The study examined the impact of land reclamation on vegetal cover in Bayelsa State.For the purpose of this study,both quantitative and qualitative research methods were adopted.Field observations,questionnaire ...The study examined the impact of land reclamation on vegetal cover in Bayelsa State.For the purpose of this study,both quantitative and qualitative research methods were adopted.Field observations,questionnaire survey and landsat imagery of land cover changes in the year 1986 and 2018 were generated from the global ground cover facility stream.The time series study design and supervised classification of the image processing were adopted to determine the impact of land reclamation on vegetal cover of the study area.It was therefore recommended that recovery of land will make strategic urban planning initiatives sustainable in overcrowded areas and institutions should also put in place laws and strategies to regulate reclamation activities across the region and also geo-spatial skills should be put in place to help quantify the dynamics,trends and rate of reclamation induced land cover change in the environment.展开更多
The effect of slope gradient and vegetal cover on soil infiltration and erosion were studied with field simulator. Results showed that infiltration decreases with slope gradients (especially for gradient less than 10&...The effect of slope gradient and vegetal cover on soil infiltration and erosion were studied with field simulator. Results showed that infiltration decreases with slope gradients (especially for gradient less than 10°) and increases with vegetal covers, while soil erosion increases with slope gradients and decreases with vegetal covers. Fittlng the data by Philip's infiltration equation it was found that in the equation, gravitational conductivity decreases with gradient and increases with vegetation, while diffusion decreases with vegetal cover and does not vary with slope gradient In the erosion process, the formation of a layer of thin water is crucial in dctermining the rainsplash and sheetwash. The increasing of erosion with slope gradient contributes mainly to the increase of velocity.展开更多
Timing of vegetal-endodermal cell determination in amphioxus embryos remains uncertain. We tentatively testal effects of A23187, the calcium ionophore, on the deveopment of vegetal blastomeres isolated at the 16-cell ...Timing of vegetal-endodermal cell determination in amphioxus embryos remains uncertain. We tentatively testal effects of A23187, the calcium ionophore, on the deveopment of vegetal blastomeres isolated at the 16-cell stage. It was found that when vegetal blastomres committed to endodermwere treated with A23187 prior to gastrulation, they were transformed into ectodermal cells as evidenced by the cell morphology and function characteristic of epidermis. Howver, the developmental fate of the sam blastomeres untreated or treated with DMSO at the same stage or of those treated with A23187 after gastrulation remained unchanged. Thus, vegetal-endodermal cells in amphioxus embryos are not irreversibly deermined before the gastrula stage, and artificial incarease in intracelluar Ca2+ concentration can induce transdetermination of the predetermined endodermal cells into ectodermal cells.展开更多
Since the reform and opening-up,there has been a great change in spatial pattern of China's vegetable production. This paper studied vegetable production in provinces of China in 1978- 2013. From the sequential ch...Since the reform and opening-up,there has been a great change in spatial pattern of China's vegetable production. This paper studied vegetable production in provinces of China in 1978- 2013. From the sequential characteristics,China's vegetable production area is constantly growing and takes on stage characteristic. From the spatial distribution,China's vegetable production takes on the trend of " going down the south" and " marching the west". In order to grasp rules of changes of vegetable production and the influence factors,this paper made theoretical and empirical analysis on factors possibly influencing distribution of vegetable production. Results show that major factors influencing distribution of China's vegetable production include irrigation condition,non-agricultural employment,market demand,knowledge spillover,comparative effectiveness,rural road and government policies.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
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
Objective:To determine the chemical constituents of the traditional vegetal salts and find out if they are safe to consume.Methods:Seven different salts have been obtained from three provinces,of which five belong to ...Objective:To determine the chemical constituents of the traditional vegetal salts and find out if they are safe to consume.Methods:Seven different salts have been obtained from three provinces,of which five belong to Morobe Province.The cations were determined using inductively coupled plasma atomic emission spectroscopy and anions using titrimetry,gravimetry and spectrophotometry.Others like solubility,electrical conductivity,pH,antimicrobial,Fourier transform infrared spectral and volatility studies have been carried out for these salts.Results:While few salts were found to be stable,others were deliquescent;and the colour varies from white to black through yellow and brown.It was found that the potassium ion was dominant while others including sodium and calcium were found in lower concentrations.For the first time,certain d-block metal concentrations were measured though most of them were found to be present at very low levels.Other parameters like volatility,solubility,electrical conductivity,antimicrobial and Fourier transform infrared spectral studies were carried out for the first time for these vegetal salts in Papua New Guinea.Conclusions:The salt’s deliquescence could be correlated to the presence of anions like carbonate,bicarbonate and hydroxide which strongly contribute towards it.Similarly,solubility and conductivity of the salts could be correlated well.The salts were found to be harmless for consumption,but for the high potassium content.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
