or "anisohydric" syndromes, those patterns masked a surprising and counterintuitive combination of underlying physiological causes. Our novel analysis highlight the importance of non‐stomatal mechanisms for leaf cooling, and the variability in drought resilience traits among closely related crop legumes. [ABSTRACT FROM AUTHOR]

The geotechnical centrifuge is an efficient alternative to the slurry consolidometer and settling columns for expedited testing of mine tailings and dredged clay slurries, while accurately reproducing the field stress conditions. Existing numerical models for centrifuge consolidation use piecewise linear and finite-difference methods, and are computationally expensive. This study introduces, for the first time, a finite-element formulation for centrifuge finite-strain consolidation. The proposed model accounts for the nonlinearity induced by the hydraulic conductivity, soil compressibility, and acceleration factor variation along the depth of the centrifuge test specimen. The model incorporates the modified Newton–Raphson method and an implicit time integration technique, leading to a significant reduction in the computational expense. The settlement rate curves generated by the proposed model are validated with corresponding experimental data from the literature studies. The computational cost of the proposed model and existing finite-difference based models are compared for centrifuge and normal gravity consolidation testing conditions. Finally, a parametric analysis is presented to show the influence of various parameters on the functional time steps chosen for the finite-element simulations. The model demonstrates computational robustness and is instrumental for parameter estimation through inverse analysis, and prediction of in-field finite-strain consolidation behavior of slurry wastes. [ABSTRACT FROM AUTHOR]

This study assessed the ability of experimental materials consisting of dicalcium silicate (DCS) and tricalcium silicate (TCS) with nanosized particles to form intratubular crystals under phosphate-buffered saline (PBS) and the effect on dentin permeability reduction. By isolating the cervical part of the extracted premolars, 195 specimens were obtained. Two experimental materials (DCS/TCS and TCS) were applied to the dentin surface by brushing and stored in PBS (n = 65). Another 65 specimens were not treated. Each group was randomly divided into five subgroups based on the PBS immersion period (1, 15, 30, 60, and 90 days, n = 10). The dentin permeability was measured, and the hydraulic conductance, Lp (%), was calculated. After acid challenge with 1 M acetic acid, Lp (%) was remeasured. Data were analyzed using two-way analysis of variance and Fisher's least significant difference test (α = 0.05). Three specimens of each subgroup were longitudinally sectioned and examined using scanning electron microscopy and a field emission-electron probe micro analyzer. The Lp (%) of the experimental groups gradually decreased over time (P < 0.05). The hydroxyapatite-like crystals that grew were observed and found to have a Ca/P ratio similar to that of hydroxyapatite. The crystals remained after the acid challenge, and the Lp (%) was not significantly different from that before acid treatment. Intratubular crystals formed from the experimental materials consisted of DCS and TCS and were resistant to acid. These crystals significantly reduced dentin permeability. [ABSTRACT FROM AUTHOR]

Tubular occlusion is an effective method to treat dentin hypersensitivity. This study aimed to determine the effect of a modified methyl methacrylate-p-styrene sulfonic acid copolymer-based gel desensitizer on dentin permeability and tubule occlusion in extracted human premolars. Hydraulic conductance (HC) measurement (n = 50) and scanning electron microscopy (SEM; n = 64) were performed. Tooth specimens were divided into 6 groups and treated with: G1, distilled water for 30 s; G2, distilled water for 5 min; G3, gel desensitizer for 30 s; G4, gel desensitizer for 5 min; G5, 3% potassium oxalate for 30 s; G6, 3% potassium oxalate for 5 min. HC of dentin were measured before and after 30 s-etching with 35% phosphoric acid, at 0, 30, 60 min after group treatment and after 5-min acid challenge with 6% citric acid. The degree of tubule occlusion and the penetration depth of each agent were also determined. ANOVA and multiple comparison tests were used for data analysis. G3, G4, G5 and G6 significantly decreased in HC after group treatment every observation period, compared to after acid-etching (P < 0.001), and had 100% degree of tubule occlusion with penetration depth about 7.62, 7.94, 8.59 and 8.66 μm, respectively. However, G6 showed the greatest reduction in HC (P < 0.05). Gel desensitizer treatment, for only 30 s, could reduce dentin permeability and completely occlude the dentinal tubules, even though after acid challenge. However, 5-min treatment with potassium oxalate showed the greatest decrease in dentin permeability. [ABSTRACT FROM AUTHOR]

