Search Results (246)

Under the ongoing trend of climate warming and increasing humidity on the Qinghai–Tibet Plateau, the Three River Source Region (TRSR) has shown strong sensitivity to global climate change. Its vegetation change is particularly worthy of attention and research. The Normalized Difference Vegetation Index (NDVI) is a key indicator for assessing the growth status of vegetation. However, the insufficiency of existing NDVI datasets in terms of spatiotemporal continuity has limited the accuracy of long-term vegetation change studies. This study proposed a machine learning-based downscaling framework that integrates the Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI and the Global Inventory Monitoring and Modeling System (GIMMS) NDVI data to reconstruct a long-term, high-resolution NDVI dataset. Unlike conventional statistical fusion approaches, the proposed framework employs machine learning-based nonlinear relationships to generate long-term, high-resolution NDVI data. Three machine learning algorithms—Random Forest (RF), LightGBM, and CatBoost—were evaluated. Their performance was validated using the MODIS NDVI as reference, with the coefficient of determination (R²), root mean square error (RMSE), mean absolute error (MAE), and Pearson’s correlation coefficient (R) as evaluation metrics. Based on model comparison, the CatBoost model was identified as the optimal algorithm for spatiotemporal data fusion (R² = 0.9014, RMSE = 0.0674, MAE = 0.0445), significantly outperforming RF and LightGBM models and demonstrating stronger capability for NDVI spatiotemporal reconstruction. Using this model, a long-term, 1 km monthly GIMMS-MODIS NDVI dataset from 1982 to 2014 was successfully reconstructed. On the basis of this dataset, the spatiotemporal variation characteristics of vegetation in the TRSR from 1982 to 2014 were systematically analyzed. The research results show that: (1) The constructed long-series high-resolution NDVI dataset has a high consistency with MODIS NDVI data; (2) From 1982 to 2014, the NDVI in the TRSR showed an increasing trend, with an average growth rate of 0.0020/10a (p < 0.05). NDVI showed obvious spatial heterogeneity, characterized by a decreasing gradient from southeast to northwest. (3) The Yellow River source exhibited the most evident vegetation recovery, the Yangtze River Source area showed a moderate improvement, whereas the Lancang River Source area displayed little noticeable change. (4) Broad-leaved forests experienced the most significant growth, while cultivated vegetation displayed a marked tendency toward degradation. This study provides both a high-accuracy long-term NDVI product for the TRSR and a methodological foundation for advancing vegetation dynamics research in other high-altitude regions. Full article

Background/Objectives: Dietary inorganic nitrate (NO₃⁻), primarily sourced from vegetables such as beetroot, has been shown to enhance nitric oxide (NO) bioavailability, with emerging evidence suggesting its potential to modulate autonomic function. However, the effects of NO₃⁻ supplementation on cardiac autonomic recovery post-exercise in hypertensive postmenopausal women remain poorly understood. Using data from a previously conducted randomised controlled trial, this study investigated the effects of acute (800 mg) and seven-day (400 mg/day) beetroot juice NO₃⁻ supplementation on ultra-short-term post-exercise cardiac parasympathetic recovery in hypertensive older women. Methods: In a triple-blind, placebo-controlled crossover design, fourteen postmenopausal women (59 ± 4 y) with hypertension completed two intervention arms (NO₃⁻ and placebo). Ultra-short-term heart rate variability (HRV) indices (SDNN, RMSSD, HF) were assessed across 5 min post-exercise recovery using 60 s windows. Plasma NO₂⁻ and NO₃⁻ concentrations were measured via chemiluminescence. Results: Both acute and seven-day NO₃⁻ supplementation significantly increased plasma NO₂⁻ and NO₃⁻ concentrations compared to placebo (p < 0.001). Cardiac vagal recovery, assessed via SDNN and RMSSD, was significantly enhanced in both conditions, with greater and more sustained improvements observed after the seven-day protocol. HF power was significantly higher, but only after seven-day supplementation (p = 0.009). Conclusions: Inorganic NO₃⁻ supplementation enhances post-exercise cardiac parasympathetic reactivation in hypertensive postmenopausal women. Notably, the seven-day intake (400 mg/day) protocol elicited superior autonomic benefits compared to an acute high dose. These findings highlight the potential of NO₃⁻ as a non-pharmacological strategy for improving cardiovascular autonomic recovery in high-risk populations. Full article

