The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkyl...The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkylated/nitrated/oxygenated PAHs(APAHs/NPAHs/OPAHs)into the Yellow River poses a potential risk to the aquatic ecosystem and human health.A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons,and 19 PAHs,5 APAHs,16 NPAHs,and 7 OPAHswere measured.The concentrations of ƩPAHs,ƩAPAHs,ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L,6.9–81 ng/L,0.64–9.0 ng/L,and 7.2–81 ng/L in water,respectively,and 27–420 ng/g,5.1–130 ng/g,0.19–1.8 ng/g and 3.9–51 ng/g in sediment,respectively.The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment,and port activities had a notable influence on the proportion of 1-methylpyrene in both water and sediment.The fugacity fraction analysis suggested that sediment was a secondary source of OPAHs,while benzo[k]fluoranthene,benzo[e]pyrene,benzo[a]pyrene,and 5-methylchrysene migrated from water to sediment.The main contributors to PAHs,APAHs,NPAHs,and OPAHs in water and sediment were combustion and petroleum sources.Compared to water,sediment displayed a heightened ecological risk associated with PAHs,APAHs,NPAHs,and OPAHs.Adults residing in the YRD region were at higher risk of cancer than children,which deserves special attention.展开更多
The interactions between fire,ecosystems,and climate are complex.Tropical ecosystems have dominated global active fires nowadays,yet its causes,mechanisms,and consequences remain relatively poorly understood.To in-ves...The interactions between fire,ecosystems,and climate are complex.Tropical ecosystems have dominated global active fires nowadays,yet its causes,mechanisms,and consequences remain relatively poorly understood.To in-vestigate temporal response of remotely-sensed active fires to intra-annual climate change,several 1-km datasets,including the Moderate-resolution Imaging Spectroradiometer Collection 6(MODIS C6)active fires and the Cli-matologies at High Resolution for the Earth’s Land Surface Areas(CHELSA)climate variables,were gathered to examine the climatic characteristics of active fire incidences,fire-climate correlations,and the average monthly response of active fire occurrences to climate change using the Geographic Information System(GIS)Fishnet tool,Theil-Sen Median slope estimation,Mann-Kendall significance test,and Pearson’s correlation.We concluded that climate variables’trends of nearly two-decade active fires displayed varied degrees of increment in precipitation(Pre),temperature(Tas),and surface downwelling shortwave radiation(Rsds)and inconsistent decrement in near-surface relative humidity(Hurs)and near-surface wind speed(sfcWind).MODIS multi-year(2003-2018)active fires were moderately to strongly correlated negatively with Pre and Hurs at 10 km grid-resolution but positively with sfcWind and Rsds,showing marked geographical variations in correlation direction and strength.The most significant finding is the newly observed inverse relationship between active fires and precipitation on both sides of the equator.High occurrence areas of active fires regularly appear back and forth along with latitudinal changes(at one-degree intervals)in monthly minimum precipitation between the tropical Northern and Southern Hemispheres.The present study contributes to exploring the underlying mechanism of fire-climate interactions against the backdrop of climate warming.展开更多
The Changjiang River Estuary(CRE) and its offshore plumes host a diverse phytoplankton community;however, the spatiotemporal dynamics of these microorganisms and their environmental drivers remain poorly understood. T...The Changjiang River Estuary(CRE) and its offshore plumes host a diverse phytoplankton community;however, the spatiotemporal dynamics of these microorganisms and their environmental drivers remain poorly understood. This study aims to elucidate the spatiotemporal variations and environmental heterogeneity of phytoplankton communities in the CRE, as well as to understand the factors driving their assemblage. Utilizing ecological survey data collected from the CRE and adjacent waters during spring and summer from 2018 to 2020, we conducted a spatiotemporal analysis of phytoplankton β-diversity in the region. We decomposed β-diversity into species contributions to β-diversity(SCBD)and local contributions to β-diversity(LCBD) to examine spatial differences in phytoplankton diversity and the contributions of individual species within the community. Our findings reveal that spatial differences, primarily driven by water salinity and distance from the coastline, are key factors influencing the heterogeneity of phytoplankton community composition. Key species such as Skeletonema costatum, Melosira granulata, and M. granulata var.angustissima significantly affected β-diversity. Further, β-diversity decomposition reveals that community assembly is driven by interactive biogeochemical forces: salinity gradients shape spatial heterogeneity through runoff-seawater mixing, eutrophic conditions promote the dominance of nutrient-dependent taxa, and silica availability regulates diatom-to-flagellate succession. This study provides a methodological paradigm for analyzing phytoplankton community assembly mechanisms in estuaries, thereby offering scientific support for biogeography-based ecosystem management in the CRE.展开更多
Lake area information in the Badain Jaran Desert in 1973, 1990, 2000, and 2010 was obtained by visual interpretation and water index analysis of remote sensing images, based on the spatial and temporal characteristics...Lake area information in the Badain Jaran Desert in 1973, 1990, 2000, and 2010 was obtained by visual interpretation and water index analysis of remote sensing images, based on the spatial and temporal characteristics of lake area changes during 37 years. Results indicated that the nttmber of lakes declined from 94 to 82 and the total surface area was reduced by 3.69 km2 during 1973-2010. The desert lake area reduced by different degrees in different periods, but this occurred most rapidly during 1973-1990. According to the statistics of lake area changes, lake area decreases mainly occurred in the lakes with areas less than 0.2 km2, while the areas of lakes greater than 0.9 km2 only fluctuated. The changes of lake areas were probably due to changes in the quantity of underground water supplies rather than the effects of local climate change or human factors.展开更多
In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future...In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.展开更多
As one of the strongest convection bands in the Southern Hemisphere,the South Pacific Convergence Zone(SPCZ)substantially influences the variabilities in the atmospheric circulation and Antarctic climate.In this study...As one of the strongest convection bands in the Southern Hemisphere,the South Pacific Convergence Zone(SPCZ)substantially influences the variabilities in the atmospheric circulation and Antarctic climate.In this study,it is revealed that the intensity of the SPCZ can change the characteristics of sea ice in the West Antarctica during austral autumn,which is significantly independent of the El Niño-Southern Oscillation(ENSO).Observational and numerical results suggest that a stronger-than-usual SPCZ can generate a poleward-propagating Rossby wave train along a great circular route and induce a weakening of the Amundsen Sea Low(ASL)near West Antarctica,which may somewhat offset the teleconnections exerted by ENSO.These changes in the strength and zonal extent of ASL is noticeable and robustly lead to a tripole response of sea-ice perturbations in the Ross,Amundsen,and Weddell Seas.We find that the wind-driven dynamical processes determine the local sea-ice changes,while the influence from thermodynamic processes is trivial.This research underscores the need to consider the SPCZ variability for a comprehensive understanding of sea-ice changes in West Antarctica on interannual timescales.展开更多
