Search Results (509)

Riparian land use and land cover (LULC) exerts scale- and season-dependent controls on surface water quality, yet its influence in regulated agricultural–urban rivers is poorly characterized. We combined seasonal t-tests, one-way ANOVA, and redundancy analysis (RDA) at three riparian buffer scales (500, 1000, and 2000 m) to examine discharge, dissolved oxygen (DO), temperature, turbidity, and pH at four USGS stations along the Kansas River mainstem (2019–2026). DO and temperature showed the strongest seasonal contrasts: DO was 3.1–3.7 mg/L higher in the dry season and temperature 13–15 °C higher in the wet season, a coupling central to aquatic habitat suitability. Turbidity rose significantly in the wet season, consistent with agricultural runoff and sediment mobilization, whereas discharge showed no significant seasonal difference at three of four stations, reflecting upstream reservoir regulation. Spatial ANOVA detected station-level differences only for wet-season DO ($F_{3,28}=4.91$, $p=0.007$), which was lowest at the downstream urbanized station. RDA linked agricultural cover to turbidity and urban cover to reduced wet-season DO, although permutation tests were non-significant ($p\ge 0.42$) at $n=4$ replicates. Seasonality and riparian LULC jointly shape water quality along this regulated river, and the 500 m buffer is the most spatially discriminating scale for land-cover assessment. Full article

In 2024, an accident involving two tankers in the Kerch Strait resulted in the release of approximately 2400 tons of fuel oil into the Black Sea, causing significant contamination of seawater and the coastal zone. This study presents the first microbiological and molecular–ecological assessment of prokaryotic community composition and hydrocarbon-oxidizing bacteria (HOB) in coastal seawater and sand near Anapa (Russian Federation) following the spill. The taxonomic composition of nine samples was analyzed using high-throughput sequencing of 16S rRNA genes (V3–V4 regions), identifying Bacteria as the dominant domain (85.3–99.8%). In seawater samples, bacteria of the phyla Pseudomonadota, Cyanobacteriota, and Bacteroidota and archaea of the phyla Thermoplasmatota and Crenarchaeota predominated. Eighteen aerobic bacterial strains, including members of the genera Shewanella, Pseudoalteromonas, Halopseudomonas, Marinomonas, Pseudomonas, Vibrio, Alcanivorax, Ectopseudomonas, Nitratireductor, and Echinicola, were isolated from the zone of fuel oil spill. Several isolates demonstrated heavy oil degradation and biosurfactant production. Screening of collection strains isolated from other habitats revealed that Rhodococcus erythropolis TG65 and Marinobacter lutaoensis Pd1 and Pd2 degraded 92–94% of fuel oil n-alkanes. Elevated dissolved iron concentrations in the seawater indicate the possibility of a metabolic coupling between hydrocarbon oxidation and microbial iron reduction, mediated by indigenous Shewanella and Pseudomonas species. These findings indicate that indigenous HOB may contribute to the natural attenuation of aliphatic hydrocarbons in fuel oil. Full article

Cropland fragmentation affects regional ecosystem functioning and biodiversity conservation, making the spatio-temporal coupling between cropland fragmentation (CLF) and habitat quality (HQ) a key basis for land management and ecological protection. However, the reported CLF–HQ coupling differs in sign between regions, and the mechanism underlying this divergence remains unclear. This study evaluated the spatio-temporal dynamics of CLF and HQ and their interrelationship across Hunan Province, China, at the township scale (∼2450 units) from 1994 to 2024. CLF was measured by a four-dimensional index consisting of Scale (SPI), Natural Endowment (NPI), Aggregation (API), and Convenience (CPI), with weights determined by a combined AHP–Entropy method; HQ was modelled with InVEST. The relationship between the two was analysed through bivariate spatial autocorrelation, Mantel tests, Random Forest, redundancy analysis (RDA), and XGBoost–SHAP. CLF peaked in urban fringes and was lowest in the western mountains; mean HQ declined modestly, mainly before 2014. Spatially, CLF and HQ were negatively associated (bivariate Moran’s I between −0.38 and −0.51, $p<0.001$), opposite in sign to the positive coupling found in arid Northwest China. Decomposition of the composite index showed that the negative association was carried largely by the natural-endowment dimension, in which slope and elevation were the dominant indicators. Structural fragmentation dimensions uniquely explained only 1.5–5.4% of HQ variance, and controlling for terrain reduced the CLF–HQ correlation by 67–96%. The sign also reversed under an alternative directional standardisation, so it is not robust to a defensible analytical choice. In these data, the observed negative coupling is largely consistent with a shared topographic gradient rather than a direct fragmentation effect. For management, this correlational evidence suggests that reducing fragmentation alone may do little to improve habitat quality; conservation is better guided by the underlying terrain and land-use gradients. More broadly, CLF–HQ assessments become more reliable when cropland structure is separated from natural endowment and terrain confounding is accounted for. Full article