The article "Investigating the Functional and Architectural Diversity of Leaf Venation Networks" explores the diverse leaf venation network architectures in plants and the potential trade-offs among various leaf functions. A team of students led by Dr. Matos collected samples from the University of California Botanical Garden to study 31 functional and architectural leaf venation traits across 122 species. The dataset generated is being used to identify trade-offs in venation architecture-function and understand the evolutionary processes behind the diversity of networks. [Extracted from the article]

Bauxite ore processing industry in West Kalimantan generates a voluminous waste that posses potential environmental risks due to its high pH and mineral contents. However, the substantial presence of calcium, silica, aluminum, and iron in the bauxite ore processing waste (BOPW) also presents opportunities for beneficial utilization. This study investigates the potential use of BOPW as liner material in municipal solid waste landfills, in order to minimize groundwater contamination risk. Physical, chemical, mineralogical, and environmental characteristics, which comprise water content, specific gravity, particle size, toxicity characteristic leaching procedure (TCLP), atterberg limit, compaction, consolidation were measured using relevant ASTM and USEPA methods. The results showed that the BOPW exhibited favorable properties as landfill liner. The low moisture content (20.35%), cohesiveness, and specific gravity of 2.94, low hydraulic conductivity (7.56 x 10-7 cm/s) suggested suitability of the BOPW for landfill liner. Chemical analysis revealed predominant components of Fe2O3, Al2O3, SiO2, and Na2O, while mineralogical examination identified the presence of quartz, magnetite, hematite, and lime. The high pH value (11.93) supported chemical stability and immobilization of heavy metal contaminants. Despite favorable results of TCLP test, leachate quality analysis revealed elevated sodium concentrations (266 mg/L), which raised concerns about potential impact on surface water quality, particularly with the absence of specific regulatory standards. This study highlights BOPW's potential as a suitable landfill liner material, although further assessment for its long-term performance and application suitability is needed. [ABSTRACT FROM AUTHOR]

ABSTRACT Corner's rules are well known in describing inter‐specific scaling relationships for plant organ size‐related traits, from species with thick terminal stems, large leaves, and sparsely branched twigs to species with opposite traits; however, the implications of organ size on physiological functions and growth performance of trees remain unclear. Moreover, whether Corner's rules spectra differ between tree species with simple and compound leaves is not known. Here, we measured key twig morphological traits, physiological characteristics, and radial growth rates of 27 simple‐ and 6 compound‐leaved tree species in a common garden in Northeast China. The size scaling relationships between leaf lamina and supporting structures were mostly allometric (slope < 1) in simple‐leaved species. In contrast, such relationships were predominantly isometric (slope = 1) in compound‐leaved species. Consistently, twig hydraulic conductance and photosynthetic rate increased significantly faster as twig size increased across the compound‐leaved species. Consequently, compound‐leaved species equipped with twigs of fewer but larger leaves have the potential to achieve remarkably high growth rates. Our study revealed divergent investment‐return strategies between the two functional groups, that is, ‘diminishing returns’ in simple‐leaved species and ‘stable returns’ in compound‐leaved species, and identified mechanistic associations among twig architecture, physiological characteristics and tree growth rate. [ABSTRACT FROM AUTHOR]

The article discusses the role of capacitance in water flow through plants to the atmosphere. It explores the physical dimensions of water transport in plants and the formalization of water flux density. The text delves into the differences between transpiration and sap flow, highlighting the impact of capacitance on transient flow. The study emphasizes the reciprocal links between flow and water-stress-induced physiological changes in plants. It concludes by advocating for a proper quantification of plant hydraulic capacitance to enhance the understanding of water transport in plants. [Extracted from the article]

ABSTRACT Vapour pressure deficit (VPD) is a primary determinant of stomatal behaviour and water balance in plants. With increasing global temperature, the accompanying rise in VPD is likely to have a significant impact on the performance of plant species in the future. However, the plasticity of stomatal response to VPD remains largely unexplored. This study examines the plasticity of whole plant stomatal conductance (gc) response to VPD in Pinus radiata plants grown under two temperatures and a water‐deficient treatment over a period of 3 months. The soil–stem water potential gradient (ΔΨ), gc and soil−stem hydraulic conductance (Ks‐s) were evaluated. The different treatment groups showed significant differences in maximum gc relating to differences in Ks‐s, however, gc dynamic response to VPD was very similar in all treatments such that ΔΨ was conserved once VPD increased above an average threshold of 0.64 kPa. The ability to robustly quantify water potential regulation in Pinus presents opportunities to explore variation in this globally important tree genus as well as providing a new approach to characterize the regulation of gas exchange in response to VPD. [ABSTRACT FROM AUTHOR]

