Search Results (1,257)

Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely detected in aquatic ecosystems, but its subcellular targets and the mechanisms by which it disrupts light resource utilization in photosynthetic protozoa remain poorly understood at concentrations spanning environmentally typical to supra-environmental levels. Here, Euglena gracilis G.A. Klebs was exposed to PFOS at concentrations spanning environmentally typical (0.5 µg/L), hotspot-relevant (5 µg/L), and supra-environmental (50 µg/L) levels. Subcellular distribution, phototaxis, photosynthetic light reactions, and energy metabolism were investigated using isolated chloroplast assays, transcriptomics, and proteomics. TEM-EDS mapping revealed pronounced fluorine signal enrichment, attributable to PFOS, in the eyespot and chloroplasts. Eyespot fluorine enrichment was associated with impaired phototactic motility and an altered light perception threshold. PFOS did not acutely inhibit the maximum photochemical efficiency of photosystem II (Fv/Fm); instead, a transient upregulation of photosynthesis-related genes was observed, which weakened with prolonged exposure, whereas the photosynthetic electron transport rate (ETR) was significantly reduced. PFOS significantly reduced ATP levels and ETR, while Fv/Fm remained unchanged and non-photochemical quenching (NPQ) was elevated. Isolated chloroplast assays revealed that PFOS inhibits Mg²⁺-dependent ATP hydrolytic activity in the chloroplast-enriched fraction and impairs thylakoid electron transport, consistent with impaired chloroplast ATP synthase function, though the specific molecular target and mechanism remain to be conclusively demonstrated. Transcriptomic and proteomic analyses revealed compensatory upregulation of photosynthesis pathways but suppression of ATP synthesis and redox homeostasis. Collectively, our results suggest that PFOS impairs chloroplast ATP synthase function, accompanied by reduced ETR and elevated NPQ. Together with the eyespot-associated phototaxis impairment, these effects suggest that PFOS may dually disrupt light acquisition (behavioral) and light conversion (physiological) in E. gracilis. This dual impairment may compromise the ecological fitness of Euglena in PFOS-contaminated environments, especially under prolonged exposure. It should be noted that the subcellular fluorine mapping is qualitative, the phototaxis assay reflects population-level responses, and the ATP synthase impairment interpretation is indirect; the proposed mechanistic model remains a hypothesis requiring further direct experimental validation. Full article

Quantifying vegetation ecological quality and ecological water requirement is essential for understanding ecosystem sustainability in arid regions. However, large-scale assessments of vegetation ecological quality and ecological water requirement thresholds remain limited in Central Asia. In this study, we developed a Vegetation Ecological Quality Index (VEQI) for Central Asia based on fractional vegetation cover (FVC) and net primary productivity (NPP) and estimated vegetation ecological water requirement quota (VEWRq) and total vegetation ecological water requirement (VEWR) using the Penman–Monteith method, the soil moisture limitation coefficient (SMLC), and GIS-based spatial analysis. We further examined the spatiotemporal variations in VEQI and VEWR during 2001–2020 and identified VEWRq thresholds corresponding to different VEQI levels. The results showed that (1) the multi-year mean VEQI in Central Asia was 28.46 and exhibited a slight increasing trend during 2001–2020; (2) the annual mean minimum, maximum, and optimal VEWRq were 147.53, 179.71, and 162.52 mm, respectively, corresponding to mean annual VEWR values of 146.98 × 10⁹ m³, 179.04 × 10⁹ m³ and 161.91 × 10⁹ m³, respectively; and (3) VEQI was positively correlated with VEWRq in 89.48% of the vegetation area. The VEWRq threshold increased with vegetation ecological quality. The five VEQI levels in Central Asia, namely very poor, poor, moderate, good, and very good, corresponded to VEWRq thresholds of 28.62–35.96, 88.33–107.81, 190.69–233.32, 362.86–432.81, and 678.59–838.31 mm, respectively. This study provides a remote sensing-based framework for evaluating vegetation ecological quality and quantifying ecological water requirement thresholds in arid regions and offers scientific support for regional ecological management and water resource allocation. Full article