Heat stress (HS) during the grain-filling stage severely limits yield in waxy maize by impairing leaf physiology and suppressing photosynthetic capacity. Although exogenous brassinosteroids are recognized for enhancing thermotolerance, their specific role in sustaining photosynthetic performance in waxy maize under HS has not been thoroughly investigated. This study investigated whether exogenous 24-epibrassinolide (BR) application could alleviate HS-induced damage in two waxy maize hybrids. Plants were exposed to HS with/without BR treatment over two growing seasons. Yield components, photosynthetic parameters, chloroplast ultrastructure, antioxidant enzyme activities, and physiological traits were analyzed. HS during the grain-filling stage significantly reduced maturity yields (SYN5: −42.8%; YN7: −39.0%) by impairing photosynthetic efficiency, chloroplast integrity, antioxidant capacity, and the translocation amount and rate of vegetative organs photosynthate after pollination. Chloroplasts exhibited structural disorganization and pronounced swelling. Photosynthetic pigment content and enzyme activities (ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxylase) declined, while reactive oxygen species accumulation increased. Exogenous BR substantially restored yields by preserving the chloroplast ultrastructure, enhancing photosynthetic function, reactivating antioxidant enzymes (ascorbate, catalase, superoxide dismutase), and reducing oxidative damage. BR also optimized hormone balance (reduced abscisic acid, increased indole-3-acetic acid) and elevated soluble protein/sugar contents. Meanwhile, BR reversed the negative effects of HS on dry matter accumulation and translocation. SYN5 suffered greater HS damage but exhibited stronger BR-mediated recovery than YN7. In conclusion, BR application mitigates HS by protecting the chloroplast structure, boosting photosynthetic resilience, and activating antioxidant defenses, offering a strategy to safeguard waxy maize productivity under HS. Full article

Forest-type national nature reserves and their surrounding areas have experienced a series of drought events, which have influenced forest ecosystem stability. Assuming that drought events do not cause a shift in the ecosystem’s stable state, we quantified the stability of forest ecosystems in China’s national nature reserves and their surrounding areas in response to drought events from 2000 to 2018, using satellite-observed Enhanced Vegetation Index (EVI) and Standardized Precipitation Index (SPI) data. We further examined differences in ecosystem stability across regions and forest types, and identified the impacts of environmental factors using correlation analysis, analysis of variance (ANOVA), and random forest models. The results show that both national nature reserves and their surrounding areas primarily experienced single, moderate-intensity drought events, most of which occurred in spring and summer. Compared with surrounding areas, national nature reserves exhibited higher ecosystem stability, with a mean drought resistance index of 31.45 ± 21.09. The difference in ecosystem stability between reserves and their surrounding areas was most pronounced in deciduous forests, which was attributed to their high hydraulic conductivity and distinctive leaf phenological traits. Additionally, climatic factors were the dominant drivers of both resistance and recovery rate, each contributing more than 30% to the overall explained variance. Our results provide valuable guidance for enhancing drought resilience and promoting the sustainable management of China’s national forest reserves. Full article

Investigating the optimal planting strategies for brassica vegetables under variable climatic conditions is essential for developing sustainable production systems in northern agricultural regions. However, comprehensive knowledge about how planting timing modulates growth, physiological responses, and yield parameters across different cultivars remains limited. We investigated vegetative development, root morphology, physiological efficiency, and marketable yield in six cauliflower cultivars (‘Amazing’, ‘Cheddar’, ‘Clementine’, ‘Flame Star’, ‘Snow Crown’, and ‘Vitaverde’) subjected to four planting dates (May 1, May 15, June 1, and June 15) across two growing seasons (2023–2024), followed by detailed morphological and physiological profiling. Planting date, cultivar selection, and seasonal variation significantly influenced all measured parameters (p < 0.001), with notable interaction effects observed for fresh root weight, stomatal conductance, water use efficiency, and yield components. Early planted cultivars consistently demonstrated superior performance under variable environmental conditions, maintaining higher growth rates, enhanced root development, and improved physiological efficiency, particularly ‘Flame Star’, ‘Snow Crown’, and ‘Cheddar’, compared to late-planted treatments. Recovery of optimal plant development was most pronounced at May planting dates, with early-established crops showing better maintenance of vegetative growth patterns and enhanced yield potential, including higher curd weights (585.7 g for ‘Flame Star’) and superior marketable grades. Morphological profiling revealed distinct clustering patterns, with early-planted cultivars forming separate groups characterized by elevated root biomass, enhanced physiological parameters, and superior yield characteristics. In contrast, late-planted crops showed reduced performance, indicative of environmental stress responses. We conclude that strategic early planting significantly enhances cauliflower production resilience through comprehensive optimization of growth, physiological, and yield parameters, particularly under May establishment conditions. The differential performance responses between planting dates provide insights for timing-based management strategies, while the quantitative morphological and physiological profiles offer valuable parameters for assessing crop adaptation and commercial viability potential under variable climatic scenarios in northern agricultural systems. Full article