Degraded industrial sites in arid and semi-arid regions often suffer from loose surface substrates, weak water-retention capacity, high wind-erosion risk, and poor early vegetation establishment. Combining photovoltaic (PV) deployment with ecological utilization may improve near-surface habitats by shading, reducing wind speed, and regulating soil heat and moisture. This study investigated an ash storage yard of a coal-fired power plant in Ordos, Inner Mongolia, China, by comparing soil temperature, soil moisture, and near-surface wind-speed responses under three representative fixed PV tilt angles of 36°, 43°, and 50°, together with the corresponding early plant-growth suitability. A multi-physics model coupling near-surface airflow, water-vapor transport, and porous-media hydrothermal migration was established. A Gaussian suitability function combined with AHP-CRITIC weighting was used to construct a model-based comprehensive growth index (CGI) from soil temperature and moisture, while short-term field monitoring was used to validate afternoon soil hydrothermal trends. Among the three scenarios, the 36° configuration produced the widest horizontal heat–moisture-affected zone and the highest CGI values for alfalfa and Elymus nutans, reaching 0.7741 and 0.6875, respectively. Relative to the outside reference area, the rear PV zone reduced the near-surface wind speed by 33–40% and increased the plant heights of alfalfa and Elymus nutans by 49.4% and 37.8%, respectively. A first-order PVsyst assessment showed that the 43° configuration achieved the highest specific energy yield of 1814 kWh kWp⁻¹ year⁻¹, whereas the annual grid-connected output at 36° was only 0.59% lower. These findings indicate that the 36° configuration may provide a favorable compromise between early vegetation establishment and photovoltaic electricity generation among the tested scenarios. By linking renewable-energy production with microenvironment regulation and early vegetation establishment, the proposed framework provides a decision basis for the multifunctional and sustainable reuse of degraded industrial land. Nevertheless, the results represent a site-specific, single-season assessment and should not be interpreted as a universal optimum. Full article

Inter-basin water transfer source areas must sustain local habitat quality while ensuring downstream water security, yet the spatial differentiation mechanisms, driving mechanisms, and scenario-dependent responses of their ecosystem services have not been statistically tested. This study aimed to assess historical changes and future trajectories of ecosystem services in the core water source area of the Middle Route of the South-to-North Water Diversion Project, and established a historical assessment–spatial statistics–driver attribution–scenario projection analytical framework. Five ecosystem services—water yield, soil conservation, nitrogen export, carbon storage, and habitat quality—were quantified using InVEST from 2005 to 2020 and projected to 2050 under SSP126, SSP245, and SSP585 via the PLUS–InVEST coupled model. Spatial patterns were analyzed using Getis–Ord Gi* hot–cold spot analysis, hexagon-based spatial statistics (4.5 km bins), Mantel tests, and the optimal-parameter-based geographical detector. Results show that slope was the dominant spatial driver, exhibiting highly significant Mantel correlations with all five services (p < 0.001), and two-factor interactions consistently exceeded individual factor effects (e.g., population density × temperature: q = 0.527 for habitat quality; slope × temperature: q = 0.516 for soil conservation). Hexagon-based statistics revealed that carbon storage declined substantially from 2005 to 2020 (−3.23%, from 98.75 t/ha to 95.56 t/ha), while water yield and soil conservation showed no pronounced temporal trends. Scenario projections revealed divergent trajectories: relative to the 2020 baseline (267.84 mm), water yield increased by 20.1% under SSP126 (321.86 mm) but declined by 56.3% under SSP585 (117.13 mm); nitrogen export increased under all scenarios; and habitat quality declined continuously to 0.557, 0.546, and 0.539 under SSP126, SSP245, and SSP585, respectively. Within this scenario framework, SSP126 and SSP245 may better support the maintenance of water source ecosystem functions, whereas SSP585 may be associated with greater potential ecological pressures, reflected in lower water yield, higher nitrogen export, and lower habitat quality. Full article

