Search Results (3,655)

Mountain treelines are among the most climate-sensitive ecosystems on Earth, yet their fine-scale structural and species level dynamics remain poorly resolved in the Himalayas. In particular, the absence of three-dimensional, crown level measurements have hindered the detection of structural thresholds and species turnover that often precede treeline shifts. To bridge this gap, we introduce UAV LiDAR—applied for the first time in the Hindu Kush Himalayas—to quantify canopy structure and tree species distributions across a steep treeline ecotone in the Manang Valley of central Nepal. High-density UAV-LiDAR data acquired over elevations of 3504–4119 m was used to quantify elevation-dependent changes in canopy stature and cover from a canopy height model derived from the 3D point cloud, while individual tree segmentation and species classification were performed directly on the 3D, height-normalized point cloud at the crown level. Individual trees were delineated using a watershed-based segmentation algorithm while tree species were classified using a random forest model trained on LiDAR-derived structural and intensity metrics, supported by field-validated reference data. Results reveal a sharply defined treeline characterized by an abrupt collapse in canopy height and cover within a narrow ~60–80 m vertical interval. Treeline “threshold” was quantified as a breakpoint elevation from a piecewise model of tree cover versus elevation, and the elevation span over which modeled cover and height distributions rapidly declined from forest values to near-zero. Segmented regression identified a distinct structural breakpoint near 3995 m elevation. Crown-level species predictions aggregated by elevation quantified an ordered turnover in dominance, with Pinus wallichiana most frequent at lower elevations, Abies spectabilis peaking mid-slope, and Betula utilis concentrated near the upper treeline. Species classification achieved high overall accuracy (>85%), although performance varied among taxa, with broadleaf Betula more difficult to discriminate than conifers. These findings underscore UAV LiDAR’s value for resolving sharp ecological thresholds, identifying elevation-driven simplification in forest structure, and bridging observation gaps in remote, rugged mountain ecosystems. Full article

Glycerol fatty acid esters (GFAEs) exhibit potential applications in ruminant production, including enhancing animal performance, improving nutrient utilization, and modulating rumen function. However, studies on indigenous Dabieshan beef cattle are lacking. This study aimed to evaluate GFAE’s effects on their performance, meat quality, and rumen function. Thirty 2-year-old cattle (294.73 ± 3.21 kg; mean ± SD), were randomly divided into three groups (n = 10): on a dry matter (DM) basis, CON (basal diet), 0.05 GFAE (basal + 0.05% GFAE), 0.1 GFAE (basal + 0.1% GFAE), fed for 60 days. The crude protein (CP) digestibility of the 0.05 GFAE group showed a significant 4.55% increase compared with the CON group, while that of the 0.1 GFAE group was significantly elevated by 2.76% relative to the CON group. For key meat quality indices of Dabieshan beef cattle, compared with the CON group, the 0.05 GFAE and 0.1 GFAE groups showed increases in L value by 10.14% and 7.11%, respectively (p = 0.042); decreases in shear force by 5.24% and 1.48%, respectively (p = 0.024); and increases in ether extract(EE) content by 10.91% and 2.33%, respectively (p = 0.019). Compared with the CON group, the 0.05 GFAE and 0.1 GFAE groups showed significant alterations in key serum biochemical indices of Dabieshan beef cattle: TP (total protein) levels elevated significantly by 6.44% and 13.04%, respectively (p = 0.010); total antioxidant capacity (T-AOC) increased significantly by 33.96% and 46.23%, respectively (p = 0.001); UREA concentrations decreased significantly, by 22.67% and 33.53%, respectively (p = 0.002); superoxide dismutase (SOD) activity rose significantly, by 7.30% and 7.99%, respectively (p = 0.020); and malondialdehyde (MDA) content declined significantly, by 20.25% and 28.03%, respectively (p = 0.040). Relative to the CON group, dietary supplementation with GFAE significantly increased ruminal butyrate concentrations, with the 0.05 GFAE and 0.1 GFAE supplemented groups exhibiting respective increments of 17.38% and 18.03% (p = 0.025). Both Groups 0.05 GFAE and 0.1 GFAE reduced CH4 emissions (p = 0.005) and elevated Prevotella abundance (p = 0.001). The study findings revealed that dietary supplementation with GFAE at concentrations of 0.05% and 0.1% of dry matter resulted in substantial decreases in daily methane emissions, representing respective reductions of 6.91% and 11.63% compared to the control group (p = 0.005). At the species level of the rumen microbial community, the relative abundance of the genus Prevotella_sp. was significantly elevated by 60.52% and 38.48% in the 0.05 GFAE and 0.1 GFAE groups, respectively, when contrasted with the CON group (p = 0.001). Collectively, these results demonstrate that the inclusion of dietary 0.05% GFAE supplementation conferred multifaceted benefits to Dabieshan beef cattle, thereby highlighting its potential as a viable strategy to enhance the sustainability of beef cattle production systems. Full article