This study evaluates the ecological impacts of seawater desalination discharge on coastal marine ecosystems through a sequential analytical framework linking systematic literature synthesis, field-monitoring evidence, spatial analysis, and predictive ecological modeling. The novelty of the study lies in combining multi-regional evidence from Mediterranean coastal zones, Persian Gulf waters, and Pacific coastal environments with threshold-based ecological risk assessment, thereby linking discharge-related environmental stressors with biological responses and ecosystem-function alterations. The systematic review first retained 750 studies published between 2004 and 2024 for qualitative synthesis. On this basis, 59 high-quality references with sufficient numerical information were selected for the main quantitative meta-analysis, while field-monitoring data were used to support the interpretation of distance-based discharge gradients. Spatial interpolation and hierarchical modeling were then applied to evaluate exposure–response patterns and ecological threshold behavior. The results showed that desalination facilities generated measurable ecological impacts mainly within 50–200 m of discharge points, with a critical transition distance of approximately 127 m where hypersaline conditions, typically 1.5–2.0 times ambient seawater levels, were associated with marked changes in marine community structure. Benthic assemblages showed taxon-specific responses, with mollusks and echinoderms exhibiting greater sensitivity than polychaetes and small crustaceans. Marine vegetation declined strongly under combined salinity, thermal, and chemical stress, while phosphonate-based antiscalants accumulated in filter-feeding organisms and produced bioaccumulation factors up to 42.1 times ambient levels. Ecosystem-function indicators, including microbial community composition and sediment organic matter processing, remained altered up to 300 m from discharge points, indicating that functional impacts may extend beyond the primary hypersaline plume. The predictive modeling framework further demonstrated that ecological risk decreased nonlinearly with distance and varied according to discharge intensity, local hydrodynamics, and biological sensitivity. These findings indicate that conventional uniform buffer-based assessment may underestimate the ecological footprint of desalination discharge. Sustainable desalination management should therefore adopt site-specific monitoring, species-sensitive protection thresholds, improved brine-management technologies, and adaptive mitigation strategies based on real-time environmental feedback. Full article

Disentangling the coupled, nonlinear impacts of climate change and anthropogenic activities on vegetation dynamics is critical yet challenging for global change research. The Qinghai–Tibetan Plateau (QTP), a highly climate-sensitive and ecologically strategic region, serves as a vital arena for examining such complex socio-ecological attributions. Based on multi-source environmental datasets from 2000 to 2020, this study developed an integrated, spatially explicit framework coupling residual trend analysis (RESTREND) and GeoDetector to quantify individual drivers and nonlinear climate–human interactions. The QTP exhibited a significant, widespread greening trend during 2000–2020, featuring prominent spatial clustering with “High–High” clusters in the southeast and “Low–Low” clusters in the northwest. Attribution modeling revealed that vegetation dynamics were governed not by isolated variables, but by multifaceted, nonlinear synergies among precipitation, temperature, topography, vegetation type, and land-use change. Key interactive pairs, particularly elevation–temperature and slope–precipitation, dramatically increased explanatory power over single-factor models. Crucially, climate–human synergies explained substantially more variance than climate variables alone, bounded by a distinct elevational threshold: human activities dominated vegetation dynamics at mid-elevations (2500–3500 m), while climate factors took over as the primary controller at high altitudes (above 3500 m). Quantitatively, human activities induced vegetation improvement across 38.6% of the plateau, maintained stability in 35.8%, and caused degradation in 25.6%. By successfully merging trend decomposition with spatial stratified heterogeneity analysis, this study provides a transferable approach to uncoupling complex environmental interactions. These insights highlight the intensifying human footprint on alpine ecosystems and advocate for zone-specific adaptive management: mitigating human disturbances at mid-elevations and fostering climate adaptation in higher zones to preserve plateau resilience. Full article

