The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake--a closed one in the arid region. The pollen assemblag...The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake--a closed one in the arid region. The pollen assemblage and other geochemical indices showed that, the temperature was somewhat low in the period (8.0-11.5 cal kaBP) as a whole, but in the early period (11.5-10.6 cal kaBP) the temperature was higher, in company with more precipitation. In the conversion period from the early Holocene epoch to the middle Holocene epoch (8.9-8.0 cal kaBP) the climate fluctuated remarkably. Particularly the three layers of peat sediment revealed the strong instability of climate in the early Holocene epoch in the Ebinur region. All information on the development of peat and the experimental data of pollen and stable isotopes implied that, the climatic condition at 8.2, 8.6 and 10.5 cal kaBP was characterized by noticeable cold and humidness, and could be regarded as three cold and humid events in the early Holocene epoch.展开更多
Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating a...Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological modelling.This study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological stations.Based on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation method.The daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more robust.The error analysis between DBMA-fused precipitation dataset and the more advanced Integrated Multi-satellite Retrievals for Global Pre展开更多
Soil respiration in wetlands surrounding lakes is a vital component of the soil carbon cycle in arid regions. However, information remains limited on the soil respiration around highly saline lakes during the plant gr...Soil respiration in wetlands surrounding lakes is a vital component of the soil carbon cycle in arid regions. However, information remains limited on the soil respiration around highly saline lakes during the plant growing season. Here, we aimed to evaluate diurnal and seasonal variation in soil respiration to elucidate the controlling factors in the wetland of Ebinur Lake, Xinjiang Uygur Autonomous Region, western China. We used a soil carbon flux automatic analyzer （LI-840A） to measure soil respiration rates during the growing season （April to November） in two fields covered by reeds and tamarisk and one field with no vegetation （bare soil） from 2015 to 2016. The results showed a single peak in the diurnal pattern of soil respiration from 11：00 to 17：00 for plots covered in reeds, tamarisk, and bare soil, with minimum values being detected from 03：00 to 07：00. During the growing season, the soil respiration of reeds and tamarisk peaked during the thriving period （4.16 and 3.75 μmol.m-2.s-1, respectively）, while that of bare soil peaked during the intermediate growth period （0.74 pmol-m-2-s-1）. The soil respiration in all three plots was lowest during the wintering period （0.08, 0.09, and -0.87 μmol.m-2.s-1, respectively）. Air temperature and relative humidity significantly influenced soil respiration. A significant linear relationship was detected between soil respiration and soil temperature for reeds, tamarisk, and bare soil. The average Q10 of reeds and tamarisk were larger than that of bare soil. However, soil moisture content was not the main factor controlling soil respiration. Soil respiration was negatively correlated with soil pH and soil salinity in all three plot types. In contrast, soil respiration was positively correlated with organic carbon. Overall,CO2 emissions and greenhouse gases had a relatively weak effect on the wetlands surrounding the highly saline Ebinur Lake.展开更多
Under the background of global warming and excessive human activities,much surface water in drylands is experiencing rapid degradation or shrinkage in recent years.The shrinkage of surface water,especially the degrada...Under the background of global warming and excessive human activities,much surface water in drylands is experiencing rapid degradation or shrinkage in recent years.The shrinkage of surface water,especially the degradation of lakes and their adjacent wetlands in drylands,may lead to the emergence of new salt dust storm hotspots,which causes greater danger.In this paper,based on high spatial resolution global surface water(GSW)and multiangle implementation of atmospheric correction(MAIAC)AOD data,we systematically analyze the dynamic characteristics of surface water and aerosols in typical drylands(Central Asia,CA)between 2000 and 2018.Simultaneously,combined with auxiliary environment variables,we explore the driving mechanisms of surface water on the regional salt/sand aerosols on different spatial scales.The results show that the seasonal surface water features an increasing trend,especially a more dramatic increase after 2015,and the permanent surface water indicates an overall decrease,with nearly 54.367%at risk of receding and drying up.In typical lakes(Aral Sea and Ebinur Lake),the interannual change feature of the surface water area(WA)is that a continuous decrease during the study period occurs in Aral Sea area,yet a significant improvement has occurred in Ebinur Lake after 2015,and the degradation of Ebinur Lake takes place later and its recovery earlier than Aral Sea.The aerosol optical depth(AOD)in CA shows obvious seasonal variation,with the largest in spring(0.192±0173),next in summer(0.169±0.106),and the smallest in autumn(0.123±0.065).The interannual variation of AOD exhibits an increase from 2000 to 2018 in CA,with high AOD areas mainly concentrated in the Taklamakan Desert and some lake beds resulting from lake degradation,including Aral Sea and Ebinur Lake.The AOD holds a similar trend between Aral Sea and Ebinur Lake on an interannual scale.And the AOD over Ebinur Lake is lower than that over Aral Sea in magnitude and lags behind in reaching the peak compared with Aral Sea.The WA change can s展开更多