Rift Valley fever (RVF) is a climate-sensitive mosquito-borne zoonosis long regarded as a rural, pastoral disease, yet accelerating tropical urbanization and intensifying climate variability may be reshaping its epidemiology at the urban–peri-urban interface. This narrative review examines how global climate change and urban-specific climatic conditions jointly shape RVF virus (RVFV) vector habitats, transmission, and burden in tropical and subtropical cities, synthesizing 51 of 412 English-language records identified by a structured, non-systematic search of PubMed, Scopus, Web of Science, and Google Scholar (2009–2026) and selected for relevance to urban and peri-urban RVF. This research draws on human, livestock, and vector evidence from Sub-Saharan Africa, the Arabian Peninsula, and Indian Ocean islands across epidemic and inter-epidemic periods. The synthesis indicates that impervious surfaces, poor drainage, and open water storage can recreate the water-retaining function of rural dambos, sustaining a year-round larval habitat, and that Culex quinquefasciatus dominance together with peri-urban cattle may form an amplification bridge to humans. Direct evidence remains scarce, anchored by a single peri-urban serosurvey and limited urban slaughterhouse entomology. Critical gaps include urban primary-vector ecology, infection-rate data, urban-heat effects, city-specific exposure studies, and coupled climate–urban burden models. We conclude that RVF is a plausible emerging urban threat warranting proactive inter-epidemic surveillance and integration of RVF into urban planning and One Health systems. Full article

Pholidota chinensis is a valuable medicinal epiphytic orchid in China. While its ethnomedicinal importance is recognized, the environmental constraints governing its distribution and its response to future climate change remain insufficiently understood. This study employed the Maximum Entropy (MaxEnt) model to identify dominant environmental drivers and project current (1970–2000) and future (2041–2060, 2061–2080) potential climatically suitable habitats under SSP245 and SSP370 scenarios. Using 184 filtered occurrence records and 11 screened environmental variables, the model achieved high discrimination performance (mean AUC = 0.9614 ± 0.0092). Annual precipitation and precipitation of the driest quarter were identified as principal predictors, reflecting a coupled water-temperature niche. Future projections suggested an overall expansion of climatically suitable areas, particularly under SSP245, and a northwestward shift in suitability centroids. However, these projections represent potential climatic suitability rather than confirmed future distribution, as establishment depends on dispersal capacity, host availability, and microhabitat conditions. These findings provide a scientific basis for conservation prioritization and climate-adaptive cultivation planning. Full article