Carpathian mountain grasslands are increasingly affected by management intensification and climatic variability, with consequences for species composition and ecosystem functioning. This study assessed the long-term effects of a mineral fertilization gradient and interannual climatic variability on indicator species dynamics and biomass production in a semi-natural high-nature-value (HNV) grassland in the Apuseni Mountains, based on a 17-year field experiment. Increasing fertilization intensity promoted a clear shift from species-rich oligotrophic communities toward simplified mesotrophic and eutrophic grassland types, accompanied by a decline in indicator species richness and the increasing dominance of competitive grasses. Biomass production increased consistently along the fertilization gradient. Climate-driven effects were assessed using unfertilized control plots, allowing management effects to be disentangled from interannual climatic variability. Variations in temperature and precipitation influenced floristic composition and productivity across the years, highlighting the sensitivity of mountain grasslands to short-term climatic fluctuations. Multivariate analyses revealed increasing vegetation homogenization under high fertilization and distinct year-to-year shifts in species composition under unfertilized conditions. These results emphasize the vulnerability of Carpathian HNV grasslands to both nutrient enrichment and climatic variability, and underline the need for climate-adaptive, biodiversity-oriented management strategies. Full article

Milk fat globule membrane (MFGM) phospholipids could promote the development of infants’ brain, nervous system and digestive system. This research conducted a comparative analysis of phospholipid composition in MFGM of colostrum from different bovine species (Holstein cattle, yak, and Buffalo), with a particular focus on analyzing phospholipid variations in yak MFGM across different lactation stages. Chromatographic quantification revealed phosphatidylcholine (PC) as the predominant phospholipid class (34.7–47.44%) in all examined species. Notably, Holstein cow milk contains significantly higher levels of phosphatidylethanolamine (PE). Distinct phospholipid profiles emerged between species: yak milk demonstrated significantly higher concentrations of sphingomyelin (SM), lysophosphatidylethanolamine (LPE), dimethylphosphatidylethanolamine (dMePE), and bis-methylphosphatidic acid (BisMePA), whereas buffalo milk showed preferential accumulation of phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylglycerol (PG), and lysophosphatidylcholine (LPC). Longitudinal analysis revealed dynamic changes in yak milk phospholipids during lactation: as the lactation period in-creases, PC, PS, LPC, LPE, methylphosphatidylcholine (MePC), BisMePA, and dMePE exhibited progressive decline, while PE, SM, PI and PG showed incremental increases. Analysis of phospholipid metabolism pathways indicates that yak colostrum supports early calf development by enriching phospholipids associated with immune and neuroprotection, while mature milk shifts toward maintaining membrane stability. These compositional characteristics position yak milk as a promising phospholipid-fortified alternative to human breast milk. Full article

Understanding how plant community characteristics and soil properties vary along altitudinal gradients is essential for ecosystem conservation, restoration, and for predicting ecosystem responses to global environmental change. This study investigated altitudinal patterns and their potential drivers in mountain meadow communities on the southern slope of Wutai Mountain, Northern China. Community characteristics and soil physicochemical properties were measured along an altitudinal gradient ranging from 1800 to 3000 m a.s.l. Most community characteristics exhibited clear altitudinal trends. Species richness, Shannon–Wiener index, Simpson index, aboveground biomass and average plant height all declined significantly with increasing altitude. In contrast, vegetation cover showed a unimodal pattern, initially decreasing and then increasing at higher elevations. Soil physicochemical properties also varied significantly along the altitudinal gradient and were closely associated with changes in community characteristics. Variation partitioning analysis revealed that environmental factors, including altitude and soil properties, explained 71.9% of the total variation in mountain meadow communities. Altitude alone contributed more to community variation than soil factors, indicating its dominant role in shaping community structure. Nevertheless, specific soil properties, particularly soil depth, soil bulk density and soil pH, also exerted significant influences on community characteristics. Overall, our results demonstrate that altitude is a key driver of both vegetation and soil variation in mountain meadows on the southern slope of Wutai Mountain. In addition to altitudinal effects, soil physicochemical properties should be considered when developing conservation and management strategies for mountain meadow ecosystems. Full article

