Migration of vegetational zone during the Quaternary is very obvious, as it is in the north of China. However, there are only a few data about the tropical and the south subtropical zones in the coastal region of Sout...Migration of vegetational zone during the Quaternary is very obvious, as it is in the north of China. However, there are only a few data about the tropical and the south subtropical zones in the coastal region of South China and few systematic researches have been done. This note deals with sporopollen assemblages of the Quaternary from展开更多
This study investigates the changes in soil microbial populations as vegetational succession progress from abandoned farmland to climax forest in the Ziwuling Forest,which is located in the northern part of the Loess ...This study investigates the changes in soil microbial populations as vegetational succession progress from abandoned farmland to climax forest in the Ziwuling Forest,which is located in the northern part of the Loess Plateau,China.Different organic C and total extractable N between the fumigated and non-fumigated soils were assumed to be released from soil microorganisms.Soil microbial C was calculated using Kec=0.38 and microbial N was calculated using Ken=0.45.The released P was converted to microbial biomass P using Kep=0.40.Soil bacteria,fungi,and actinomycetes increased as the vegetational succession progressed.Microbial C was of the highest amount in farmland.Microbial C,N,and P generally increased from abandoned land to climax community.The results indicated significant(P<0.05)diversities of soil microbial biomass under different vegetation.There was a significant correlation between microbial biomass and soil nutrients.Knowledge about soil microbial populations is important for forecasting vegetational succession and determining the ecological condition of the environment.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
Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships w...Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.展开更多
1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrest...1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrestrial ecosystems.展开更多
Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what exten...Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.展开更多
The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and envi...The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.展开更多
Forest ecosystems play key roles in mitigating human-induced climate change through enhanced carbon uptake;however,frequently occurring climate extremes and human activities have considerably threatened the stability ...Forest ecosystems play key roles in mitigating human-induced climate change through enhanced carbon uptake;however,frequently occurring climate extremes and human activities have considerably threatened the stability of forests.At the same time,detailed accounts of disturbances and forest responses are not yet well quantified in Asia.This study employed the Breaks For Additive Seasonal and Trend method-an abrupt-change detection method-to analyze the Enhanced Vegetation Index time series in East Asia,South Asia,and Southeast Asia.This approach allowed us to detect forest disturbance and quantify the resilience after disturbance.Results showed that 20%of forests experienced disturbance with an increasing trend from 2000 to 2022,and Southeast Asian countries were more severely affected by disturbances.Specifically,95%of forests had robust resilience and could recover from disturbance within a few decades.The resilience of forests suffering from greater magnitude of disturbance tended to be stronger than forests with lower disturbance magnitude.In summary,this study investigated the resilience of forests across the low and middle latitudes of Asia over the past two decades.The authors found that most forests exhibited good resilience after disturbance and about two-thirds had recovered to a better state in 2022.The findings of this study underscore the complex relationship between disturbance and resilience,contributing to comprehension of forest resilience through satellite remote sensing.展开更多
Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was a...Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was also expected to achieve this purpose.However,the magnitude and mechanism of carbon dioxide(CO_(2))emission affected by submerged vegetation is not clear enough in complex aquatic ecosystems.This study investigated the influences of submerged plants on CO_(2)emission,ecosystem metabolism features,and microbial community traits based on observations in river networks on the Changjiang River Delta.The results showed that CO_(2)emission from planted waters accounted for 73%of unplanted waters.Meanwhile,planted waters had higher dissolved organic carbon removal capacity in overlying water and higher potential of carbon sequestration in sediment at the same time.These distinctions between the two habitats were attributed to(1)improved CO_(2)and bicarbonate consumption in water columns via enhancing photosynthesis and(2)inhibited CO_(2)production by reconstructing the benthic microbial community.Additional eco-advantages were found in planted sediments,such as a high potential of methane oxidation and xenobiotics biodegradation and a low risk of becoming black and odorous.In brief,submerged vegetation is beneficial in promoting pollution removal and carbon retention synchronously.This study advances our understanding of the feedback between aquatic metabolism and CO_(2)emission.展开更多