The coordinated development of urban renewal (UR) and ecological resilience (ER) is essential for regional sustainability and livable city construction. Based on data from 108 cities in the Yangtze River Economic Belt (YREB) during 2012–2023, this study constructs the UR indicator system from the dimensions of urban infrastructure construction, social function development, and cultural and leisure facility construction. ER is evaluated in terms of resistance, adaptability, and recoverability. The spatiotemporal evolution of their coupling coordination degree (CCD) is then examined. In addition, the XGBoost-SHAP model is employed to identify the threshold of digital technological innovation (DTI) on CCD and its interactions with different development conditions. The results show that (1) CCD remained relatively low but improved slowly during the study period. UR lagged behind ER in most cities, indicating that insufficient UR development capacity was the main constraint on coordination between the two systems. (2) CCD exhibited a pronounced core–periphery pattern, with high-value areas mainly concentrated in provincial capitals and centrally administered municipalities within the YREB. (3) DTI was positively associated with CCD and exhibited a nonlinear pattern with a model-derived turning point, while the strength and pattern of this association varied across different development contexts. These findings enrich the understanding of UR-ER coordination and offer policy implications for sustainable urban governance. Full article

Under the concurrent advancement of ecological civilization and resource-dependent region transformation, key state-owned forest areas in northeast China have shifted from timber supply to ecosystem protection. However, while the Natural Forest Protection Program has restored forest resources and increased coverage, it has also led to the contraction of traditional industries, reduced employment, population outflow, and a structural tension between weak economic growth and enhanced ecological functions. This study aims to investigate how labor mobility affects the coordinated development of economic and ecological welfare in these regions. To achieve this, we construct economic and ecological welfare indices using entropy weighting and calculate their coupling coordination degree based on panel data from the China Forestry Statistical Yearbook (2000–2017) and the China Forestry and Grassland Statistical Yearbook (2018–2025). Our key scientific contributions are as follows: (1) we reveal a nonlinear and significantly negative impact of labor mobility on coupling coordination; (2) we identify industrial structure as a partial mediating channel; and (3) we uncover significant regional and developmental stage heterogeneity. Methodologically, we employ fixed-effects, mediation, threshold, and spatial panel models to ensure robustness. The findings provide novel insights into labor–environment trade-offs in forest-dependent regions and offer policy implications for optimizing labor allocation, strengthening ecological compensation and industrial synergy, and improving regional governance to achieve coordinated economic–ecological development. Full article

This study evaluates the multi-year taxonomic diversity and functional structure of beetle assemblages (Coleoptera) within Sub Arini Park, a historic urban green space in Sibiu, Romania. Following a preliminary baseline and methodological calibration phase in 2023, systematic monitoring was conducted during the 2024 and 2025 seasonal cycles utilizing standardized pitfall trapping across diverse park zones. We explicitly tested two hypotheses: (H1) that long-standing historic park management preserves a resilient and functional insect community structure, and (H2) that local spatial heterogeneity and microhabitat variations significantly drive species distribution. A total of 14,843 individuals belonging to 39 species were analyzed. While total abundance exhibited a slight decrease from 2024 (N = 7112) to 2025 (N = 6551), true diversity metrics (Hill numbers) revealed a significant increase in raw species richness (q = 0) from 30 to 39 species, alongside an enhanced equity of frequent species (Shannon diversity, q = 1, increased from 4.26 to 5.12). Functional guild analysis and multivariate PCA demonstrated a highly structured biocenotic distribution; specialist and hygrophilous species (e.g., Carabus variolosus Fabricius, 1787) were strictly constrained to high-humidity riparian corridors, whereas thermophilous generalists dominated open lawns under high anthropogenic stress. Our spatial analysis identified critical degradation within these heavily managed zones, specifically driven by intensive mowing, soil compaction, and organic debris removal. These findings confirm both hypotheses, revealing that the park operates as a heterogeneous mosaic of ecological refugia rather than a uniform habitat block. Crucially, this study provides a concrete, quantitative basis—derived from empirical thresholds of species richness, abundance shifts, and mapped microhabitat preferences—for implementing nature-based management strategies (such as establishing buffer zones with reduced mowing frequencies, limiting trampling, and retaining coarse woody debris) aimed at mitigating urban biodiversity loss and maintaining vital biological pest control services in Central–Eastern Europe. Full article

