[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of ...[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of Hongze Lake Wetland National Nature Reserve was taken as the study area. Through the field survey based on environmental characteristics of aquatic areas and non-aquatic areas, combined with laboratory test, the content changes of nutrients （N and P）, COD （chemical oxygen demand） and SD （transparency） levels in the water body of lake wetland were measured; the purification effect of the lake wetland ecosystem in the growth process of aquatic vegetation was quantitatively analyzed, and possible influ- encing factors were discussed. [Result] Aquatic vegetation could remove the TN, TP, COD, Chla in wetland water environment and had obvious effects on the changes of SD content. Competition between aquatic plants can inhibit the growth of algae and relieve the eutrophication of water body. [Conclusion] This study provided theoretical basis for ecological restoration and enhancement of self-purification capability in the lakeside zone of Hongze Lake.展开更多
[Objective] Taking Xijing Mountain for example,this study investigates characteristics of roadside plant communities and width changes of trampled vegetations by the tourist road,analyzes influence of tourism activiti...[Objective] Taking Xijing Mountain for example,this study investigates characteristics of roadside plant communities and width changes of trampled vegetations by the tourist road,analyzes influence of tourism activities on environment.[Method] Characteristics of roadside plant communities are studied by applying species diversity index,coverage and other such indexes;from the bottom to the top of Xijing Mountain,investigation objects are selected along the tourist road to measure the trampled width of vegetations.[Result] Characteristics of plant communities,trampled vegetations are both closely related to the design of tourist road.[Conclusion] Suggestions are proposed for the design of tourist road.展开更多
BACKGROUND Infective endocarditis(IE)is a life-threatening infection with an annual mortality of 40%.Embolic events reported in up to 80%of patients.Vegetations of>10 mm size are associated with increased embolic e...BACKGROUND Infective endocarditis(IE)is a life-threatening infection with an annual mortality of 40%.Embolic events reported in up to 80%of patients.Vegetations of>10 mm size are associated with increased embolic events and poor prognosis.There is a paucity of literature on the association of multiple vegetations with outcome.AIM To study the echocardiographic(ECHO)features and outcomes associated with the presence of multiple vegetations.METHODS In this retrospective,single-center,cohort study patients diagnosed with IE were recruited from June 2017 to June 2019.A total of 84 patients were diagnosed to have IE,of whom 67 with vegetation were identified.Baseline demographic,clinical,laboratory,and ECHO parameters were reviewed.Outcomes that were studied included recurrent admission,embolic phenomenon,and mortality.RESULTS Twenty-three(34%)patients were noted to have multiple vegetations,13(56.5%)were male and 10(43.5%)were female.The mean age of these patients was 50.Eight(35%)had a prior episode of IE.ECHO features of moderate to severe valvular regurgitation[odds ratio(OR)=4],presence of pacemaker lead(OR=4.8),impaired left ventricle(LV)relaxation(OR=4),and elevated pulmonary artery systolic pressure(PASP)(OR=2.2)are associated with higher odds of multiple vegetations.Of these moderate to severe valvular regurgitation(P=0.028),pacemaker lead(P=0.039)and impaired relaxation(P=0.028)were statistically significant.These patients were noted to have an increased association of recurrent admissions(OR=3.6),recurrent bacteremia(OR=2.4),embolic phenomenon(OR=2.5),intensive care unit stay(OR=2.8),hypotension(OR=2.1),surgical intervention(OR=2.8)and device removal(OR=4.8).Of this device removal(P=0.039)and recurrent admissions(P=0.017)were statistically significant.CONCLUSION This study highlights the associations of ECHO predictors and outcomes in patients with IE having multiple vegetations.ECHO features of moderate to severe regurgitation,presence of pacemaker lead,impaired LV relaxation,and elevated PASP and outcomes including recurrent admissions and device removal were found to be associated with multiple vegetations.展开更多
Fractal method is a new method to estimate soil structure. It has been shown to be a useful tool in studies related to physical properties of soil as well as erosion and other hydrological processes. Fractal dimension...Fractal method is a new method to estimate soil structure. It has been shown to be a useful tool in studies related to physical properties of soil as well as erosion and other hydrological processes. Fractal dimension was used to study the soil structure in soil at different stages of vegetative succession on the Ziwuling Mountains. The land use and vegetation types included cultivated land, abandoned land, grassland, two types of shrub land, and three types of forests. The grassland, shrub land, and forested areas represented a continuum in vegetative succession that had occurred naturally, as the land was abandoned in 1862. Disturbed and undisturbed soil samples were collected from ten vegetation types from depths of 0-10, 10-20, and 20-30 cm on the Ziwuling Mountains, at a site with