Vegetation annual gross primary production(AGPP),the total yearly carbon assimilation via photosynthesis,serves as a key indicator of ecosystem carbon uptake.While AGPP variations are jointly influenced by both vegeta...Vegetation annual gross primary production(AGPP),the total yearly carbon assimilation via photosynthesis,serves as a key indicator of ecosystem carbon uptake.While AGPP variations are jointly influenced by both vegetation phenology and physiology,the effectiveness of satellite-derived indicators in capturing these variations has not been fully evaluated.This study develops and evaluates the satellite-derived phenology and physiology indicators for modeling AGPP variability.We assessed the performance of satellite-derived metrics,including solar-induced chlorophyll fluorescence(SIF),leaf area index(LAI),and enhanced vegetation index(EVI),in capturing AGPP variations.Among these,SIF-based indicators exhibited the highest accuracy(Pearson's r=0.79;root mean square error=414.7 gC·m^(-2)·year^(-1)),outperforming LAI-and EVI-based indicators.To further investigate the mechanisms driving AGPP variability,we used a structural equation model based on in situ observations to quantify the direct and indirect effects of climate on AGPP through phenology and physiology.Our results reveal that vegetation physiology,particularly the seasonal maximum gross primary production,plays a more dominant role in regulating AGPP than phenology.Furthermore,we found that globally,SIF-derived phenology indicators tend to be lower than those from LAI and EVI,whereas SIF-derived physiology indicators are elevated in tropical regions and the Southern Hemisphere.These findings highlight the potential of satellite-derived indicators in advancing AGPP modeling and emphasize the predominant role of vegetation physiology in regulating ecosystem carbon uptake.This study contributes to a refined understanding of global carbon cycle dynamics and provides insights for improving large-scale carbon assessments in the context of climate change.展开更多
In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,...In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,and soil properties of livestock trampling routes and inter-route spaces in northern and southern facing hillslopes.Overall,both hillslope aspects were visually similar,whereas the ground surface of the routes was brighter(74.4%were characterized as having a'light'color)than the inter-route spaces(86.8%were characterized as having a'dark'color).These observations were supported by morphological identification of biocrust composition,which was dominated by cyanobacteria(67%)in the routes,and by mixed cyanobacteria/moss(56%)in the inter-routes.Mean Normalized Difference Vegetation Index(NDVI)was 24%higher in the inter-routes,while the mean Brightness Index(BI)was 12%higher in the routes.At the same time,the mean Crust Index(CI)was identical in the two microhabitats.Soil quality index(SQI),calculated based on the(pedoderm)soil properties of the two microhabitats,was 6%greater in the inter-routes than in the routes.This study suggests that recurrent trampling exacerbates soil compaction and shearing along the routes,thus preventing the successional development of complex biocrust compositions.展开更多
Tufa is an important type of landscape in karst regions.In recent years,the loss of landscape diversity due to tufa dissolution is affecting the stability of local ecosystems.Therefore,determining the factors and thei...Tufa is an important type of landscape in karst regions.In recent years,the loss of landscape diversity due to tufa dissolution is affecting the stability of local ecosystems.Therefore,determining the factors and their mechanisms involved in tufa dissolution is important for preserving regional landscape diversity and local ecosystem stability.In this study,we selected four tufa sites with different degrees of dissolution(undissolved tufa,lightly dissolved tufa,moderately dissolved tufa,and heavily dissolved tufa)in Xiangzhigou karst region of Guizhou Province as the study objects.We explored the effects of natural plant colonization on tufa dissolution using changes inαandβdiversity indices,soil physicochemical indicators,tufa components,and tufa substrate.The results indicated that the Shannon-wiener index,Simpson index and Patrick richness index gradually increased with tufa's increasing degree of dissolution.Additionally,the dissolution degree exhibited a significantly negative correlation with the species diversity(p<0.05).Natural vegetation colonization is the primary cause of changes in the proportion of tufa components and changes in the physicochemical properties of overlying tufa soils.The proportion of CaO components decreased significantly,and the proportion of loss on ignition components increased significantly.Soil organic carbon,pH,total nitrogen,available nitrogen,total phosphorus,available phosphorus,total potassium,available potassium,β-glucosidase,and urease gradually increased with deeper tufa dissolution and were negatively correlated with the degree of dissolution(p<0.05).It indicates that tufa is a process of dissolution into the soil and gradual improvement of the physicochemical properties of the overlying soil.Furthermore,scanning electron micrographs revealed the transition from dense to fragmented tufa structure under the influence of plants.In conclusion,this study found that improving plant diversity exacerbated tufa dissolution.Our findings provide a theoretical reference for the preventing and controlling of tufa dissolution in karst.展开更多