Background: Underground research laboratories (URLs) provide a window on the deep biosphere and enable investigation of potential microbial impacts on nuclear waste, CO2 and H2 stored in the subsurface. We carried out the first multi-year study of groundwater microbiomes sampled from defined intervals between 140 and 400 m below the surface of the Horonobe and Mizunami URLs, Japan. Results: We reconstructed draft genomes for > 90% of all organisms detected over a four year period. The Horonobe and Mizunami microbiomes are dissimilar, likely because the Mizunami URL is hosted in granitic rock and the Horonobe URL in sedimentary rock. Despite this, hydrogen metabolism, rubisco-based CO2 fixation, reduction of nitrogen compounds and sulfate reduction are well represented functions in microbiomes from both URLs, although methane metabolism is more prevalent at the organic- and CO2-rich Horonobe URL. High fluid flow zones and proximity to subsurface tunnels select for candidate phyla radiation bacteria in the Mizunami URL. We detected near-identical genotypes for approximately one third of all genomically defined organisms at multiple depths within the Horonobe URL. This cannot be explained by inactivity, as in situ growth was detected for some bacteria, albeit at slow rates. Given the current low hydraulic conductivity and groundwater compositional heterogeneity, ongoing inter-site strain dispersal seems unlikely. Alternatively, the Horonobe URL microbiome homogeneity may be explained by higher groundwater mobility during the last glacial period. Genotypically-defined species closely related to those detected in the URLs were identified in three other subsurface environments in the USA. Thus, dispersal rates between widely separated underground sites may be fast enough relative to mutation rates to have precluded substantial divergence in species composition. Species overlaps between subsurface locations on different continents constrain expectations regarding the scale of global subsurface biodiversity. Conclusions: Our analyses reveal microbiome stability in the sedimentary rocks and surprising microbial community compositional and genotypic overlap over sites separated by hundreds of meters of rock, potentially explained by dispersal via slow groundwater flow or during a prior hydrological regime. Overall, microbiome and geochemical stability over the study period has important implications for underground storage applications. [ABSTRACT FROM AUTHOR]

Drilling wells in unconsolidated formations is commonly undertaken to extract drinking water and other applications, such as aquifer thermal energy storage (ATES). To increase the efficiency of an ATES system, the drilling campaigns are targeting greater depths and enlarging the wellbore diameter in the production section to enhance the flow rates. In these cases, wells are more susceptible to collapse. Drilling fluids for shallow formations often have little strengthening properties and, due to single‐string well design, come into contact with both the aquifer and the overburden. Drilling fluids and additives are experimentally investigated to be used to improve wellbore stability in conditions simulating field conditions in unconsolidated aquifers with a hydraulic conductivity of around 10 m/d. The impact on wellbore stability is evaluated using a new experimental setup in which the filtration rate is measured, followed by the use of a fall cone penetrometer augmented with an accelerometer to directly test the wellbore strengthening, and imaging with a scanning electron microscope (SEM) to investigate the (micro)structure of the filter cakes produced. Twelve drilling fluids are investigated with different concentrations of bentonite, polyanionic cellulose (PAC), Xanthan Gum, calcium carbonate (CaCO3), and aluminum chloride hexahydrate ([Al(H2O)6]Cl3). The filtration results indicate that calcium carbonate, average dp <20 μm, provides pore throat bridging and filter cake formation after approximately 2 min, compared to almost instantaneous discharge when using conventional drilling fluids. The drilling fluid containing 2% [Al(H2O)6]Cl3 forms a thick (4 mm) yet permeable filter cake, resulting in high filtration losses. The fall cone results show a decrease of cone penetration depth up to 20.78%, and a 40.27% increase in deceleration time while penetrating the sample with CaCO3 compared with conventional drilling fluid containing bentonite and PAC, indicating a significant strengthening effect. The drilling fluids that contain CaCO3, therefore, show high promise for field implementation. [ABSTRACT FROM AUTHOR]