The Kubuqi Desert serves as a critical zone for both renewable energy development and ecological management in China. Large-scale photovoltaic (PV) deployment has fundamentally altered the regional underlying surface, impacting near-surface wind–sand dynamics. To elucidate these disturbance mechanisms, we selected three representative surfaces—a PV area, a resource base, and Qixing Lake—and conducted field observations from September to December 2023 using meteorological towers and wind erosion sensors. Results indicate that all surfaces significantly attenuated near-surface wind speeds by over 30% through modified flow field structures. A strong linear positive correlation existed between wind speed and friction velocity (R² ≈ 0.99). Notably, for the same friction velocity, the actual wind speed required to initiate sand movement was lowest in the PV zone (high k) and highest at Qixing Lake (low k), signifying enhanced surface stability due to PV infrastructure and moisture. Threshold analysis revealed distinct initiation speeds: >6.0 m·s⁻¹ in peripheral quicksand, >4.3 m·s⁻¹ in inter-panel zones, and >4.6 m·s⁻¹ beneath panels. The tilted PV panels accelerate airflow downward, generating cyclonic vortices that intensify sand particle impacts under and between panels. This study reveals the tri-dimensional mechanism of wind regulation–sand suppression–stability enhancement, providing theoretical support for mitigating wind–sand disasters while advancing green energy in desert regions. Full article

Sustaining agricultural economic performance under climate and market disruptions has become a strategic priority for developing economies facing escalating climate risks and persistent rural development challenges. Using an unbalanced panel of 281 prefecture-level cities in China (2011–2023), this study examines the association between the Digital Village Pilot policy and relative agricultural economic performance (RAEP)—a city’s agricultural growth measured against the national agricultural benchmark, which captures the resistance dimension (whether a city maintains its agricultural-economic position during disruptions) rather than the recovery, adaptability, ecological, or household-livelihood dimensions of the broader resilience concept—through difference-in-differences estimation, Hansen panel threshold regression, and a two-step channel analysis. The results indicate that the Pilot is associated with a statistically significant improvement in relative agricultural economic performance, an effect that remains broadly stable across specification checks. A threshold pattern emerges: the estimated policy association is negligible in city-year observations where digital infrastructure falls below an identified cutoff but rises substantially above it. Because a large share of cities falls below this threshold, the program’s benefits remain unevenly distributed. Channel analysis reveals that the Pilot is associated with a marginally significant increase in digital financial inclusion and a significant reduction in agricultural agglomeration, with the latter reflecting a shift toward diversified rather than spatially concentrated agricultural activity, a pattern theoretically linked to greater shock resistance. These findings advance understanding of how digital rural policies affect relative agricultural economic performance and provide empirical evidence for identifying the enabling conditions under which digital transformation strengthens sustainable agriculture. Full article

Dynamic trade-offs and synergies among ecosystem services (ESs) are highly sensitive to land-use change, spatial scale, and future uncertainty. However, most ES-based zoning studies rely on static assessments that overlook temporal dynamics and scenario robustness. To address this limitation, we propose a novel intensity–trend–stability framework that integrates historical interaction strength, projected future trajectories, and cross-scenario consistency to assess and spatially zone ES interactions. The framework was applied to the Songnen Plain, China, using multi-scale analysis and four contrasting land-use scenarios for 2030. An XGBoost–SHAP model was further employed to identify key drivers and nonlinear effects underlying ES interaction dynamics. Results show that (1) land-use transitions exhibit strong scenario dependency under different development pathways. (2) Water yield consistently exhibits trade-offs with other ESs, whereas soil retention, carbon sequestration, and habitat quality maintain stable synergies, with interaction intensity generally weakening at coarser scales. (3) The proposed framework effectively identifies stable conflict zones, synergistic hotspots, and transitional areas, with HHH zones of water-related interactions accounting for 30.72–37.43% of the study area, while LLH zones of other ES pairs each occupy more than 39%. (4) Climatic and topographic factors primarily regulate water-related interactions, whereas vegetation conditions and landscape configuration dominate synergistic ES relationships, with pronounced nonlinear threshold effects. The proposed framework improves the detection of dynamic ES interaction patterns and supports scenario-based ecological zoning and sustainable land-use management. Full article