The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosy...The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosystems,and from humid forests in the east to arid Gobi or desert vegetation in the west,the QTP encompasses nearly all the ecosystem types found in the Northern Hemisphere(The Comprehensive ScientificExpedition to Qinghai-Xizang Plateau,Academia Sinica,1988).展开更多
The hydrodynamic response of overland flow to vegetation coverage on convex slopes remains inadequately quantified despite it is critical for soil erosion control in terrains dominated by such topography.This study sy...The hydrodynamic response of overland flow to vegetation coverage on convex slopes remains inadequately quantified despite it is critical for soil erosion control in terrains dominated by such topography.This study systematically investigated the influence of varying vegetation coverage(0%,1.08%,3.24%,4.69%and 9.81%)on the hydrodynamic characteristics of convex slopes through indoor flume experiments under diverse flow discharges(5.5-13.5 m^(3)/h)and slopes(5°-25°).The results revealed three key hydrodynamic mechanisms:(1)Flow retardation and energy dissipation:Increasing vegetation coverage significantly reduced overland flow velocity and promoted higher flow depth,thereby enhancing water retention and energy dissipation.Both stream power(Ω)and unit stream power(ω)declined by 13.9%-30.1%compared to bare slopes.(2)Flow Regime Transition:Froude number(Fr)decreased with increasing vegetation coverage,promoting the transition from supercritical to subcritical flow.The Reynolds number(Re)consistently exceeded 500,indicating the absence of laminar flow.(3)Modification of flow resistance:Vegetation resistance increased nonlinearly with coverage.Maximum bed shear stress was observed at 4.69%coverage(23.5%higher than bare slopes).However,Manning’s(n)and Darcy-Weisbach(f)coefficients did not correlate clearly with Re,indicating that vegetation coverage and slope type feedback significantly change flow resistance mechanisms.展开更多
This study explores the determinants of impact on ecology in Northern Tanzania.By examining key socio-economic,institutional,and structural factors influencing engagement the study provides insights in strengthening a...This study explores the determinants of impact on ecology in Northern Tanzania.By examining key socio-economic,institutional,and structural factors influencing engagement the study provides insights in strengthening agribusiness networks and improving livelihoods.Data was collected from 215 farmers and 320 traders through a multistage sampling procedure.Heckman AI sample selection model was used in data analysis whereby the findings showed key factors influencing farmers’decisions on ecology were gender and years of formal education at p<0.1,and access to finance and off-farm income at p<0.05.The degree of farmers participation in social groups was influenced by age,household size,off-farm income and business network at p<0.05,number of years in formal education and access to finance at p<0.01,and distance to the market at p<0.1.The decision of traders to impact on ecology was significantly influenced by age and trading experience at p<0.1.Meanwhile,the degree of their involvement in social groups was strongly affected by gender,formal education,and trust at p<0.01,as well as by access to finance and business networks at p<0.05.The study concluded that natural ecology is influenced by socio economic and structural factors but trust among group members determine the degree of participation.The study recommends that strategies to improve agribusiness networks should understand underlying causes of impact on ecology and strengthen available social groups to improve performance of farmers and traders.展开更多
Several days ago,we had a nice picnic in the woods at the foot of a hill.Our teachers took food,drinks and vegetables for us.When we arrived at the woods,we found it quiet and beautiful.We began to look for dry wood t...Several days ago,we had a nice picnic in the woods at the foot of a hill.Our teachers took food,drinks and vegetables for us.When we arrived at the woods,we found it quiet and beautiful.We began to look for dry wood to make a fire.Half an hour later,all the things were ready.展开更多