an elevation of about 1 500 m. Particle size distribution was determined by the pipette method and aggregate size distribution was determined by wet sieving. The results were used to calculate the particle and aggregate fractal dimension. The results showed that particle and aggregate fractal dimensions varied between vegetation types. There was a positive correlation between the particle fractal dimension and the weight of particles with diameter 〈 0.001 mm, but no relationship between particle fractal dimension and the other particle size classes. Particle fractal dimension was lower in vegetated soils compared to cropland and there was no consistent relationship between fractal dimension and vegetation type. Aggregate fractal dimension was positively correlated with the weight of 〉 0.25 mm aggregates. Aggregate fractal dimension was lower in vegetated soils compared with cropland. In contrast to particle fractal dimension, aggregate fractal dimension described changes in soil structure associated with vegetative succession. The results of this study indicate that aggregate fractal dimension is more effective in describing soil structure and function compared with particle fractal dimension.展开更多
Terrestrial ecosystem and climate system are closely related to each other. Faced with the unavoidable global climate change, it is important to investigate terrestrial ecosystem responding to climate change. In inlan...Terrestrial ecosystem and climate system are closely related to each other. Faced with the unavoidable global climate change, it is important to investigate terrestrial ecosystem responding to climate change. In inland river basin of arid and semi-arid regions in China, sensitivity difference of vegetation responding to climate change from 1998 to 2007 was analyzed in this paper. （1） Differences in the global spatio-temporal distribution of vegetation and climate are obvious. The vegetation change shows a slight degradation in this whole region. Degradation is more obvious in densely vegetated areas. Temperature shows a general downward trend with a linear trend coefficient of -1.1467. Conversely, precipitation shows an increasing trend with a linear trend coefficient of 0.3896. （2） About the central tendency response, there are similar features in spatial distribution of both NDVI responding to precipitation （NDVI-P） and NDVI responding to AI （NDVI-AI）, which are contrary to that of NDVI responding to air temperature （NDVI-T）. Typical sensitivity region of NDVI-P and NDVI-AI mainly covers the northern temperate arid steppe and the northern temperate desert steppe. NDVI-T typical sensitivity region mainly covers the northern temperate desert steppe. （3） Regarding the fluctuation amplitude response, NDVI-T is dominated by the lower sensitivity, typical regions of the warm temperate shrubby, selui-shrubby, bare extreme dry desert, and northern temperate meadow steppe in the east and temperate semi-shrubby, dwarf arboreous desert in the north are high response. （4） Fluctuation amplitude responses between NDVI-P and NDVI-AI present a similar spatial distribution. The typical sensitivity region mainly covers the northern temperate desert steppe. There are various linear change trend responses of NDVI-T, NDVI-P and NDVI-AI. As to the NDVI-T and NDVI-AI, which are influenced by the boundary effect of semi-arid and semi-humid climate zones, there is less correlation of their linear change tendency along the border. There is stronger correlation in other regions, especially in the NDVI-T in the northern temperate desert steppe and NDVI-AI in the warm temperate shrubby, selui-shrubby, bare, extreme and dry desert.展开更多
Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the r...Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the relationships between plants and phosphorus＇ fractions and availability in the Loess Plateau of China. Twenty-two plant communities were surveyed and soil samples under different plant canopies were collected for the determination of soil properties and inorganic phosphorus fractionation. The results showed that Leguminosae and Lilaceae reduced pH and increased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies, while Labiatae and Rosaceae increased pH and decreased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies. The contents of Ca2P, CasP, AI-P and Fe-P were highly related with soil Oisen phosphorus. They were all higher in soils under Leguminosae and Lilaceae and lower in softs under Labiatae and Rosaceae. The results of this study indicate that Leguminosae and Lilaceae improved phosphorus nutrition in soils, yet Labiatae and Rosaceae impeded the improvement of phosphorus nutrition in soils under their canopies, which will be of more help to instruct vegetation restoration in the region and provide information for soil development.展开更多
By choosing a PVC slice to simulate flexible vegetation, we carried out experiments in an open channel with submerged flexible vegetation. A 3D acoustic Doppler velocimeter （micro ADV） was used to measure local flow...By choosing a PVC slice to simulate flexible vegetation, we carried out experiments in an open channel with submerged flexible vegetation. A 3D acoustic Doppler velocimeter （micro ADV） was used to measure local flow velocities and Reynolds stress. The results show that hydraulic characteristics in non-vegetation and vegetation layers are totally different. In a region above the vegetation, Reynolds stress distribution is linear, and the measured velocity profile is a classical logarithmic one. Based on the concept of new-riverbed, the river compression parameter representing the impact of vegetation on river is given, and a new assumption of mixing length expression is made. The formula for time-averaged velocity derived from the expression requires less parameters and simple calculation, and is useful in applications.展开更多
Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional pr...Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.展开更多
Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bang...Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bangladesh were investigated to measure their floral diversity, physico-chemical properties of soil and the soil-plant interrelationship which is responsible for the diversification of wild flora within the regions. From Shannon and Simpson diversity indexes, it can be deducted that the floral diversity within the abandoned mansions ha</span><span style="font-family:"">s</span><span style="font-family:""> a<span style="color:red;"> </span>positive relationship with their territory size. The high values of Marg<span>alef’s and Menhinick’s species richness indexes confirmed that these areas are a rich source of a large number of plant species. A great variation in soil physico-chemical properties has been observed during the analysis. Soil organic matter, nitrogen, phosphorus, potassium & moisture contents were varied significantly from one quadrat to another in every site. Biplot analysis showed that the distribution of plant species in abandoned mansions </span></span><span style="font-family:"">is</span><span style="font-family:""> primarily determined by the organic matter, pH, moisture and potassium contents of soil. As t</span><span style="font-family:"">hese factors were present in versatile distribution within the studied regions, a great number of plants can grow in the same area simultaneously. So these areas should be protected from human intervention to proce</span><span style="font-family:"">ss</span><span style="font-family:""> natural selection and in situ conservation of plant species.展开更多
The scalar transport phenomena in vertical two-dimensional flows are studied using the random walk method. The established Lagrangian model is first applied to study the idealized longitudinal dispersion in open chann...The scalar transport phenomena in vertical two-dimensional flows are studied using the random walk method. The established Lagrangian model is first applied to study the idealized longitudinal dispersion in open channels, before being used to investigate the scalar mixing characteristics of the flows through submerged vegetations. The longitudinal dispersion coefficients of the fully-developed boundary layer flows, with and without vegetations, are calculated based on the positions of the particles. A convenient way of incorporating the effects of vegetations is proposed, where all the flow parameters are regarded to be continually distributed over the depth. The simulation results show high accuracy of the developed random walk method, and indicate that the new method of accounting for the vegetation effects is appropriate for all the test cases considered. The predicted longitudinal dispersion coefficients agree well with the measurements. The merit of the new method is highlighted by its simplicity and efficiency in comparison with the conventional method that assumes the discontinuous distribution of the flow parameters over the depth.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
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
[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
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
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
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
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
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
基金Supported by the Social Development Project of Jiangsu Provincial Science and Technology Department(BK2010023)江苏省科技厅社会发展项目(BK2010023)资助
文摘[Objective] To study the purification effect of plant community on wetland water environment in Hongze Lake, and to provide references to the ecological restoration of this area. [Methed] The typical lakeside zone of Hongze Lake Wetland National Nature Reserve was taken as the study area. Through the field survey based on environmental characteristics of aquatic areas and non-aquatic areas, combined with laboratory test, the content changes of nutrients （N and P）, COD （chemical oxygen demand） and SD （transparency） levels in the water body of lake wetland were measured; the purification effect of the lake wetland ecosystem in the growth process of aquatic vegetation was quantitatively analyzed, and possible influ- encing factors were discussed. [Result] Aquatic vegetation could remove the TN, TP, COD, Chla in wetland water environment and had obvious effects on the changes of SD content. Competition between aquatic plants can inhibit the growth of algae and relieve the eutrophication of water body. [Conclusion] This study provided theoretical basis for ecological restoration and enhancement of self-purification capability in the lakeside zone of Hongze Lake.