On the basis of lacustrine sedimentary profile of Ebinur Lake,sequences of evolution of paleoclimate and paleoenvironment in Ebinur Lake area have been rebuilt by analysing the sedimentary stratigraphy,bio-stratigraph...On the basis of lacustrine sedimentary profile of Ebinur Lake,sequences of evolution of paleoclimate and paleoenvironment in Ebinur Lake area have been rebuilt by analysing the sedimentary stratigraphy,bio-stratigraphy and gepochemistry as well as the chronological records.The results show that,during the last 10 ha years,the general change trends of the paleoclimate in Ebinur Lake area can be divided into three stages: (1) 10. 2-8.3 ka B. P., a warm-cool dry climate stage;(2) 8.3-3.5 ka B.P.,a warmer moist climate stage (specially,7.3-6. 4 ka B. P.,a relatively stable humid temperate stage);(3) 3. 5 ka B. P.-present, adraught temperate climate stage,similar to the present climate. In addition,there existed clearly several times of secondary undulations of dry-humid climate,i.e. 8.3 ka and 7.3 ka for dry climate展开更多
Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake B...Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the 展开更多
The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter...The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter grounds are unclear.This research focused on distribution sites,habitat,behavior,population size and seasonal changes of Relict Gull.Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake.The result showed Relict Gull was summer visitor to Xinjiang,Western China.Population curve with a single peak was obtained.This gull appeared in early April and was 63 individuals(1% of the global population).The number remained stable from May to July in 2009.The discovery of fledglings indi-cates that Relict Gull may breed here.They left Ebinur Lake in August.Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation,which was the most westerly record in China.展开更多
Airborne pollen is indicative of vegetation and climatic conditions.This study investigates airborne pollen trapping in the Betula microphylla-dominated wetland of Ebinur Lake in Northwestern China from September 2012...Airborne pollen is indicative of vegetation and climatic conditions.This study investigates airborne pollen trapping in the Betula microphylla-dominated wetland of Ebinur Lake in Northwestern China from September 2012 to August 2015 using Pearson correlation analysis and the Hybrid Single-particle Lagrangian Integrated Trajectory model.Higher temperatures and moderate precipitation during the flowering period facilitated an increase in birch pollen with more exotic spruce pollen carried from the Tianshan Mountains by airflows,leading to the highest arbor pollen concentrations from September 2012 to August 2013.Peak pollen concentrations from September 2013 to August 2014 were possibly due to an increase in herbaceous pollen resulting from higher temperatures,lower precipitation and more exotic pollen from the desert of southwest Ebinur Lake and Central Asia in summer and autumn.Between September 2014 and August 2015,unfavorable climate conditions in summer and autumn decreased the pollen dispersal of xerophytes such as Artemisia and Chenopodiaceae,with little pollen transported from the Kazakh hilly area in late summer,resulting in the lowest pollen concentrations.Climatic parameters and air mass movements both greatly affected the atmospheric pollen concentration.The results provide information concerning the dispersion and distribution of birch pollen,paleoenvironmental reconstruction and wetland conservation.展开更多
Based on soil under seven vegetation types,the carbon sequestration potential in the Ebinur Lake wetland was estimated using the maximum value method,the saturation value method,and the classification and grading meth...Based on soil under seven vegetation types,the carbon sequestration potential in the Ebinur Lake wetland was estimated using the maximum value method,the saturation value method,and the classification and grading method.Results indicated that:1)Soil carbon sequestration results for the top 20 cm soil layer were about 1.88 Mt using the maximum value method;the middle level standard of the classification and grading method result was 1.71 Mt.2)Soil carbon sequestration potential in the top 20 cm layer under different vegetation types,evaluated using the saturation value method and the classificationgrading method,ranged from 0.45 to 0.67 Mt,accounting for about 5/16 of the ideal carbon sequestration potential.3)Carbon sequestration potential calculated using the saturation method and the classification method(middle level standard),combining the soil organic carbon increment under different vegetation types in Ebinur Lake wetland,recorded an average growth rate of soil organic carbon around 0.7-1 kg/(hm^2·a).Time required to reach its carbon sequestration potential was 41 to 144 a.These results indicate that soil organic carbon content dynamically changes,and different forms of land use affect soil organic carbon content.The potential and ability of soil carbon sequestration and its mechanism of dynamic change are investigated,providing a scientific basis for understanding regional carbon cycle and climate change in wetlands.展开更多