Understanding the complex relationship between vegetation change and both natural and anthropogenic factors is a subject of global importance.However,comprehensive explanations of vegetation cover trends across China...Understanding the complex relationship between vegetation change and both natural and anthropogenic factors is a subject of global importance.However,comprehensive explanations of vegetation cover trends across China’s different regions and the dynamic roles of their drivers remain limited.This study analyzed national and regional vegetation change trends from 2000 to 2020 and evaluated the evolving impacts of natural and anthropogenic factors.Results indicate that 44.14%of China’s land experienced significant increase(P<0.05)in vegetation coverage.The Northeast(A1),Southwest(A5),and South China(A8)regions showed extremely significant increases in vegetation cover,with over 65%of vegetation exhibiting extremely significant growth(P<0.01).In contrast,less than 25%of vegetation in Inner Mongolia(A2),Northwest(A3),and the Qinghai-Tibetan Plateau(A4)subregions demonstrated an extremely significant increasing trend(P<0.01).Precipitation(q=0.766)and land use type(q=0.636)were the most influential natural and anthropogenic factors,respectively,with their interaction(q=0.838)dominating national vegetation patterns.On the west side of the Hu Line,vegetation dynamics were mainly limited by arid and semi-arid climates,with precipitation as the dominant factor,though land use measures have contributed to some vegetation improvement.Between 2000 and 2020,the influence of precipitation on vegetation cover increased in regions A3 and A4,with q-values rising by 26.73%and 101.13%,respectively.Additionally,soil type exerted a significant effect(P<0.001)on vegetation cover across all regions,being most pronounced in A2(q=0.692).On the east side of the Hu Line,vegetation growth benefited generally from warm and humid conditions,while local decline in urbanized areas was largely attributable to land use change and economic expansion.Concurrently anthropogenic factors such as land use and population density increasingly influenced vegetation dynamics in eastern urban areas of the Hu Line.Population density and GDP were the most influential factors affecting vegetation cover in region A8,with q-values of 0.443 and 0.380,respectively(P<0.001).Future efforts should maintain the benefits of large-scale ecological projects and harmonize the relationship between urban vegetation and anthropogenic influences.展开更多
基金Project supported by the National Natural Science Foundation of China and the Fund of Research Depart ment of Loess and Quaternary Geology of Academia Sinica, Xi'an
文摘Migration of vegetational zone during the Quaternary is very obvious, as it is in the north of China. However, there are only a few data about the tropical and the south subtropical zones in the coastal region of South China and few systematic researches have been done. This note deals with sporopollen assemblages of the Quaternary from
基金the National Basic Research Program of China(No.2005CB121102)the State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau of China(No.10501-138)。
文摘This study investigates the changes in soil microbial populations as vegetational succession progress from abandoned farmland to climax forest in the Ziwuling Forest,which is located in the northern part of the Loess Plateau,China.Different organic C and total extractable N between the fumigated and non-fumigated soils were assumed to be released from soil microorganisms.Soil microbial C was calculated using Kec=0.38 and microbial N was calculated using Ken=0.45.The released P was converted to microbial biomass P using Kep=0.40.Soil bacteria,fungi,and actinomycetes increased as the vegetational succession progressed.Microbial C was of the highest amount in farmland.Microbial C,N,and P generally increased from abandoned land to climax community.The results indicated significant(P<0.05)diversities of soil microbial biomass under different vegetation.There was a significant correlation between microbial biomass and soil nutrients.Knowledge about soil microbial populations is important for forecasting vegetational succession and determining the ecological condition of the environment.
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.
文摘Fatty acids are the main constituents of vegetable oils.To determine the fatty acid compositions of small trade vegetable oils and some less well studied beneficial vegetable oils,and investigate their relationships with antioxidant activity and oxidative stability,gas chromatography-mass spectrometry was performed to characterize the associated fatty acid profiles.The antioxidant activity of vegetable oils,based on their DPPH-scavenging capacity(expressed as IC_(50) values),was used to assess their impact on human health,and their oxidative stability was characterized by performing lipid oxidation analysis to determine the oxidative induction time of fats and oils.In addition,correlation analyses were performed to examine associations between the fatty acid composition of the oils and DPPH-scavenging capacity and oxidative stability.The results revealed that among the assessed oils,coffee seed oil has the highest saturated fatty acid content(355.10 mg/g),whereas Garddenia jaminoides oil has the highest unsaturated fatty acid content(844.84 mg/g).Coffee seed oil was also found have the lowest DPPH IC_(50) value(2.30 mg/mL)and the longest oxidation induction time(17.09 h).Correlation analysis revealed a significant linear relationship(P<0.05)between oxidative stability and unsaturated fatty acid content,with lower contents tending to be associated with better oxidative stability.The findings of this study provide reference data for the screening of functional edible vegetable oils.