Decarbonization of compression-ignition engines requires evaluation of carbon-free and low-carbon fuel alternatives. Ammonia (${NH}_3$) offers zero direct carbon emissions but faces combustion challenges including low flame speed (7 $\mathrm{c}\mathrm{m}/\mathrm{s}$) and high auto-ignition temperature (657 °$\mathrm{C}$). Methanol provides improved reactivity and bound oxygen content that can enhance ignition characteristics. This computational study investigates diesel–ammonia–methanol ternary fuel blends using validated three-dimensional CFD simulations (ANSYS Forte 2023 R2; ANSYS, Inc., Canonsburg, PA, USA) with merged chemical kinetic mechanisms (247 species, 2431 reactions). The model was validated against experimental in-cylinder pressure data with deviations below 5% on a single-cylinder diesel engine (510 cm³, 17.5:1 compression ratio, 1500 rpm). Ammonia energy ratios were systematically varied (10–50%) with methanol substitution levels (0–90%). Fuel preheating at 530 K was employed for high-alcohol compositions exhibiting ignition failure at standard temperature. Results demonstrate that peak cylinder pressures of 130–145 bar are achievable at 10–30% ammonia with M30K–M60K configurations, comparable to baseline diesel (140 bar). Indicated thermal efficiency reaches 38–42% at 30% ammonia-representing 5–8 percentage point improvements over diesel baseline (31%)-but declines to 30–32% at 50% ammonia due to fundamental combustion limitations. ${CO}_2$ reductions scale approximately linearly with ammonia content: 35–55% at 30% ammonia and 75–78% at 50% ammonia. ${NO}_X$ emissions demonstrate 30–60% reductions at efficiency-optimal configurations. Multi-objective optimization analysis identifies the A30M60K configuration (30% ammonia, 60% methanol, 530 K preheating) as optimal, achieving 42% thermal efficiency, 58% ${CO}_2$ reduction, 51% ${NO}_X$ reduction, and 11% power enhancement versus diesel. This configuration occupies the Pareto frontier “knee point” with cross-scenario robustness. Full article

Wildfire is a dominant ecological force in Mediterranean pine forests, and post-fire silvicultural practices can substantially alter their recovery trajectories. In this study, we examined how natural regeneration and artificial plantations influence the composition, structure, and functional roles of medium and large-sized mammal communities in burned Pinus brutia forests of southwestern Türkiye. Camera trap data were combined with linear mixed-effects models, functional diversity metrics, and indicator species analysis to assess community responses. Mammalian assemblages showed marked shifts across treatments: generalist carnivores such as Vulpes vulpes and Canis aureus dominated burned areas, whereas higher-trophic specialists like Caracal caracal were restricted to unburned forests. Functional richness was consistently higher in unburned stands, while artificial plantations reduced both richness and evenness. Natural regeneration partly mitigated these declines by sustaining more balanced community structures. Indicator species analysis confirmed these patterns, with Lepus europaeus strongly associated with burned sites and C. caracal with unburned forests. Overall, findings demonstrate that post-fire silvicultural practices strongly shape mammalian community assembly and functional diversity. Natural regeneration preserves structural heterogeneity and supports functionally diverse assemblages, whereas artificial plantations promote homogenization. Effective restoration strategies should therefore integrate wildlife responses with vegetation recovery to strengthen ecosystem resilience and maintain the ecological roles of mammals. Full article