Girdling is a crucial technique for promoting the close-to-nature transformation of plantation forests in Hainan Tropical Rainforest National Park (HNNP). It has shown effectiveness in aspects such as community structure and biodiversity restoration. However, its impacts on ecological functions like eco-hydrology still require further in-depth investigation. This study analyzes the impact of girdling on the eco-hydrological indices of three plantations—Acacia mangium, Pinus caribaea, and Cunninghamia lanceolata—through field investigations and laboratory tests. The data was evaluated using a game theory combination weighting-cloud model. The results show that the eco-hydrological indicators of leaf litter in A. mangium increased by 5.77% while those of P. caribaea and C. lanceolata decreased by 11.86% and 5.29%, respectively. Soil bulk density decreased slightly across all plantations while total porosity increased, with A. mangium showing the highest increase of 20.31%. Organic carbon content increased by 76.81% in A. mangium and 7.24% in C. lanceolata, whereas it decreased in P. caribaea. Saturated hydraulic conductivity increased by 33.32% in P. caribaea and 20.91% in A. mangium but decreased in C. lanceolata. Based on the cloud model, the eco-hydrological function of A. mangium improved from 'medium' to 'good', while that of P. caribaea and C. lanceolata declined towards the 'poor' level. In summary, during the process of close-to-nature transformation of tropical rainforests, girdling is an effective method to enhance the ecohydrological functions of broadleaf planted forests. However, for coniferous species, the ecohydrological functions of the planted forests weaken in the short term following the transformation. [ABSTRACT FROM AUTHOR]

Most previous investigations for consolidation-induced solute transport models have been limited to one-dimensional studies in unsaturated porous media and lack systematic parameter sensitivity analysis. This study addresses these gaps by analyzing the effects of hydraulic conductivity (K), shear modulus (G), saturation ( S r ), Poisson's ratio (ν), partitioning coefficient ( K d ), and anisotropy ratio ( K x K z and K y K z ) on pore water pressure, soil deformation, and solute transport. The findings reveal that higher K d values significantly hinder solute migration through enhanced adsorption and reduced vertical transport to deeper layers, while increasing anisotropy ratios primarily enhance horizontal migration, with their effects diminishing beyond a threshold. Additionally, a higher K accelerates pressure dissipation and solute movement, while a lower G increases soil deformation and speeds up solute migration. Saturation has a minor effect on solute concentration, with slight increases under higher S r . The Poisson ratio significantly impacts the transport of the solute, with smaller ν accelerating and larger ν slowing migration. These insights offer valuable theoretical support for optimizing models in unsaturated porous media. [ABSTRACT FROM AUTHOR]

Water conservation and effective irrigation management are vital for sustainable agriculture in arid regions. While organic soil amendments have been widely used to enhance water retention in sandy soils, research on the use of date palm waste-derived biochar remains limited. Thus, this study aimed to explore the innovative application of biochar produced from date palm waste, focusing on its effects on the hydrological properties of sandy soil. Biochars of varying particle sizes (0.5, 1, and 2 mm) and pyrolysis temperatures (300 °C, 450 °C, and 600 °C) were produced and their impacts were assessed under both saturated and unsaturated conditions on soil hydrological properties. The biochar was incorporated into soil columns at application rates of 0%, 1%, 3%, and 5% (w/w) within a 10 cm layer on top of 35 cm deep soil columns. The soil columns were placed vertically into water basins for saturation. Evaporation, infiltration, and saturated hydraulic conductivity were measured. The findings revealed that the application of 1%, 3%, and 5% biochar significantly increased soil water retention by 36.80%, 34.18%, and 29.66%, while cumulative evaporation decreased by 7.30%, 2.00%, and 1.35%, respectively, as compared to the control. Water retained at the end of the experiment was increased by 100.63%, 112.29%, and 101.68%, while unsaturated hydraulic conductivity decreased by 21.27%, 26.15%, and 26.17% after amending the soil with 1%, 3%, and 5% biochar, respectively, as compared to the control. The water retention ranged between 30.34 and 42.51%, 22.59 and 43.20%, and 22.48 and 38.81% for biochar produced at 300 °C, 450 °C, and 600 °C, respectively. Water infiltration rate and pore size was decreased with the increased pyrolysis temperature. Overall, the application rates of 3% and 5% with particle sizes of 1 and 0.5 mm and low pyrolysis temperature were most efficient for improving soil properties such as water retention, reducing unsaturated hydraulic conductivity, reducing the rate and volume of infiltration, and enhancing the micro-porosity reduction of sandy soils. In a nutshell, this study highlights the potential of date palm waste-derived biochar as an effective soil amendment, significantly enhancing water retention by up to 112.29% and reducing evaporation. By optimizing irrigation management in sandy soils, these findings contribute to more sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Hydraulic functionality is crucial for tree productivity and stress tolerance. According to the theory of the fast–slow economics spectrum, the adaptive strategies of different tree species diverge along a spectrum defined by coordination and trade-offs of a suite of functional traits. The fast- and slow-growing species are expected to differ in hydraulic efficiency and safety; however, there is still a lack of investigation on the mechanistic association between tree growth rate and tree hydraulic functionality. Here, in a common garden condition, we measured radial growth rate and hydraulic traits in a fast-growing (Populus alba L. × P. berolinensis Dippel) and a slow-growing tree species (Acer truncatum Bunge), which are both important tree species for afforestation in northern China. In line with the contrasts in radial growth rate and wood anatomical traits at both the tissue and pit levels between the two species, stem hydraulic conductivity of the Populus species was significantly higher than that of the Acer species, but the resistance to drought-induced xylem cavitation was the opposite. A trade-off between hydraulic efficiency and safety was observed across the sampled trees of the two species. Higher water-transport efficiency supports the greater leaf net photosynthetic carbon assimilation capacity of the Populus species and hence facilitates fast growth, while the conservative hydraulic traits of the Acer species result in a slower growth rate but enhanced drought tolerance. [ABSTRACT FROM AUTHOR]