基金supported by the National Natural Science Foun dation of China(52374170 and 51974313)the National Key Research and Development Plan Project(2022YFF1303300).
文摘1.Introduction Changes in land use are key factors promoting global climate change,and the side effects of mining activity that destroy the soil,vegetation,and biodiversity lead to imbalanced carbon cycling in terrestrial ecosystems.
基金National Natural Science Foundation of China,No.41761003The Karst Science Research Center of Guizhou Province,No.U1812401。
文摘Terrestrial ecosystems heavily depend on vegetation,which responds to carbon dioxide(CO_(2))fertilization in hot and humid regions.The subtropical humid karst region is a hot and humid region;whether and to what extent CO_(2)fertilization affects vegetation changes in such regions remains unclear.In this study,we investigated the degree to which CO_(2)fertilization influences vegetation changes,along with their spatial and temporal differences,in the subtropical humid karst region using time-lag effect analysis,a random forest model,and multiple regression analysis.Results showed that CO_(2)fertilization plays an important role in vegetation changes,exhibiting clear spatial variations across different geomorphological zones,with its degree of influence ranging mainly between 11%and 25%.The highest contribution of CO_(2)fertilization was observed in the karst basin and non-karstic region,whereas the lowest contribution was found in the karst plateau region.Previous studies have primarily attributed vegetation changes in subtropical humid karst region to ecological engineering,leading to an overestimation of its contribution to these changes.The findings of this study enhance the understanding of the mechanism of vegetation changes in humid karst region and provide theoretical and practical insights for ecological and environmental protection in these regions.
基金This research was supported by the Fundamental Research Program of Shanxi Province(202203021212497,20210302123265)the Shanxi Normal University School Fund(Research Project on Major Issues of High-Quality Development in Shanxi Province,GZLFZ2327).
文摘The middle reaches of the Yellow River represent a critically ecologically sensitive and fragile area within the Yellow River Basin(YRB),holding significant scientific value for ecological security assessment and environmental management strategies.This study comprehensively evaluates the evolution of the eco-environment in the“Two Mountains,Seven Rivers,and One Basin”(TSO)area of Shanxi Province from 2000 to 2020 based on fraction vegetation cover(FVC)derived from the Normalized Difference Vegetation Index(NDVI),net primary productivity(NPP)calculated via the Carnegie–Ames–Stanford approach(CASA),and the remote sensing ecological index(RSEI).The results indicate a significant improvement in the TSO’s eco-environment from 2000 to 2020,with the RSEI values increased from 0.34 in 2000 to 0.41 in 2020(an increase of 17.76%).Both FVC and NPP demonstrated notable upward trends,with FVC increasing by 22.74%and NPP by 53.11%.Spatially,FVC rose by 21.84%,19.72%and 26.06%,respectively in the Two Mountains,Seven Rivers,and the YRB in Shanxi Province.Similarly,the NPPs increased by 51.60%,48.60%,and 61.65%in these regions over the past 21 years.Both FVC and NPP exhibited decreasing patterns from southeast to northwest,with significant eco-environmental improvements in the northern region and slower recovery in the southern region.Precipitation was the primary causes influencing vegetation recovery,showing positive trends in the central and northern TSO regions,while this trend reversed in the southern.The RSEI value indicate substantial eco-environment improvements in the central and northern areas(Sanggan,Daqing and Hutuo River Basins),whereas the southern regions(e.g.,Zhang,Qin,Fen and Sushui River Basins)remain in poor grade.Human activities,particularly land use/cover changes marked by increased forestation and urbanization alongside decreased cultivated land,significantly affected vegetation cover patterns.This study provides scientific references for formulating policies on ecological construction and high-quality development in the YRB.
