Search Results (252)

Soil organic carbon (SOC) pool plays an extremely important role in regulating the global carbon (C) cycle and climate change. Atmospheric nitrogen (N) and phosphorus (P) deposition caused by human activities has significant impacts on soil C sequestration potential of terrestrial ecosystem. To investigate the effects of N and P deposition on soil C sequestration and C-N coupling relationship in broad-leaved evergreen forests, a 6-year field nutrient regulation experiment was implemented in subtropical Castanopsis sclerophylla forests with four different N and P additions: N addition (100 kg N·hm⁻²·year⁻¹), N + P (100 kg N·hm⁻²·year⁻¹ + 50 kg P·hm⁻²·year⁻¹), P addition (50 kg P·hm⁻²·year⁻¹), and CK (0 kg N·hm⁻²·year⁻¹). The changes in the C and N contents and stable isotope distributions (δ¹³C and δ¹⁵N) of different soil organic fractions were examined. The results showed that the SOC and total nitrogen (STN) (p > 0.05) increased with N addition, while SOC significantly decreased with P addition (p < 0.05), and N + P treatment has low effect on SOC, STN (p > 0.05). By density grouping, it was found that N addition significantly increased light fraction C and N (LFOC, LFN), significantly decreased the light fraction C to N ratio (LFOC/N) (p < 0.05), and increased heavy fraction C and N (HFOC, HFN) accumulation and light fraction to total organic C ratio (LFOC/SOC, p > 0.05). Contrary to N addition, P addition was detrimental to the accumulation of LFOC, LFN and reduced LFOC/SOC. It was found that different reactive oxidized carbon (ROC) increased under N addition but ROC/SOC did not change, while N + P and P treatments increased ROC/SOC, resulting in a decrease in SOC chemical stability. Stable isotope analysis showed that N addition promoted the accumulation of new soil organic matter, whereas P addition enhanced the transformation and utilization of C and N from pre-existing organic matter. Additionally, N addition indirectly increased LFOC by significantly decreasing pH; significantly contributed to LFOC and ROC by increasing STN accumulation promoted by NO₃⁻-N and NH₄⁺-N; and decreased light fraction δ¹³C by significantly increasing dissolved organic C (p < 0.05). P addition had directly significant negative effect on LFOC and SOC (p < 0.05). In conclusion, six-year N deposition enhances soil C and N sequestration while the P enrichment reduces the content of soil C, N fractions and stability in Castanopsis sclerophylla forests. The results provide a scientific basis for predicting the soil C sink function of evergreen broad-leaved forest ecosystem under the background of future climate change. Full article

The Tuztaşı low-sulfidation epithermal Au–Ag deposit (Biga Peninsula, Türkiye) records a multi-stage hydrothermal history that can be interpreted through the trace and rare-earth-element (REE) chemistry of quartz. High-precision LA-ICP-MS analyses of five representative quartz samples (23 ablation spots; 10 analytically robust) reveal two fluid stages. Early fluids were cold, dilute meteoric waters (δ¹⁸O₍H₂O₎ ≈ −6.8 to +0.7‰), whereas later fluids circulated deeper, interacted with felsic basement rocks, and evolved in composition. Mineralized quartz displays marked enrichment in As (raw mean = 2854 ± 6821 ppm; filtered mean = 70 ± 93 ppm; one spot 16,775 ppm), K (498 ± 179 ppm), and Sb (57.8 ± 113 ppm), coupled with low Ti/Al (<0.005) and elevated Ge/Si (0.14–0.65 µmol mol⁻¹). Chondrite-normalized REE patterns show pronounced but variable LREE enrichment ((La/Yb)_n ≤ 45.3; ΣLREE/ΣHREE up to 10.8) and strongly positive Eu anomalies (δEu ≤ 9.3) with slightly negative Ce anomalies (δCe ≈ 0.29); negligible Ce–Eu covariance (r² ≈ 0.05) indicates discrete redox pulses. These signatures indicate chemically evolved, reducing fluids conducive to Au–Ag deposition. By contrast, barren quartz is characterized by lower pathfinder-element contents, less fractionated REE profiles, higher Ti/Al, and weaker Eu anomalies. A composite exploration toolkit emerges: As > 700 ppm, As/Sb > 25, Ti/Al < 0.005, Ge/Si > 0.15 µmol mol⁻¹, and δEu ≫ 1 reliably identify ore-bearing zones when integrated with δ¹⁸O data and fluid-inclusion microthermometry from earlier studies on the same vein system. This study provides one of the first systematic applications of integrated trace-element and REE analysis of quartz to a Turkish low-sulfidation epithermal system, offering an applicable model for vectoring mineralization in analogous settings worldwide. Full article