Suancai has a lengthy history and a wide range of categories,which has some influence on the pickled diet culture around the world.Suancai production is transitioning to a large-scale,standardized production due to th...Suancai has a lengthy history and a wide range of categories,which has some influence on the pickled diet culture around the world.Suancai production is transitioning to a large-scale,standardized production due to the growth of the market.It has a unique flavor and is rich in nutrients,and its abundance of free amino acids,vitamins and phenolics has many positive effects on the human body.This review gives the types and history of suancai,as well as its impact on the world’s pickled culture.The changes in nutritional composition and flavor of suancai during fermentation are summarized.It presented the production technology and influencing factors of the northeast suancai,examined the quality and safety issues in suancai,and put forth some ideas and opinions on the standardization development of the suancai industry.It also summarized the geographic distribution and flora diversity of pickles around the world.In order to provide some knowledge and guidance for the promotion of modern industrial production in the suancai industry.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
As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical ...As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical traits.Although extensive research has been conducted on light-mediated growth regulation in horticultural crops,most reviews focus primarily on leafy and fruiting vegetables,with limited attention given to berry crops such as strawberries.Additionally,most existing reviews concentrate on one or several growth stages,failing to systematically characterize light’s effects throughout the entire growth cycle and postharvest stage.This review briefly summarizes the regulatory roles of light across key stages of strawberry growth,including seedling propagation,vegetative growth,reproductive growth,and postharvest stages.It seeks to address the knowledge gap by systematically organizing research findings across these developmental phases.The integrated analysis provides a theoretical foundation for designing stage-specific lighting strategies to improve strawberry yield and quality.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
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
Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has b...Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has been limited.This study quantified the impacts of chilling(CS,22/14℃,day/night temperature),heat(HS,38/30℃),drought(DS,50%irrigation of the control),and salt(SS,8 d S m-1)stresses on pigments,physiology,growth,and development of 14 upland cotton cultivars under ambient CO_(2)(aCO_(2),420 ppm;current)and eCO_(2)(700 ppm;future)levels during the vegetative stage.The eCO_(2)partially negated the effects of all stresses by improving one or more of the pigments,physiological,growth,and development traits,except CS.For instance,HS at aCO_(2)significantly increased stomatal conductance by 36%compared with non-stressed plants at aCO_(2).However,HS at eCO_(2)significantly decreased stomatal conductance by 18%compared with HS at aCO_(2).The first squaring was delayed by one day under SS at aCO_(2)but two days earlier under SS at eCO_(2)than non-stressed plants at aCO_(2).Root and shoot dry mass and the total leaf area were significantly higher under all stresses,except for CS,at the eCO_(2)compared with similar stresses at the aCO_(2).Most growth and development traits,including plant height,leaf area,and shoot dry mass,displayed a mirroring response pattern between aCO_(2)and eCO_(2)under all environments except CS.Cultivars exhibited significant interaction with stressed environments.Further,results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO_(2)levels.This study highlights the need to consider eCO_(2)in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.展开更多
Climate change is altering vegetation phenology,differentially affecting food quality and availability for the gosling development(and therefore fitness)of migratory herbivores,especially those experiencing range cont...Climate change is altering vegetation phenology,differentially affecting food quality and availability for the gosling development(and therefore fitness)of migratory herbivores,especially those experiencing range contraction and fragmentation.By quantifying the climate-vegetation nexus for two waterbird species of contrasting conservation status,we assessed the differential implications of climate change in semi-arid landscapes for gosling development windows in different parts of their mid-latitude breeding ranges.We defined breeding ranges using telemetry data from 663 summering tracks of tagged Swan Geese(Anser cygnoides)and Greylag Geese(A.anser)breeding across the Mongolian Plateau.Within these areas,we systematically analyzed spatiotemporal variations in vegetation phenology based on MODIS NDVI datasets from 2000 to 2024 and their response to climate factors.Combining the above data,we demonstrated synchrony between goose breeding phenology and vegetation phenological indices:gosling hatching coincided with the start of growing season(SOS),autumn migration initiation with the end of growing season(EOS).We determined temporal and geographical variation in vegetation SOS,EOS and the length of growing season(LOS=EOS-SOS)as a proxy for gosling development windows across the Mongolian Plateau.Mean LOS was 107±13 days,generally sufficient for gosling development(c.113 days),but showed spatial heterogeneity,increasing in the west but shortening in the east of Mongolian Plateau.SOS was delayed with higher land surface temperature and lower precipitation/aridity in central/eastern Mongolian Plateau,but advanced in the west.Elevation of these three climatic factors delayed EOS across Mongolian Plateau.Climate warming and hydric stress may trigger synergistic SOS-delay and EOS-advance effects in the central and eastern Mongolian Plateau,increasing differential phenological mismatch risks to offspring fitness,thereby potentially affecting population growth rates and distributions.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