The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevel...The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevels. It was thus the first international treaty to endow the 2 ℃ global temperature target with legal effect.The qualitative expression of the ultimate objective in Article 2 of the United Nations Framework Conventionon Climate Change （UNFCCC） has now evolved into the numerical temperature rise target in Article 2 of theParis Agreement. Starting with the Second Assessment Report （SAR） of the Intergovernmental Panel on Cli-mate Change （IPCC）, an important task for subsequent assessments has been to provide scientific informa-tion to help determine the quantified long-term goal for UNFCCC negotiation. However, due to involvementin the value judgment within the scope of non-scientific assessment, the IPCC has never scientifically af-firmed the unacceptable extent of global temperature rise. The setting of the long-term goal for addressingclimate change has been a long process, and the 2 ℃ global temperature target is the political consensuson the basis of scientific assessment. This article analyzes the evolution of the long-term global goal foraddressing climate change and its impact on scientific assessment, negotiation processes, and global low-carbon development, from aspects of the origin of the target, the series of assessments carried out by the 1PCCfocusing on Article 2 of the UNFCCC, and the promotion of the global temperature goal at the political level.展开更多
This manuscript features the promising findings of a study conducted by Ju et al,who used graphene nanocomposites for air disinfection in dental clinics.Their study demonstrated that,compared with conventional filters...This manuscript features the promising findings of a study conducted by Ju et al,who used graphene nanocomposites for air disinfection in dental clinics.Their study demonstrated that,compared with conventional filters,graphene nanocom-posites substantially improved air quality and reduced microbial contamination.This manuscript highlights the innovative application of graphene materials,emphasizing their potential to enhance dental clinic environments by minimizing secondary pollution.On the basis of the unique antimicrobial properties of gra-phene and the original study’s rigorous methodology,we recommend using gra-phene nanocomposites in clinical settings to control airborne infections.展开更多
The Paris Climate Change Conference was successfully concluded with the Paris Agreement, which is a milestone for the world in collectively combating climate change. By participating in IPCC assessments and conducting...The Paris Climate Change Conference was successfully concluded with the Paris Agreement, which is a milestone for the world in collectively combating climate change. By participating in IPCC assessments and conducting national climate change assessments, China has been increasing its understanding of the issue. For the first time, China＇s top leader attended the Conference of the Parties, which indicates the acknowledgement of the rationality and necessity of climate change response by China at different levels. Moreover, this participation reflects China＇s commitment to including climate change in its ecology improvement program and pursuing a low-carbon society and economy. In order to ensure the success of the Paris Conference, China has contributed significantly. China＇s constructive participation in global governance shows that China is a responsible power. These principles such as the creation of a future of win-win cooperation with each country contributing to the best of its ability; a future of the rule of law, fairness, and justice; and a future of inclusiveness, mutual learning, and common development will serve as China＇s guidelines in its efforts to facilitate the implementation of the Paris Agreement and participate in the design of international systems.展开更多
Urban agglomeration is caused by the continuous acceleration of the urbanization process in China. Studying the expansion of construction land can not only know the changes and development of urban agglomeration in ti...Urban agglomeration is caused by the continuous acceleration of the urbanization process in China. Studying the expansion of construction land can not only know the changes and development of urban agglomeration in time, but also obtain the great significance of the future management. In this study, taking Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan) urban agglomeration in Hunan province as a study area, Landsat images from 1995 to 2014 and Autologistic-CLUE-S model simulation data were used. Moreover, several factors including gravity center, direction, distance and landscape index were considered in the analysis of the expansion. The results revealed that the construction area increased by 132.18%, from 372.28 km^2 in 1995 to 864.37 km^2 in 2014. And it might even reach 1327.23 km^2 in 2023. Before 2014, three cities had their own respective and discrete development directions. However, because of the integration policy implementation in 2008, the Chang-Zhu-Tan began to gather, the gravity center moved southward after 2014, and the distance between cities decreased, which was in line with the development plan of urban expansion. The research methods and results were relatively reliable, and these results could provide some reference for the future land use planning and spatial allocation in the urbanization process of Chang-Zhu-Tan urban agglomeration.展开更多
Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential su...Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.展开更多
The Conversion of Land Use and its Effects at Small regional extent （CLUE-S） model is a widely used method to simulate land use change. An ordinary logistic regression model was integrated into the CLUE-S model to i...The Conversion of Land Use and its Effects at Small regional extent （CLUE-S） model is a widely used method to simulate land use change. An ordinary logistic regression model was integrated into the CLUE-S model to identify explanatory variables without considering the spatial autocorrelation effect. Using image-derived maps of the Changsha- Zhuzhou-Xiangtan urban agglomeration, the CLUE-S model was integrated with the ordinary logistic regression and autologistic regression models in this paper to simulate land use change in 2000, 2005 and 2009 based on an observation map from 1995. Significant positive spatial autocorrelation was detected in residuals of ordinary logistic models. Some variables that were much more significant than they should be were selected. Autologistic regression models, which used autocovariate incorporation, were better able to identify driving factors. The Receiver Operating Characteristic Curve （ROC） values of autologistic regression models were larger than 0.8 and the pseudo R^2 values were improved, compared with results of logistic regression model. By overlapping the observation maps, the Kappa values of the ordinary logistic regression model （OL）-CLUE-S and autologistic regression model （AL）-CLUE-S models were larger than 0.75. The results showed that the simulation results were indeed accurate. The Kappa fuzzy （Kfuzzy） values of the AL-CLUE-S models （0.780, 0.773, 0.606） were larger than the values of the OL-CLUE-S models （0.759, 0.760, 0.599） during the three periods. The AL-CLUE-S models performed better than the OL-CLUE-S models in the simulation of land use change. The results showed that it is reasonable to integrate autocovariates into CLUE-S models. However, the Kfuzzy values decreased with prolonged duration of simulation and the maximum range of time was not discussed in this paper.展开更多