Rare earth elements (REEs) are emerging soil contaminants due to increasing fertilizer use, mining activities, and technological applications. However, few studies have assessed their concentrations in soils or associated environmental risks. Here, we evaluate the influence of land cover types (Eucalyptus plantation, forest, and pasture), parent material, and soil physicochemical properties (predictor variables) on REE content in the Brazilian Atlantic Forest and measure pseudo-total REE content using inductively coupled plasma mass spectrometry (ICP-MS). Differences in REE content across land cover types, parent materials, and soil properties were assessed using similarity and variance analyses (ANOSIM, ANOVA, and Kruskal–Wallis) followed by post hoc tests (Tukey HSD and Dunn’s). We used model selection based on the Akaike criterion (ΔAICc < 2) to determine the influence of predictor variables on REE content. Our results showed that parent materials (igneous and metamorphic rocks) were the best predictors, yielding plausible models (Adj R² ≥ 0.3) for Y, δEu, and La_N/Sa_N. In contrast, Ca:Mg alone provided a plausible model (Adj R² = 0.15) for δCe anomalies, while clay content (Adj R² = 0.11) influenced the Sa_N/Yb_N ratio, though soil properties had weaker effects than parent materials. However, we found no evidence that Eucalyptus plantations or pastures under non-intensive management increase REE content in Brazilian Atlantic Forest soils. Full article

In the context of China’s ecosystem facing a high intensity of nitrogen loads, carbon–nitrogen interactions are receiving increasing attention. Physical protection by soil aggregates is critical for soil carbon and nitrogen sequestration in terrestrial ecosystems; however, there is currently limited information on how nitrogen addition influences carbon and nitrogen dynamics across different stages of forest ageing. Herein, a field nitrogen manipulation experiment over 6 years was established in subtropical forests (46, 78, and about 200 years old) in China. Aggregate fractions and stable isotope analyses were used to assess the effects of nitrogen addition. The results show that forest soil was dominated by macroaggregates, and these increased with forest ageing (p > 0.05). The macroaggregates’ carbon content decreased with forest ageing (p > 0.05), while the macroaggregates’ nitrogen content was highest in the 200-year-old forest. Nitrogen addition increased the aggregates’ carbon and nitrogen concentrations in the 46- and 200-year-old forests. The macroaggregates, under nitrogen addition in the 78- and 200-year-old forests, were relatively weak, while forest age and nitrogen addition mainly affected macroaggregate carbon and nitrogen concentrations to promote their carbon and nitrogen storage, and the macroaggregates were the main storage unit for fixing and protecting new carbon in soils. Nitrogen addition increased the macroaggregates’ δ¹³C abundance in the 78- and 200-year-old forests and decreased it in the 46-year-old forest (p > 0.05); significantly increased the macroaggregates’ δ¹⁵N in the 46-year-old forest (p < 0.05), and decreased the macroaggregates’ δ¹⁵N in the 200-year-old forest (p > 0.05). Considering the distribution of δ¹³C and δ¹⁵N in the aggregates, the effect of nitrogen addition on the dynamic mechanism of soil aggregate carbon and nitrogen fractions varied based on forest age and aggregate size. Correlation analysis further revealed that soil total phosphorus, NH₄⁺-N, NO₃⁻-N, dissolved organic nitrogen, pH, texture, etc., were the primary predictors explaining most of the variation in aggregate fractions and their δ¹³C distribution. In summary, the effect of nitrogen deposition on the carbon and nitrogen stability of soil aggregates in broad-leaved forests depends on forest age. Full article