Analysis of tree vegetation recovery on abandoned agricultural lands is one of the key tasks in landscape research. This study considered the factors of forest cover of postagrogenic lands typical of the Central Russian forest-steppe. We applied a combination of geoinformation and statistical methods to analyze the relationship between climatic, geomorphological, and soil factors and the forest cover of abandoned agricultural lands. The results of this study showed varying strengths of the relationship between the climatic factors of the warm and cold seasons and the afforestation rate of postagrogenic lands. In the flat terrain region, warm-season climatic variables have a major effect on forest cover. Among the climatic factors, the precipitation of the warmest quarter and the hydrothermal coefficient show the strongest direct correlation with the forest cover of the abandoned agricultural lands. The accumulated temperature over the period with values above 10 °C and the average temperature of the warmest quarter show the strongest inverse correlation with forest cover. It has been established that soil type has a significant impact on the rate of abandoned lands afforestation. Forest cover on even-aged abandoned agricultural lands on gray forest soils (Haplic Phaeozems) is, on average, twice that of chernozem soils. The variation in forest cover is higher on abandoned croplands located on Chernozem. We analyzed forest cover as a variable dependent on various environmental conditions and proposed a number of multivariate regression models that estimate forest cover as a response to a combination of climatic, geomorphological, and soil conditions. As a result, the influence of various factors on the afforestation rate of postagrogenic lands was quantitatively shown. Full article

Complex matrix of vegetable severely interferes with enzyme-linked immunosorbent assay (ELISA) accuracy, limiting its application in parathion residue detection. This study investigated the interference mechanism of vegetable matrix, including chlorophyll, perilla protein, glucose, fructose, and sucrose, on ELISA. Furthermore, we validated the vegetable matrix interference on parathion residue ELISA by comparing the matrix interference index (I_m) and recovery rate of vegetable samples before and after acetic acid-treatment. The results demonstrate that the addition of vegetable matrix significantly interferes with ELISA, with the antibody–IgG-HRP binding being subject to the most pronounced interference. Compared to the I_m (16–26%) of non-acetic acid treatment, the I_m (10–13%) was significantly reduced after the acetic acid treatment. Concomitantly, spiked recovery experiments of acid-treated samples yielded satisfactory average recovery rate (80–113%) as the matrix interference was minimized. The findings of this study provide valuable insights into the mechanism of vegetable matrix interference on ELISA. Full article

Sprayers for vineyards with solution recovery represent an important innovation, offering several advantages, the most important being the efficient use of pesticides and environmental protection. This paper presents the experimental equipment designed to study the treatment process of grapevine foliage, the applied research methods, and the results of optimizing key technological parameters (hydraulic pressure p of the working solution, speed V of the airflow at the nozzle outlet) and design parameters (surface area S of the central orifice of the diffuser) in different growth stages of grapevines with varying foliar density ρ, the response function being the recovery rate of the working solution. The construction of the SVE 1500 (Experimental model, manufactured at the Institute of Agricultural Technology “Mecagro”, Chisinau, Republic of Moldova) vineyard sprayer with solution recovery is presented, along with test results obtained in field conditions, which demonstrated that the experimental model of our machine ensures a 38% reduction in working solution consumption during the active vegetation phase while maintaining treatment quality in compliance with agrotechnical requirements. The SVE 1500 machine can be towed with a sufficient turning radius for use in modern vineyard plantations. Construction documentation has been developed for the production and delivery of the experimental batch of SVE 1500 machines to agricultural enterprises. Full article

This study developed a gas chromatography–tandem mass spectrometry (GC-MS/MS) method for detecting dinotefuran residues in fruits and vegetables. The modified extraction procedure employed solvent conversion for GC-MS/MS compatibility, achieving a linear range of 0.001–2.0 mg/kg (r² > 0.999), a LOD of 0.003 mg/kg, and a LOQ of 0.01 mg/kg. Recovery rates ranged from 88.2% to 104.5% (RSD: 3.5–5.8%). The analysis of 18 commercial samples from Weifang, China, revealed the highest residues in nectarines (0.12 mg/kg) and lowest residues in cucumbers (0.02 mg/kg), with the dietary exposure risk assessment indicating hazard quotients well below safety thresholds. The literature review showed that dinotefuran has a shorter soil half-life (10–30 days) than most neonicotinoids, a low adsorption coefficient (Koc 30–50), high leaching potential, and significant toxicity to pollinators (LD₅₀ = 0.023 μg/bee). The validated method provides reliable detection across diverse matrices, while the environmental behavior analysis highlights the need for the careful management of dinotefuran applications to minimize ecological impacts despite its favorable degradation profile compared to other neonicotinoids. Full article