基金jointly supported by the National Natural Science Foundation of China [grant number 42265012]the Funding by the Fengyun Application Pioneering Project [grant number FY-APP-ZX-2022.0221]。
文摘Forest ecosystems play key roles in mitigating human-induced climate change through enhanced carbon uptake;however,frequently occurring climate extremes and human activities have considerably threatened the stability of forests.At the same time,detailed accounts of disturbances and forest responses are not yet well quantified in Asia.This study employed the Breaks For Additive Seasonal and Trend method-an abrupt-change detection method-to analyze the Enhanced Vegetation Index time series in East Asia,South Asia,and Southeast Asia.This approach allowed us to detect forest disturbance and quantify the resilience after disturbance.Results showed that 20%of forests experienced disturbance with an increasing trend from 2000 to 2022,and Southeast Asian countries were more severely affected by disturbances.Specifically,95%of forests had robust resilience and could recover from disturbance within a few decades.The resilience of forests suffering from greater magnitude of disturbance tended to be stronger than forests with lower disturbance magnitude.In summary,this study investigated the resilience of forests across the low and middle latitudes of Asia over the past two decades.The authors found that most forests exhibited good resilience after disturbance and about two-thirds had recovered to a better state in 2022.The findings of this study underscore the complex relationship between disturbance and resilience,contributing to comprehension of forest resilience through satellite remote sensing.
基金supported by the Youth Exploration Foundation of Chinese Research Academy of Environmental Sciences(No.2022YSKY-55).
文摘Various technologies and projects have been explored and developed for the synergetic control of environmental pollution and carbon emissions in aquatic ecosystems.Planting submerged vegetation in shallow waters was also expected to achieve this purpose.However,the magnitude and mechanism of carbon dioxide(CO_(2))emission affected by submerged vegetation is not clear enough in complex aquatic ecosystems.This study investigated the influences of submerged plants on CO_(2)emission,ecosystem metabolism features,and microbial community traits based on observations in river networks on the Changjiang River Delta.The results showed that CO_(2)emission from planted waters accounted for 73%of unplanted waters.Meanwhile,planted waters had higher dissolved organic carbon removal capacity in overlying water and higher potential of carbon sequestration in sediment at the same time.These distinctions between the two habitats were attributed to(1)improved CO_(2)and bicarbonate consumption in water columns via enhancing photosynthesis and(2)inhibited CO_(2)production by reconstructing the benthic microbial community.Additional eco-advantages were found in planted sediments,such as a high potential of methane oxidation and xenobiotics biodegradation and a low risk of becoming black and odorous.In brief,submerged vegetation is beneficial in promoting pollution removal and carbon retention synchronously.This study advances our understanding of the feedback between aquatic metabolism and CO_(2)emission.
基金support from the National Natural Science Foundation of China(Nos.42450226,42371483,and 42171308)the Natural Science Foundation of Guangdong Province,China(No.2025A1515010770)the Postdoctoral Fellowship Program of CPSF(No.GZB20240880).
文摘Vegetation annual gross primary production(AGPP),the total yearly carbon assimilation via photosynthesis,serves as a key indicator of ecosystem carbon uptake.While AGPP variations are jointly influenced by both vegetation phenology and physiology,the effectiveness of satellite-derived indicators in capturing these variations has not been fully evaluated.This study develops and evaluates the satellite-derived phenology and physiology indicators for modeling AGPP variability.We assessed the performance of satellite-derived metrics,including solar-induced chlorophyll fluorescence(SIF),leaf area index(LAI),and enhanced vegetation index(EVI),in capturing AGPP variations.Among these,SIF-based indicators exhibited the highest accuracy(Pearson's r=0.79;root mean square error=414.7 gC·m^(-2)·year^(-1)),outperforming LAI-and EVI-based indicators.To further investigate the mechanisms driving AGPP variability,we used a structural equation model based on in situ observations to quantify the direct and indirect effects of climate on AGPP through phenology and physiology.Our results reveal that vegetation physiology,particularly the seasonal maximum gross primary production,plays a more dominant role in regulating AGPP than phenology.Furthermore,we found that globally,SIF-derived phenology indicators tend to be lower than those from LAI and EVI,whereas SIF-derived physiology indicators are elevated in tropical regions and the Southern Hemisphere.These findings highlight the potential of satellite-derived indicators in advancing AGPP modeling and emphasize the predominant role of vegetation physiology in regulating ecosystem carbon uptake.This study contributes to a refined understanding of global carbon cycle dynamics and provides insights for improving large-scale carbon assessments in the context of climate change.