As a vital oil and cereal crop in China, soybean requires efficient and low-loss harvesting to ensure food security and sustainable agricultural development. However, pod-shattering losses during soybean harvesting in Xinjiang remain severe due to low pod moisture content and poor mechanical strength, while existing studies lack a systematic analysis of the interaction mechanism between reeling devices and pods. The current research on soybean harvester headers predominantly focuses on conventional rigid designs, with limited exploration of flexible reel mechanisms and their biomechanical interactions with soybean pods. To address this, this study proposes an optimization method for low-loss harvesting technology based on mechanical-crop interaction mechanisms, integrating dynamic simulation, contact mechanics theory, and field experiments. Texture analyzer tests revealed pod-shattering force characteristics under different compression directions, showing that vertical compression exhibited the highest shattering risk with an average force of 14.3271 N. A collision model between the spring tooth and pods was established based on Hertz contact theory, demonstrating that reducing the elastic modulus of the spring tooth and increasing the contact area significantly minimized mechanical damage. Simulation verified that the PVC-nylon spring tooth reduced the maximum equivalent stress on pods by 90.3%. Furthermore, the trajectory analysis of spring-tooth tips indicated that effective pod-reeling requires a reel speed ratio (Δ) exceeding 1.0. Field tests with a square flexible spring tooth showed that the optimized reel reduced header loss to 1.371%, a significant improvement over conventional rigid teeth. This study provides theoretical and technical foundations for developing low-loss soybean harvesting equipment. Future work should explore multi-parameter collaborative optimization to enhance adaptability in complex field conditions. Full article

Although drunken horse grass (Achnatherum inebrians) can be simultaneously infected by the foliar endophyte Epichloë gansuensis and colonized by Bacillus subtilis, it remains unclear whether Epichloë endophyte symbiosis influences B. subtilis colonization, as well as how their interaction affects nitrogen fixation and assimilation. The purpose of the present study was to investigate whether E. gansuensis endophyte infection facilitates the colonization of B. subtilis in the roots of host plants, with a focus on understanding the interaction effects of the E. gansuensis endophyte and B. subtilis on plant growth and nutrient absorption. In this study, we measured the colony growth rate of B. subtilis LZU7 when co-cultured with E. gansuensis strains. In addition to an in vitro test, we investigated the root colonization of Epichloë endophyte-infected plants (E+) and Epichloë endophyte-free plants (E−) with the GFP-tagged B. subtilis LZU7 in an inoculation test. Furthermore, we evaluated the interactions between E. gansuensis endophyte symbiosis and B. subtilis LZU7 colonization on the dry weight, nitrogen fixation, nitrogen converting-enzyme activity, and nutrients for E+ and E− plants by labeling with ¹⁵N₂. The results showed that the growth rates of B. subtilis LZU7 were altered and increased in a co-culture with the E. gansuensis endophyte. A significantly greater colonization of GFP-tagged B. subtilis LZU7 was detected in the roots of E+ plants compared with the roots of E− plants, suggesting that E. gansuensis endophyte symbiosis enhances the colonization of beneficial microorganisms. The combination of E. gansuensis endophyte symbiosis and B. subtilis LZU7 inoculation significantly altered the expression of the nitrogenase (nifH) gene, thereby promoting increased biological nitrogen fixation (BNF). The E. gansuensis endophyte infection and inoculation with B. subtilis LZU7 significantly increased δ15NAir in plants. Co-inoculation with the E. gansuensis endophyte and B. subtilis LZU7 significantly elevated NH₄⁺ accumulation in the roots, depleted the NH₄⁺ availability in the surrounding soil, and showed no measurable impact on the foliar NH₄⁺ content. The observed alterations in the NH₄⁺ content were linked to nitrogen-fixing microorganisms that promoted nitrogen fixation, thereby enhancing nitrogen uptake and contributing to greater biomass production in A. inebrians. Our findings highlighted the fact that a foliar symbiosis with the E. gansuensis endophyte enhances the recruitment of beneficial bacteria, and that the resulting interaction significantly impacts nitrogen fixation, assimilation, and allocation in host plants. Full article