Disaster risk reduction,an essential function of protected areas(PAs),has been generally overlooked in PA design.Using primates as a model,we designed a disaster risk index(DRI)to measure the disaster sensitivity of p...Disaster risk reduction,an essential function of protected areas(PAs),has been generally overlooked in PA design.Using primates as a model,we designed a disaster risk index(DRI)to measure the disaster sensitivity of primate species.High-conservation-need(HCN)areas were identified by both their richness and number of threatened primate species.We also constructed high-disaster-risk(HDR)areas and climate-sensitive(CS)areas based on a disaster risk assessment and temperature change under climate change.We overlaid HCN and HDR areas to obtain HDR-HCN areas.We defined species conservation targets as the percent of each species’range that should be effectively conserved using“Zonation”.Landslides had the highest DRI(1.43±0.88),but have been overlooked in previous studies.PA coverage in HDR-HCN(30%)areas was similar to that in HCN areas(28%),indicating that current PA design fails to account for disaster risk reduction.About 50%of the HDR-HCN areas overlapped with CS areas.Presently,43%of primate species meet their conservation targets.Fifty-seven of primate species would meet their conservation targets and 67%of primates could benefit from PA expansion if HDR-HCN areas are fully incorporated into PAs.Increasing PA coverage in HDR-HCN areas is essential to achieving both primate conservation and disaster risk reduction.The study calls for integrating disaster risk reduction into PA design guidelines,particularly in regions like the western Amazon,and recommends flexible conservation approaches in other areas.展开更多
The response of lake environments in arid Central Asia to climate change during the Late Holocene over the centennial to millennial timescales remains contentious.The reason that primarily paleoenvironmental proxies d...The response of lake environments in arid Central Asia to climate change during the Late Holocene over the centennial to millennial timescales remains contentious.The reason that primarily paleoenvironmental proxies diverse and the scarcity of accurate quantitative reconstruction records.In this study,we employed diatoms and pollen records from lacustrine sediment in the Aibi Lake of Southwest Junggar Basin to quantitatively reconstruct salinity and watershed precipitation amounts while exploring the associated forcing mechanisms.The results indicate that Aibi Lake salinity varied between 2 and 47 g/L during the Late Holocene Period,indicating a generally brackish environment,and corresponding to prevailing Tryblionella granulata diatom in the lake basin.Westerly-dominated annual precipitation varied between 250 and 320 mm during the Late Holocene Period in the basin,exhibiting a generally semi-arid environment and prevailing desert steppe vegetation.The Aibi Lake has a low salinity of average value of~15 g/L and exhibits elevated precipitation(average value of~280 mm)during the periods of the 2900-1990,1570-1140,and 590-120 cal yr BP.The reconstructed precipitation and salinity exhibit a periodicity of~200 years,which is consistent with the cycle of phase changes of the North Atlantic oscillation(NAO)and total solar irradiance(TSI).This correlation suggests that variations in NOA and TSI significantly influence the precipitation and salinity changes in Central Asia over centennial to millennial timescales.展开更多
Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key p...Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.展开更多
BACKGROUND Antibiotic resistance significantly impacts the treatment failure rates of Helicobacter pylori(H.pylori)infections.AIM To investigate the trends in primary antibiotic resistance of H.pylori in Taiwan of Chi...BACKGROUND Antibiotic resistance significantly impacts the treatment failure rates of Helicobacter pylori(H.pylori)infections.AIM To investigate the trends in primary antibiotic resistance of H.pylori in Taiwan of China over the past six years.METHODS We conducted a retrospective analysis of H.pylori isolates from Taiwan residents,China who had not undergone previous treatments(n=1408),collected between January 1,2019 and December 31,2024.Susceptibility of these strains to amoxicillin,clarithromycin,levofloxacin,metronidazole,and tetracycline was tested using the Epsilometer test.We analyzed the trends in single and dual resistance profiles over the study period,and compared antibiotic resistance across different regions(northern,southern and eastern areas)of Taiwan of China.RESULTS The overall resistance rates for H.pylori to amoxicillin,clarithromycin,metronidazole,tetracycline,and levofloxacin in Taiwan of China were 1.3%,18.0%,31.0%,0.8%,and 28.7%,respectively.Tetracycline resistance increased significantly from 0%in 2019 to 3.5%in 2024(P value inχ^(2)test for linear trend:<0.001),while metronidazole resistance declined from 35.5%to 13.0%(P value inχ^(2)test for linear trend:<0.001).No significant changes of amoxicillin,clarithromycin and levofloxacin resistances were observed.The dual resistances to clarithromycin plus tetracycline,and metronidazole plus tetracycline both increased significantly from 0%to 1.7%from 2019 to 2024(P value inχ^(2)test for linear trend:<0.05).Furthermore,no significant regional differences in resistance frequencies except for levofloxacin were detected.CONCLUSION Primary antibiotic resistance to tetracycline in H.pylori has increased in Taiwan of China from 2019 to 2024,while resistance to metronidazole has decreased during the same period.The dual resistance to clarithromycin plus tetracycline and metronidazole plus tetracycline both increased significantly.展开更多
Changes in arid and semi-arid regions are primarily identified through hydroclimatic and land cover variations.Therefore,analyzing the temporal and spatial patterns of water-climate changes and land cover in the Great...Changes in arid and semi-arid regions are primarily identified through hydroclimatic and land cover variations.Therefore,analyzing the temporal and spatial patterns of water-climate changes and land cover in the Great Lakes Depression Region in western Mongolia is crucial for studying this basin and similar areas.This research used the Mann-Kendall(MK)test,Innovative Trend Analysis Method(ITAM),Sen's Slope Estimator Test(SSET),and land cover change analysis to examine the statistical relationships among climate variability,river discharge,lake level fluctuations,and land cover changes.Air temperature increased during the study period(Z=1.16*),while total annual precipitation(Z=-0.79)declined slightly.Major river discharges in the basin(Z=-3.92***),as well as lake water levels(Z=-2.51**),also decreased.Land cover changes were closely related to climate change,with indicators such as precipitation,river discharge,and lake water levels showing strong connections.Additionally,in 2020,basin grassland cover and bare area decreased,whereas impervious surfaces and cropland—land cover types influenced by human activity significantly increased.Consequently,future research should focus on human factors impacting the Great Lakes Depression Region in western Mongolia.展开更多