When making assessments of forest resources,there is nearly ubiquitous interest in quantifying current status and trends in tree biomass and carbon stocks.While important at various spatial scales,typical estimations ...When making assessments of forest resources,there is nearly ubiquitous interest in quantifying current status and trends in tree biomass and carbon stocks.While important at various spatial scales,typical estimations pertinent to broad forest management and policy issues are conducted for large areas such as state,regional,and national perspectives.These assessments are usually accomplished using large-area forest inventory data collected by National Forest Inventory(NFI)programs.While NFI efforts commonly collect size data for individual trees,there is often limited information for tree seedlings,e.g.,frequency by species.To fully describe the tree population across the entire range of sizes present,this study proposes methods to predict individual seedling groundline diameter and height using models developed from trees having a diameter at breast height(DBH)less than 7.62 cm.These attributes are subsequently used for the prediction of seedling stem volume,total aboveground biomass,and carbon content.The results suggest a smooth transition in tree attributes as size increases to where direct measurement of individual trees and prediction of their volume,biomass,and carbon are implemented as part of standard inventory protocols.Analyses including the full spectrum of tree sizes show that seedlings contribute roughly 0.6%–0.7%of the total tree volume/mass.This additional suite of information provides opportunities for more holistic assessments across the full spectrum of the tree resource or for specialized subdomains that include the seedling component.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
文摘The study examined the impact of land reclamation on vegetal cover in Bayelsa State.For the purpose of this study,both quantitative and qualitative research methods were adopted.Field observations,questionnaire survey and landsat imagery of land cover changes in the year 1986 and 2018 were generated from the global ground cover facility stream.The time series study design and supervised classification of the image processing were adopted to determine the impact of land reclamation on vegetal cover of the study area.It was therefore recommended that recovery of land will make strategic urban planning initiatives sustainable in overcrowded areas and institutions should also put in place laws and strategies to regulate reclamation activities across the region and also geo-spatial skills should be put in place to help quantify the dynamics,trends and rate of reclamation induced land cover change in the environment.
文摘The effect of slope gradient and vegetal cover on soil infiltration and erosion were studied with field simulator. Results showed that infiltration decreases with slope gradients (especially for gradient less than 10°) and increases with vegetal covers, while soil erosion increases with slope gradients and decreases with vegetal covers. Fittlng the data by Philip's infiltration equation it was found that in the equation, gravitational conductivity decreases with gradient and increases with vegetation, while diffusion decreases with vegetal cover and does not vary with slope gradient In the erosion process, the formation of a layer of thin water is crucial in dctermining the rainsplash and sheetwash. The increasing of erosion with slope gradient contributes mainly to the increase of velocity.
文摘Timing of vegetal-endodermal cell determination in amphioxus embryos remains uncertain. We tentatively testal effects of A23187, the calcium ionophore, on the deveopment of vegetal blastomeres isolated at the 16-cell stage. It was found that when vegetal blastomres committed to endodermwere treated with A23187 prior to gastrulation, they were transformed into ectodermal cells as evidenced by the cell morphology and function characteristic of epidermis. Howver, the developmental fate of the sam blastomeres untreated or treated with DMSO at the same stage or of those treated with A23187 after gastrulation remained unchanged. Thus, vegetal-endodermal cells in amphioxus embryos are not irreversibly deermined before the gastrula stage, and artificial incarease in intracelluar Ca2+ concentration can induce transdetermination of the predetermined endodermal cells into ectodermal cells.
基金Supported by Special Industrial Economy Research Project for National Common Vegetable Industry Technology System(nycytx-35)
文摘Since the reform and opening-up,there has been a great change in spatial pattern of China's vegetable production. This paper studied vegetable production in provinces of China in 1978- 2013. From the sequential characteristics,China's vegetable production area is constantly growing and takes on stage characteristic. From the spatial distribution,China's vegetable production takes on the trend of " going down the south" and " marching the west". In order to grasp rules of changes of vegetable production and the influence factors,this paper made theoretical and empirical analysis on factors possibly influencing distribution of vegetable production. Results show that major factors influencing distribution of China's vegetable production include irrigation condition,non-agricultural employment,market demand,knowledge spillover,comparative effectiveness,rural road and government policies.