Cultivating crops in the hot, arid conditions of the Arabian Peninsula often requires irrigation with brackish water, which exposes plants to salinity and heat stress. Timely, cost-effective monitoring of plant health can significantly enhance crop management. In this context, remote sensing techniques offer promising alternatives. This study evaluates several low-cost, ground-level remote sensing methods and compares them with benchmark analytical techniques for assessing salt stress in two economically important woody species, moringa and pomegranate. The species were irrigated under three salinity levels: low (2 dS m⁻¹), medium (5 dS m⁻¹), and high (10 dS m⁻¹). Remote sensing tools included RGB, multispectral, and thermal cameras mounted on selfie sticks for canopy imaging, as well as portable leaf pigment and chlorophyll fluorescence meters. Analytical benchmarks included sodium (Na) accumulation, carbon isotope composition (δ¹³C), and nitrogen (N) concentration in leaf dry matter. As salinity increased from low to medium, canopy temperatures, vegetation indices, and δ¹³C values rose. However, increasing salinity from medium to high levels led to a rise in Na accumulation without further significant changes in other remote sensing and analytical parameters. In moringa and across the three salinity levels, the Normalized Difference Red Edge (NDRE) and leaf chlorophyll content on an area basis showed significant correlations with δ¹³C (r = 0.758, p < 0.001; r = 0.423, p < 0.05) and N (r = 0.482, p < 0.01; r = 0.520, p < 0.01). In pomegranate, the Normalized Difference Vegetation Index (NDVI) and chlorophyll were strongly correlated with δ¹³C (r = 0.633, p < 0.01 and r = 0.767, p < 0.001) and N (r = 0.832, p < 0.001 and r = 0.770, p < 0.001). Remote sensing was particularly effective at detecting plant responses between low and medium salinity, with stronger correlations observed in pomegranate. Full article

Rare earth elements (REEs) are critical mineral resources that play a pivotal role in modern technology and industry. Currently, the global supply of light rare earth elements (LREEs) remains adequate. However, the supply of heavy rare earth elements (HREEs) is associated with substantial risks due to their limited availability. Ion-adsorption type rare earth deposits (IAREDs), which represent the predominant source of HREEs, have become a focal point for exploration activities, with a notable increase in global interest in recent years. This study systematically collected stream sediments and stream water samples from the Jiaping IARED in Guangxi, as well as from adjacent granitic and carbonate background areas, to investigate the exploration significance of geochemical surveys for IAREDs. Additionally, mineralized soil layers, non-mineralized soil layers, and bedrock samples from the weathering crust of the Jiaping deposit were analyzed. The results indicate that stream sediments originating from the Jiaping IARED and granite-hosted background regions display substantially elevated REE concentrations relative to those from carbonate-hosted background areas. Moreover, δEu values in stream sediments can serve as an effective indicator for differentiating weathering products derived from granitic and carbonate lithologies. Within the mining area, three coarse-grained fractions of stream sediments (i.e., +20 mesh, 20–60 mesh, and 60–150 mesh) exhibit REE concentrations comparable to those observed in both granite-hosted and carbonate-hosted background regions. However, the HREEs content in the finer -150-mesh stream sediments from Jiaping IARED is markedly higher than that in the two background regions. The (La/Sm)_N versus (La/Yb)_N ratios of -150-mesh stream sediments in the Jiaping IARED may reflect the mixing processes involving HREE-enriched ore layer, non-mineralized layer, and LREE-enriched ore layer. This observation implies that fine-grained (-150-mesh) stream sediments can partially inherit the REE characteristics of mineralized layers within IAREDs. Scanning electron microscopy (SEM) observations indicate that the enrichment of REEs in fine-grained stream sediments primarily originates from REE-rich accessory minerals derived from parent rocks and mineralized weathering crusts. A comparative analysis reveals that the concentrations of REEs in stream water collected during the rainy season are significantly higher than those collected during the dry season. Moreover, the levels of REEs, especially HREE, in stream water from the Jiaping IARED substantially exceed those in background areas. Collectively, these findings suggest that the geochemical signatures of REEs in rainy season stream water possess diagnostic potential for identifying IAREDs. In conclusion, the integrated application of geochemical surveys of stream water and -150-mesh stream sediments can effectively delineate exploration targets for IAREDs. Full article