The purpleback flying squid (Sthenoteuthis oualaniensis) is an important commercially exploited cephalopod resource in tropical open oceans. The formation and spatial variability of its fishing grounds are jointly regulated by local marine environmental conditions, ocean dynamic processes, and multiscale climate variability. In recent years, substantial progress has been achieved in understanding the environmental characteristics and formation mechanisms of S. oualaniensis fishing grounds with the development of satellite remote sensing, multisource oceanographic observations, and ecological statistical models. However, due to differences in study regions, data sources, and modeling approaches, considerable discrepancies remain among studies regarding the mechanisms through which environmental factors and climate modes influence the distribution and abundance variations in S. oualaniensis resources. This review systematically summarizes recent advances in the application of remote sensing and multisource marine data in S. oualaniensis fishing ground studies and highlights the ecological significance of major environmental drivers. Current evidence indicates that the formation of S. oualaniensis fishing grounds is not controlled by a single environmental factor but results from the integrated effects of SST, Chl-a, oceanographic dynamic processes (e.g., mesoscale eddies, fronts, and upwelling), and subsurface environmental conditions such as thermocline structure and dissolved oxygen. Suitable thermal conditions and moderate productivity levels provide fundamental environmental prerequisites for resource aggregation, whereas mesoscale physical processes and three-dimensional ecological structures further regulate prey transport, habitat availability, and squid aggregation processes. Moreover, substantial regional differences exist in fishing ground formation mechanisms. In the northwestern Indian Ocean, fishing grounds are primarily controlled by monsoon-driven upwelling and large-scale circulation systems, exhibiting strong continuity and pronounced climate-related variability. In contrast, fishing grounds in the South China Sea are more strongly influenced by Kuroshio intrusion, island–reef topography, and regional circulation processes, resulting in greater spatial heterogeneity. With advances in analytical approaches, fishing ground prediction methods for S. oualaniensis have gradually evolved from empirical statistical analyses toward multifactor statistical modeling and machine-learning-based prediction frameworks. Nevertheless, resolving three-dimensional ecological processes, developing physical–biological coupled models, and improving model interpretability remain key challenges for future research. This review provides theoretical insights for remote sensing-based investigations of S. oualaniensis fishing ground formation mechanisms, resource assessment, and sustainable exploitation. Full article

Polylepis forests are the highest-elevation woody ecosystems on Earth and are severely threatened by climate change and land use, yet habitat models that go beyond binary presence/absence remain scarce. The current and future habitat suitability (2021–2100; CMIP6, four to five GCMs × four SSPs) of two co-occurring Andean species, Polylepis rugulosa and Polylepis tarapacana, was modelled with MaxEnt and Random Forest calibrated across their full range (Peru, Bolivia, Chile and Argentina) and clipped to the Tacna region of southern Peru. Internal spatial cross-validation was complemented by two external validations: 228 field-mapped stand polygons and 35 inventory plots (883 trees), the latter used to test whether suitability also tracks measured stand structure. Both algorithms performed well (AUC $=0.78$–$0.94$ across internal and external validation). Once within-plot non-independence and residual spatial autocorrelation were accounted for, no structural attribute was significantly associated with suitability: a positive suitability–multi-stemming trend persisted in Polylepis rugulosa ($p=0.06$–$0.09$) but not in Polylepis tarapacana, so this coupling is reported as a preliminary, hypothesis-generating result rather than as a validated predictive relationship. Within Tacna, suitable habitat above the maxSSS threshold is projected to contract by $17.4\%$ for Polylepis rugulosa and by $100\%$ for Polylepis tarapacana under SSP585 by 2081–2100 (MaxEnt ensemble; the near-total loss is unanimous across the contributing GCMs), revealing divergent climatic vulnerabilities. Reading suitability as a map of habitat quality rather than of habitat presence therefore remains a working hypothesis that larger plot networks and demographic data are needed to test. Full article

Helichrysum arenarium (L.) Moench is a European native species typically associated with dry, sunny, sandy, and nutrient-poor habitats. In European herbal practice, preparations from H. arenarium inflorescences are traditionally used for the symptomatic relief of digestive complaints. Polyphenolic constituents, particularly flavonoid and chalcone derivatives, are among the most characteristic compounds detected in the inflorescences. Intensive harvesting and degradation of natural habitats have increased pressure on wild populations. Since H. arenarium is legally protected in many countries, biotechnological approaches for plant biomass production represent a promising alternative. In the present study, shoot and callus cultures were established, and detailed extract profiling was performed using ultra-high-performance liquid chromatography coupled with diode-array detection and electrospray ionization multistage mass spectrometry (UHPLC-DAD-ESI-MS³). Cytotoxic, antioxidant, anti-inflammatory, wound-healing, anti-collagenase, and anti-hyaluronidase activities were also evaluated. In vitro-derived materials were compared with inflorescences and shoots of the maternal plant. The analyzed materials showed pronounced tissue-dependent metabolic differentiation. The highest callus growth rate was observed for the Ha-C-1 line, which also accumulated the highest levels of chlorogenic acid (25.80 ± 3.09 mg/g dry extract) and isochlorogenic acid A (55.83 ± 13.78 mg/g dry extract). Apigenin was detected in the inflorescence extract, reaching 3.55 ± 1.42 mg/g dry extract. The extracts did not markedly affect HaCaT viability at 15.63–500 µg/mL, while the strongest bioactivities were observed for inflorescence and maternal plant extracts. Full article