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 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Objective:To determine the chemical constituents of the traditional vegetal salts and find out if they are safe to consume.Methods:Seven different salts have been obtained from three provinces,of which five belong to Morobe Province.The cations were determined using inductively coupled plasma atomic emission spectroscopy and anions using titrimetry,gravimetry and spectrophotometry.Others like solubility,electrical conductivity,pH,antimicrobial,Fourier transform infrared spectral and volatility studies have been carried out for these salts.Results:While few salts were found to be stable,others were deliquescent;and the colour varies from white to black through yellow and brown.It was found that the potassium ion was dominant while others including sodium and calcium were found in lower concentrations.For the first time,certain d-block metal concentrations were measured though most of them were found to be present at very low levels.Other parameters like volatility,solubility,electrical conductivity,antimicrobial and Fourier transform infrared spectral studies were carried out for the first time for these vegetal salts in Papua New Guinea.Conclusions:The salt’s deliquescence could be correlated to the presence of anions like carbonate,bicarbonate and hydroxide which strongly contribute towards it.Similarly,solubility and conductivity of the salts could be correlated well.The salts were found to be harmless for consumption,but for the high potassium content.
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 the Foundation of National Dairy Technology Innovation Center(2022-Open Funding Project-12)Foundation of National Dairy Technology Innovation Center(2022-Scientific Research-9)+2 种基金Key Project of National Dairy Innovation Research Center of Inner Mongolia(2021-National Dairy Innovation Research Center-8)Key Projects of Research Operating Expenses of Provincial Research Institutes in Heilongjiang Province(CZKYF2021-2-B017)Key Project of Natural Science Foundation of Heilongjiang Province(ZD2022C007).
文摘Suancai has a lengthy history and a wide range of categories,which has some influence on the pickled diet culture around the world.Suancai production is transitioning to a large-scale,standardized production due to the growth of the market.It has a unique flavor and is rich in nutrients,and its abundance of free amino acids,vitamins and phenolics has many positive effects on the human body.This review gives the types and history of suancai,as well as its impact on the world’s pickled culture.The changes in nutritional composition and flavor of suancai during fermentation are summarized.It presented the production technology and influencing factors of the northeast suancai,examined the quality and safety issues in suancai,and put forth some ideas and opinions on the standardization development of the suancai industry.It also summarized the geographic distribution and flora diversity of pickles around the world.In order to provide some knowledge and guidance for the promotion of modern industrial production in the suancai industry.
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 National Key Research and Development Program of China(2023YFF1001700)the Unveiling and Leading Projects(2022kj05)+1 种基金Yafu Technology Innovation Team of Jiangsu Vocational College of Agriculture and Forestry(2024kj02)the Innovation&Entrepreneurship Training Program for College Students of Qingdao Agricultural University(QNDC20250149).
文摘As a pivotal environmental factor,light,comprising intensity,photoperiod,and spectrum,governs the entire life cycle of strawberries by mediating alterations in the plant’s morphological,physiological,and biochemical traits.Although extensive research has been conducted on light-mediated growth regulation in horticultural crops,most reviews focus primarily on leafy and fruiting vegetables,with limited attention given to berry crops such as strawberries.Additionally,most existing reviews concentrate on one or several growth stages,failing to systematically characterize light’s effects throughout the entire growth cycle and postharvest stage.This review briefly summarizes the regulatory roles of light across key stages of strawberry growth,including seedling propagation,vegetative growth,reproductive growth,and postharvest stages.It seeks to address the knowledge gap by systematically organizing research findings across these developmental phases.The integrated analysis provides a theoretical foundation for designing stage-specific lighting strategies to improve strawberry yield and quality.
