Search Results (1,693)

Understanding the interactions between vegetation dynamics and surface water availability is essential for assessing the resilience of tropical floodplain ecosystems under increasing hydroclimatic variability. This study analyzes the spatio-temporal dynamics of vegetation cover, surface water, and land use in Zambrano, a floodplain-dominated sector of the lower Magdalena River basin (Colombian Caribbean), over the period 1990–2025. Multi-temporal Landsat imagery was used to derive the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Water Index (NDWI), enabling the evaluation of seasonal and interannual ecohydrological variability under contrasting dry and rainy conditions. In addition, land-use classification was performed using a CORINE Land Cover methodology adapted for Colombia (CLC-C) to characterize the spatial organization of the landscape and its influence on vegetation–water interactions. Results show that vegetation dynamics are strongly controlled by hydroclimatic seasonality. Dense vegetation consistently expands during rainy periods, while dry seasons promote the expansion of open and sparse vegetation, reflecting seasonal vegetation stress rather than long-term degradation. NDWI patterns indicate that surface water and soil moisture are highly seasonal and spatially constrained, with open water largely confined to the Magdalena River channel and localized floodplain depressions. Extreme hydroclimatic events associated with the El Niño–Southern Oscillation (ENSO) produce abrupt but temporary changes in vegetation structure and surface moisture distribution. A strong inverse correlation between NDVI and NDWI reflects the contrasting spectral responses of vegetation and water surfaces resulting from the shared near-infrared (NIR) band in both indices. This spectral relationship is consistent with the observed seasonal variations in vegetation greenness and surface moisture across the floodplain. Land-use analysis reveals the progressive consolidation of the landscape, where the agropastoral matrix expanded from ~18,000 ha in 1990 to over 22,000 ha by 2025, driving a systematic reduction in natural and semi-natural forest structures. Forest conservation areas serve as critical ecological buffers, exhibiting lower seasonal variability in vegetation greenness. Overall, the results indicate that the Zambrano floodplain functions as a structurally stable yet highly responsive ecohydrological system, where vegetation dynamics and surface water availability are predominantly governed by interannual hydroclimatic pulses rather than long-term directional degradation. These findings demonstrate that while the structural matrix of the floodplain exhibits strong baseline resilience, its ecological functioning remains critically coupled with, and vulnerable to, the extreme phase shifts in ENSO cycles. Full article

The lipoxygenase (LOX) pathway plays a crucial role in the biosynthesis of characteristic aroma compounds in fruit. Despite the progress in understanding the LOX pathway in model plants like tomato, the distinct roles of individual members within the LOX gene family in flavor formation in the complex octoploid strawberry are still not fully understood. In this study, we identified 13 LOX genes in the strawberry genome and focused on a specific lipoxygenase gene, designated FaLOX11, which exhibited the highest expression during fruit ripening. Spatiotemporal expression analysis revealed that FaLOX11 expression was significantly correlated with 3-hexenal accumulation, quantified via headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Functional characterization via transient overexpression of FaLOX11 in strawberry fruits resulted in a significant increase in C6 volatile content, specifically a ~72% increase in 3-hexenal content. Conversely, RNA interference (RNAi)-mediated transient silencing of FaLOX11 significantly downregulated the expression of this gene and led to a marked reduction in the production of these key aroma compounds. Our findings demonstrate that FaLOX11 acts as a positive regulator of C6 aldehyde and alcohol biosynthesis, thereby playing a pivotal role in determining the characteristic aroma profile of strawberry fruit. This study provides new insights into the LOX pathway in strawberry and lays a solid molecular foundation for improving strawberry flavor quality. Full article