Bryophytes are key components of acid–soil ecosystems; however, their capacity for aluminum (Al) accumulation and tolerance remains poorly understood. In this study, bryophytes and a limited number of pteridophyte and lichen species were collected from acidic soils of tea plantations and adjacent forest stands in the Caspian region of northern Iran and analyzed. Nearly all bryophyte specimens exhibited Al concentrations above the critical accumulation threshold (1000 µg g⁻¹ DW), with some reaching values exceeding 28,000 µg g⁻¹ DW, confirming their strong accumulation capacity. After Al, iron was the most abundantly accumulated metal (1430–22,800 µg g⁻¹ DW), followed by manganese (100–3100 µg g⁻¹ DW). The sampled lichen species accumulated Al at concentrations between 1063 and 9154 µg g⁻¹ DW, while Al levels in the aerial parts of pteridophytes rarely exceeded the critical threshold; when they did, accumulation occurred predominantly in old and fertile fronds rather than sterile ones. Three field-collected bryophyte species—Barbula unguiculata, Palamocladium euchloron, and Hypnum cupressiforme—were acclimated to laboratory conditions and treated with two Al levels (without or with 150 µM Al, pH 4.0) for 12 weeks. The leafy shoots were analyzed for their antioxidant response, osmolyte accumulation, phenolic metabolism, callose deposition, and carboxylic-acid profile. Histochemical analyses revealed predominant localization of Al in cell walls, associated with enrichment of pectin and uronic acids. These responses were most pronounced in H. cupressiforme, followed by P. euchloron, and least evident in B. unguiculata. Elevated levels of intracellular detoxification compounds—phenolics, flavonoids, and carboxylic acids (tartaric, oxalic, malic, and citric acids)—were detected, again with species-specific differences. Overall, the results reveal that bryophytes employ multiple physiological strategies to tolerate Al toxicity, with substantial interspecific variation. These findings emphasize their ecological significance and provide a foundation for future research on the physiological and evolutionary mechanisms underlying Al tolerance and accumulation in early land plants. Full article

Background and Objectives: Healthcare-associated infections (HAIs) remain a major challenge in emergency hospital settings, where high patient turnover and empirical antibiotic use may contribute to the emergence and spread of multidrug-resistant organisms. Monitoring antibiotic consumption is essential for antimicrobial stewardship and infection prevention. This study evaluated antibiotic consumption patterns across multiple hospital units and explored their ecological relationship with HAI rates. Materials and Methods: A retrospective observational study was conducted in a tertiary-level emergency hospital in Romania between 1 January 2021 and 31 October 2025. Antibiotic consumption was quantified using Defined Daily Dose per 100 bed-days (DDD/100 bed-days) according to World Health Organization (WHO) methodology and categorized using the WHO Access, Watch, and Reserve (AWaRe) classification. HAI data were collected using standardized surveillance definitions. Statistical analyses were primarily descriptive and exploratory and included graphical trend assessment, simple linear regression for temporal trend description, and Spearman correlation analysis for exploratory ecological co-variation assessment. Results: Antibiotic consumption showed substantial variability across hospital units, without a consistent temporal trend over the study period. The Watch group predominated over the Access group from 2023 onward, while Access antibiotics remained below the WHO-recommended 60% threshold. The highest antibiotic consumption was observed in the Medical Wards, followed by Surgical Wards and the Intensive Care Unit. A total of 27 HAIs were identified (0.27 per 1000 patient-days), with the highest incidence observed in the ICU. The most frequent infections were Clostridioides difficile infections (33.3%) and catheter-associated urinary tract infections (29.6%). Exploratory ecological analyses did not identify robust associations between total antibiotic consumption and HAI rates across hospital units. A numerically elevated co-variation was observed between fluoroquinolone consumption and Clostridioides difficile infection incidence; however, this finding should be interpreted strictly as exploratory and hypothesis-generating. Conclusions: Antibiotic use varied across hospital units, with predominance of broad-spectrum agents and suboptimal adherence to WHO AWaRe targets. Reported HAI incidence remained low and should be interpreted within the limitations of routine surveillance systems and potential under-ascertainment. These findings support the value of continuous institutional surveillance of antibiotic use and HAIs while highlighting the limitations of aggregated ecological analyses. Full article