The South China Block hosts extensive sedimentary phosphorites that offer valuable insights into both paleoenvironmental reconstruction and rare earth element (REE) resource potential. However, the mechanisms governing REE enrichment in these deposits remain poorly understood. This study investigates two distinct phosphorite layers from the Lower Cambrian Zhujiaqing (ZJQ) Formation in the Bailongtan (BLT) area of the Yangtze Platform using integrated analyses including petrology, XRD, major and trace elements, δ¹³C and δ¹⁸O isotopes, and LA-ICP-MS. The lower thin-bedded phosphorite, composed of finer phosphatic grains (<300 μm), exhibits significantly higher REE concentrations (883.6 ± 160.9 ppm; n = 48) compared to the upper thick-bedded phosphorite (303.2 ± 82.7 ppm; n = 64), which is dominated by larger, reworked grains (300–600 μm). Intervening strata consist of laminated phosphate-bearing carbonates interbedded with quartz, dolomite, and pyrite. PAAS-normalized REE patterns display MREE–HREE enrichment, negative Ce anomalies (avg. 0.60 ± 0.18; n = 18), and positive Y anomalies—indicative of oxic depositional conditions. The elevated REE content in the lower layer, coupled with the lowest δ¹³C values (−4.59‰), suggests enrichment linked to organic matter degradation. A proposed two-stage depositional model links REE enrichment to proximity with REE-rich deep-shelf waters, underscoring the critical role of redox and depositional dynamics in phosphorite-hosted REE accumulation. Full article

Mediterranean wood pastures are the result of traditional silvo-pastoral uses that shaped these ecosystems into a mosaic of trees and open grassland. This ecosystem structure is generally associated with increased soil fertility under tree canopies. However, the response of herbaceous plant functional types (PFTs)—grasses, legumes, and non-legume forbs—to these heterogeneous microenvironments (under the canopy vs. open grassland) remains largely unknown, particularly regarding carbon (C) and nitrogen (N) acquisition and use. Even less is known about how different tree species and environmental conditions influence these responses. In this study, we aim to assess how tree canopies influence carbon and nitrogen cycling by comparing the effects of traditional oak stands and pine plantations on herbaceous PFTs and soil dynamics. For that we use C and N content and natural isotopic abundances (δ¹³C and δ¹⁵N) as proxies for biogeochemical cycling. Our results show that ecosystem C and N patterns depend not only on herbaceous PFTs and the presence or absence of tree canopies but also on tree species identity and environmental conditions, including climate. In particular, pine-dominated plantations exhibited lower nitrogen availability compared to those dominated by oak, suggesting that oak stands may contribute more effectively to enhance soil fertility in Mediterranean wood pastures. Furthermore, the canopy effect was more pronounced under harsher environmental conditions, highlighting the role of trees in buffering environmental stress, particularly in arid regions. This suggests that changes in tree cover and tree species may drive complex changes in ecosystem C and N storage and cycling. Full article