Genetic resources are becoming increasingly important in aquatic species, especially in sectors such as aquaculture and biomedical research. These advancements, however, lack standardized methodology to consistently improve efficient use of gametes for fertilization and to eliminate male variation during spawning. This study provides a conceptual basis for generalizable quality control in artificial spawning of aquatic species by using interdisciplinary, industrial-scale tools to calculate a fertilization unit (e.g., the amount of sperm required to reliably fertilize the eggs produced by a female). Blue catfish (Ictalurus furcatus), zebrafish (Danio rerio), and eastern oysters (Crassostrea virginica) were used as diverse representative species. Comparisons among aquatic species were reviewed, fertilization units were defined, and a sensitivity analysis was performed to assess how deviations from the fertilization unit could affect artificial spawning efficiency. Overall, reproductive strategy (e.g., gamete biology) and production setting significantly influenced the fertilization unit. Employing a fertilization unit decreased “wasted” sperm and reduced male variability during spawning. Furthermore, fertilization efficiency dropped significantly when sperm use strayed from the fertilization unit, declining with both underuse and overuse, especially in oysters and catfish. Standardizing gamete use in aquatic species is essential for economic planning and achieving commercial-scale production, especially when investing in selectively bred or cryopreserved sperm. Full article

Procypris rabaudi, a member of the Cyprinidae family and genus Procypris, has been designated as a national second-class protected wildlife species in China due to a significant decline in its wild populations. Understanding its genomic characteristics and mitochondrial genome structure is crucial for germplasm conservation and systematic classification. In this study, we utilized high-throughput sequencing to investigate the genome of P. rabaudi. The genome size was 1.5 Gb, with a heterozygosity rate of 0.44% and 61.47% of repetitive sequences. We identified 1,151,980 simple sequence repeats (SSRs), with mononucleotide repeats being the most abundant at 55.34%. The complete mitochondrial genome was assembled with 16,595 bp length. A phylogenetic tree constructed from 13 mitochondrial protein-coding genes indicated that genus Procypris was most closely related to genus Luciocyprinus and formed a monophyletic group with Cyprinus, Carassioides, and Carassius. Pairwise Sequentially Markovian Coalescent (PSMC) analysis revealed a rapid population expansion prior to the Last Interglacial Period, followed by a decline after reaching its peak during Last Glacial Period. Notably, P. rabaudi exhibited a two-peak demographic pattern during both the Last Glacial Period. These genomic data provide valuable resources for the conservation of P. rabaudi germplasm and for future studies on cyprinid classification and evolution. Full article

Urban green spaces host complex arthropod communities, in which natural insect antagonists play a key role in regulating pest populations. The jumping plant-louse Cacopsylla pulchella is a sap-sucking pest widespread across Europe that attacks Cercis siliquastrum L., which is commonly used as an ornamental tree. Heavy infestations may contribute to host tree decline and cause indirect damage in urban environments by reducing aesthetic value and by extensive deposition of honeydew secretions on surrounding surfaces. As with many phytophagous insects occurring in urban contexts, information on the natural enemies of this species remains limited, particularly in Italy, and requires further documentation. Here, we investigated the parasitoids associated with C. pulchella in central and southern Italy based on surveys conducted between 2022 and 2025. Specimens were obtained from infested plant material and identified using an integrative taxonomic approach combining detailed morphological examination with DNA barcoding. Prionomitus mitratus was confirmed as the primary parasitoid of C. pulchella, while two species, Pachyneuron muscarum and Pachyneuron aphidis, were identified as hyperparasitoids. In addition, a single specimen of Anastatus bifasciatus was also recorded emerging from the psyllid as a hyperparasitoid. Molecular analyses generated the first publicly available mitochondrial and nuclear sequences for P. mitratus. For Pachyneuron, molecular results showed variable correspondence with available reference sequences, reflecting the uneven representation of species-level data for Pteromalidae in public databases. By integrating morphological and molecular evidence, this study clarifies trophic relationships within the C. pulchella parasitoid complex. It provides vouchered molecular references to support future taxonomic and ecological research in urban ecosystems. Full article