文摘In drylands,biocrusts play crucial roles in regulating ecosystem functions.The study was conducted in the hilly rangelands of the semi-arid northern Negev of Israel,where we assessed the visual,morphological,spectral,and soil properties of livestock trampling routes and inter-route spaces in northern and southern facing hillslopes.Overall,both hillslope aspects were visually similar,whereas the ground surface of the routes was brighter(74.4%were characterized as having a'light'color)than the inter-route spaces(86.8%were characterized as having a'dark'color).These observations were supported by morphological identification of biocrust composition,which was dominated by cyanobacteria(67%)in the routes,and by mixed cyanobacteria/moss(56%)in the inter-routes.Mean Normalized Difference Vegetation Index(NDVI)was 24%higher in the inter-routes,while the mean Brightness Index(BI)was 12%higher in the routes.At the same time,the mean Crust Index(CI)was identical in the two microhabitats.Soil quality index(SQI),calculated based on the(pedoderm)soil properties of the two microhabitats,was 6%greater in the inter-routes than in the routes.This study suggests that recurrent trampling exacerbates soil compaction and shearing along the routes,thus preventing the successional development of complex biocrust compositions.
基金the National Natural Science Foundation of China(Grant No:32360052)。
文摘Tufa is an important type of landscape in karst regions.In recent years,the loss of landscape diversity due to tufa dissolution is affecting the stability of local ecosystems.Therefore,determining the factors and their mechanisms involved in tufa dissolution is important for preserving regional landscape diversity and local ecosystem stability.In this study,we selected four tufa sites with different degrees of dissolution(undissolved tufa,lightly dissolved tufa,moderately dissolved tufa,and heavily dissolved tufa)in Xiangzhigou karst region of Guizhou Province as the study objects.We explored the effects of natural plant colonization on tufa dissolution using changes inαandβdiversity indices,soil physicochemical indicators,tufa components,and tufa substrate.The results indicated that the Shannon-wiener index,Simpson index and Patrick richness index gradually increased with tufa's increasing degree of dissolution.Additionally,the dissolution degree exhibited a significantly negative correlation with the species diversity(p<0.05).Natural vegetation colonization is the primary cause of changes in the proportion of tufa components and changes in the physicochemical properties of overlying tufa soils.The proportion of CaO components decreased significantly,and the proportion of loss on ignition components increased significantly.Soil organic carbon,pH,total nitrogen,available nitrogen,total phosphorus,available phosphorus,total potassium,available potassium,β-glucosidase,and urease gradually increased with deeper tufa dissolution and were negatively correlated with the degree of dissolution(p<0.05).It indicates that tufa is a process of dissolution into the soil and gradual improvement of the physicochemical properties of the overlying soil.Furthermore,scanning electron micrographs revealed the transition from dense to fragmented tufa structure under the influence of plants.In conclusion,this study found that improving plant diversity exacerbated tufa dissolution.Our findings provide a theoretical reference for the preventing and controlling of tufa dissolution in karst.
基金funded by Key Project of Regional Innovation and Development Joint Fund of National Natural Science Foundation of China(U23A20149)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502,2024QZKK0200).
文摘The Qinghai-Tibet Plateau(QTP),the“Third Pole of the Earth,”boasts the most complex,diverse,and unique ecosystem in the world.From tropical vegetation on the southern slopes of the Himalayas to alpine subnival ecosystems,and from humid forests in the east to arid Gobi or desert vegetation in the west,the QTP encompasses nearly all the ecosystem types found in the Northern Hemisphere(The Comprehensive ScientificExpedition to Qinghai-Xizang Plateau,Academia Sinica,1988).
基金financially supported by the National Natural Science Foundation of China(Grant NO.52279056)Inner Mongolia open list project(Grant NO.2024JBGS0023)。
文摘The hydrodynamic response of overland flow to vegetation coverage on convex slopes remains inadequately quantified despite it is critical for soil erosion control in terrains dominated by such topography.This study systematically investigated the influence of varying vegetation coverage(0%,1.08%,3.24%,4.69%and 9.81%)on the hydrodynamic characteristics of convex slopes through indoor flume experiments under diverse flow discharges(5.5-13.5 m^(3)/h)and slopes(5°-25°).The results revealed three key hydrodynamic mechanisms:(1)Flow retardation and energy dissipation:Increasing vegetation coverage significantly reduced overland flow velocity and promoted higher flow depth,thereby enhancing water retention and energy dissipation.Both stream power(Ω)and unit stream power(ω)declined by 13.9%-30.1%compared to bare slopes.(2)Flow Regime Transition:Froude number(Fr)decreased with increasing vegetation coverage,promoting the transition from supercritical to subcritical flow.The Reynolds number(Re)consistently exceeded 500,indicating the absence of laminar flow.(3)Modification of flow resistance:Vegetation resistance increased nonlinearly with coverage.Maximum bed shear stress was observed at 4.69%coverage(23.5%higher than bare slopes).However,Manning’s(n)and Darcy-Weisbach(f)coefficients did not correlate clearly with Re,indicating that vegetation coverage and slope type feedback significantly change flow resistance mechanisms.