Wood fiber substrates are widely used as peat substitutes in horticulture, but the impact of their high carbon-to-nitrogen ratio on nitrogen immobilization and crop photosynthetic performance remains unclear. This study systematically examined the effects of wood fiber substrates on lettuce photosynthetic performance and underlying physiological mechanisms using pot experiments. Two substrate treatments—peat (control) and wood fiber—were combined with three nitrogen levels: low, medium, and high (63, 127, and 210 mg N·L⁻¹). Results indicated that wood fiber substrates significantly reduced the availability of fast-acting nitrogen, leading to a substantial decrease in lettuce biomass (39.0–56.8%), total nitrogen content (7.2–39.9%), and chlorophyll content (13.7–36.2%). Chlorophyll fluorescence kinetics analysis revealed that wood fiber substrates impair photosystem function through multiple pathways. At the early stage (15 days), key effects included structural damage to the donor side of PSII(Photosystem II), indicated by L and K peaks, and inhibited electron transfer on the PSI(Photosystem I) acceptor side (δRo decreased by 15.08–27.90%, along with a reduction in W_OI amplitude). The findings provide an important theoretical basis for optimising nitrogen management strategies for wood fibre substrates. Full article

This study aims to evaluate the effect of extraction solvent type on the physicochemical properties and bioactive compounds of Actinostemma lobatum Maxim. kernel oil for two successive harvest years. Oils were extracted using the bio-based solvent 2-methyltetrahydrofuran (2-MeTHF) and conventional petroleum-derived solvents (n-hexane and 2-methylpentane). Results indicated that 2-MeTHF achieved significantly higher oil yields (27.60% in 2021 and 29.77% in 2022) compared to n-hexane and 2-methylpentane. Unfortunately, 2-MeTHF-extracted oils exhibited greater susceptibility to oxidation, displaying elevated levels of primary and secondary oxidation products relative to other solvents. Meanwhile, 2-methylpentane-extracted oil showed a relatively high oxidative stability index. In addition, differential scanning calorimetry results also aligned with the oxidative status. Further variance analysis revealed that the harvest year exerted a more pronounced impact on fatty acid and triacylglycerol profiles than the solvent type. Additionally, tocopherols and tocotrienols were abundant, with β- and δ-tocopherols predominating. 2-MeTHF-extracted oils harvested in 2022 contained the highest total tocols (1118.83 mg/kg) among all samples. Also, phytosterols were detected, with β-sitosterol constituting the predominant compound. Furthermore, the 2-MeTHF-extracted oils contained higher β-carotene contents compared to other samples. These above findings concluded that 2-MeTHF is a good alternative to conventional solvents for extracting of A. lobatum kernel oil. Full article

The water contents and geochemical evidence of nominally anhydrous minerals in peridotite xenoliths provide critical insights into lithospheric mantle features, offering a deep understanding of cratonic destruction and mantle evolution processes. Damaping, located in the central part of the intra-North China Craton, hosts abundant mantle peridotite xenoliths’ samples, providing new constraints on lithospheric mantle evolution. In this study, spinel lherzolite samples from Damaping Cenozoic basalts were analyzed for major and trace elements, water content, and oxygen isotope to investigate the factors controlling mantle water distribution and lithospheric mantle modification. The olivines of Damaping spinel lherzolite have a range of Mg# values from 89.73 to 91.01, indicating moderately refractory mantle characteristics. Clinopyroxenes display an LREE-depleted pattern, suggesting a consistency with 1–6% of batch partial melting and 1–5% fractional partial melting. The high (La/Yb)_N (0.20–0.73) and low Ti/Eu (3546.98–5919.48) ratios of Damaping clinopyroxenes reveal that the lithosphere mantle beneath the Damaping has undergone silicate metasomatism. The water contents of Damaping clinopyroxenes and orthopyroxenes range from 13.39 to 19.46 ppm and 4.60 to 7.82 ppm, respectively. The water contents of the olivines are below the detection limit (<2 ppm). The whole-rock water contents can be estimated based on the mineral modes and partition coefficients, with values ranging from 3.21 to 5.44 ppm. Partial melting indicators (Mg# in Ol and Yb_n in Cpx) correlate with the water content in clinopyroxenes and orthopyroxenes but show no correlation with the redox state (Fe³⁺/∑Fe ratios in spinel) or metasomatism ((La/Yb)_N in clinopyroxene). These results suggest that the degree of partial melting primarily controls the heterogeneous water distribution in Damaping spinel lherzolite, rather than the redox state or metasomatism. The δ¹⁸O values of clinopyroxenes from Damaping spinel lherzolites (5.27–5.59‰) fall within the range of mid-ocean ridge basalts (MORB), indicating a mantle source characterized by MORB-like isotopic signatures. The low whole-rock water contents are attributed to lithospheric reheating resulting from asthenospheric upwelling during the Late Mesozoic–Early Cenozoic. Therefore, the lithosphere is predominantly composed of ancient Proterozoic residues, with localized contributions of younger asthenospheric material near deep faults. Full article