The introduction of understory vegetation can increase species diversity and potential productivity in forest ecosystems, which is considered a viable solution to the global problem of declining soil quality caused by deteriorating climatic conditions and human activities. The forest management model that achieves economic and ecological benefits by introducing legumes is widely used. However, there have been rare studies on the effects of introducing legumes under Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations on soil nutrient content and microbial diversity. In this study, we investigated the soil chemical properties, microbial diversity, and enzymatic activities in Chinese fir plantations introduced with Spatholobus suberectus (SRS), Dalbergia balansae (DRS), both species (BS), and in a monoculture plantation (CK). As indicated by the results, soil pH, total phosphorus (TP), available phosphorus (AP), available potassium (AK), urease activities, and the ratios of C:P and N:P decreased in SRS, DRS, and BS treatments, whereas soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), phosphatase, and sucrase activities increased. The decrease in soil pH and the effects of Chytridiomycota and Glomeromycota elevated phosphatase activity. Accordingly, the mineralization rate of soil phosphorus increased. This increase enhanced phosphorus availability and the risk of loss, resulting in the depletion of soil phosphorus and the inhibition of urease activity. The findings of this study reveal that the introduction of legumes effectively improves the soil microbial community and nitrogen accumulation in Chinese fir plantations while resulting in phosphorus depletion, highlighting the need for balanced nutrient management. Full article

Porphyridium species are known red microalgae for producing valuable bioactive compounds such as sulfated exopolysaccharides (EPS) with diverse industrial biomedical applications due to their functional and rheological properties. Recent studies have investigated how abiotic stresses, particularly nitrogen deprivation, affect Porphyridium’s metabolic regulation and EPS production through transcriptomic analysis. Still, the mechanisms governing EPS biosynthesis and the involvement of carbohydrate-activated enzymes (CAZymes) remain poorly understood. This study investigated the progressive effects of nitrate consumption on the unicellular red alga, P. purpureum, by integrating physiological, biochemical, and transcriptomic analyses through RNA-Seq, further validated by RT-qPCR. P. purpureum displayed a gradual, phase-dependent metabolic response to progressive nitrogen stress. EPS release coincided with the decline in nitrate uptake, linking nitrogen availability to carbon redirection towards polysaccharide secretion. Transcriptomic data revealed global metabolic downregulation with targeted upregulation of stress-responsive, carbohydrate catabolic, and nucleotide–sugar synthesis pathways, including the upregulation of CAZyme families GT4, GT8, and GT77. Our results give insights into the coordinated nitrogen and carbon metabolic regulation underlying polysaccharide biosynthesis, while opening future perspectives on enzyme compartmentalization and regulatory flux distribution under nitrogen stress in P. purpureum. Full article

Bacterial contamination remains a challenge for multiple facets of modern life. While antibiotics are a primary tool for bacterial control, their overuse has accelerated the appearance of multidrug-resistant bacteria and raises global health concerns. In swine, semen is stored at 17 °C in extenders that contain antibiotics to prevent bacterial growth. Apart from the potential consequences for the female, the proliferation of bacteria in liquid-stored semen is associated with a decline in sperm quality, ultimately reducing farrowing rates and litter sizes. With the aim of reducing the use of antibiotics while keeping bacterial growth under control, we herein investigated whether metal ions could exert an antimicrobial effect without impairing sperm quality. Separate metal ions (Ag, silver sulfadiazine; Al, aluminum chloride; Zn, zinc chloride; and Cu, and cooper chloride) were added at different concentrations (100 μM, 300 μM, 500 μM, 1 mM, and 10 mM) to seminal doses, which were stored at 17 °C for 48 h. Motility, viability, and the intracellular levels of reactive oxygen species (ROS) were tested to determine their effects on sperm quality maintenance. In addition, ions were added to bacterial strains and to extended seminal samples to assess the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results showed that, although silver sulfadiazine exerted an antimicrobial effect at all the concentrations tested, it also affected sperm quality negatively (p < 0.05). In contrast, aluminum chloride did not impair sperm quality but failed to inhibit bacterial growth at any of the tested concentrations (p > 0.05). Finally, 1 mM concentrations of copper and zinc chloride reduced microbial growth (p < 0.05) without affecting sperm quality. In spite of this, the inhibition of bacterial growth was not complete, thus suggesting that these two ions could contribute to reducing bacterial growth but should be combined with other strategies, such as a lower storage temperature and a decreased concentration of antibiotics. Further research is warranted to address whether copper and zinc chloride could have a synergistic effect when added together. Full article