Quantification of the impacts of environmental changes on runoff in the transitional area from the Tibetan Plateau to the Loess Plateau is of critical importance for regional water resources management.Trends and abru...Quantification of the impacts of environmental changes on runoff in the transitional area from the Tibetan Plateau to the Loess Plateau is of critical importance for regional water resources management.Trends and abrupt change points of the hydro-climatic variables in the Tao River Basin were investigated during 1956-2015.It also quantitatively separates the impacts of climate change and human activities on runoff change in the Tao River by using RCC-WBM model.Results indicate that temperature presented a significant rising trend(0.2℃per decade)while precipitation exhibited an insignificant decreasing trend(3.8 mm per decade)during 1956-2015.Recorded runoff in the Tao River decreased significantly with a magnitude of-13.7 mm per decade and abrupt changes in 1968 and 1986 were identified.Relative to the baseline period(1956-1968),runoff in the two anthropogenic disturbed periods of 1969-1986 and 1987-2015 decreased by 27.8 mm and 76.5 mm,respectively,which can be attributed to human activities(accounting for 69%)and climate change(accounting for 31%).Human activities are the principal drivers of runoff reduction in the Tao River Basin.However,the absolute influences on runoff reductions by the both drivers tend to increase,from 7.7 mm in 1969-1986 to 24.4 mm in 1987-2015 by climate change and from 20.2 mm to 52.2 mm by human activities.展开更多
An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and ...An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and associated drivers remain to be explored. This study used a satellite Leaf Area Index(LAI) dataset(the GLASS LAI dataset) and examined vegetation changes in humid and arid regions of the TP during 1982–2012. Based on distributions of the major vegetation types, the TP was divided roughly into a humid southeastern region dominated by meadow and a dry northwestern region covered mainly by steppe. It was found that the dividing line between the two regions corresponded well with the lines of mean annual precipitation of 400 mm and the mean LAI of 0.3. LAI=0.3 was subsequently used as a threshold for investigating vegetation type changes at the interanual and decadal time scales: if LAI increased from less than 0.3 to greater than0.3 from one time period to the next, it was regarded as a change from steppe to meadow, and vice versa. The analysis shows that changes in vegetation types occurred primarily around the dividing line of the two regions, with clear growth(reduction) of the area covered by meadow(steppe), in consistency with the findings from using another independent satellite product. Surface air temperature and precipitation(diurnal temperature range) appeared to contribute positively(negatively) to this change though climate variables displayed varying correlation with LAI for different time periods and different regions.展开更多
The quantity and quality changes of cropland in Jilin province are analyzed by combining the statistics from 1949 to 1999 and land-use maps interpreted from TM images in 1986 and in 2000. In general, t...The quantity and quality changes of cropland in Jilin province are analyzed by combining the statistics from 1949 to 1999 and land-use maps interpreted from TM images in 1986 and in 2000. In general, the decreasing trend of the cropland in Jilin province was derived from the statistic data in 1949-1999. While since 1983, the cropland area has increased slightly, because of the conversion from other land-use types to cropland. It is showed that the net increase of cropland was about 43.40×10 4 ha. While the quality change of the cropland can be seen from that mainly caused by the conversion from forestland, grassland to cropland and the change mainly took place in the west, where it is ecologically fragile. According to the spatial distribution model, the centroids' move of the cropland and the grain production are calculated, whose directions are not consistent. The impact of the dynamic change of the cropland on food security is further analyzed.展开更多
基金supported by the Natural Science Foundation of Qingdao(No.23-2-1-224-zyyd-jch).
文摘The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkylated/nitrated/oxygenated PAHs(APAHs/NPAHs/OPAHs)into the Yellow River poses a potential risk to the aquatic ecosystem and human health.A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons,and 19 PAHs,5 APAHs,16 NPAHs,and 7 OPAHswere measured.The concentrations of ƩPAHs,ƩAPAHs,ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L,6.9–81 ng/L,0.64–9.0 ng/L,and 7.2–81 ng/L in water,respectively,and 27–420 ng/g,5.1–130 ng/g,0.19–1.8 ng/g and 3.9–51 ng/g in sediment,respectively.The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment,and port activities had a notable influence on the proportion of 1-methylpyrene in both water and sediment.The fugacity fraction analysis suggested that sediment was a secondary source of OPAHs,while benzo[k]fluoranthene,benzo[e]pyrene,benzo[a]pyrene,and 5-methylchrysene migrated from water to sediment.The main contributors to PAHs,APAHs,NPAHs,and OPAHs in water and sediment were combustion and petroleum sources.Compared to water,sediment displayed a heightened ecological risk associated with PAHs,APAHs,NPAHs,and OPAHs.Adults residing in the YRD region were at higher risk of cancer than children,which deserves special attention.
基金funded by National Natural Science Foundation of China(Grants No.42371282 and 42130508)the Second Ti-betan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK1006)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2020055)。
文摘The interactions between fire,ecosystems,and climate are complex.Tropical ecosystems have dominated global active fires nowadays,yet its causes,mechanisms,and consequences remain relatively poorly understood.To in-vestigate temporal response of remotely-sensed active fires to intra-annual climate change,several 1-km datasets,including the Moderate-resolution Imaging Spectroradiometer Collection 6(MODIS C6)active fires and the Cli-matologies at High Resolution for the Earth’s Land Surface Areas(CHELSA)climate variables,were gathered to examine the climatic characteristics of active fire incidences,fire-climate correlations,and the average monthly response of active fire occurrences to climate change using the Geographic Information System(GIS)Fishnet tool,Theil-Sen Median slope estimation,Mann-Kendall significance test,and Pearson’s correlation.We concluded that climate variables’trends of nearly two-decade active fires displayed varied degrees of increment in precipitation(Pre),temperature(Tas),and surface downwelling shortwave radiation(Rsds)and inconsistent decrement in near-surface relative humidity(Hurs)and near-surface wind speed(sfcWind).MODIS multi-year(2003-2018)active fires were moderately to strongly correlated negatively with Pre and Hurs at 10 km grid-resolution but positively with sfcWind and Rsds,showing marked geographical variations in correlation direction and strength.The most significant finding is the newly observed inverse relationship between active fires and precipitation on both sides of the equator.High occurrence areas of active fires regularly appear back and forth along with latitudinal changes(at one-degree intervals)in monthly minimum precipitation between the tropical Northern and Southern Hemispheres.The present study contributes to exploring the underlying mechanism of fire-climate interactions against the backdrop of climate warming.