Background/Objectives: Total knee arthroplasty (TKA) is the standard surgical treatment for end-stage knee osteoarthritis (KOA); however, restoration of normal gait biomechanics remains an important challenge. Objective assessment of gait recovery may provide valuable information beyond conventional clinical outcome measures. This study aimed to evaluate changes in spatiotemporal gait parameters, symmetry restoration, and functional recovery during the first year following primary TKA, and to identify predictors of postoperative gait performance. Methods: A prospective longitudinal cohort study was conducted in 150 patients undergoing primary unilateral TKA for end-stage KOA. Spatiotemporal gait parameters, symmetry-related variables, and functional outcomes were assessed preoperatively and at 3, 6, and 12 months postoperatively. Gait analysis included walking speed, step length, cadence, stance phase symmetry, symmetry index (SI), loading asymmetry, and single-limb support time. Functional evaluation included the Timed Up and Go (TUG) test, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Knee Society Score (KSS). Repeated-measures analysis of variance (ANOVA), Pearson correlation analysis, and multivariate linear regression were performed. Results: Significant improvements were observed in all gait and functional parameters throughout follow-up (all p < 0.001). Walking speed increased from 0.84 ± 0.16 m/s preoperatively to 1.21 ± 0.18 m/s at 12 months, while step length increased from 49.8 ± 7.4 cm to 64.0 ± 6.4 cm and cadence from 91 ± 10 to 108 ± 8 steps/min. SI improved from 73 ± 11% to 93 ± 6%, whereas loading asymmetry decreased from 18.2 ± 6.1% to 4.8 ± 2.3%. Walking speed demonstrated strong correlations with WOMAC score (r = −0.74, p < 0.001) and TUG performance (r = −0.79, p < 0.001). Multivariate regression analysis identified preoperative walking speed (β = 0.47, p < 0.001) as the strongest predictor of postoperative gait recovery, while age and body mass index (BMI) were significant negative predictors. Conclusions: Patients undergoing primary TKA demonstrated substantial improvements in gait biomechanics, symmetry restoration, and functional performance during the first postoperative year. Objective gait assessment was strongly associated with clinical outcomes and may facilitate identification of patients at risk of delayed recovery. Incorporating quantitative gait analysis into postoperative evaluation may support individualized rehabilitation strategies aimed at optimizing functional outcomes following TKA. Full article

Using daily rainfall observations from 1961 to 2022 (62 years) across 15 typical sub-regions within the water-receiving area of the Zhejiang East Water Diversion Project, this study systematically examines the spatiotemporal distribution, long-term trends, multi-scale variability, and inter-regional correlations of rainfall. An integrated framework was employed, including the Mann–Kendall (MK) trend test, Sen’s slope estimator, Hurst exponent analysis, and multi-scale sliding window analysis. Spatially, the multi-year average daily rainfall ranges from 3.47 mm to 5.68 mm, following a distinct “high in the center, low in the west” pattern, with the Yuyao Plain Mazhu Midstream Area identified as the regional rainfall maximum. In the raw Mann–Kendall test all 15 sub-regions exhibit increasing trends, of which 14 remain statistically significant (p < 0.05) after trend-free pre-whitening; Sen’s slopes follow a “coastal > riverine > hilly” gradient. Hurst exponents greater than 0.5 suggest persistent behavior in the rainfall series, although attribution to external forcing or separation from low-frequency climate variability requires additional analysis. Multi-scale sliding window analysis reveals strong scale dependence: the amplitude of trend fluctuations decreases by approximately 90% from ±16 mm at the 3-month scale to ±1.7 mm at the 12-month scale, while inter-regional correlation coefficients increase from 0.83 to 0.87. Notably, the Yuyao Plain Mazhu Midstream Area displays a unique “increase-then-decrease” correlation pattern, reflecting its distinctive hydro-geographic conditions. These findings provide a scientific basis for climate-adaptive scheduling of water diversion projects, supporting water security, urban resilience, and climate action. Full article

Drought is one of the major factors affecting terrestrial ecosystem functioning under climate change. However, the interactions among different drought indices and the response of gross primary productivity (GPP) to them remain unclear. This study used multi-source remote sensing data of China from 2003 to 2020, employing the standardized precipitation evapotranspiration index (SPEI), temperature condition index (TCI), soil moisture condition index (SMCI), and vegetation condition index (VCI) to characterize the spatiotemporal dynamics of drought and quantify the response mechanism between drought indices and GPP. Partial correlation analysis and structural equation modeling were used to distinguish the direct and indirect effects of different drought types on GPP. The results show that GPP exhibited a fluctuating upward trend from 2003 to 2020, ranging from 163.71 to 458.56 g C·m⁻². In 2005, GPP declined significantly across most regions of China relative to 2004, decreasing by 14.47% in North China, 13.93% in Central China, 12.05% in East China, 8.45% in South China, 4.21% in Northwest China, and 4.15% in Northeast China, whereas Southwest China exhibited a slight increase of 0.34%. Different types of drought exhibited distinct occurrence characteristics. SMCI exhibited a drought frequency of 44.35% and a mean duration of 75.64 days. Among the four indices, SPEI showed the lowest frequency (12.54%) and the highest intensity (0.14), whereas TCI exhibited both the highest frequency (60.22%) and the longest duration (98.46 days), and VCI yielded the lowest drought severity (1.96). The TCI was considered a major driver of GPP variations, showing a significant positive correlation with GPP in all regions (r = 0.45–0.88, p < 0.001). In contrast, the SPEI had a relatively weak impact on GPP. The “TCI→VCI → GPP” pathway represented the main pathway of drought–GPP interaction at the national scale. This study provides methods for assessing the response characteristics of GPP under future climate change. Full article