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supported by the Mississippi Agricultural and Forestry Experiment Station,Special Research Initiative(MAFES-SRI),USA,the USDA-Agricultural Research Service(USDA-ARS)(58-6064-3-007)the National Institute of Food and Agriculture,USA(MIS-430030)。
文摘Elevated CO_(2)(eCO_(2))may mitigate stress-induced damage to cotton(Gossypium spp.)growth and development.However,understanding the early-stage responses of cotton to multiple abiotic stressors at eCO_(2)levels has been limited.This study quantified the impacts of chilling(CS,22/14℃,day/night temperature),heat(HS,38/30℃),drought(DS,50%irrigation of the control),and salt(SS,8 d S m-1)stresses on pigments,physiology,growth,and development of 14 upland cotton cultivars under ambient CO_(2)(aCO_(2),420 ppm;current)and eCO_(2)(700 ppm;future)levels during the vegetative stage.The eCO_(2)partially negated the effects of all stresses by improving one or more of the pigments,physiological,growth,and development traits,except CS.For instance,HS at aCO_(2)significantly increased stomatal conductance by 36%compared with non-stressed plants at aCO_(2).However,HS at eCO_(2)significantly decreased stomatal conductance by 18%compared with HS at aCO_(2).The first squaring was delayed by one day under SS at aCO_(2)but two days earlier under SS at eCO_(2)than non-stressed plants at aCO_(2).Root and shoot dry mass and the total leaf area were significantly higher under all stresses,except for CS,at the eCO_(2)compared with similar stresses at the aCO_(2).Most growth and development traits,including plant height,leaf area,and shoot dry mass,displayed a mirroring response pattern between aCO_(2)and eCO_(2)under all environments except CS.Cultivars exhibited significant interaction with stressed environments.Further,results revealed differential sensitivity and adaptation potential of cultivars to stress environments at varying CO_(2)levels.This study highlights the need to consider eCO_(2)in designing breeding programs to develop stress-tolerant varieties for future cotton-growing environments.
基金supported by the JOINT CAS-MPG Research Project(Grant No.HZXM20225001MI)the National Natural Science Foundation of China(Grant No.W2412056,42271116 and 32100373)the China Biodiversity Observation Networks(Sino BON)。
文摘Climate change is altering vegetation phenology,differentially affecting food quality and availability for the gosling development(and therefore fitness)of migratory herbivores,especially those experiencing range contraction and fragmentation.By quantifying the climate-vegetation nexus for two waterbird species of contrasting conservation status,we assessed the differential implications of climate change in semi-arid landscapes for gosling development windows in different parts of their mid-latitude breeding ranges.We defined breeding ranges using telemetry data from 663 summering tracks of tagged Swan Geese(Anser cygnoides)and Greylag Geese(A.anser)breeding across the Mongolian Plateau.Within these areas,we systematically analyzed spatiotemporal variations in vegetation phenology based on MODIS NDVI datasets from 2000 to 2024 and their response to climate factors.Combining the above data,we demonstrated synchrony between goose breeding phenology and vegetation phenological indices:gosling hatching coincided with the start of growing season(SOS),autumn migration initiation with the end of growing season(EOS).We determined temporal and geographical variation in vegetation SOS,EOS and the length of growing season(LOS=EOS-SOS)as a proxy for gosling development windows across the Mongolian Plateau.Mean LOS was 107±13 days,generally sufficient for gosling development(c.113 days),but showed spatial heterogeneity,increasing in the west but shortening in the east of Mongolian Plateau.SOS was delayed with higher land surface temperature and lower precipitation/aridity in central/eastern Mongolian Plateau,but advanced in the west.Elevation of these three climatic factors delayed EOS across Mongolian Plateau.Climate warming and hydric stress may trigger synergistic SOS-delay and EOS-advance effects in the central and eastern Mongolian Plateau,increasing differential phenological mismatch risks to offspring fitness,thereby potentially affecting population growth rates and distributions.
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.
文摘When making assessments of forest resources,there is nearly ubiquitous interest in quantifying current status and trends in tree biomass and carbon stocks.While important at various spatial scales,typical estimations pertinent to broad forest management and policy issues are conducted for large areas such as state,regional,and national perspectives.These assessments are usually accomplished using large-area forest inventory data collected by National Forest Inventory(NFI)programs.While NFI efforts commonly collect size data for individual trees,there is often limited information for tree seedlings,e.g.,frequency by species.To fully describe the tree population across the entire range of sizes present,this study proposes methods to predict individual seedling groundline diameter and height using models developed from trees having a diameter at breast height(DBH)less than 7.62 cm.These attributes are subsequently used for the prediction of seedling stem volume,total aboveground biomass,and carbon content.The results suggest a smooth transition in tree attributes as size increases to where direct measurement of individual trees and prediction of their volume,biomass,and carbon are implemented as part of standard inventory protocols.Analyses including the full spectrum of tree sizes show that seedlings contribute roughly 0.6%–0.7%of the total tree volume/mass.This additional suite of information provides opportunities for more holistic assessments across the full spectrum of the tree resource or for specialized subdomains that include the seedling component.
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.