基金The program of opening ceremony to select the best candidates of the Key Laboratory of Marine Ecological Monitoring and Restoration Technologies,MNR under contract No. MEMRT2024JBGS01。
文摘The Changjiang River Estuary(CRE) and its offshore plumes host a diverse phytoplankton community;however, the spatiotemporal dynamics of these microorganisms and their environmental drivers remain poorly understood. This study aims to elucidate the spatiotemporal variations and environmental heterogeneity of phytoplankton communities in the CRE, as well as to understand the factors driving their assemblage. Utilizing ecological survey data collected from the CRE and adjacent waters during spring and summer from 2018 to 2020, we conducted a spatiotemporal analysis of phytoplankton β-diversity in the region. We decomposed β-diversity into species contributions to β-diversity(SCBD)and local contributions to β-diversity(LCBD) to examine spatial differences in phytoplankton diversity and the contributions of individual species within the community. Our findings reveal that spatial differences, primarily driven by water salinity and distance from the coastline, are key factors influencing the heterogeneity of phytoplankton community composition. Key species such as Skeletonema costatum, Melosira granulata, and M. granulata var.angustissima significantly affected β-diversity. Further, β-diversity decomposition reveals that community assembly is driven by interactive biogeochemical forces: salinity gradients shape spatial heterogeneity through runoff-seawater mixing, eutrophic conditions promote the dominance of nutrient-dependent taxa, and silica availability regulates diatom-to-flagellate succession. This study provides a methodological paradigm for analyzing phytoplankton community assembly mechanisms in estuaries, thereby offering scientific support for biogeography-based ecosystem management in the CRE.
基金supported by the National Natural Science Foundation of China(41371114,41101187)the National Environmental Protection Public Welfare Industry Tar-geted Research Fund(201209034)the Ministry of Education,Humanities and Social Science Projects(10YJCZH053)
文摘Lake area information in the Badain Jaran Desert in 1973, 1990, 2000, and 2010 was obtained by visual interpretation and water index analysis of remote sensing images, based on the spatial and temporal characteristics of lake area changes during 37 years. Results indicated that the nttmber of lakes declined from 94 to 82 and the total surface area was reduced by 3.69 km2 during 1973-2010. The desert lake area reduced by different degrees in different periods, but this occurred most rapidly during 1973-1990. According to the statistics of lake area changes, lake area decreases mainly occurred in the lakes with areas less than 0.2 km2, while the areas of lakes greater than 0.9 km2 only fluctuated. The changes of lake areas were probably due to changes in the quantity of underground water supplies rather than the effects of local climate change or human factors.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program[grant number 2019QZKK0101]。
文摘In the context of global warming,it is anticipated that both the intensity and the frequency of future global extreme high precipitation(EHP)and extreme high temperature(EHT)events will increase.To evaluate the future extreme climate changes in the Asian arid region and Tibetan Plateau,this study applied the NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP-CMIP6)to assess the changes in EHP(Rx5d and R95pTOT)and EHT(TX90p and TXx)under different emission scenarios in the 21st century.Findings suggest that both the frequency and the intensity of the extreme indices will increase,exhibiting accelerated growth under higher emission scenarios,particularly under the SSP5-8.5 emission scenario.It is suggested that the growth of EHT and EHP in the early subperiod of the 21st century(2026-2045)will be relatively moderate,with small differences between different emission scenarios.However,by the middle subperiod of the 21st century(2041-2060),the differences between different emission scenarios will become larger than the 2035s and the growth will become more intense.In western central Asia,TX90p,TXx,Rx5d,and R95pTOT increase by 9.7%-14.2%(13.3%-24.7%),1.3℃-1.7℃(1.6℃-2.7℃),6.5%-8.9%(8.2%-8.8%),and 18.1%-27.0%(25.6%-30.0%)by the early(middle)subperiod;in eastern central Asia,TX90p,TXx,Rx5d,and R95pTOT increase 8.1%-12.0%(11.3%-21.1%),1.4℃-1.8℃(1.9℃-2.9℃),7.4%-9.7%(10.4%-13.8%),and 20.2%-29.3%(32.0%-40.8%)by the early(middle)subperiod;and over the Tibetan Plateau,TX90p,TXx,Rx5d,and R95pTOT increase 12.5%-17.4%(17.0%-31.0%),1.2℃-1.5℃(1.6℃-2.5℃),7.2%-10.0%(9.9%-15.0%),and 26.6%-33.1%(36.1%-55.3%)by the early(middle)subperiod.
基金supported by the National Natural Science Foundation of China(Grant No.42375024).
文摘As one of the strongest convection bands in the Southern Hemisphere,the South Pacific Convergence Zone(SPCZ)substantially influences the variabilities in the atmospheric circulation and Antarctic climate.In this study,it is revealed that the intensity of the SPCZ can change the characteristics of sea ice in the West Antarctica during austral autumn,which is significantly independent of the El Niño-Southern Oscillation(ENSO).Observational and numerical results suggest that a stronger-than-usual SPCZ can generate a poleward-propagating Rossby wave train along a great circular route and induce a weakening of the Amundsen Sea Low(ASL)near West Antarctica,which may somewhat offset the teleconnections exerted by ENSO.These changes in the strength and zonal extent of ASL is noticeable and robustly lead to a tripole response of sea-ice perturbations in the Ross,Amundsen,and Weddell Seas.We find that the wind-driven dynamical processes determine the local sea-ice changes,while the influence from thermodynamic processes is trivial.This research underscores the need to consider the SPCZ variability for a comprehensive understanding of sea-ice changes in West Antarctica on interannual timescales.