Ecological zoning is important for understanding spatial heterogeneity and supporting landscape-level management. However, existing approaches rarely integrate ecosystem service supply with ecological risk, and their underlying nonlinear relationships remain insufficiently explored. This study aims to develop an integrated framework linking ecosystem service value (ESV) and landscape ecological risk (LER) based on a two-dimensional quadrant model. This framework integrates ESV and LER from complementary benefit–risk perspectives, advancing ecological zoning beyond single-indicator approaches. Using the Miyun Reservoir Basin as a case study, multi-source data from 2000 to 2020 were used to quantify ESV and LER and to examine their spatiotemporal dynamics. The ESV-LER framework was applied to identify ecological functional zones. In addition, the XGBoost-SHAP model combined with the Geographical Detector was used to explore the nonlinear effects and interactions of natural and anthropogenic drivers. ESV showed a “decline-recovery” trend, whereas LER exhibited an opposite “decrease-increase” pattern. Areas with both high ESV and high LER were mainly distributed around the reservoir and river networks, suggesting a spatial mismatch between ecological value and risk. Ecological improvement and conservation zones accounted for approximately 79% of the basin, while ecological risk prevention zones expanded over time, indicating increasing human disturbance. NDVI was identified as a dominant factor with dual effects, enhancing ESV while reducing LER, whereas population density and NPP exhibited nonlinear threshold effects that increased ecological risk. Overall, this study advances ecological zoning by integrating functional value and risk perspectives while explicitly revealing their nonlinear drivers. The proposed framework provides a transferable and interpretable approach for watershed-scale ecological management and supports more targeted and differentiated governance strategies. Full article

Forests constitute a large part of the global vegetation biomass, and various ecological metrics such as biodiversity and carbon stock can be determined by scanning them using LiDAR. LiDAR data is, however, inherently uncertain due to the finite beamwidth, and this uncertainty is propagated to any metrics derived from it. This study presents a methodology to propagate this uncertainty to tree metrics derived from quantitative structure models (QSMs), such as volume. First, the point cloud uncertainty is quantified using the laser beamwidth and an initial geometry estimate to create the so-called fuzzy cloud. This fuzzy cloud is then sampled iteratively using the Monte Carlo method until the variance estimate has converged. As a case study, we applied this method to three trees of varying size and present a selection of metrics for the trees as a whole, different branch orders and distributions along their heights. We show that the number of scanning locations has a large effect on both the volume and its uncertainty. We attained convergence at a 5% variance threshold within 30 iterations. Full article

Aquatic environments that support tourism, including coasts, lakes, reservoirs, and estuaries, are experiencing accelerating eutrophication worldwide. This trend increases the frequency and intensity of algal blooms. These blooms undermine ecosystem services and weaken the socio-economic performance of destination areas. Despite these challenges, existing research remains fragmented. Aquatic sciences mainly examine nutrient enrichment and bloom dynamics. In contrast, tourism studies often treat blooms as episodic disturbances and rarely integrate exposure pathways, risk communication, or feedback to destination governance. This review synthesizes evidence across freshwater and marine systems to develop a coupled tourism–water ecosystem perspective. We link eutrophication drivers and bloom typologies to three dimensions. These are the degradation of tourism-supporting ecosystem services, compound health stressors, and communication filters. The first includes losses of water clarity and aesthetic value. The second involves multi-route exposure through contact, inhalation, and seafood ingestion. The third shapes perceived safety, trust, and behavioral adaptation. We further connect perceived health risks to observable tourist behaviors, including cancellation, destination substitution, and activity avoidance. These micro-level responses can aggregate into market-level demand contractions and consumption reallocation. They can also trigger regional economic cascades, including public management costs, employment impacts, and long-term reputational damage. Crucially, tourism is not merely a victim of blooms. It can also act as a reinforcing anthropogenic driver through wastewater burdens, infrastructure expansion, and pulse pressures. These pressures lower ecological resilience, especially under warming and hydrological stabilization. Finally, we identify governance leverage points. These include early-warning systems, threshold-based graded interventions, transparent risk communication, and integrated social–ecological modeling. These strategies can reduce uncertainty-driven losses and support adaptive destination management. Overall, this review reframes algal blooms as systemic social–ecological risks. It provides a structured basis for future empirical attribution and policy design in tourism-dependent waters under climate stress. Full article