Cold-water lakes in high-latitude regions are experiencing rapid changes in community structure and functioning associated with local and global stressors (e.g., climate change, hydropower and invasive species). However, the long-term ecological responses of cold-adapted top predators are relatively poorly monitored despite their high importance for structuring ecological communities and for the provisioning of ecosystem services. We studied long-term changes (2010–2021) in the population structure and trophic niche of two cold-adapted coregonid fishes in oligotrophic Lake Osensjøen, southeastern Norway. Our gillnet surveys indicated that the whitefish (Coregonus lavaretus) population declines simultaneously with the increasing population density of roach (Rutilus rutilus), whereas vendace (Coregonus albula) showed more stable densities. Both whitefish and vendace became increasingly dominated by small-sized individuals following the increase in coexisting roach and perch (Perca fluviatilis) populations. Our stomach content and stable isotope data indicated a marked overlap in the trophic niches of whitefish and roach, with both species showing high among-individual variation in δ¹³C and δ¹⁵N values as compared to the more specialized zooplanktivorous vendace. Our study provides further evidence that the ongoing environmental changes in high-latitude lakes may induce rapid changes in community structures and lead to the population declines of cold-adapted fishes, likely associated with strong resource competition with warm-adapted cyprinid and percid fishes. Such shifts in fish community structure may, in turn, affect the benthic and pelagic food-web compartments and reduce valuable ecosystem services such as local fisheries targeting salmonids. Full article

Background/Objectives: This study investigates the effects of a high-fat diet (HFD) during pregnancy and lactation on maternal and offspring health, focusing on behavioral, metabolic, and fatty acid composition outcomes in a rat model. Methods: Twelve female Sprague–Dawley rats were fed either a control diet, CD (n = 6), or HFD (n = 6) for 12 weeks, encompassing mating, gestation, and lactation periods (18 weeks). Anxiety-like behavior, maternal behavior, depression-like behavior, and social play were studied. Post mortem, the liver function, hepatic steatosis, and fatty acid composition (erythrocytes, liver, adipose tissue) were evaluated. In regard to desaturase enzymes (Δ-6D and Δ-5D), liver activity, protein mass, and gene expression (RT-PCR) were analyzed. Additionally, gene expression of PPAR-α, ACOX, CPT1-α, SREBP-1c, ACC, and FAS was assessed. Statistical analysis was performed using Student’s t-test, mean ± SD (p < 0.05). Results: The HFD significantly increased maternal weight and anxiety-like behavior while reducing social interactions exclusively in male offspring (p < 0.05). It also led to a significant decrease in the synthesis and content of n-3 PUFAs in the analyzed tissues, induced hepatic steatosis, and upregulated the expression of pro-lipogenic genes in the maternal liver. Conclusions: These findings suggest that long-term HFD consumption alters tissue fatty acid composition, disrupts metabolic homeostasis, and contributes to behavioral changes, increasing anxiety-like behaviors in pregnant dams and reducing social interactions in male offspring. Overall, this study provides further insight into the detrimental effects of HFD consumption during the perinatal period. Full article