Black soil degradation poses critical threats to agricultural sustainability and global food security, yet systematic frameworks integrating ecological security assessment, driver identification, and forward-looking early warning remain underdeveloped for black soil watersheds. This study develops and implements a comprehensive assessment–interpretation–early warning framework for the Xingkai Lake Basin, a representative black soil region at the China–Russia border. We developed a multivariate ecological security index (MESI) to describe the spatiotemporal dynamics between 2000 and 2023. An XGBoost–SHAP framework was applied to quantify dominant drivers of ecological security spatial heterogeneity and examine synergistic effects among driving factors through geographical detector interaction analysis. A Bayesian network model was subsequently employed to simulate the probability of warning grade occurrence under multiple univariate and multivariate scenarios. Findings revealed the following: (1) Spatial analysis revealed persistent north–south differentiation, with high spatial association zones contracting from 25% to 21% despite strengthened global spatial auto correlation. (2) XGBoost–SHAP driver analysis quantified that land use intensity and landscape fragmentation collectively explained over 75% of spatial heterogeneity in MESI. (3) BN models demonstrated greater sensitivity in simulating no warning and severe warning levels. This study provides scientifically rigorous insights into the sustainable management of ecosystems in black soil river basins and offers a generalizable decision-support framework for conducting ecological safety early warning research in other regions facing similar agricultural pressures. Full article

Objective: To assess correlations between maternal obesity and fetal interventricular septum (IVS) volume measured by means of spatiotemporal image correlation and Virtual Organ Computer-Aided Analysis (STIC-VOCAL), after adjustment for gestational age. Methods: This cross-sectional observational study included 88 consecutive singleton pregnancies undergoing routine obstetric ultrasound at our center between January 2024 and December 2025. Fetal IVS volume was assessed using STIC-VOCAL, and its association with maternal characteristics was evaluated by means of univariate and multivariable regression analyses adjusted for gestational age. Results: Fetal IVS volume increased with estimated fetal weight (r = 0.860, p < 0.0001) and gestational age (r = 0.891, p < 0.0001), which represented the main determinant of absolute fetal cardiac volume. The association between maternal obesity and fetal IVS volume was not evident on univariate analysis (U = 987.5, p = 0.874) but became significant after adjustment for gestational age in multivariable regression models (β = +89.1 mm³, p < 0.0001). At comparable gestational ages, maternal obesity was associated with an adjusted increase in fetal IVS volume of approximately 22.6 mm³. Conclusions: Maternal obesity was independently associated with a modest increase in fetal IVS volume after adjustment for gestational age. STIC-VOCAL volumetry may provide a sensitive tool for detecting subtle fetal cardiac structural changes, although these findings remain exploratory. Full article