An improved QuEChERS method based on magnetic nanomaterials was established, and coupled with ultra-high-performance liquid chromatography and a quadrupole electrostatic field orbitrap mass spectrometer, enabling non-targeted screening and quantitative analysis of commonly used pesticide and veterinary drug residues in Brassica rapa chinensis. The combination of magnetic PSA and magnetic multi-walled carbon nanotubes (MWCNTs) was utilized for purification of 121 organic compounds spanning a wide range of polarities. Spiking experiments showed that the developed non-target screening workflow exhibited convincing identification results, with over 89.3% of chemical substances being screened out even at spiking levels as low as 2 μg/kg. The linear ranges of these target substances were between 1 and 200 μg/kg, with determination coefficients all exceeding 0.99. The limits of quantification were between 2 μg/kg and 10 μg/kg. The average recovery rates were in the range of 61.7% to 121.6%. Nineteen compounds were confirmed (meeting all the restriction conditions) and quantified from Brassica rapa chinensis collected from vegetable-planting bases in Jiangsu Province. The results indicated that the magnetic bead-based pretreatment strategy can be utilized for the simultaneous screening and quantitative analysis of pesticide and veterinary drug residues in Brassica rapa chinensis. Full article

With the expansion of the scale of ultra-high-voltage transmission lines and the complexity of the corridor environment, the traditional manual inspection method faces serious challenges in terms of efficiency, cost, and safety. In this study, based on power laser inspection technology with a high-precision servo control system, a complete set of laser point cloud processing technology is proposed, covering three core aspects: transmission line extraction, scene recovery, and operation status monitoring. In transmission line extraction, combining the traditional clustering algorithm with the improved PointNet++ deep learning model, a classification accuracy of 92.3% is achieved in complex scenes; in scene recovery, 95.9% and 94.4% of the internal point retention rate of transmission lines and towers, respectively, and a vegetation denoising rate of 7.27% are achieved by RANSAC linear fitting and density filtering algorithms; in the condition monitoring segment, the risk detection of tree obstacles based on KD-Tree acceleration and the arc sag calculation of the hanging chain line model realize centimetre-level accuracy of hidden danger localisation and keep the arc sag error within 5%. Experiments show that this technology significantly improves the automation level and decision-making accuracy of transmission line inspection and provides effective support for intelligent operation and maintenance of the power grid. Full article

Since the launch of the Grain for Green (GFG) program in 1999, the Loess Plateau has undergone significant vegetation changes. However, the driving mechanisms behind these changes in the post-GFG period remain insufficiently understood. This study analyzes the spatiotemporal dynamics of vegetation on the Loess Plateau from 1982 to 2015, based on long-term NDVI time series, and quantitatively identifies the relative contributions of climate variability and human activities using partial correlation and multiple regression residual analysis. The results reveal a significant increase in NDVI after 2000, with the annual variation rate rising from 0.0009 to 0.0028, and the proportion of rapidly greening areas expanding from 13.3% to 62.9%. Spatially, vegetation recovery was more prominent in the eastern and lower-latitude regions. While both climate and anthropogenic factors influenced vegetation changes, the latter became dominant after 2000. The area where human activities significantly enhanced vegetation increased from 1.9% to 60.6%, with the most notable improvements observed in forests, followed by croplands and grasslands. Vegetation in the southern plateau was more sensitive to temperature, while the northern region responded more strongly to precipitation. From 2000 to 2015, the GFG program contributed to increases of 17,059.46 km² in grasslands and 10,105.78 km² in forests. These findings improve our understanding of vegetation change drivers on the Loess Plateau and offer a scientific basis for ecological restoration, policy-making, and sustainable development in the Yellow River Basin. Full article

