The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on th...The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.展开更多
Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadens...Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.展开更多
Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechani...Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechanisms.This study introduced a novel method that leverages the high binding affinity of vancomycin(Van)and ampicillin sodium(Amp)to vegetative cells,integrated with magnetic separation technology,to selectively collect spores from complex environments by eliminating vegetative cells.First,Van/Amp-modified magnetic Fe_(3)O_(4) nanoparticles(Fe_(3)O_(4) NPs)were synthesized and characterized.Subsequently,these NPs bound vegetative cells,forming magnetic conjugates that could be efficiently removed using a magnetic field.Concurrently,spores were collected with an efficiency exceeding 95%,completing the entire process within 30 min and achieving a spore separation efficiency of up to 10^(5) CFU/mL.This method was successfully applied to actual samples,including tap water and milk.The state of the collected spores was confirmed using Raman spectroscopy and microscopic techniques,verifying that their characteristics matched those of typical spores.The proposed novel method for rapid spore separation,leveraging the"remove bacterial effect'facilitated by Van/Amp-Fe_(3)O_(4) NPs,showed outstanding spore collection capabilities while preserving the excellent physiological state of spores.展开更多
[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucid...[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.展开更多
The establishment of plantations has become a critical approach for reducing greenhouse gas emissions,particularly in fragile environments with carbon sequestration potential.In karst areas,plantations based on fastgr...The establishment of plantations has become a critical approach for reducing greenhouse gas emissions,particularly in fragile environments with carbon sequestration potential.In karst areas,plantations based on fastgrowing afforestation species made significant contributions to enhancing carbon sequestration.However,the impact of understory vegetation on carbon accumulation remains unclear.Especially,the carbon accumulation associated with litter produced during the replacement of understory species receives insufficient attention,which leads to the neglect of the carbon sequestration potential in plantations of karst areas.Leaf is a crucial organ that links the litter production.To explore how leaf traits adapt to competitive environments and drive litter carbon accumulation during understory species replacement,this study observed leaf traits and litter carbon content changes in three types of plantations in the Liujiang River Basin,a typical karst area.A total of 37 sampling plots were selected for field investigation over a twoyear period.Leaf traits,species diversity,vegetation coverage,and litter carbon characteristics in understory vegetation were measured.Variance analysis,allometric equations,and path analysis were used for data analysis.The results showed that most understory species adopted a biomass conservation strategy under high-coverage conditions(>44.27%)and expanded competitive leaf area under low-coverage conditions(<44.27%).However,Bidens pilosa and Miscanthus floridulus exhibited strong competitiveness during understory species replacement.They showed an expansion of competitive leaf area under high-coverage conditions.This competitive strategy reduced species diversity and community specific leaf area.But the rapid expansion of Bidens pilosa and Miscanthus floridulus increased understory vegetation coverage,and their increased specific leaf area facilitated leaf shedding,resulting in significant litter weight accumulation(P<0.05),thereby enhancing litter carbon content per unit area.These competitive strategies were key driving factors for the increase in litter carbon content per square meter,which reached a maximum of 49.6% higher than that in natural grasslands.And the maximum increase in litter carbon accumulation derived from understory vegetation reached 3.37 times from 2023 to 2024 in plantations.In the understory vegetation of plantations,the competitive strategies reflected by leaf adaptation of key competitive species are critical factors influencing litter carbon accumulation.Future research could deeply explore the carbon sequestration effects resulting from the dynamic changes in competition within the understory vegetation of plantations.展开更多
Dear Editor,With the growing food demands and the rapid development of intensive vegetable cultivation,the vegetable yield and planting area have increased to 230 million tons and 2.13 million hectares,respectively,in...Dear Editor,With the growing food demands and the rapid development of intensive vegetable cultivation,the vegetable yield and planting area have increased to 230 million tons and 2.13 million hectares,respectively,in China in 2021(MARAPRC,2023).展开更多
The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronou...The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronounced spatiotemporal heterogeneity and fragmented distribution patterns,rendering them highly sensitive to environmental change.This study integrated Sentinel-2 remote sensing imagery with the SedInConnect model to delineate wetland patch distributions and calculate the Index of Connectivity(IC)values across the basin.Based on IC values,we stratified field sampling sites into high-,moderate-,and lowconnectivity gradient groups to analyze the relationships among plant community characteristics,vegetation spatial patterns,and wetland connectivity in the Qaidam Basin.Partial Least Squares Path Modeling(PLSPM)was further employed to quantify the driving mechanisms underlying wetland vegetation characteristics.The results revealed that wetland connectivity across the basin was generally low,with IC values up to 1.32 and displaying a west-to-east decreasing gradient.The west and northwest were characterized by relatively continuous high-connectivity wetland networks,while fragmented and low-connectivity wetlands predominated in the east and southeast.Connectivity regulated wetland vegetation patterns primarily by affecting patch size,fragmentation,and internal adjacency.High-connectivity areas had higher class area(CA),largest patch index(LPI),and area-weighted mean patch size(AREA_AM)than low-connectivity areas.Connectivity had the strongest effect on vegetation coverage,which declined sharply from 87.577%in highconnectivity areas to 12.152%in low-connectivity areas.Meanwhile,species diversity showed a moderately negative response to connectivity changes,whereas species evenness remained relatively unaffected.PLS-PM explained 78.300%and 67.500%of the variance in vegetation community and vegetation pattern,respectively.Climate played a dominant role in shaping vegetation characteristics,with significant negative effects on both vegetation community and pattern.Topography influenced vegetation indirectly through climate,and connectivity was influenced by both drivers and exerted positive effects on vegetation community and pattern.This study reveals the multi-pathway driving mechanisms underlying vegetation pattern formation in alpine wetlands,providing a theoretical foundation and decision-support framework for the scientific conservation and adaptive management of wetlands in the Qaidam Basin.展开更多
Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon ...Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon peaking and neutrality.However,its complex terrain,fragile ecosystem,and variable climate challenge carbon sink stability.Vegetation phenology significantly impacts carbon absorption and release,making accurate phenological data essential for understanding carbon sequestration dynamics.The widespread distribution of evergreen forests and their weak seasonal variation in canopy introduce significant uncertainties in extracting phenology using traditional remote sensing information in this region.These limitations can lead to inaccurate assessments of carbon sink dynamics.Therefore,precise phenology extraction and analysis are vital for improving ecosystem dynamics and the carbon cycle in Southwest China.Firstly,we employed different ways to evaluate the ability of solar-induced chlorophyll fluorescence(SIF)and traditional remote sensing information to extract phenology.Secondly,based on SIF,we analyzed the spatial and temporal changes in the start of the growing season(SOS),the end of the growing season(EOS),and the length of the growing season(LOS)from 2001 to 2020.Finally,we systematically analyzed the response of SOS and EOS to five preseason climatic factors.The results showed that(1)SIF outperformed traditional remote sensing information in extracting phenology.(2)Vegetation phenology exhibited significant spatial heterogeneity.Moreover,SOS,EOS,and LOS showed trends of advancement,delay,and extension both overall and across all vegetation types.(3)Precipitation was the main factor influencing SOS,while surface downward solar radiation and mean temperature were the main factors affecting EOS,and the phenology of different vegetation types showed a great difference in response to preseason climate factors.These findings improve our understanding of vegetation phenology and its dynamics over Southwest China.展开更多