Land subsidence is one of the most critical geological hazards in Hainan Province, primarily driven by groundwater overexploitation. This study integrates regional-scale SBAS-InSAR deformation results with groundwater observations from nine representative monitoring wells to investigate the spatiotemporal evolution of land subsidence and its groundwater-related response mechanisms in Hainan Province. Sentinel-1A imagery from 2019 to 2023 was used to derive LOS deformation time series, which were converted into vertical land subsidence using local incidence-angle correction under the assumption of negligible horizontal displacement. Seasonal and Trend decomposition using Loess (STL), Pearson correlation analysis, dynamic time warping (DTW), and lag correlation analysis were applied to separate multiscale signals and examine groundwater–subsidence responses in representative hydrogeological settings. The results indicate that (1) land subsidence in Hainan Province is mainly concentrated in coastal plains, with Haikou, Wenchang, and Danzhou identified as the main subsidence centers, where local annual subsidence rates exceed −50 mm/yr; (2) representative well-based analysis shows that groundwater-level decline is closely synchronized with cumulative subsidence in major subsidence-sensitive areas, with DTW distances consistently below 10, indicating high temporal consistency; long-term groundwater depletion is an important driver of cumulative subsidence in these representative areas; (3) lag correlation analysis reveals spatially heterogeneous lag responses of 1–6 months between groundwater-level fluctuations and land subsidence, with lag time and phase relationship closely related to aquifer structure, low-permeability layer distribution, and groundwater extraction intensity. This study provides a scientific basis for land subsidence mitigation and sustainable groundwater management in tropical island regions. Full article

(1) Background: As a central element of plant configuration and the ornamental performance of pedestrian refuge islands, quantitative color analysis provides a novel approach to evaluating landscape plant diversity. (2) Methods: Using spring and winter survey data on plant diversity, color, and traffic flow, we analyzed the spatiotemporal gradients of plant communities. (3) Results: A total of fifty-three species were documented across 17 islands. The predominant species is Eleusine indica (L.) Gaertn., with a utilization frequency of 9. The foliage exhibits 28 standard colors across both seasons, with winter featuring three color series and 13 hues (blackness 20%–80%), and spring featuring two series and 11 hues (blackness 10%–60%). Quantitative traits and alpha diversity are ranked as follows: herb layer > shrub layer > arbor layer. There is a positive correlation between community alpha diversity and cycle length. Additionally, the mean blackness in spring is significantly positively correlated with pedestrian flow and the density of green light slow-traffic, whereas the mean chromaticness in winter correlates with the green split ratio. (4) Conclusions: The presence of diverse horticultural plants contributes to vibrant landscapes with distinct seasonal dynamics on the pedestrian refuge islands of urban Xinyang. Furthermore, slow-moving traffic at intersections is identified as a key anthropogenic factor influencing patterns of roadside plant diversity. Full article

Against the backdrop of optimizing national energy mix and advancing industrial low-carbon transformation to achieve sustainable socioeconomic development, this study adopts prefecture-level panel data covering 2005–2020 to reveal the spatiotemporal evolution law of carbon emissions generated by urban energy consumption. We systematically characterize emission disparities from three dimensions: total carbon output, per capita carbon emissions, and carbon emission intensity, and further adopt regression analysis to quantitatively identify core socioeconomic and industrial drivers behind energy-related carbon flows. The results indicate that China’s total urban energy carbon emissions kept rising over the research window with decelerating growth momentum. Driven by cross-regional industrial transfer and uneven energy resource endowments, high-emission zones gradually spread from eastern coastal agglomerations to northern and western inland territories, forming a stable spatial layout of high emissions in the east and north, and low emissions in the west and south. Per capita carbon emissions present striking regional differentiation: northwest resource-abundant provinces become concentrated high-value clusters, while populous southeast regions maintain relatively low levels, with inter-regional per capita emission gaps continuously widening. Nationwide carbon emission intensity maintained a persistent downward trend; high-intensity zones shrank markedly while low-carbon areas expanded continuously, and inter-regional efficiency gradients gradually converged, reflecting tangible achievements in nationwide energy conservation and low-carbon industrial transition. Overall, the gravity center of energy carbon emissions shifted northwestward, with Inner Mongolia, Xinjiang, and Ningxia evolving into major high-emission hotspots relying on fossil energy exploitation and heavy industrial layout. Statistical regression associations suggest that urban construction land expansion, economic expansion, foreign capital agglomeration, and industrial energy carbon outputs are positively correlated with urban carbon emissions; by contrast, commercial housing scale and domestic enterprise development present significant negative correlational links with emission levels. The differentiated spatiotemporal carbon landscape arises from the joint interplay of regional resource endowment, coal-dominated energy structure, industrial layout restructuring, and tiered low-carbon policy implementation, demonstrating China’s overall shift from high-carbon extensive industrial growth toward energy-efficient, low-carbon intensive sustainable development. This research delivers empirical evidence for formulating zoned carbon abatement schemes, optimizing regional energy allocation and industrial layouts, and advancing long-term low-carbon sustainable development to fulfill China’s carbon peaking and carbon neutrality targets. Full article