Soybean oil has recently emerged as the most widely consumed genetically modified (GM) vegetable oil globally. DNA-based methods offer considerable advantages for monitoring GM-derived products; however, their efficacy strongly depends on the quality and quantity of extracted DNA. Owing to intensive processing, refined oils typically contain extremely low concentrations of severely fragmented DNA, making DNA extraction highly challenging. To address this issue, we introduce an innovative magnetic bead-based DNA extraction protocol specifically tailored to refined soybean oils. Optimal DNA adsorption was achieved using 300 nm carboxyl (-COOH)-modified magnetic beads under optimized conditions, including 1 M guanidine isothiocyanate (GITC) buffer at pH 6.0, combined with ethanol at a 1:1 ratio. Subsequently, we developed a cetyltrimethylammonium bromide (CTAB)-magnetic bead method in which DNA was efficiently transferred from the oil phase to the aqueous phase, concentrated via precipitation, resuspended in GITC buffer, and finally purified using magnetic beads. Comparative evaluations using nested polymerase chain reaction (PCR) and real-time PCR confirmed that this method significantly outperformed traditional CTAB-based methods (CTAB alone, CTAB-hexane) and two representative silica membrane-based extraction kits. Spike recovery experiments further demonstrated its superior efficacy, achieving a DNA recovery rate of 76.37%. The proposed protocol is simple, user-friendly, cost-effective, and highly efficient, markedly reducing reliance on large volumes of organic solvents (e.g., hexane and chloroform) and minimizing the required centrifugation steps. This novel method established an effective approach for DNA extraction from refined vegetable oils, facilitating the development of rapid and reliable GM detection. Full article

Organic fertilization management for vegetable transplant production is challenging to growers due to the slow and unpredictable release nature of organic fertilizers. Nutrients in organic fertilizers, particularly nitrogen (N), often fail to meet the demands of rapidly growing transplants in soilless substrate. This study aimed to develop fertilization guidelines for organic bell pepper (Capsicum annuum L.) transplants by evaluating the performance of one conventional fertilizer, two organic fertilizers (Drammatic, Pre-Empt), and one naturally derived fertilizer (Bio-Matrix) at a range of N rates in supporting transplant growth. Bell pepper transplants were grown in an indoor growing chamber for 28 days with weekly fertilizer application. We found that the initial nitrate-N concentration in the fertilizer solution was the sole predictor of shoot dry weight (R² = 0.62), confirming that N availability was the primary limiting factor for transplant growth. The conventional fertilizer produced the largest transplants (370.9 mg/plant in shoot dry weight) while Drammatic resulted in the lowest maximum shoot growth (196.6 mg/plant), likely due to its high salinity and the accumulation of ammonium in the substrate. Bell pepper transplants exhibited low nutrient uptake capability and resulted in low N recovery efficiency, especially with the two organic fertilizers, Drammatic and Pre-Empt (15.6% and 23.8%, respectively). Furthermore, we found no carryover effects of the fertilizer treatments during the transplant stage on bell pepper growth after being transplanted to the greenhouse for 18 days. The final shoot dry weight only correlated with transplant shoot dry weight at the time of transplanting (R² = 0.87) but not with fertilizer type (p = 0.2849). Overall, Pre-Empt emerged as the most effective fertilizer for organic bell pepper transplant production. It is cost-effective, has low electrical conductivity, and is associated with low ammonium accumulation in the substrate. Therefore, it can be applied at high N rates to meet the N demand of bell pepper transplants. Based on our growing conditions, we recommend 23.1 g/L substrate of Pre-Empt for organic bell pepper transplant production. Full article

As an important coal-producing region in China, open-pit coal mining in Shaoyang, Hunan Province, has a significant impact on the ecological environment. This study focuses on the three major open-pit mining areas in the city, utilizing remote sensing data from 1998 to 2024. By calculating the normalized difference vegetation index (NDVI) and fractional vegetation cover (FVC), and combining climate factors such as temperature and precipitation with Net Primary Productivity (NPP), this study analyzes the spatiotemporal evolution characteristics of vegetation cover and carbon sinks, and explores the impact of climate and environmental policies on vegetation recovery. The study employed trend analysis and autoregressive integrated moving average (ARIMA) model predictions, which showed that vegetation cover in the mining areas decreased overall from 1998 to 2011, gradually recovered after 2011, and reached a relatively high level by 2024. Changes in carbon sinks were consistent with the trends in vegetation cover. Spatially, the north mining area experienced the most severe vegetation degradation in the early stages, the middle area recovered earliest, and the south area had the fastest vegetation cover recovery rate. Climate factors had a certain influence on vegetation recovery, but precipitation, temperature, and FVC showed no significant correlation. The study indicates that vegetation recovery in mining areas is jointly influenced by mining intensity, climate conditions, and policy interventions, with geological environment management policies in Hunan mining areas playing a key role in promoting vegetation recovery. Full article