High-altitude animals rely on vertical spatial adaptation to cope with harsh environments, yet the underlying drivers of their seasonal altitudinal distribution remain poorly understood. This study investigated how solar radiation, seasonal high-quality food resources and stable foods shape the altitudinal distribution of the highest-altitude primate Rhinopithecus bieti, to uncover its survival strategies. Through systematic environmental data collection and three-year field tracking of a wild group in the Lasha Mountains, northwest Yunnan, China, we identified consistent seasonal patterns: spring in low-altitude habitats, summer at highest elevations, and intermediate ranges during autumn/winter. Statistical modeling revealed seasonally shifting environmental dependencies. Summer showed no resource limitations, while autumn introduced solar exposure and mature leaves as positive synergistic factors (50% model explanatory power). Winter exhibited peak environmental pressure (80%), with solar and buds becoming critical, though revealing a trade-off between foraging and thermoregulation. Spring demonstrated the strongest environmental coupling (86%), where solar and high-quality food showed significant positive synergy, enabling physical recovery. The species displays remarkable ecological plasticity, with solar being the core cold-season driver. The winter-to-spring transition from resource trade-off to synergy reflects dynamic behavioral adaptations to seasonal climate and nutritional bottlenecks, offering new insights into primate survival strategies in extreme environments. Full article

Hainan Tropical Rainforest National Park is a prime example of a “continental island” tropical rainforest and holds significant value for biodiversity conservation. However, human activities have led to frequent changes in land use and increased habitat fragmentation within the park; a precise analysis of the underlying mechanisms is necessary for ecological restoration. Consequently, drawing upon land-use data from 2000 to 2020, this study coupled multi-dimensional fragmentation metrics (CFI, AFI, and SFI) with the XGBoost-SHAP framework to systematically unravel the spatiotemporal dynamics and underlying driving mechanisms of landscape fragmentation in Hainan Tropical Rainforest National Park. Our findings revealed that the spatial configuration of fragmentation predominantly propagated along river networks and transport corridors, accompanied by a fluctuating ‘decline–rise–decline’ temporal trajectory. Notably, the XGBoost-SHAP attribution highlighted a distinct temporal shift in the dominant drivers: fragmentation was primarily mitigated (negatively driven) by NDVI between 2000 and 2010 but was subsequently exacerbated (positively driven) by GDP growth from 2010 to 2020. The findings of this study provide data support and a scientific basis for ecosystem restoration and land use planning in Hainan Tropical Rainforest National Park. Full article