The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based o...The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based on the use of ArcGIS 10.8 software for processing multispectral images,as well as the calculation of the Normalized Difference Vegetation Index(NDVI),which enables the observation of variations in vegetation cover over time.The findings show that biodiversity is pretty abundant,but they also show that some places with low vegetation density are under a lot of stress.Due in large part to overuse of natural resources,uncontrolled human activity,and environmental factors,these regions seem to be more vulnerable to degradation.However,a decrease in deforestation over the past 20 years is revealed by comparing the two periods(1984–2003 and 2003–2022).The participation of governmental agencies,especially the Department of Water and Forests,through concrete projects like reforestation,forest fire prevention,and awareness-raising campaigns among local communities,is responsible for this progress.In several areas,these measures have stabilized or even improved the state of the vegetation.The analysis emphasizes how crucial sustainable,integrated,and participatory management is to protecting the Izarene forest,which is a significant resource for maintaining the region’s ecological balance.展开更多
Leaf thickness in rice critically influences photosynthetic efficiency and yield,yet its genetic basis remains poorly understood,with few functional genes previously characterized.In this study,we employ a pangenome-w...Leaf thickness in rice critically influences photosynthetic efficiency and yield,yet its genetic basis remains poorly understood,with few functional genes previously characterized.In this study,we employ a pangenome-wide association study(Pan-GWAS)on 302 diverse rice accessions from southern China,identifying 49 quantitative trait loci(QTLs)associated with leaf thickness.The most significant locus,qLT9,is fine-mapped to a 79-kb region on chromosome 9.Transcriptomic and genomic sequence analyses identify LOC_Os09g33480,which encodes a protein belonging to Multiple Organellar RNA Editing Factor family,as the key candidate gene.Overexpression and complementation transgenic experiments confirm LOC_Os09g33480(OsLT9)as the functional gene underlying qLT9,demonstrating a 24-bp Indel in its promoter correlates with the expression levels and leaf thickness.Notably,OsLT9 overexpression lines show not only thicker leaf,but also significantly enhanced photosynthetic efficiency and grain yield,establishing a link between leaf thickness modulation and yield enhancement.Population genomic analyses indicate strong selection for OsLT9 during domestication and breeding,with modern cultivars favoring thick leaf haplotype of OsLT9.This study establishes OsLT9 as a key regulator controlling leaf thickness in rice,and provides a valuable genetic resource for molecular breeding of high-yielding rice through optimization of plant architecture.展开更多
Urban forests are essential components of green infrastructure,however,rapid urbanization-induced changes in landscape patterns may affect their ecosystem services through complex ecological processes.A total of 184 s...Urban forests are essential components of green infrastructure,however,rapid urbanization-induced changes in landscape patterns may affect their ecosystem services through complex ecological processes.A total of 184 sample plots in the built-up areas of Nanchang,China,were used as research sites.Urbanization intensities were categorized by the rate of impervious surface area,and forest types were classified into landscape and relaxation forest,attached forest(AF),road forest(RF),and ecological public welfare forest.This study aimed to explore the spatial variations in vegetation characteristics and landscape pattern indices of different forest types under rapid urbanization.The results indicated that the largest patch index(LPI),aggregation index(AI),and percentage of landscape(PLAND)in RF and AF were lower than those in the other forest types(p<0.05).With increasing urbanization intensity,the mean perimeter-area ratio increased by 130.84%,whereas the PLAND,LPI,and AI decreased by 22−86%(p<0.05).Redundancy analysis and variation partitioning suggested that the interpretation rate of landscape pattern indices for variations in vegetation characteristics increased from low to heavy urbanization areas.Especially,the landscape shape index,patch connection index,PLAND,and mean patch size were significantly correlated with vegetation characteristics(e.g.,tree richness,herb coverage,and tree height).In the future,appropriate landscape layout superiority cases should be considered in different urbanization areas and forest types;for instance,increasing the patch connection index will beneficially improve the diversity of trees and herbs in heavy urbanization areas and the RF.This study serves as a reference for maximizing the ecosystem services of urban forests.展开更多
In the arid regions of Northwest China,vegetation cover plays a crucial role in maintaining unique terrestrial ecosystems.Vegetation growth is highly sensitive to variations in topographical factors,and the influence ...In the arid regions of Northwest China,vegetation cover plays a crucial role in maintaining unique terrestrial ecosystems.Vegetation growth is highly sensitive to variations in topographical factors,and the influence of topography on vegetation cover has attracted increasing attention.This study analyzed vegetation dynamics and their relationship with topography in the Tianshan Mountains of China using Landsat Normalized Difference Vegetation Index(NDVI)data during 2000–2022 and Shuttle Radar Topography Mission(SRTM)-derived topographical factors(elevation,slope,and aspect).Theil-Sen slope estimation and Mann-Kendall trend tests were applied to quantify temporal changes in vegetation,while a terrain area correction coefficient(K)was used to assess spatial associations of vegetation with topography.Random Forest(RF)regression and SHapley Additive exPlanations(SHAP)analysis evaluated the relative importance of topographical factors in shaping vegetation cover(multi-year mean NDVI)distribution.Key findings included that over the 23-a period,59.46%of the vegetated area exhibited significant improvement(P<0.05),with the southern Tianshan Mountains showing the most pronounced increase(70.59%),whereas vegetation degradation(3.10%)was primarily concentrated in river valleys with intensive human activities.RF-SHAP analysis revealed that elevation is the primary driver of vegetation cover patterns,explaining 52.00%of the NDVI variation.The peak NDVI(0.42)occurred at elevations between 2800 and 3200 m.Slope and aspect also significantly influenced vegetation distribution,and higher NDVI values and greater improvement trends were observed on shady(north-facing)slopes compared to sunny(south-facing)slopes.K-index analysis indicated pronounced vegetation change—both degradation and improvement—in areas with elevations between 1100 and 2800 m and slopes exceeding 5°,particularly on sunny slopes.Low-elevation desert areas in the southern Tianshan Mountains were highly susceptible to degradation.This study underscores the critical role of topography in regulating vegetation cover and its spatiotemporal dynamics,providing a scientific basis for sustainable management of arid mountain ecosystems.展开更多
[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cul...[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cultivation bases of Guanba Village,Sidu Village,and Banqiao Village in Huichuan District,Zunyi City,were selected as the subjects of this study.The concentrations of five heavy metals,including lead(Pb),mercury(Hg),cadmium(Cd),arsenic(As),and chromium(Cr),were measured at different soil depths.The Nemerow comprehensive pollution index method was employed to assess heavy metal contamination,and the analysis was conducted in accordance with the farmland environmental quality evaluation standards for edible agricultural products.[Results]The concentrations of Cd and As at the sample collection sites were relatively elevated.The pollution level of Cd reached grade III or above,indicating moderate contamination in certain topsoil areas.Most As concentrations corresponded to grade II and grade III pollution levels.In contrast,Hg,Pb,and Cr concentrations remained within the safety standards established for agricultural products.However,Cd and As levels predominantly surpassed these safety thresholds.Notably,Guanba Village and Sidu Village exhibited significant pollution levels,warranting comprehensive investigations into the sources of contamination.[Conclusions]This study offers valuable insights for advancing the sustainable development of local agriculture and for the prevention and management of soil contamination.展开更多