This study addresses the challenge of accurately estimating groundwater-surface water fluxes, essential for sustainable water resource management, by improving traditional temperature time series methods. Existing approaches often struggle with distinguishing natural temperature variations from significant water exchanges, especially across different spatial and temporal scales under varying conditions like recharge and discharge. To overcome these issues, advanced statistical tools were applied to temperature data, and COMSOL Multiphysics was used to simulate interactions by coupling fluid flow and heat transport. Multisite and multivariate calibration techniques refined parameters like hydraulic conductivity and porosity, while models accounted for external factors such as climate variability and land-use changes. The findings reveal that the combined method was effective in estimating groundwater-surface water fluxes under recharge conditions. The COMSOL model achieved an MAE of 0.71, MAP has 0.92, RMSE of 0.80, and RMSLE has 0.30, indicating consistent performance across evaluation metrics. This advancement improves groundwater-surface water model precision, especially in distinguishing natural temperature variations from significant water exchanges. It offers more accurate flux estimation, aiding better water resource management. [ABSTRACT FROM AUTHOR]

ABSTRACT Microbial communities in riverine hyporheic zones provide essential ecosystem services. However, the mechanisms whereby they respond to hyporheic water exchange under different habitat stress conditions remain poorly understood. Therefore, investigating the impact of riverine hyporheic exchange on the microbial community composition and its potential ecological function is essential, particularly in the seasonal rivers of northern China. To elucidate the structure and function of hyporheic zone sediment microbial communities in response hyporheic exchange and environmental fluctuations, we examined associations by performing in situ falling‐head permeameter tests and eDNA techniques. The primary findings were as follows: (1) We detected variations in the spatial distribution patterns of streambed hydraulic conductivity (range, 0.055–3.490 m/day) and vertical fluxes (range, 1.886–342.0 mm/day) among different monitoring stations. (2) Microbial communities displayed compositional similarities and spatial heterogeneity. Stations with limited vertical exchange were characterised by reduced species diversity. (3) Prokaryotes showed better modularity characteristics with higher stability and functional diversity than eukaryotic communities. (4) Differences in the abundance of microbial metabolism and genetic functions were observed among different habitats. This study emphasises the significance of local hydrological patterns (such as downwelling) in maintaining riverine environmental elements and acting as hotspots for microbial diversity within the hyporheic zone. The heterogeneity of the hydrological patterns governing hyporheic water exchange can explain the abundance, species diversity and biogeochemical processes of microorganisms within this zone. [ABSTRACT FROM AUTHOR]

Until now, the contribution of soils in urban spaces has been underestimated and, as a result, the services they provide have been severely undervalued in urban planning. This article aims to address this issue through a study of Chapultepec Park in Mexico City. We provide two methodological proposals for the analysis of soil ecosystem services characterized by the interaction of natural and anthropic processes: the morpho-pedological landscapes (MpL), in which we quantify soil carbon sequestration (SOC Mg ha−1) and the comparison of two methods for the analysis of hydraulic conductivity: Pedotransfer functions (PTF) and direct measurement with a double ring infiltrometer. Among the 12 MpL, we found the highest SOC content in slopes with mixed tree vegetation and Phaeozem soils. However, SOC retention decreased by 40%–50% due to sealing surfaces. For infiltration measures, despite the diversity of soils and vegetation, direct measurements values are highly homogeneous, while values calculated using PTFs better reflect the morphopedological landscape heterogeneity. In all the MpLs, the hydraulic conductivity was higher than the maximum rainfall intensity report, indicating that the soils in Chapultepec Park, despite the differences in soils and intensity of use, provide the ecosystem service of infiltration. These results would allow the establishment of a baseline for monitoring these services and provide information to decision makers and urban planners seeking to reduce the construction of gray infrastructure that seals soils and reduces their capacity to provide these ecosystem services. [ABSTRACT FROM AUTHOR]