Litter-inhabiting fungi drive organic matter mineralization, regulate nutrient cycling, and support ecosystem stability. Understanding their dynamics in unique geological habitats is essential for predicting ecological recovery on volcanic landforms. Using high-throughput ITS sequencing and physicochemical analyses, we investigated litter-inhabiting fungal communities across four stand types on the Jingpo Lake lava plateau—shrub forest (SF), deciduous broad-leaved forest (DB), coniferous and broad-leaved mixed forest (CB), and coniferous forest (CF)—at the early (t₁) and late (t₂) stages of decomposition. The results showed significant differences in litter physical and chemical properties among forest stand types (p < 0.05). Regarding community composition, Ascomycota and Basidiomycota dominated throughout, and the core genera were primarily unclassified_o__Helotiales, Mortierella, and unclassified_k__Fungi. Alpha diversity analysis showed that DB had the highest Shannon and Pielou-e indices at stage t₁, while CB exhibited higher OTUs and Chao1 indices at stage t₂. Beta diversity showed that SF communities were significantly separated between the two stages. Co-occurrence networks showed the highest connectivity in CF with pronounced modularity. Notably, LEfSe analysis revealed that DB had the fewest biomarkers, suggesting matrix heterogeneity suppresses single-taxon dominance. Functionally, saprotrophs dominated initially but transitioned toward complex soil saprotroph and endophyte assemblages over time. Redundancy analysis (RDA) identified litter moisture content (LMC) and carbon (C) content as primary drivers, orchestrating a systematic shift in community assembly from “moisture-driven colonization” at t₁ to “carbon quality screening” at t₂. These findings provide a microecological basis for understanding plant-litter-microorganism coupling mechanisms and guiding ecological restoration in lava plateau ecosystems. Full article

As high-density cities face severe conflicts between urban expansion and limited ecological space, exploring the potential drivers of carbon sequestration within urban green spaces is crucial. The overarching aim of this study is to establish an interpretable, model-based analytical framework for assessing the Annual Carbon Fixation Rate (ACFR). To address the limitations of linear models and “black-box” machine learning algorithms, this study analyzed 149 urban parks in Nanjing by coupling Sentinel-2 high-resolution data with a Random Forest algorithm and the SHAP framework to model Annual Carbon Fixation Rate. The model achieved high predictive reliability (R² = 0.9690). This study quantitatively identified critical nonlinear thresholds: an impervious surface proportion exceeding 30% is associated with a structural decline in carbon sinks, while the optimal Leaf Area Index interval for maximum efficiency is 2.5–3.5. Moreover, the present research identified a potential model-derived ecological compensation effect; optimizing vegetation community structures under high anthropogenic disturbance showed a 23.9% higher modeled marginal ACFR response compared to low-disturbance habitats. This explainable framework attempts to translate complex model-derived biophysical associations into referenced quantitative thresholds. Importantly, the ACFR and derived thresholds represent remote sensing-based model estimates rather than field-measured ecological causality, serving as exploratory planning references. These findings challenge the assumption that greening is inefficient in degraded environments and provide concrete control indicators for targeted micro-renewal and sustainable urban regeneration. Full article

Traditional species distribution models can identify climatically suitable areas but offer limited guidance for spatially explicit agricultural planning. In this study, we constructed a three-dimensional coupled framework of “suitability prediction–habitat quality filtering–ecological security screening” by integrating BIOMOD2 ensemble modeling, InVEST habitat quality assessment, and ecological security evaluation to identify candidate cultivation zones for Piper nigrum L. in China under climate change. Based on occurrence records and environmental variables, we simulated potential suitable habitats under current and future climate scenarios, identified key climatic drivers, and delineated candidate zones by overlaying habitat quality and ecological security levels. The results show that the current total suitable area for P. nigrum is 87.76 × 10⁴ km², with low-, moderate-, and high-suitability areas accounting for 37.28 × 10⁴ km², 25.12 × 10⁴ km², and 25.36 × 10⁴ km², respectively. Temperature seasonality and winter cold stress were identified as the dominant factors shaping the suitability pattern. Under future climate scenarios, the total suitable area shows an increasing trend, with highly suitable areas expanding toward the coastal regions of South China and the low-latitude hilly zones. After overlaying with habitat quality and ecological security, climatically suitable but ecologically fragile or intensively disturbed areas were effectively excluded, and the current candidate cultivation zones were identified as mainly concentrated in the southern Yunnan–southern Guangxi–Guangdong–Hainan coastal region. This framework enables a transition from identifying climatic suitability to collaborative climate–habitat–ecology screening, providing a scientific basis for sustainable cultivation and germplasm management of P. nigrum, and is transferable to priority cultivation area identification for other tropical cash crops. Full article