Urbanization alters vegetation productivity by both direct(ωd)and indirect(ω_(i))effects.The direct effect is from the change of vegetated area indicated by impervious surface intensity(ISI),while indirect effects a...Urbanization alters vegetation productivity by both direct(ωd)and indirect(ω_(i))effects.The direct effect is from the change of vegetated area indicated by impervious surface intensity(ISI),while indirect effects arise from changes in urban environmental factors,such as near-surface air temperatures,precipitation,urban heat island(UHI)intensity,and population density(POP).The respective contributions ofω_(d) andω_(i) to vegetation net primary productivity(NPP)under various phases of urbanization are not well quantified.Using multisource remote-sensing data from 1990 to 2020,we analyzed the spatiotemporal variation in urban expansion and the effect thatω_(d) andω_(i) had on NPP in the megalopolis of Beijing,China,over 5-year intervals.During this period,Beijing underwent significant planar expansion rates of about 58.9 km^(2)/yr.Annual mean loss of NPP byω_(d) was estimated to be about 77.1 g C/(m^(2)·yr)during the 1990-2020 period,while annual mean improvement to NPP byω_(i) amounted to an increase of 28.9 g C/(m^(2)·yr).The NPP losses were partially offset by NPP improvements in the order of 18.6%-69.3%.The impact of forcing variables on NPP varied spatially.Air temperature,precipitation,UHI,POP,and ISI explained about 13.8%,23.2%,23.7%,14.7%,and 24.6%of the spatial variation in NPP.The impact of air temperature on NPP was related to available moisture,negatively affecting NPP in regions with water deficits.Our findings demonstrate the dual impact of urbanization on vegetation and underscore the necessity for spatially adaptive ecological management strategies in regions experiencing rapid urban growth.展开更多
Leaf angle is a pivotal agronomic trait that significantly influences crop architecture and yield.Plant hormones,such as auxin,play a critical role in regulating leaf angle;however,the underlying molecular mechanisms ...Leaf angle is a pivotal agronomic trait that significantly influences crop architecture and yield.Plant hormones,such as auxin,play a critical role in regulating leaf angle;however,the underlying molecular mechanisms remain to be fully elucidated.Here,we reveal that the auxin response factor gene,OsARF12,which is highly expressed in the leaf lamina joint,negatively regulates rice(Oryza sativa L.)leaf angle via affecting shoot gravitropism.Overexpression lines of OsARF12 exhibit more erect leaf angles,while the osarf12 mutants display enlarged leaf angles compared to the wild type.Further studies demonstrate that OsARF12 directly activates the expression of Loose Plant Architecture1(LPA1)and LAZY1 by binding to their promoters.The osarf12 mutant presents impaired shoot gravitropism,a phenotype consistent with that of the lpa1 and lazy1 mutants.Collectively,we elucidate the biological functions of OsARF12,which modulates leaf angle through its impact on shoot gravitropism by regulating the expression levels of LPA1 and LAZY1.This study provides insight into the role of auxin in determining rice leaf angle,potentially holding profound effects for the optimization of crop architecture.展开更多
This study investigates the impact of vegetation-climate feedback on the global land monsoon system during the Last Interglacial(LIG,127000 years BP)and the mid-Holocene(MH,6000 years BP)using the earth system model E...This study investigates the impact of vegetation-climate feedback on the global land monsoon system during the Last Interglacial(LIG,127000 years BP)and the mid-Holocene(MH,6000 years BP)using the earth system model EC-Earth3.Our findings indicate that vegetation changes significantly influence the global monsoon area and precipitation patterns,especially in the North African and Indian monsoon regions.The North African monsoon region experienced the most substantial increase in vegetation during both the LIG and MH,resulting in significant increases in monsoonal precipitation by 9.8%and 6.0%,respectively.The vegetation feedback also intensified the Saharan Heat Low,strengthened monsoonal flows,and enhanced precipitation over the North African monsoon region.In contrast,the Indian monsoon region exhibited divergent responses to vegetation changes.During the LIG,precipitation in the Indian monsoon region decreased by 2.2%,while it increased by 1.6%during the MH.These differences highlight the complex and region-specific impacts of vegetation feedback on monsoon systems.Overall,this study demonstrates that vegetation feedback exerts distinct influences on the global monsoon during the MH and LIG.These findings highlight the importance of considering vegetation-climate feedback in understanding past monsoon variability and in predicting future climate change impacts on monsoon systems.展开更多
The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beesw...The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beeswax on the hygroscopic resistance and mechanical stability of PALF.The fibres were functionalised with three formulations(oil,wax,and a 1:2 oil/wax blend)applied at different mass ratios(CR=0.5-2).Treatments increased the average bundle diameter by up to+46%(238μm)and reduced density down to 1.06 g/cm^(3).Hygroscopically,water absorption decreased from 202.4%(raw fibres)to 76.3%(CR=2),representing a maximum reduction of 59.4%in saline medium,while moisture regain dropped from 27.9%to 14.6%(−47.7%).The oil/wax blend proved most effective,simultaneously reducing water absorption(−51.2%)and moisture regain(−46.8%)at CR=1.Mechanically,the fibres retained tensile strength(415.2 vs.460.8 MPa,+11%at CR=1)and exhibited enhanced ductility(+62.5%,with elongation at break increasing from 1.6%to 2.6%),without significantly altering Young’s modulus(12.3 to 10 GPa).Water absorption kinetics were accurately described by the Czel and Mohsenin models(R^(2)>0.98).These findings clearly demonstrate that bio-based lipid coatings can provide an eco-friendly alternative to conventional chemical treatments.They improve hygroscopic resistance and preserve mechanical integrity of PALF,providing original quantitative data for their integration into durable cement-and gypsum-based composites subjected to humid or cyclic wet-dry conditions.展开更多
Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we ...Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we developed the BETR-Urban-Rural-Veg model to quantitatively evaluate the influences of both natural vegetation and crops on the multimedia transport processes of Phenanthrene(PHE)and Benzo(a)pyrene(BaP)in mainland of China.The geographic distribution of polycyclic aromatic hydrocarbon(PAH)emissions and concentrations were consistent,displaying higher levels in northern China while lower levels in southern China.Under seasonal simulations,for both natural vegetation and crops,PAH concentrations in winter and spring were 1.5 to 27-fold higher than in summer and autumn,especially for PHE.Owing to the higher leaf area index(LAI)of natural vegetation and harvesting of crops,the filter and sequestration effect of natural vegetation was stronger than crops,while the seasonal changes of PAH concentrations in crops were more significant than natural vegetation.Temperature,precipitation rates and LAI might have important influences on seasonal concentrations and overall persistence of PAHs.PHE was more sensitive to the impacts of seasonal environmental parameters.Under different landscape scenarios,average annual PAH concentrations in natural vegetation were always a little higher than those in crops,and the overall persistence of BaP was greatly affected increasing by 15.15%-16.47%.This improved model provides a useful tool for environmental management.The results of this study are expected to support land use plans and decision-making in China's mainland.展开更多