文摘[Objective] Taking Xijing Mountain for example,this study investigates characteristics of roadside plant communities and width changes of trampled vegetations by the tourist road,analyzes influence of tourism activities on environment.[Method] Characteristics of roadside plant communities are studied by applying species diversity index,coverage and other such indexes;from the bottom to the top of Xijing Mountain,investigation objects are selected along the tourist road to measure the trampled width of vegetations.[Result] Characteristics of plant communities,trampled vegetations are both closely related to the design of tourist road.[Conclusion] Suggestions are proposed for the design of tourist road.
文摘BACKGROUND Infective endocarditis(IE)is a life-threatening infection with an annual mortality of 40%.Embolic events reported in up to 80%of patients.Vegetations of>10 mm size are associated with increased embolic events and poor prognosis.There is a paucity of literature on the association of multiple vegetations with outcome.AIM To study the echocardiographic(ECHO)features and outcomes associated with the presence of multiple vegetations.METHODS In this retrospective,single-center,cohort study patients diagnosed with IE were recruited from June 2017 to June 2019.A total of 84 patients were diagnosed to have IE,of whom 67 with vegetation were identified.Baseline demographic,clinical,laboratory,and ECHO parameters were reviewed.Outcomes that were studied included recurrent admission,embolic phenomenon,and mortality.RESULTS Twenty-three(34%)patients were noted to have multiple vegetations,13(56.5%)were male and 10(43.5%)were female.The mean age of these patients was 50.Eight(35%)had a prior episode of IE.ECHO features of moderate to severe valvular regurgitation[odds ratio(OR)=4],presence of pacemaker lead(OR=4.8),impaired left ventricle(LV)relaxation(OR=4),and elevated pulmonary artery systolic pressure(PASP)(OR=2.2)are associated with higher odds of multiple vegetations.Of these moderate to severe valvular regurgitation(P=0.028),pacemaker lead(P=0.039)and impaired relaxation(P=0.028)were statistically significant.These patients were noted to have an increased association of recurrent admissions(OR=3.6),recurrent bacteremia(OR=2.4),embolic phenomenon(OR=2.5),intensive care unit stay(OR=2.8),hypotension(OR=2.1),surgical intervention(OR=2.8)and device removal(OR=4.8).Of this device removal(P=0.039)and recurrent admissions(P=0.017)were statistically significant.CONCLUSION This study highlights the associations of ECHO predictors and outcomes in patients with IE having multiple vegetations.ECHO features of moderate to severe regurgitation,presence of pacemaker lead,impaired LV relaxation,and elevated PASP and outcomes including recurrent admissions and device removal were found to be associated with multiple vegetations.
基金funded by the National Natural Science Foundation of China(90302001)CAS Knowledge Innovation(KZCX3-SW-421)the Fund of the State Key Laboratory of Soil Erosion and DrylandFarming on the Loess Plateau(10501-152).