文摘The Paris Agreement proposed to keep the increase in global average temperature to well below 2 ℃ abovepre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 ℃ above pre-industriallevels. It was thus the first international treaty to endow the 2 ℃ global temperature target with legal effect.The qualitative expression of the ultimate objective in Article 2 of the United Nations Framework Conventionon Climate Change （UNFCCC） has now evolved into the numerical temperature rise target in Article 2 of theParis Agreement. Starting with the Second Assessment Report （SAR） of the Intergovernmental Panel on Cli-mate Change （IPCC）, an important task for subsequent assessments has been to provide scientific informa-tion to help determine the quantified long-term goal for UNFCCC negotiation. However, due to involvementin the value judgment within the scope of non-scientific assessment, the IPCC has never scientifically af-firmed the unacceptable extent of global temperature rise. The setting of the long-term goal for addressingclimate change has been a long process, and the 2 ℃ global temperature target is the political consensuson the basis of scientific assessment. This article analyzes the evolution of the long-term global goal foraddressing climate change and its impact on scientific assessment, negotiation processes, and global low-carbon development, from aspects of the origin of the target, the series of assessments carried out by the 1PCCfocusing on Article 2 of the UNFCCC, and the promotion of the global temperature goal at the political level.
文摘This manuscript features the promising findings of a study conducted by Ju et al,who used graphene nanocomposites for air disinfection in dental clinics.Their study demonstrated that,compared with conventional filters,graphene nanocom-posites substantially improved air quality and reduced microbial contamination.This manuscript highlights the innovative application of graphene materials,emphasizing their potential to enhance dental clinic environments by minimizing secondary pollution.On the basis of the unique antimicrobial properties of gra-phene and the original study’s rigorous methodology,we recommend using gra-phene nanocomposites in clinical settings to control airborne infections.
文摘The Paris Climate Change Conference was successfully concluded with the Paris Agreement, which is a milestone for the world in collectively combating climate change. By participating in IPCC assessments and conducting national climate change assessments, China has been increasing its understanding of the issue. For the first time, China＇s top leader attended the Conference of the Parties, which indicates the acknowledgement of the rationality and necessity of climate change response by China at different levels. Moreover, this participation reflects China＇s commitment to including climate change in its ecology improvement program and pursuing a low-carbon society and economy. In order to ensure the success of the Paris Conference, China has contributed significantly. China＇s constructive participation in global governance shows that China is a responsible power. These principles such as the creation of a future of win-win cooperation with each country contributing to the best of its ability; a future of the rule of law, fairness, and justice; and a future of inclusiveness, mutual learning, and common development will serve as China＇s guidelines in its efforts to facilitate the implementation of the Paris Agreement and participate in the design of international systems.
基金National Natural Science Foundation of China,No.41571077National Key Research and Development Program of China,No.2016YFC0503002
文摘Urban agglomeration is caused by the continuous acceleration of the urbanization process in China. Studying the expansion of construction land can not only know the changes and development of urban agglomeration in time, but also obtain the great significance of the future management. In this study, taking Changsha-Zhuzhou-Xiangtan(Chang-Zhu-Tan) urban agglomeration in Hunan province as a study area, Landsat images from 1995 to 2014 and Autologistic-CLUE-S model simulation data were used. Moreover, several factors including gravity center, direction, distance and landscape index were considered in the analysis of the expansion. The results revealed that the construction area increased by 132.18%, from 372.28 km^2 in 1995 to 864.37 km^2 in 2014. And it might even reach 1327.23 km^2 in 2023. Before 2014, three cities had their own respective and discrete development directions. However, because of the integration policy implementation in 2008, the Chang-Zhu-Tan began to gather, the gravity center moved southward after 2014, and the distance between cities decreased, which was in line with the development plan of urban expansion. The research methods and results were relatively reliable, and these results could provide some reference for the future land use planning and spatial allocation in the urbanization process of Chang-Zhu-Tan urban agglomeration.
基金Under the auspices of China Global Change Research Program(No.2010CB950103)National Natural Science Foundation of China(No.40901099)
文摘Climate change affected the agricultural expansion and the formation of farming-grazing transitional patterns during historical periods. This study analyzed the possible range of the boundary shift of the potential suitable agriculture area in the farming-grazing transitional zone in the northeastern China during the 20th century. Based on modem weather data, 1 km-resolution land cover data, historical climatic time series, and estimation by using similar historical climatic scenes, the following was concluded： 1） The climate conditions of suitable agriculture areas in the farming-grazing transitional zone in the northeastern China between 1971 and 2000 required an average annual temperature above 1℃ or ≥ 0℃ accumulated temperature above 2500℃-2700℃, and annual precipitation above 350 mm. 2） The northern boundary of the potential suitable agriculture area during the relatively warmer period of 1890-1910 was approximately located at the position of the 1961-2000 area. The northern boundary shifted back to the south by 75 km on average during the colder period of the earlier 20th century, whereas during the modem warm period of the 1990s, the area shifted north by 100 km on average. 3） The western and eastern boundaries of the suitable agricul^re area during the heaviest drought periods between 1920s and 1930s had shifted northeast by 250 km and 125 km, respectively, contrasting to the boundaries of 1951-2008. For the wettest period, that is, the 1890s to the 1910s, the shift of western and eastern boundaries was to the southwest by 125 km and 200 km, respectively, compared with that in the 1951-2008 period. This study serves as a reference for identifying a climatically sensitive area and planning future land use and agricultural production in the study area.
基金National Natural Science Foundation of China,No.41171318National Key Technology Support Program,No.2012BAH32B03+1 种基金No.2012BAH33B05Special Fund for Forest Scientific Research in the Public Welfare,No.201204201
文摘The Conversion of Land Use and its Effects at Small regional extent （CLUE-S） model is a widely used method to simulate land use change. An ordinary logistic regression model was integrated into the CLUE-S model to identify explanatory variables without considering the spatial autocorrelation effect. Using image-derived maps of the Changsha- Zhuzhou-Xiangtan urban agglomeration, the CLUE-S model was integrated with the ordinary logistic regression and autologistic regression models in this paper to simulate land use change in 2000, 2005 and 2009 based on an observation map from 1995. Significant positive spatial autocorrelation was detected in residuals of ordinary logistic models. Some variables that were much more significant than they should be were selected. Autologistic regression models, which used autocovariate incorporation, were better able to identify driving factors. The Receiver Operating Characteristic Curve （ROC） values of autologistic regression models were larger than 0.8 and the pseudo R^2 values were improved, compared with results of logistic regression model. By overlapping the observation maps, the Kappa values of the ordinary logistic regression model （OL）-CLUE-S and autologistic regression model （AL）-CLUE-S models were larger than 0.75. The results showed that the simulation results were indeed accurate. The Kappa fuzzy （Kfuzzy） values of the AL-CLUE-S models （0.780, 0.773, 0.606） were larger than the values of the OL-CLUE-S models （0.759, 0.760, 0.599） during the three periods. The AL-CLUE-S models performed better than the OL-CLUE-S models in the simulation of land use change. The results showed that it is reasonable to integrate autocovariates into CLUE-S models. However, the Kfuzzy values decreased with prolonged duration of simulation and the maximum range of time was not discussed in this paper.