Low-visibility weather poses a significant threat to aviation safety and operational efficiency. Lhasa Airport is situated in a high-altitude river valley region prone to dust events. Clarifying the characteristics and dominant factors of low-visibility weather is crucial for enhancing aviation meteorological support capabilities. This study systematically analyzed the weather types, spatiotemporal distribution characteristics, and key meteorological influencing factors of low-visibility events using ground-based automated meteorological observation data, monthly summary records, and wind lidar data from Lhasa Airport from January 2020 to July 2024. The results indicate that dust weather (blowing sand and floating dust) is the primary cause of low visibility, accounting for over 90% of low-visibility days. Low-visibility events exhibit significant monthly variations, with the longest cumulative duration occurring in January and February, while being extremely rare from July to November. Under low-visibility conditions, visibility levels are predominantly concentrated in the 3–4 km range (72.5%), and most events last less than one hour. Factor analysis reveals that north, easterly, and west winds are commonly associated with dust-induced low visibility. Wind speed demonstrates a significant negative correlation with visibility and serves as the primary driving factor. Moderate relative humidity is most conducive to maintaining visibility between 3 and 5 km. Case studies further confirm that sustained strong low-level winds (≥10 m/s), high surface wind speeds (≥7.5 m/s), and intense upward motion are the key dynamic conditions for triggering and maintaining dust-related low-visibility processes. This study presents, for the first time, quantitative thresholds for key meteorological parameters and their season-dependent characteristics for dust-induced low-visibility events at Lhasa Airport, and proposes actionable forecasting indicators. These findings offer clear practical implications for aviation meteorological services at high-altitude valley airports. Full article

Gas concentration in coal mine return-air corners is affected by ventilation, mining disturbance and gas drainage conditions, and it shows strong nonstationarity, local fluctuation and dynamic multi-point correlations. To improve frequency information separation, monitoring point relationship modeling, and short-term prediction accuracy, a variational mode decomposition (VMD)-based dual-branch spatiotemporal graph method is proposed. Gas concentrations from four key monitoring points are used as inputs, and the return-air corner gas concentration is taken as the output. First, the raw series are decomposed by VMD and reconstructed into low- and high-frequency components. Then, two branches are built for different frequency components. The low-frequency branch combines adaptive graph learning, graph convolution and gated recurrent units to extract global variation features, while the high-frequency branch combines graph attention and gated recurrent units to capture local disturbance features. Finally, a feature-fusion module generates multi-step predictions, and a lightweight short-term warning strategy is developed based on the predicted values. The proposed model achieves MAE, RMSE and R² values of 0.0338, 0.0471 and 0.9499 in one-step prediction, respectively, and outperforms GRU, LSTM, GCN-GRU, GAT-GRU, VMD-GRU, Informer and STGCN under three-step and six-step conditions. Cross-dataset validation and inference time analysis indicate good adaptability and online prediction potential. Full article

The Cascade Reservoir System (CRS) in the upper Yellow River delivers integrated benefits (flood control, water supply, hydro-power generation, and ecological regulation), but it also alters the natural runoff regime and exerts non-negligible impacts on the regional eco-environment. However, the long-term trajectory of reservoir-cascade effects on land use/land cover (LULC) in alpine basins has not yet been systematically quantified. Here, we focused on the Hualong-Xunhua reach and delineated two impact domains—the Reservoir Influence Zone (RIZ, enclosed by the first-order mountain ridge lines closest to the river channel representing direct hydrological impacts) and the Local Microclimate Influence Zone (LMIZ, spanning from the first-order ridges to the outer watershed boundary representing indirect climatic impacts)—to investigate the spatiotemporal dynamics of LULC associated with reservoir development. Results show that, from 1985 to 2023 in the CRS area, cropland and shrub-land decreased by 89.56 km² (−16.09%) and 9.41% (−9.41%), respectively, whereas forest and grassland increased by 79.92 km² (+14.36%) and 7.74% (+7.74%). Within the RIZ, cropland declined by 29.49 km² (−20.14%), while water bodies increased markedly by 32.19 km² (+22%); forest cover also expanded by 9.09 km² (+6.21%). In the LMIZ, forest and grassland exhibited pronounced increases of 70.83 km² (+17.27%) and 39.37 km² (+9.60%), respectively. Correlation analysis indicates that GDP and air temperature are strongly and positively correlated with forest, water bodies, and impervious surfaces (Pearson’s r > 0.9), whereas cropland shows significant negative correlations with GDP, forest, and grassland (Pearson’s r < −0.8). Overall, the distinct spatiotemporal contrasts between the RIZ and LMIZ, coupled with the temporal alignment of cropland-to-forest transitions post-2000, suggest that reservoir-cascade construction and the Grain-for-Green Project are associated with these major LULC transitions, serving as contributing factors, while temperature rise and GDP growth represented the background environmental and socioeconomic context. These findings provide data support and a conceptual basis for long-term monitoring and assessment of eco-environmental responses to reservoir cascade development, and offer scientific evidence particularly relevant to reservoir planning and management in high-altitude cold regions. Full article