The connection between climatic factors and grazing is essential for maintaining ecosystem function and vegetation productivity.This study examined the impact of grazing intensity on vegetation across a broad climatic...The connection between climatic factors and grazing is essential for maintaining ecosystem function and vegetation productivity.This study examined the impact of grazing intensity on vegetation across a broad climatic gradient spanning the Espinal,Argentine Low Monte,and Patagonian Steppe ecoregions of Argentina.The research was carried out at eight sampling sites with radial grazing gradients generated around artificial water sources(piospheres),exhibiting two contrasting response patterns of vegetation to grazing pressure.One of the response patterns shows a typical vegetation response to grazing that the vegetation productivity increases with the distance to the water sources(decreasing grazing intensity).The second pattern is found in drier regions,where vegetation presents an inverse productivity response that vegetation productivity is higher near water sources(high grazing intensity)due to increased shrub cover.Vegetation productivity was measured using the Normalized Difference Vegetation Index(NDVI).Vegetation patch structure and cover were determined for each site with high,medium,and low grazing intensities.Results indicated that shrub cover is the primary driver of vegetation productivity,showing contrasting responses to grazing intensity between the two identified patterns.While NDVI proved to be a reliable proxy for shrub cover and total vegetation cover(R2>0.70),it failed to reflect grass cover dynamics.Furthermore,mean annual temperature was more strongly correlated with vegetation cover changes,while grazing intensity significantly altered vegetation patch structure and soil cover distribution.Specifically,in drier regions,high grazing intensity led to larger patches while,in wetter regions,it led to smaller patches(fragmentation).Shrubs,with their deeper roots and drought tolerance,were less preferred and more resistant to grazing in arid environments and thrived under grazing pressure in these arid conditions.Our results underscored the need for adaptive management strategies in grazing systems.Traditional approaches may require significant adjustments,as the efficacy of management hinges on the interplay of specific climatic conditions and the varied responses of vegetation.Furthermore,effective conservation efforts should prioritize the recognition and protection of shrubs given their critical contribution to ecosystem function and biodiversity.Ultimately,this research provides a valuable framework to understand the complex dynamics between grazing and vegetation in arid and semi-arid environments,highlighting that sustainable grazing practices should be tailored to account for both climatic variables and the unique characteristics of different plant communities.展开更多
The banks in the middle and lower reaches of the Tarim River in China are weak in erosion resistance and prone to collapse.Vegetation,as a natural reinforcement material,can effectively improve slope stability and cur...The banks in the middle and lower reaches of the Tarim River in China are weak in erosion resistance and prone to collapse.Vegetation,as a natural reinforcement material,can effectively improve slope stability and curb soil erosion.In March and July 2023,a field survey was conducted on the types and distribution characteristics of vegetation along both banks of a certain section in the lower reaches of the Tarim River.Taking COMSOL Multiphysics as the finite element numerical simulation platform,we investigated the variation law of bank slope stability in the middle and lower reaches of the Tarim River under different root morphologies,considering changes in transpiration time,rainfall,and water level under the action of hydro-mechanical reinforcement.The findings showed that vegetation transpiration has a significant effect on soil pore water pressure.Given the same transpiration rate,shorter root systems produced greater pore water pressure.For equal root lengths,the pore water pressures generated by roots in exponential and triangular morphologies were significantly greater than those generated by roots in uniformly distributed and parabolic morphologies.The water absorption capacity of the root system increased with transpiration rate.After 7 d of transpiration,the maximum safety factor of the bank slope reinforced by exponential roots was 1.568,which was a 9.88%improvement over that of the bare slope.After 24 h of rainfall,the effect of vegetation transpiration on soil pore water pressure weakened rapidly;the pore water pressure of the surface soil generated by transpiration from vegetation with different root morphologies was concentrated near–10.00 kPa.After rainfall,the displacement of the exponential root reinforced slope was minimized to 0.137 m.The effect of transpiration-induced changes in substrate suction on slope stability was negligible during the rainfall period.Compared with that of the bare slope,the displacements of bank slopes reinforced by root systems significantly increased.The maximum displacement occurred when the water level changed by 1.5 m/d;the displacement of the bare slope was 0.554 m,whereas the displacements of bank slopes reinforced by roots in different morphologies were 0.260–0.273 m.The impact of vegetation transpiration on the safety factor of riverbanks under sudden water level drops was relatively minor,but it can enhance the stability of riverbanks to a certain extent.Among these,riverbanks reinforced by roots in triangular and exponential morphologies exhibited superior stability compared with those reinforced by uniformly distributed or parabolic root systems.The findings offer a theoretical basis and practical guidance for designing vegetation slope protection in the middle and lower reaches of the Tarim River.展开更多
文摘The leafing rates of fourteen rice varieties were measured in a sowing-time experiment, and a rapid leafing genotype at the vegetative growth stage was discovered in an indica variety Yanhui 559. The leaf number on the main culm of Yanhui 559 was always 4-5 leaves more than that of Lemont, and the leafing rate of Yanhui 559 was significantly higher than that of Lemont based on similar growth durations from sowing to heading. Furthermore, the difference of the leafing rate was significant at the vegetative growth stage, but not distinctive at the panicle initiation stage. Genetic analysis of the leafing rates in the two backcross populations of Yanhui 559 and Lemont showed that major and quantitative genes controlled the expression of rapid leafing character. Based on results of investigation for some plants with similar growth durations in the backcrossing populations, the rapid leafing genotypes exhibited earlier tillering and more tiller numbers per plant, and its yield components including the number of panicles per plant and number of grains per panicle were superior to those of the slow leafing genotypes. Further research and application feasibility of the rapid leafing genotype in breeding were discussed.
文摘Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.
基金supported by the General Program of National Natural Science Foundation of China(32472417)the Major Science and Technology Projects in Henan Province(221100110500,231100110400)+2 种基金the Science and Technology Innovation Team of Henan Universities(22IRTSTHN021)the Science and Technology of Henan Province(232102110136)Henan Provincial Joint Fund(Science and Technology Tackling)Category(232103810023).
文摘Bacterial spores commonly co-exist with vegetative cells,presenting challenges in spore separation and detection.The separation of spores is a crucial process for laboratory research and the detection of spore mechanisms.This study introduced a novel method that leverages the high binding affinity of vancomycin(Van)and ampicillin sodium(Amp)to vegetative cells,integrated with magnetic separation technology,to selectively collect spores from complex environments by eliminating vegetative cells.First,Van/Amp-modified magnetic Fe_(3)O_(4) nanoparticles(Fe_(3)O_(4) NPs)were synthesized and characterized.Subsequently,these NPs bound vegetative cells,forming magnetic conjugates that could be efficiently removed using a magnetic field.Concurrently,spores were collected with an efficiency exceeding 95%,completing the entire process within 30 min and achieving a spore separation efficiency of up to 10^(5) CFU/mL.This method was successfully applied to actual samples,including tap water and milk.The state of the collected spores was confirmed using Raman spectroscopy and microscopic techniques,verifying that their characteristics matched those of typical spores.The proposed novel method for rapid spore separation,leveraging the"remove bacterial effect'facilitated by Van/Amp-Fe_(3)O_(4) NPs,showed outstanding spore collection capabilities while preserving the excellent physiological state of spores.