基金supported by the Ministry of Science and Technology of China(Grant No.2022YFF1301500)the National Natural Science Foun-dation of China(Grants No.32000352,32171485,and 32371741)+1 种基金the Natural Science Foundation of Guangdong Province(Grant No.2021A1515010968)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(Grant No.23lgzy002).
文摘Disaster risk reduction,an essential function of protected areas(PAs),has been generally overlooked in PA design.Using primates as a model,we designed a disaster risk index(DRI)to measure the disaster sensitivity of primate species.High-conservation-need(HCN)areas were identified by both their richness and number of threatened primate species.We also constructed high-disaster-risk(HDR)areas and climate-sensitive(CS)areas based on a disaster risk assessment and temperature change under climate change.We overlaid HCN and HDR areas to obtain HDR-HCN areas.We defined species conservation targets as the percent of each species’range that should be effectively conserved using“Zonation”.Landslides had the highest DRI(1.43±0.88),but have been overlooked in previous studies.PA coverage in HDR-HCN(30%)areas was similar to that in HCN areas(28%),indicating that current PA design fails to account for disaster risk reduction.About 50%of the HDR-HCN areas overlapped with CS areas.Presently,43%of primate species meet their conservation targets.Fifty-seven of primate species would meet their conservation targets and 67%of primates could benefit from PA expansion if HDR-HCN areas are fully incorporated into PAs.Increasing PA coverage in HDR-HCN areas is essential to achieving both primate conservation and disaster risk reduction.The study calls for integrating disaster risk reduction into PA design guidelines,particularly in regions like the western Amazon,and recommends flexible conservation approaches in other areas.
基金supported by the Gansu Province Outstanding Youth Fund(No.23JRRA1016)the National Natural Science Foundation of China(Nos.42422102,42071101,41907379)the National Key R&D Program of China(No.2022YFF0801501)。
文摘The response of lake environments in arid Central Asia to climate change during the Late Holocene over the centennial to millennial timescales remains contentious.The reason that primarily paleoenvironmental proxies diverse and the scarcity of accurate quantitative reconstruction records.In this study,we employed diatoms and pollen records from lacustrine sediment in the Aibi Lake of Southwest Junggar Basin to quantitatively reconstruct salinity and watershed precipitation amounts while exploring the associated forcing mechanisms.The results indicate that Aibi Lake salinity varied between 2 and 47 g/L during the Late Holocene Period,indicating a generally brackish environment,and corresponding to prevailing Tryblionella granulata diatom in the lake basin.Westerly-dominated annual precipitation varied between 250 and 320 mm during the Late Holocene Period in the basin,exhibiting a generally semi-arid environment and prevailing desert steppe vegetation.The Aibi Lake has a low salinity of average value of~15 g/L and exhibits elevated precipitation(average value of~280 mm)during the periods of the 2900-1990,1570-1140,and 590-120 cal yr BP.The reconstructed precipitation and salinity exhibit a periodicity of~200 years,which is consistent with the cycle of phase changes of the North Atlantic oscillation(NAO)and total solar irradiance(TSI).This correlation suggests that variations in NOA and TSI significantly influence the precipitation and salinity changes in Central Asia over centennial to millennial timescales.
基金the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030004)the National Natural Science Foundation of China(Grant Nos.42275002 and 42275006)+1 种基金the National Institute of Natural Hazards,Ministry of Emergency Management of China(Grant Nos.ZDJ2024-01 and ZDJ2024-25)the Science and Technology Planning Project of Guangdong Province(Grant No.2023B1212060019).
文摘Active atmospheric convection on the monsoon coast is crucial for the Earth’s climate system.In particular,the upscale convective growth(UCG)from ordinary isolated convection to organized convective system is a key process causing severe weather,but its activities on the monsoon coast are less understood because of the lack of fine-resolution datasets.For the first time,we present the climatology of UCG on a typical monsoon coast using kilometer-mesh radar data from southern China.The UCG undergoes pronounced subseasonal and diurnal variations in the early-summer rainy season.The subseasonal UCG increase is attributed to the onshore flows shifting from easterlies in April to monsoon southwesterlies in June.UCG becomes vigorous following summer monsoon onset,with hotspots near windward coastal mountains.Daytime UCG first peaks near noontime along coastal land,where onshore flows are destabilized by boundary-layer heating and mountains.Afternoon inland peaks and off-coast minimums are recognized due to land–sea thermal contrast and sea-breeze circulation.Nighttime UCG is revived at the coast by nocturnally enhanced southerlies,followed by offshore activity as the convergence of land-breeze northerlies shifts seaward.The UCG thus responds strongly to changing atmospheric conditions,land heating/cooling,and thermally driven local circulations.Our results may help clarify the predictability of monsoon coastal convection.
基金Supported by the An Nan Hospital,China Medical University,No.ANHRF114-20 and No.ANHRF114-21.