基金financed as part of the project“Development of a methodology for instrumental base formation for analysis and modeling of the spatial socio-economic development of systems based on internal reserves in the context of digitalization”(FSEG-2023-0008).
文摘This study explores the determinants of impact on ecology in Northern Tanzania.By examining key socio-economic,institutional,and structural factors influencing engagement the study provides insights in strengthening agribusiness networks and improving livelihoods.Data was collected from 215 farmers and 320 traders through a multistage sampling procedure.Heckman AI sample selection model was used in data analysis whereby the findings showed key factors influencing farmers’decisions on ecology were gender and years of formal education at p<0.1,and access to finance and off-farm income at p<0.05.The degree of farmers participation in social groups was influenced by age,household size,off-farm income and business network at p<0.05,number of years in formal education and access to finance at p<0.01,and distance to the market at p<0.1.The decision of traders to impact on ecology was significantly influenced by age and trading experience at p<0.1.Meanwhile,the degree of their involvement in social groups was strongly affected by gender,formal education,and trust at p<0.01,as well as by access to finance and business networks at p<0.05.The study concluded that natural ecology is influenced by socio economic and structural factors but trust among group members determine the degree of participation.The study recommends that strategies to improve agribusiness networks should understand underlying causes of impact on ecology and strengthen available social groups to improve performance of farmers and traders.
文摘Several days ago,we had a nice picnic in the woods at the foot of a hill.Our teachers took food,drinks and vegetables for us.When we arrived at the woods,we found it quiet and beautiful.We began to look for dry wood to make a fire.Half an hour later,all the things were ready.
基金Under the auspices of the National Natural Science Foundation of China(No.32371863)Fundamental Research Funds for the Central Universities(No.2572025AW39)。
文摘Understanding the complex relationship between vegetation change and both natural and anthropogenic factors is a subject of global importance.However,comprehensive explanations of vegetation cover trends across China’s different regions and the dynamic roles of their drivers remain limited.This study analyzed national and regional vegetation change trends from 2000 to 2020 and evaluated the evolving impacts of natural and anthropogenic factors.Results indicate that 44.14%of China’s land experienced significant increase(P<0.05)in vegetation coverage.The Northeast(A1),Southwest(A5),and South China(A8)regions showed extremely significant increases in vegetation cover,with over 65%of vegetation exhibiting extremely significant growth(P<0.01).In contrast,less than 25%of vegetation in Inner Mongolia(A2),Northwest(A3),and the Qinghai-Tibetan Plateau(A4)subregions demonstrated an extremely significant increasing trend(P<0.01).Precipitation(q=0.766)and land use type(q=0.636)were the most influential natural and anthropogenic factors,respectively,with their interaction(q=0.838)dominating national vegetation patterns.On the west side of the Hu Line,vegetation dynamics were mainly limited by arid and semi-arid climates,with precipitation as the dominant factor,though land use measures have contributed to some vegetation improvement.Between 2000 and 2020,the influence of precipitation on vegetation cover increased in regions A3 and A4,with q-values rising by 26.73%and 101.13%,respectively.Additionally,soil type exerted a significant effect(P<0.001)on vegetation cover across all regions,being most pronounced in A2(q=0.692).On the east side of the Hu Line,vegetation growth benefited generally from warm and humid conditions,while local decline in urbanized areas was largely attributable to land use change and economic expansion.Concurrently anthropogenic factors such as land use and population density increasingly influenced vegetation dynamics in eastern urban areas of the Hu Line.Population density and GDP were the most influential factors affecting vegetation cover in region A8,with q-values of 0.443 and 0.380,respectively(P<0.001).Future efforts should maintain the benefits of large-scale ecological projects and harmonize the relationship between urban vegetation and anthropogenic influences.