文摘Fractal method is a new method to estimate soil structure. It has been shown to be a useful tool in studies related to physical properties of soil as well as erosion and other hydrological processes. Fractal dimension was used to study the soil structure in soil at different stages of vegetative succession on the Ziwuling Mountains. The land use and vegetation types included cultivated land, abandoned land, grassland, two types of shrub land, and three types of forests. The grassland, shrub land, and forested areas represented a continuum in vegetative succession that had occurred naturally, as the land was abandoned in 1862. Disturbed and undisturbed soil samples were collected from ten vegetation types from depths of 0-10, 10-20, and 20-30 cm on the Ziwuling Mountains, at a site with an elevation of about 1 500 m. Particle size distribution was determined by the pipette method and aggregate size distribution was determined by wet sieving. The results were used to calculate the particle and aggregate fractal dimension. The results showed that particle and aggregate fractal dimensions varied between vegetation types. There was a positive correlation between the particle fractal dimension and the weight of particles with diameter 〈 0.001 mm, but no relationship between particle fractal dimension and the other particle size classes. Particle fractal dimension was lower in vegetated soils compared to cropland and there was no consistent relationship between fractal dimension and vegetation type. Aggregate fractal dimension was positively correlated with the weight of 〉 0.25 mm aggregates. Aggregate fractal dimension was lower in vegetated soils compared with cropland. In contrast to particle fractal dimension, aggregate fractal dimension described changes in soil structure associated with vegetative succession. The results of this study indicate that aggregate fractal dimension is more effective in describing soil structure and function compared with particle fractal dimension.
基金Beijing Science and Technology New Star Program, No.2010B037Environmental Commonweal Projects,No.2011467026National Science and Technology Supporting Item, No.2008BAC34B06
文摘Terrestrial ecosystem and climate system are closely related to each other. Faced with the unavoidable global climate change, it is important to investigate terrestrial ecosystem responding to climate change. In inland river basin of arid and semi-arid regions in China, sensitivity difference of vegetation responding to climate change from 1998 to 2007 was analyzed in this paper. （1） Differences in the global spatio-temporal distribution of vegetation and climate are obvious. The vegetation change shows a slight degradation in this whole region. Degradation is more obvious in densely vegetated areas. Temperature shows a general downward trend with a linear trend coefficient of -1.1467. Conversely, precipitation shows an increasing trend with a linear trend coefficient of 0.3896. （2） About the central tendency response, there are similar features in spatial distribution of both NDVI responding to precipitation （NDVI-P） and NDVI responding to AI （NDVI-AI）, which are contrary to that of NDVI responding to air temperature （NDVI-T）. Typical sensitivity region of NDVI-P and NDVI-AI mainly covers the northern temperate arid steppe and the northern temperate desert steppe. NDVI-T typical sensitivity region mainly covers the northern temperate desert steppe. （3） Regarding the fluctuation amplitude response, NDVI-T is dominated by the lower sensitivity, typical regions of the warm temperate shrubby, selui-shrubby, bare extreme dry desert, and northern temperate meadow steppe in the east and temperate semi-shrubby, dwarf arboreous desert in the north are high response. （4） Fluctuation amplitude responses between NDVI-P and NDVI-AI present a similar spatial distribution. The typical sensitivity region mainly covers the northern temperate desert steppe. There are various linear change trend responses of NDVI-T, NDVI-P and NDVI-AI. As to the NDVI-T and NDVI-AI, which are influenced by the boundary effect of semi-arid and semi-humid climate zones, there is less correlation of their linear change tendency along the border. There is stronger correlation in other regions, especially in the NDVI-T in the northern temperate desert steppe and NDVI-AI in the warm temperate shrubby, selui-shrubby, bare, extreme and dry desert.