文摘BACKGROUND Antibiotic resistance significantly impacts the treatment failure rates of Helicobacter pylori(H.pylori)infections.AIM To investigate the trends in primary antibiotic resistance of H.pylori in Taiwan of China over the past six years.METHODS We conducted a retrospective analysis of H.pylori isolates from Taiwan residents,China who had not undergone previous treatments(n=1408),collected between January 1,2019 and December 31,2024.Susceptibility of these strains to amoxicillin,clarithromycin,levofloxacin,metronidazole,and tetracycline was tested using the Epsilometer test.We analyzed the trends in single and dual resistance profiles over the study period,and compared antibiotic resistance across different regions(northern,southern and eastern areas)of Taiwan of China.RESULTS The overall resistance rates for H.pylori to amoxicillin,clarithromycin,metronidazole,tetracycline,and levofloxacin in Taiwan of China were 1.3%,18.0%,31.0%,0.8%,and 28.7%,respectively.Tetracycline resistance increased significantly from 0%in 2019 to 3.5%in 2024(P value inχ^(2)test for linear trend:<0.001),while metronidazole resistance declined from 35.5%to 13.0%(P value inχ^(2)test for linear trend:<0.001).No significant changes of amoxicillin,clarithromycin and levofloxacin resistances were observed.The dual resistances to clarithromycin plus tetracycline,and metronidazole plus tetracycline both increased significantly from 0%to 1.7%from 2019 to 2024(P value inχ^(2)test for linear trend:<0.05).Furthermore,no significant regional differences in resistance frequencies except for levofloxacin were detected.CONCLUSION Primary antibiotic resistance to tetracycline in H.pylori has increased in Taiwan of China from 2019 to 2024,while resistance to metronidazole has decreased during the same period.The dual resistance to clarithromycin plus tetracycline and metronidazole plus tetracycline both increased significantly.
基金supported by the Chinese Academy of Sciences through the PIFI Fellowship for Visiting Scientistsprovided by the Mongolian Science and Technology Foundation(Grant Nos.CHN-2022/274 and CHN-2024/12)+1 种基金by the National University of Mongolia under Grant Agreement P2024-4814the National Key Research and Development Project of China(Grant No.2022YFE0119400)。
文摘Changes in arid and semi-arid regions are primarily identified through hydroclimatic and land cover variations.Therefore,analyzing the temporal and spatial patterns of water-climate changes and land cover in the Great Lakes Depression Region in western Mongolia is crucial for studying this basin and similar areas.This research used the Mann-Kendall(MK)test,Innovative Trend Analysis Method(ITAM),Sen's Slope Estimator Test(SSET),and land cover change analysis to examine the statistical relationships among climate variability,river discharge,lake level fluctuations,and land cover changes.Air temperature increased during the study period(Z=1.16*),while total annual precipitation(Z=-0.79)declined slightly.Major river discharges in the basin(Z=-3.92***),as well as lake water levels(Z=-2.51**),also decreased.Land cover changes were closely related to climate change,with indicators such as precipitation,river discharge,and lake water levels showing strong connections.Additionally,in 2020,basin grassland cover and bare area decreased,whereas impervious surfaces and cropland—land cover types influenced by human activity significantly increased.Consequently,future research should focus on human factors impacting the Great Lakes Depression Region in western Mongolia.
基金the National Key Research and Development Programs of China(2016YFA0601501)the National Natural Science Foundation of China(41830863,51879162,41601025)the Belt and Road Fund on Water and Sustainability of the State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering(2019).
文摘Quantification of the impacts of environmental changes on runoff in the transitional area from the Tibetan Plateau to the Loess Plateau is of critical importance for regional water resources management.Trends and abrupt change points of the hydro-climatic variables in the Tao River Basin were investigated during 1956-2015.It also quantitatively separates the impacts of climate change and human activities on runoff change in the Tao River by using RCC-WBM model.Results indicate that temperature presented a significant rising trend(0.2℃per decade)while precipitation exhibited an insignificant decreasing trend(3.8 mm per decade)during 1956-2015.Recorded runoff in the Tao River decreased significantly with a magnitude of-13.7 mm per decade and abrupt changes in 1968 and 1986 were identified.Relative to the baseline period(1956-1968),runoff in the two anthropogenic disturbed periods of 1969-1986 and 1987-2015 decreased by 27.8 mm and 76.5 mm,respectively,which can be attributed to human activities(accounting for 69%)and climate change(accounting for 31%).Human activities are the principal drivers of runoff reduction in the Tao River Basin.However,the absolute influences on runoff reductions by the both drivers tend to increase,from 7.7 mm in 1969-1986 to 24.4 mm in 1987-2015 by climate change and from 20.2 mm to 52.2 mm by human activities.
基金supported by National Natural Science Foundation of China (91537105, 91537211, 41322033)the Opening Research Foundation of Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regionsthe Chinese Academy of Sciences (LPCC201504)
文摘An overall greening over the Tibetan Plateau(TP) in recent decades has been established through analyses of remotely sensed Normalized Difference Vegetation Index(NDVI), though the regional pattern of the changes and associated drivers remain to be explored. This study used a satellite Leaf Area Index(LAI) dataset(the GLASS LAI dataset) and examined vegetation changes in humid and arid regions of the TP during 1982–2012. Based on distributions of the major vegetation types, the TP was divided roughly into a humid southeastern region dominated by meadow and a dry northwestern region covered mainly by steppe. It was found that the dividing line between the two regions corresponded well with the lines of mean annual precipitation of 400 mm and the mean LAI of 0.3. LAI=0.3 was subsequently used as a threshold for investigating vegetation type changes at the interanual and decadal time scales: if LAI increased from less than 0.3 to greater than0.3 from one time period to the next, it was regarded as a change from steppe to meadow, and vice versa. The analysis shows that changes in vegetation types occurred primarily around the dividing line of the two regions, with clear growth(reduction) of the area covered by meadow(steppe), in consistency with the findings from using another independent satellite product. Surface air temperature and precipitation(diurnal temperature range) appeared to contribute positively(negatively) to this change though climate variables displayed varying correlation with LAI for different time periods and different regions.
基金Knowledge Innovation Project of CASNo.KZCX1-SW-19
文摘The quantity and quality changes of cropland in Jilin province are analyzed by combining the statistics from 1949 to 1999 and land-use maps interpreted from TM images in 1986 and in 2000. In general, the decreasing trend of the cropland in Jilin province was derived from the statistic data in 1949-1999. While since 1983, the cropland area has increased slightly, because of the conversion from other land-use types to cropland. It is showed that the net increase of cropland was about 43.40×10 4 ha. While the quality change of the cropland can be seen from that mainly caused by the conversion from forestland, grassland to cropland and the change mainly took place in the west, where it is ecologically fragile. According to the spatial distribution model, the centroids' move of the cropland and the grain production are calculated, whose directions are not consistent. The impact of the dynamic change of the cropland on food security is further analyzed.