The chalcone synthase (CHS) genes play an important role in the biosynthesis of flavonoids and anthocyanins. However, research into the genomic characteristics and evolutionary patterns of the CHS gene family in lychee remains limited. In this study, six LcCHS genes were identified from the litchi genome. Most members of the LcCHS family consist of two exons and possess eight conserved motifs; furthermore, all members exhibit highly similar three-dimensional protein structures. LcCHS genes were closely related to homologs of Sapindaceae species and experienced gene duplication events during dicotevolution. Comparative colinearity analysis revealed conserved colinearity relationships among most LcCHS genes, and all members of the LcCHS family exhibited distinct colinearity with homologues in longan. LcCHS genes exhibited significant tissue-specific expression preferentially in reproductive tissues rather than vegetative tissues. Transcription analysis of ‘Jinggang Hongnuo’ litchi fruit development divided LcCHS genes into two negatively correlated expression modules and LcCHS members interacted with numerous transcription factors (e.g., flavonoid biosynthesis, hormone signaling and developmental regulation). Spatiotemporal expression profiling of LcCHS genes in ‘Guiwei’, ‘Feizixiao’ and ‘Ziniangxi’ litchi cultivars revealed obvious tissue specificity and developmental stage preference of these genes. Gene expression of LcCHS genes in ‘Guiwei’ high correlated with the flavonoid content. Furthermore, promoter cis-element analysis identified 34 types of cis elements in LcCHS promoters that participate in plant growth and development, hormone response and stress adaptation, implying that LcCHS genes may participate in litchi growth, hormone signal transduction, and stress-response processes. Comprehensive characterization of the chalcone synthase gene family could provide insights into the genetic improvement of litchi. Full article

Terrestrial ecosystems serve as key carbon reservoirs and contribute substantially to global carbon cycling and climate regulation. Shaanxi Province (SP) is located along China’s north–south geographical boundary and climatic transition zone, making it crucial to understand how carbon stocks change within its ecosystems. This study analyzed the land-use patterns, influencing factors, and spatiotemporal dynamics of carbon storage across three regions (Shanbei, Guanzhong, and Shannan) in SP. The results indicated that: (1) From 2000 to 2020, cropland and barren land areas in SP decreased significantly, while the forest land area increased markedly. Total carbon storage in SP increased from 1688.55 Tg in 2000 to 1726.12 Tg in 2020, with the highest accumulation observed in Shannan, followed by Shanbei and Guanzhong. (2) Forest land acted as the most significant carbon sink; its contribution to SP’s total carbon storage increased from 54.98% in 2000 to 60.28% in 2020. (3) Carbon storage across the three regions was positively correlated with elevation, slope, soil silt content, and precipitation, but negatively correlated with soil sand content, gross domestic product, and population distribution. (4) Geographical detector analysis identified precipitation as the key influencing factor for carbon storage in Shanbei and Guanzhong, whereas the primary factors in Shannan were temperature, elevation, and slope. This study recommends future land use priorities: maintaining grassland dominance in Shanbei, scientifically optimizing the planning of cropland and impervious land in Guanzhong, and sustaining current forest protection and management in Shannan. These results provide vital quantitative support and important references for ecologically sustainable development and the realization of China’s dual-carbon goals in SP. Full article