文摘[Objective]Vegetation restoration is an effective strategy for ecological improvement;however,inappropriate vegetation establishment can induce soil desiccation,thereby threatening ecosystem stability.Therefore,elucidating the global response patterns of soil moisture to vegetation restoration and identifying research hotspots are critical for guiding ecological construction in arid regions.[Methods]We reviewed 6,152 articles concerning soil moisture and vegetation retrieved from the Web of Science platform.Using VOSviewer,we conducted analyses of keyword co-occurrence,publication trends,and research hotspots to systematically delineate the evolving trends in this field.[Results]The results indicate a significant increasing trend in the number of publications since 2000.Global research keywords are categorized into seven clusters,including vegetation,soil moisture,rainfall-erosion-infiltration,spatial heterogeneity,and climate change.In terms of highly cited papers in 2024,China and the United States maintain a significant lead.Global research demonstrates a strong dependency on typical regional geographical features(such as climate types and topography),exhibiting differentiated research focuses.Furthermore,studies extend beyond soil moisture itself to deeply couple with ecological processes such as vegetation restoration,soil respiration,carbon cycling,and hydrothermal conditions.[Conclusions]The long-term ecological effects of afforestation in arid regions remain unclear,and empirical data from key regions highlight the current urgency.Future research should integrate climate change dynamics,innovate monitoring methodologies,and deepen the understanding of regional differentiation to provide scientific support for the adaptive management of vegetation in arid regions.
基金supported by the Scientific Research Foundation supported by Yunnan Agricultural University(A3012024035044)International Cooperation and Exchange of the National Natural Science Foundation of China(No.42361144885).
文摘The establishment of plantations has become a critical approach for reducing greenhouse gas emissions,particularly in fragile environments with carbon sequestration potential.In karst areas,plantations based on fastgrowing afforestation species made significant contributions to enhancing carbon sequestration.However,the impact of understory vegetation on carbon accumulation remains unclear.Especially,the carbon accumulation associated with litter produced during the replacement of understory species receives insufficient attention,which leads to the neglect of the carbon sequestration potential in plantations of karst areas.Leaf is a crucial organ that links the litter production.To explore how leaf traits adapt to competitive environments and drive litter carbon accumulation during understory species replacement,this study observed leaf traits and litter carbon content changes in three types of plantations in the Liujiang River Basin,a typical karst area.A total of 37 sampling plots were selected for field investigation over a twoyear period.Leaf traits,species diversity,vegetation coverage,and litter carbon characteristics in understory vegetation were measured.Variance analysis,allometric equations,and path analysis were used for data analysis.The results showed that most understory species adopted a biomass conservation strategy under high-coverage conditions(>44.27%)and expanded competitive leaf area under low-coverage conditions(<44.27%).However,Bidens pilosa and Miscanthus floridulus exhibited strong competitiveness during understory species replacement.They showed an expansion of competitive leaf area under high-coverage conditions.This competitive strategy reduced species diversity and community specific leaf area.But the rapid expansion of Bidens pilosa and Miscanthus floridulus increased understory vegetation coverage,and their increased specific leaf area facilitated leaf shedding,resulting in significant litter weight accumulation(P<0.05),thereby enhancing litter carbon content per unit area.These competitive strategies were key driving factors for the increase in litter carbon content per square meter,which reached a maximum of 49.6% higher than that in natural grasslands.And the maximum increase in litter carbon accumulation derived from understory vegetation reached 3.37 times from 2023 to 2024 in plantations.In the understory vegetation of plantations,the competitive strategies reflected by leaf adaptation of key competitive species are critical factors influencing litter carbon accumulation.Future research could deeply explore the carbon sequestration effects resulting from the dynamic changes in competition within the understory vegetation of plantations.
基金supported by the Science and Technology Planning Social Development Project of Zhenjiang City,China(No.SH2017045)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(No.SJCX23_2065)。
文摘Dear Editor,With the growing food demands and the rapid development of intensive vegetable cultivation,the vegetable yield and planting area have increased to 230 million tons and 2.13 million hectares,respectively,in China in 2021(MARAPRC,2023).
基金funded by the National Natural Science Foundation of China(42230720)the 2023 Annual Qinghai Province"Kunlun Talents-High-end Innovation and Entrepreneurship Talent"Program Project.
文摘The Qaidam Basin,a typical alpine arid inland basin on the northern Qinghai-Xizang Plateau,China,hosts wetland ecosystems that are strongly constrained by topography and extreme climate.These ecosystems exhibit pronounced spatiotemporal heterogeneity and fragmented distribution patterns,rendering them highly sensitive to environmental change.This study integrated Sentinel-2 remote sensing imagery with the SedInConnect model to delineate wetland patch distributions and calculate the Index of Connectivity(IC)values across the basin.Based on IC values,we stratified field sampling sites into high-,moderate-,and lowconnectivity gradient groups to analyze the relationships among plant community characteristics,vegetation spatial patterns,and wetland connectivity in the Qaidam Basin.Partial Least Squares Path Modeling(PLSPM)was further employed to quantify the driving mechanisms underlying wetland vegetation characteristics.The results revealed that wetland connectivity across the basin was generally low,with IC values up to 1.32 and displaying a west-to-east decreasing gradient.The west and northwest were characterized by relatively continuous high-connectivity wetland networks,while fragmented and low-connectivity wetlands predominated in the east and southeast.Connectivity regulated wetland vegetation patterns primarily by affecting patch size,fragmentation,and internal adjacency.High-connectivity areas had higher class area(CA),largest patch index(LPI),and area-weighted mean patch size(AREA_AM)than low-connectivity areas.Connectivity had the strongest effect on vegetation coverage,which declined sharply from 87.577%in highconnectivity areas to 12.152%in low-connectivity areas.Meanwhile,species diversity showed a moderately negative response to connectivity changes,whereas species evenness remained relatively unaffected.PLS-PM explained 78.300%and 67.500%of the variance in vegetation community and vegetation pattern,respectively.Climate played a dominant role in shaping vegetation characteristics,with significant negative effects on both vegetation community and pattern.Topography influenced vegetation indirectly through climate,and connectivity was influenced by both drivers and exerted positive effects on vegetation community and pattern.This study reveals the multi-pathway driving mechanisms underlying vegetation pattern formation in alpine wetlands,providing a theoretical foundation and decision-support framework for the scientific conservation and adaptive management of wetlands in the Qaidam Basin.