Ammopiptanthus mongolicus is a relict species from the ancient Mediterranean of the Tertiary period and the only strong xerophytic evergreen broad-leaved shrub in the central Asian desert. Foliar endophytic and epiphytic bacteria jointly form phyllosphere microorganisms that influence plant health. This study investigated the dynamic changes in foliar endophytic bacterial communities across four leaf growth stages (Young, Mature, Old1, and Old2). Illumina 16S region (V5–V7) amplicon sequencing was used to analyze community composition, function, construction process, and environmental driving factors. The Old1 and Old2 stages were clearly separated from the Young and Mature stages, which demonstrated closer clustering. Community diversity and evenness first increased from the Young to Mature stages, declined at the Old1 stage, and finally reached maximum values at the Old2 stage; richness increased gradually. Total amplicon sequence variant (ASV) numbers, stage-specific ASVs, and their proportion increased with leaf development, whereas the proportion of shared ASVs between adjacent, interval, and all stages decreased. Dominant genera were Rhodococcus (Young), unclassified_f__Comamonadaceae (Mature), Rhodococcus (Old1), and Bacillus (Old2). Co-occurrence networks became progressively simpler, with reduced inter-node and positive connectivity. Functional predictions revealed that chemoheterotrophy and aerobic chemoheterotrophy decreased initially and then increased, with the lowest values at Old1. N, C/P, N/P, and SOD reached maximum at the Old2 stage. P was maximum at the Mature stage. P, C/P, and N/P were significantly positively correlated with the Young stage, N with the Mature stage, and SOD with the Old2 stage (p < 0.05). These findings enhance understanding of the diversity, composition, function, and plant–endophyte relationships in xerophytic relict species, particularly evergreen desert shrubs. Full article

Parasitoids are key natural antagonists of forest insect pests and are gaining importance in integrated forest protection under increasing climate-related disturbances. This study aimed to quantify the influence of vegetation diversity and canopy structure on the abundance and diversity of the overall insect community responses to vegetation structure and to provide an ecological context. Second, detailed analyses focused on three focal parasitoid families (Braconidae, Ichneumonidae, Tachinidae), which are of particular relevance for integrated forest protection due to their central role in integrated forest protection and in pesticide-free regulation approaches for risk mitigation in forest ecosystems. Malaise traps were deployed at eight randomly selected broadleaf and coniferous sites, and insect samples from six sampling dates in summer 2024 were analyzed. The sampling period coincided with the full development of woody and vascular plants, representing the phase of highest expected activity of phytophagous insects and associated parasitoids. Vegetation surveys (Braun–Blanquet), canopy closure, and canopy cover were recorded for each site. Across all samples, five arthropod classes, 13 insect orders, and 31 hymenopteran families were identified, with pronounced site-specific differences in community composition and abundance. Our results suggest that broadleaf-dominated sites, characterized by higher plant species richness and greater structural heterogeneity, support a more diverse assemblage of phytophagous insects, thereby increasing host availability and niche diversity for parasitoids. Parasitoid communities generally showed higher diversity at broadleaf sites. Spearman correlations and multiple linear regressions revealed a strong negative relationship between canopy cover and total insect abundance ρ (Spearman’s rank correlation coefficient (Spearman ρ = −0.72, p = 0.042; p = 0.012, R² = 0.70), R² (coefficient of determination), whereas parasitoid diversity (Shannon index) and the relative proportion of Ichneumonidae were positively associated with canopy cover (ρ = 0.85, p = 0.008). In addition, canopy cover had a significant positive effect on overall insect diversity (Shannon index; p = 0.015, R² = 0.63). Time-series analyses revealed a significant seasonal decline in parasitoid abundance (p < 0.001) and parasitoid diversity (p = 0.018). Time-series analyses revealed seasonal dynamics characterized by fluctuations in parasitoid abundance and diversity and a general decrease over the course of the sampling period. The findings demonstrate that structurally diverse mixed forests, particularly those with a high proportion of broadleaf trees mixed forests with heterogeneous canopy layers can enhance the diversity of specialized natural enemies, while dense canopy cover reduces overall insect abundance. These insights provide an ecological basis for silvicultural strategies that strengthen natural regulation processes within integrated forest protection. Full article