基金supported by the National Key Basic Research Special Foundation Project(2007CB106803)National Natural Science Foundation(40801111, 41001137)One hundred-Talent Plan of Chinese Academy of Sciences,the CAS/SAFEA International Partnership Program for Creative Research Teams,and the Program for Youthful Talents in Northwest A and F University
文摘Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the relationships between plants and phosphorus＇ fractions and availability in the Loess Plateau of China. Twenty-two plant communities were surveyed and soil samples under different plant canopies were collected for the determination of soil properties and inorganic phosphorus fractionation. The results showed that Leguminosae and Lilaceae reduced pH and increased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies, while Labiatae and Rosaceae increased pH and decreased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies. The contents of Ca2P, CasP, AI-P and Fe-P were highly related with soil Oisen phosphorus. They were all higher in soils under Leguminosae and Lilaceae and lower in softs under Labiatae and Rosaceae. The results of this study indicate that Leguminosae and Lilaceae improved phosphorus nutrition in soils, yet Labiatae and Rosaceae impeded the improvement of phosphorus nutrition in soils under their canopies, which will be of more help to instruct vegetation restoration in the region and provide information for soil development.
基金supported by the National Natural Science Foundation of China (Nos. 50679061, 50709025,50749031)
文摘By choosing a PVC slice to simulate flexible vegetation, we carried out experiments in an open channel with submerged flexible vegetation. A 3D acoustic Doppler velocimeter （micro ADV） was used to measure local flow velocities and Reynolds stress. The results show that hydraulic characteristics in non-vegetation and vegetation layers are totally different. In a region above the vegetation, Reynolds stress distribution is linear, and the measured velocity profile is a classical logarithmic one. Based on the concept of new-riverbed, the river compression parameter representing the impact of vegetation on river is given, and a new assumption of mixing length expression is made. The formula for time-averaged velocity derived from the expression requires less parameters and simple calculation, and is useful in applications.
基金funded by the National Natural Science Foundation of China(grants No.30960264,31160475 and 42071258)Open Research Fund of TPESER(grant No.TPESER202208)+2 种基金Special Fund for Basic Scientific Research of Central Colleges,Chang’an University,China(grant No.300102353501)Natural Science Foundation of Gansu Province,China(grant No.22JR5RA857)Higher Education Novel Foundation of Gansu Province,China(grant No.2021B-130)。
文摘Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide.
文摘Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bangladesh were investigated to measure their floral diversity, physico-chemical properties of soil and the soil-plant interrelationship which is responsible for the diversification of wild flora within the regions. From Shannon and Simpson diversity indexes, it can be deducted that the floral diversity within the abandoned mansions ha</span><span style="font-family:"">s</span><span style="font-family:""> a<span style="color:red;"> </span>positive relationship with their territory size. The high values of Marg<span>alef’s and Menhinick’s species richness indexes confirmed that these areas are a rich source of a large number of plant species. A great variation in soil physico-chemical properties has been observed during the analysis. Soil organic matter, nitrogen, phosphorus, potassium & moisture contents were varied significantly from one quadrat to another in every site. Biplot analysis showed that the distribution of plant species in abandoned mansions </span></span><span style="font-family:"">is</span><span style="font-family:""> primarily determined by the organic matter, pH, moisture and potassium contents of soil. As t</span><span style="font-family:"">hese factors were present in versatile distribution within the studied regions, a great number of plants can grow in the same area simultaneously. So these areas should be protected from human intervention to proce</span><span style="font-family:"">ss</span><span style="font-family:""> natural selection and in situ conservation of plant species.
基金supported by the Non-profit Industry Financial Program of the Ministry of Water Resources (Grant No. 201401027)the China Scholarship Council
文摘The scalar transport phenomena in vertical two-dimensional flows are studied using the random walk method. The established Lagrangian model is first applied to study the idealized longitudinal dispersion in open channels, before being used to investigate the scalar mixing characteristics of the flows through submerged vegetations. The longitudinal dispersion coefficients of the fully-developed boundary layer flows, with and without vegetations, are calculated based on the positions of the particles. A convenient way of incorporating the effects of vegetations is proposed, where all the flow parameters are regarded to be continually distributed over the depth. The simulation results show high accuracy of the developed random walk method, and indicate that the new method of accounting for the vegetation effects is appropriate for all the test cases considered. The predicted longitudinal dispersion coefficients agree well with the measurements. The merit of the new method is highlighted by its simplicity and efficiency in comparison with the conventional method that assumes the discontinuous distribution of the flow parameters over the depth.
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 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.
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 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 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.
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 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.
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.