基金supported by the National Natural Science Foundation of China[Grant NO.42401465 and 42401464]Yunnan Fundamental Research Projects[Grant NO.202501AT070343,202401AU070169 and 202401CF070161]+1 种基金Natural Science Fund of Kunming University of Science and Technology(KKZ3202421125)Yunnan Provincial Talent Project“High-level Talent Training Support Plan”[YNWR-QNBJ-2020-031]。
文摘Accurate phenological information is essential for measuring ecosystem dynamics and carbon uptake.Southwest China is one of the country's largest terrestrial carbon sink regions and plays a crucial role in carbon peaking and neutrality.However,its complex terrain,fragile ecosystem,and variable climate challenge carbon sink stability.Vegetation phenology significantly impacts carbon absorption and release,making accurate phenological data essential for understanding carbon sequestration dynamics.The widespread distribution of evergreen forests and their weak seasonal variation in canopy introduce significant uncertainties in extracting phenology using traditional remote sensing information in this region.These limitations can lead to inaccurate assessments of carbon sink dynamics.Therefore,precise phenology extraction and analysis are vital for improving ecosystem dynamics and the carbon cycle in Southwest China.Firstly,we employed different ways to evaluate the ability of solar-induced chlorophyll fluorescence(SIF)and traditional remote sensing information to extract phenology.Secondly,based on SIF,we analyzed the spatial and temporal changes in the start of the growing season(SOS),the end of the growing season(EOS),and the length of the growing season(LOS)from 2001 to 2020.Finally,we systematically analyzed the response of SOS and EOS to five preseason climatic factors.The results showed that(1)SIF outperformed traditional remote sensing information in extracting phenology.(2)Vegetation phenology exhibited significant spatial heterogeneity.Moreover,SOS,EOS,and LOS showed trends of advancement,delay,and extension both overall and across all vegetation types.(3)Precipitation was the main factor influencing SOS,while surface downward solar radiation and mean temperature were the main factors affecting EOS,and the phenology of different vegetation types showed a great difference in response to preseason climate factors.These findings improve our understanding of vegetation phenology and its dynamics over Southwest China.
文摘The study presents an analysis of the spatiotemporal evolution of vegetation cover in the Izarene forest,using LANDSAT satellite images collected for the years 1984,2003,and 2022.The methodological approach is based on the use of ArcGIS 10.8 software for processing multispectral images,as well as the calculation of the Normalized Difference Vegetation Index(NDVI),which enables the observation of variations in vegetation cover over time.The findings show that biodiversity is pretty abundant,but they also show that some places with low vegetation density are under a lot of stress.Due in large part to overuse of natural resources,uncontrolled human activity,and environmental factors,these regions seem to be more vulnerable to degradation.However,a decrease in deforestation over the past 20 years is revealed by comparing the two periods(1984–2003 and 2003–2022).The participation of governmental agencies,especially the Department of Water and Forests,through concrete projects like reforestation,forest fire prevention,and awareness-raising campaigns among local communities,is responsible for this progress.In several areas,these measures have stabilized or even improved the state of the vegetation.The analysis emphasizes how crucial sustainable,integrated,and participatory management is to protecting the Izarene forest,which is a significant resource for maintaining the region’s ecological balance.
基金supported by the National Natural Science Foundation of China(32301845)GuangDong Basic and Applied Basic Research Foundation(2022A1515012339)+3 种基金the National Key R&D Program of China(2024YFD1200801)Seed industry revitalization project of special fund for rural revitalization strategy in Guangdong Province(2024-NPY-00-001)Modern Seed Industry Innovation Capacity Enhancement Progject of Guangdong Academy of Agricultural Sciences,Elite Rice Plan of GDRRI(2023YG01)Guangdong Key Laboratory of Rice Science and Technology(2023B1212060042).
文摘Leaf thickness in rice critically influences photosynthetic efficiency and yield,yet its genetic basis remains poorly understood,with few functional genes previously characterized.In this study,we employ a pangenome-wide association study(Pan-GWAS)on 302 diverse rice accessions from southern China,identifying 49 quantitative trait loci(QTLs)associated with leaf thickness.The most significant locus,qLT9,is fine-mapped to a 79-kb region on chromosome 9.Transcriptomic and genomic sequence analyses identify LOC_Os09g33480,which encodes a protein belonging to Multiple Organellar RNA Editing Factor family,as the key candidate gene.Overexpression and complementation transgenic experiments confirm LOC_Os09g33480(OsLT9)as the functional gene underlying qLT9,demonstrating a 24-bp Indel in its promoter correlates with the expression levels and leaf thickness.Notably,OsLT9 overexpression lines show not only thicker leaf,but also significantly enhanced photosynthetic efficiency and grain yield,establishing a link between leaf thickness modulation and yield enhancement.Population genomic analyses indicate strong selection for OsLT9 during domestication and breeding,with modern cultivars favoring thick leaf haplotype of OsLT9.This study establishes OsLT9 as a key regulator controlling leaf thickness in rice,and provides a valuable genetic resource for molecular breeding of high-yielding rice through optimization of plant architecture.
基金supported by the National Natural Science Foundation of China(32460380,42007042)State Key Laboratory of Subtropical Silviculture(SKLSSKF2023-06)+2 种基金Natural Science Foundation of Jiangxi Province(20242BAB25389)National Undergraduate Innovation and Entrepreneurship Training Program(202410410029X)Jiangxi Province Graduate Student Innovation Special Fund Project(YC2024-S330).
文摘Urban forests are essential components of green infrastructure,however,rapid urbanization-induced changes in landscape patterns may affect their ecosystem services through complex ecological processes.A total of 184 sample plots in the built-up areas of Nanchang,China,were used as research sites.Urbanization intensities were categorized by the rate of impervious surface area,and forest types were classified into landscape and relaxation forest,attached forest(AF),road forest(RF),and ecological public welfare forest.This study aimed to explore the spatial variations in vegetation characteristics and landscape pattern indices of different forest types under rapid urbanization.The results indicated that the largest patch index(LPI),aggregation index(AI),and percentage of landscape(PLAND)in RF and AF were lower than those in the other forest types(p<0.05).With increasing urbanization intensity,the mean perimeter-area ratio increased by 130.84%,whereas the PLAND,LPI,and AI decreased by 22−86%(p<0.05).Redundancy analysis and variation partitioning suggested that the interpretation rate of landscape pattern indices for variations in vegetation characteristics increased from low to heavy urbanization areas.Especially,the landscape shape index,patch connection index,PLAND,and mean patch size were significantly correlated with vegetation characteristics(e.g.,tree richness,herb coverage,and tree height).In the future,appropriate landscape layout superiority cases should be considered in different urbanization areas and forest types;for instance,increasing the patch connection index will beneficially improve the diversity of trees and herbs in heavy urbanization areas and the RF.This study serves as a reference for maximizing the ecosystem services of urban forests.
基金supported by the National Key R&D Program of China(2023YFE0207900)。
文摘In the arid regions of Northwest China,vegetation cover plays a crucial role in maintaining unique terrestrial ecosystems.Vegetation growth is highly sensitive to variations in topographical factors,and the influence of topography on vegetation cover has attracted increasing attention.This study analyzed vegetation dynamics and their relationship with topography in the Tianshan Mountains of China using Landsat Normalized Difference Vegetation Index(NDVI)data during 2000–2022 and Shuttle Radar Topography Mission(SRTM)-derived topographical factors(elevation,slope,and aspect).Theil-Sen slope estimation and Mann-Kendall trend tests were applied to quantify temporal changes in vegetation,while a terrain area correction coefficient(K)was used to assess spatial associations of vegetation with topography.Random Forest(RF)regression and SHapley Additive exPlanations(SHAP)analysis evaluated the relative importance of topographical factors in shaping vegetation cover(multi-year mean NDVI)distribution.Key findings included that over the 23-a period,59.46%of the vegetated area exhibited significant improvement(P<0.05),with the southern Tianshan Mountains showing the most pronounced increase(70.59%),whereas vegetation degradation(3.10%)was primarily concentrated in river valleys with intensive human activities.RF-SHAP analysis revealed that elevation is the primary driver of vegetation cover patterns,explaining 52.00%of the NDVI variation.The peak NDVI(0.42)occurred at elevations between 2800 and 3200 m.Slope and aspect also significantly influenced vegetation distribution,and higher NDVI values and greater improvement trends were observed on shady(north-facing)slopes compared to sunny(south-facing)slopes.K-index analysis indicated pronounced vegetation change—both degradation and improvement—in areas with elevations between 1100 and 2800 m and slopes exceeding 5°,particularly on sunny slopes.Low-elevation desert areas in the southern Tianshan Mountains were highly susceptible to degradation.This study underscores the critical role of topography in regulating vegetation cover and its spatiotemporal dynamics,providing a scientific basis for sustainable management of arid mountain ecosystems.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program of Guizhou Province(2024106640823)Natural Science Research Project of Guizhou Provincial Department of Education(QJJ[2023]043)Zunyi Science and Technology Innovation Team Project(ZKCTD008).
文摘[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cultivation bases of Guanba Village,Sidu Village,and Banqiao Village in Huichuan District,Zunyi City,were selected as the subjects of this study.The concentrations of five heavy metals,including lead(Pb),mercury(Hg),cadmium(Cd),arsenic(As),and chromium(Cr),were measured at different soil depths.The Nemerow comprehensive pollution index method was employed to assess heavy metal contamination,and the analysis was conducted in accordance with the farmland environmental quality evaluation standards for edible agricultural products.[Results]The concentrations of Cd and As at the sample collection sites were relatively elevated.The pollution level of Cd reached grade III or above,indicating moderate contamination in certain topsoil areas.Most As concentrations corresponded to grade II and grade III pollution levels.In contrast,Hg,Pb,and Cr concentrations remained within the safety standards established for agricultural products.However,Cd and As levels predominantly surpassed these safety thresholds.Notably,Guanba Village and Sidu Village exhibited significant pollution levels,warranting comprehensive investigations into the sources of contamination.[Conclusions]This study offers valuable insights for advancing the sustainable development of local agriculture and for the prevention and management of soil contamination.
基金supported by the National Key Research and Develop-ment Program of China(No.2020YFA0608100)the National Nat-ural Science Foundation of China(Nos.32071842 and 32101588).
文摘Urbanization alters vegetation productivity by both direct(ωd)and indirect(ω_(i))effects.The direct effect is from the change of vegetated area indicated by impervious surface intensity(ISI),while indirect effects arise from changes in urban environmental factors,such as near-surface air temperatures,precipitation,urban heat island(UHI)intensity,and population density(POP).The respective contributions ofω_(d) andω_(i) to vegetation net primary productivity(NPP)under various phases of urbanization are not well quantified.Using multisource remote-sensing data from 1990 to 2020,we analyzed the spatiotemporal variation in urban expansion and the effect thatω_(d) andω_(i) had on NPP in the megalopolis of Beijing,China,over 5-year intervals.During this period,Beijing underwent significant planar expansion rates of about 58.9 km^(2)/yr.Annual mean loss of NPP byω_(d) was estimated to be about 77.1 g C/(m^(2)·yr)during the 1990-2020 period,while annual mean improvement to NPP byω_(i) amounted to an increase of 28.9 g C/(m^(2)·yr).The NPP losses were partially offset by NPP improvements in the order of 18.6%-69.3%.The impact of forcing variables on NPP varied spatially.Air temperature,precipitation,UHI,POP,and ISI explained about 13.8%,23.2%,23.7%,14.7%,and 24.6%of the spatial variation in NPP.The impact of air temperature on NPP was related to available moisture,negatively affecting NPP in regions with water deficits.Our findings demonstrate the dual impact of urbanization on vegetation and underscore the necessity for spatially adaptive ecological management strategies in regions experiencing rapid urban growth.
基金funded by the National Natural Science Foundation of China(31871592)the Fundamental Research Funds for the Central Universities(2042022kf0015)+1 种基金the Creative Research Groups of the Natural Science Foundation of Hubei Province(2020CFA009)the Project for Technology Innovation of Hubei Province(2024BBA005).
文摘Leaf angle is a pivotal agronomic trait that significantly influences crop architecture and yield.Plant hormones,such as auxin,play a critical role in regulating leaf angle;however,the underlying molecular mechanisms remain to be fully elucidated.Here,we reveal that the auxin response factor gene,OsARF12,which is highly expressed in the leaf lamina joint,negatively regulates rice(Oryza sativa L.)leaf angle via affecting shoot gravitropism.Overexpression lines of OsARF12 exhibit more erect leaf angles,while the osarf12 mutants display enlarged leaf angles compared to the wild type.Further studies demonstrate that OsARF12 directly activates the expression of Loose Plant Architecture1(LPA1)and LAZY1 by binding to their promoters.The osarf12 mutant presents impaired shoot gravitropism,a phenotype consistent with that of the lpa1 and lazy1 mutants.Collectively,we elucidate the biological functions of OsARF12,which modulates leaf angle through its impact on shoot gravitropism by regulating the expression levels of LPA1 and LAZY1.This study provides insight into the role of auxin in determining rice leaf angle,potentially holding profound effects for the optimization of crop architecture.
基金supported by the Swedish Research Council(Vetenskapsradet,Grant No.202203129)the Project of Youth Science and Technology Fund of Gansu Province(Grant No.24JRRA439)partially funded by the Swedish Research Council(Vetenskapsradet,Grant No.2022-06725)。
文摘This study investigates the impact of vegetation-climate feedback on the global land monsoon system during the Last Interglacial(LIG,127000 years BP)and the mid-Holocene(MH,6000 years BP)using the earth system model EC-Earth3.Our findings indicate that vegetation changes significantly influence the global monsoon area and precipitation patterns,especially in the North African and Indian monsoon regions.The North African monsoon region experienced the most substantial increase in vegetation during both the LIG and MH,resulting in significant increases in monsoonal precipitation by 9.8%and 6.0%,respectively.The vegetation feedback also intensified the Saharan Heat Low,strengthened monsoonal flows,and enhanced precipitation over the North African monsoon region.In contrast,the Indian monsoon region exhibited divergent responses to vegetation changes.During the LIG,precipitation in the Indian monsoon region decreased by 2.2%,while it increased by 1.6%during the MH.These differences highlight the complex and region-specific impacts of vegetation feedback on monsoon systems.Overall,this study demonstrates that vegetation feedback exerts distinct influences on the global monsoon during the MH and LIG.These findings highlight the importance of considering vegetation-climate feedback in understanding past monsoon variability and in predicting future climate change impacts on monsoon systems.
文摘The high hydrophilicity of pineapple leaf fibres(PALF)limits their use in cement-and gypsum-based composites exposed to moisture.This study evaluates,for the first time,the combined effect of palm kernel oil and beeswax on the hygroscopic resistance and mechanical stability of PALF.The fibres were functionalised with three formulations(oil,wax,and a 1:2 oil/wax blend)applied at different mass ratios(CR=0.5-2).Treatments increased the average bundle diameter by up to+46%(238μm)and reduced density down to 1.06 g/cm^(3).Hygroscopically,water absorption decreased from 202.4%(raw fibres)to 76.3%(CR=2),representing a maximum reduction of 59.4%in saline medium,while moisture regain dropped from 27.9%to 14.6%(−47.7%).The oil/wax blend proved most effective,simultaneously reducing water absorption(−51.2%)and moisture regain(−46.8%)at CR=1.Mechanically,the fibres retained tensile strength(415.2 vs.460.8 MPa,+11%at CR=1)and exhibited enhanced ductility(+62.5%,with elongation at break increasing from 1.6%to 2.6%),without significantly altering Young’s modulus(12.3 to 10 GPa).Water absorption kinetics were accurately described by the Czel and Mohsenin models(R^(2)>0.98).These findings clearly demonstrate that bio-based lipid coatings can provide an eco-friendly alternative to conventional chemical treatments.They improve hygroscopic resistance and preserve mechanical integrity of PALF,providing original quantitative data for their integration into durable cement-and gypsum-based composites subjected to humid or cyclic wet-dry conditions.
基金supported by the National Natural Science Foundation of China(Nos.42107420,U23A20157,and U1910207)Shanxi Province Science Foundation for Young Scholars(No.20210302124363).
文摘Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we developed the BETR-Urban-Rural-Veg model to quantitatively evaluate the influences of both natural vegetation and crops on the multimedia transport processes of Phenanthrene(PHE)and Benzo(a)pyrene(BaP)in mainland of China.The geographic distribution of polycyclic aromatic hydrocarbon(PAH)emissions and concentrations were consistent,displaying higher levels in northern China while lower levels in southern China.Under seasonal simulations,for both natural vegetation and crops,PAH concentrations in winter and spring were 1.5 to 27-fold higher than in summer and autumn,especially for PHE.Owing to the higher leaf area index(LAI)of natural vegetation and harvesting of crops,the filter and sequestration effect of natural vegetation was stronger than crops,while the seasonal changes of PAH concentrations in crops were more significant than natural vegetation.Temperature,precipitation rates and LAI might have important influences on seasonal concentrations and overall persistence of PAHs.PHE was more sensitive to the impacts of seasonal environmental parameters.Under different landscape scenarios,average annual PAH concentrations in natural vegetation were always a little higher than those in crops,and the overall persistence of BaP was greatly affected increasing by 15.15%-16.47%.This improved model provides a useful tool for environmental management.The results of this study are expected to support land use plans and decision-making in China's mainland.
基金supported by the Universidad Nacional de Río Negro(PI-UNRN 40C-1088)the Consejo Nacional de Investigaciones Científicas y Técnicas(PIP-CONICET 2023-402).
文摘The connection between climatic factors and grazing is essential for maintaining ecosystem function and vegetation productivity.This study examined the impact of grazing intensity on vegetation across a broad climatic gradient spanning the Espinal,Argentine Low Monte,and Patagonian Steppe ecoregions of Argentina.The research was carried out at eight sampling sites with radial grazing gradients generated around artificial water sources(piospheres),exhibiting two contrasting response patterns of vegetation to grazing pressure.One of the response patterns shows a typical vegetation response to grazing that the vegetation productivity increases with the distance to the water sources(decreasing grazing intensity).The second pattern is found in drier regions,where vegetation presents an inverse productivity response that vegetation productivity is higher near water sources(high grazing intensity)due to increased shrub cover.Vegetation productivity was measured using the Normalized Difference Vegetation Index(NDVI).Vegetation patch structure and cover were determined for each site with high,medium,and low grazing intensities.Results indicated that shrub cover is the primary driver of vegetation productivity,showing contrasting responses to grazing intensity between the two identified patterns.While NDVI proved to be a reliable proxy for shrub cover and total vegetation cover(R2>0.70),it failed to reflect grass cover dynamics.Furthermore,mean annual temperature was more strongly correlated with vegetation cover changes,while grazing intensity significantly altered vegetation patch structure and soil cover distribution.Specifically,in drier regions,high grazing intensity led to larger patches while,in wetter regions,it led to smaller patches(fragmentation).Shrubs,with their deeper roots and drought tolerance,were less preferred and more resistant to grazing in arid environments and thrived under grazing pressure in these arid conditions.Our results underscored the need for adaptive management strategies in grazing systems.Traditional approaches may require significant adjustments,as the efficacy of management hinges on the interplay of specific climatic conditions and the varied responses of vegetation.Furthermore,effective conservation efforts should prioritize the recognition and protection of shrubs given their critical contribution to ecosystem function and biodiversity.Ultimately,this research provides a valuable framework to understand the complex dynamics between grazing and vegetation in arid and semi-arid environments,highlighting that sustainable grazing practices should be tailored to account for both climatic variables and the unique characteristics of different plant communities.
基金funded by the Key Research and Development Projects in Xinjiang Uygur Autonomous Region(2022B03024-3)the Xinjiang Uygur Autonomous Region Central Leading Local Science and Technology Development Fund Project(ZYYD2024CG20)the Autonomous Region'Tianshan Talents'Training Program Young Top Talents Project(2023TSYCJU0007).
文摘The banks in the middle and lower reaches of the Tarim River in China are weak in erosion resistance and prone to collapse.Vegetation,as a natural reinforcement material,can effectively improve slope stability and curb soil erosion.In March and July 2023,a field survey was conducted on the types and distribution characteristics of vegetation along both banks of a certain section in the lower reaches of the Tarim River.Taking COMSOL Multiphysics as the finite element numerical simulation platform,we investigated the variation law of bank slope stability in the middle and lower reaches of the Tarim River under different root morphologies,considering changes in transpiration time,rainfall,and water level under the action of hydro-mechanical reinforcement.The findings showed that vegetation transpiration has a significant effect on soil pore water pressure.Given the same transpiration rate,shorter root systems produced greater pore water pressure.For equal root lengths,the pore water pressures generated by roots in exponential and triangular morphologies were significantly greater than those generated by roots in uniformly distributed and parabolic morphologies.The water absorption capacity of the root system increased with transpiration rate.After 7 d of transpiration,the maximum safety factor of the bank slope reinforced by exponential roots was 1.568,which was a 9.88%improvement over that of the bare slope.After 24 h of rainfall,the effect of vegetation transpiration on soil pore water pressure weakened rapidly;the pore water pressure of the surface soil generated by transpiration from vegetation with different root morphologies was concentrated near–10.00 kPa.After rainfall,the displacement of the exponential root reinforced slope was minimized to 0.137 m.The effect of transpiration-induced changes in substrate suction on slope stability was negligible during the rainfall period.Compared with that of the bare slope,the displacements of bank slopes reinforced by root systems significantly increased.The maximum displacement occurred when the water level changed by 1.5 m/d;the displacement of the bare slope was 0.554 m,whereas the displacements of bank slopes reinforced by roots in different morphologies were 0.260–0.273 m.The impact of vegetation transpiration on the safety factor of riverbanks under sudden water level drops was relatively minor,but it can enhance the stability of riverbanks to a certain extent.Among these,riverbanks reinforced by roots in triangular and exponential morphologies exhibited superior stability compared with those reinforced by uniformly distributed or parabolic root systems.The findings offer a theoretical basis and practical guidance for designing vegetation slope protection in the middle and lower reaches of the Tarim River.