There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relat...There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relationships between microplastics and adsorbed heavy metals in the Ebinur Lake Basin,a typical arid oasis in China.Results showed that(1)the average microplastic content in all soil samples was 36.15(±3.27)mg/kg.The contents of microplastics at different sampling sites ranged from 3.89(±1.64)to 89.25(±2.98)mg/kg.Overall,the proportions of various microplastic shapes decreased in the following order:film(54.25%)>fiber(18.56%)>particle(15.07%)>fragment(8.66%)>foam(3.46%);(2)among all microplastic particles,white particles accounted for the largest proportion(52.93%),followed by green(24.15%),black(12.17%),transparent(7.16%),and yellow particles(3.59%).The proportions of microplastic particle size ranges across all soil samples decreased in the following order:1000-2000μm(40.88%)>500-1000μm(26.75%)>2000-5000μm(12.30%)>100-500μm(12.92%)>0-100μm(7.15%).FTIR(Fourier transform infrared)analyses showed that polyethylene terephthalate(PET),polypropylene(PP),polycarbonate(PC),polyethylene(PE),and polystyrene(PS)occurred in the studied soil;(3)random forest predictions showed that industrial and agricultural production activities and the discharge of domestic plastic waste were related to soil microplastic pollution,in which agricultural plastic film was the most important factor in soil pollution in the study area;and(4)seven heavy metals extracted from microplastics in the soil samples showed significant positive correlations with soil pH,EC,total salt,N,P,and K contents(P<0.01),indicating that these soil factors could significantly affect the contents of heavy metals carried by soil microplastics.This research demonstrated that the contents of soil microplastics are lower than other areas of the world,and they mainly come from industrial and agricultural activities of the Ebinur Lake Basin.展开更多
In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,n...In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,namely Populus euphratica,Haloxylon ammodendron,Nitraria sibirica,and Halostachs caspica,corresponding to different habitats(i.e.,river bank,sand dune,desert,and salt marsh)were chosen as the model vegetation in this research.Theδ^(2)H andδ^(18)O for rainwater,soil water,and plant water were applied to identify the water sources and quantify the proportions of different water sources used over the entire plant growth period(from March to October).The results showed that the precipitationδ^(2)H andδ^(18)O in the Ebinur Lake basin varied from-142.5‰to-0.6‰and from-20.16‰to 1.20‰,respectively.The largestδ^(2)H andδ^(18)O values occurred in summer and the smallest in winter.The soil waterδ^(2)H andδ^(18)O of the four habitats decreased gradually with increasing depth.Theδ^(2)H andδ^(18)O values of water extracted from the stems of the four plants had similar variation trends,that is,the maximum was observed in spring and the minimum in summer.Among the four plants,H.caspica had the highest stable isotopic values in the stem water,followed by N.sibirica,H.ammodendron,and P.euphratica.The water sources and utilization ratios of desert vegetation varied across different growth stages.Throughout the growing period,H.ammodendron mainly used groundwater,whereas the water source proportions used by N.sibirica varied greatly throughout the growing season.In spring,plants mainly relied on surface soil water,with a contribution rate of 80%-94%.However,in summer,the proportion of deep soil water used was 31%-36%;and in autumn,the proportion of middle soil water used was 33%-36%.H.caspica mainly relied on topsoil water in spring and autumn,and the proportion of soil water in the middle layer slightly increased to 20%-36%in summer.P.euphratica mainly used intermediate soil water in spring with a util展开更多
基金supported by the Key Innovation Project of the Chinese Academy of Saiences(Grant Nos.CXNIGLAS-A01 and KZCX2-SW-118)the National Natural Sci ence Foundation of China(GrantNo.40 172102).
文摘The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake--a closed one in the arid region. The pollen assemblage and other geochemical indices showed that, the temperature was somewhat low in the period (8.0-11.5 cal kaBP) as a whole, but in the early period (11.5-10.6 cal kaBP) the temperature was higher, in company with more precipitation. In the conversion period from the early Holocene epoch to the middle Holocene epoch (8.9-8.0 cal kaBP) the climate fluctuated remarkably. Particularly the three layers of peat sediment revealed the strong instability of climate in the early Holocene epoch in the Ebinur region. All information on the development of peat and the experimental data of pollen and stable isotopes implied that, the climatic condition at 8.2, 8.6 and 10.5 cal kaBP was characterized by noticeable cold and humidness, and could be regarded as three cold and humid events in the early Holocene epoch.
基金supported by The Technology Innovation Team(Tianshan Innovation Team),Innovative Team for Efficient Utilization of Water Resources in Arid Regions(2022TSYCTD0001)the National Natural Science Foundation of China(42171269)the Xinjiang Academician Workstation Cooperative Research Project(2020.B-001).
文摘Xinjiang Uygur Autonomous Region is a typical inland arid area in China with a sparse and uneven distribution of meteorological stations,limited access to precipitation data,and significant water scarcity.Evaluating and integrating precipitation datasets from different sources to accurately characterize precipitation patterns has become a challenge to provide more accurate and alternative precipitation information for the region,which can even improve the performance of hydrological modelling.This study evaluated the applicability of widely used five satellite-based precipitation products(Climate Hazards Group InfraRed Precipitation with Station(CHIRPS),China Meteorological Forcing Dataset(CMFD),Climate Prediction Center morphing method(CMORPH),Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record(PERSIANN-CDR),and Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis(TMPA))and a reanalysis precipitation dataset(ECMWF Reanalysis v5-Land Dataset(ERA5-Land))in Xinjiang using ground-based observational precipitation data from a limited number of meteorological stations.Based on this assessment,we proposed a framework that integrated different precipitation datasets with varying spatial resolutions using a dynamic Bayesian model averaging(DBMA)approach,the expectation-maximization method,and the ordinary Kriging interpolation method.The daily precipitation data merged using the DBMA approach exhibited distinct spatiotemporal variability,with an outstanding performance,as indicated by low root mean square error(RMSE=1.40 mm/d)and high Person's correlation coefficient(CC=0.67).Compared with the traditional simple model averaging(SMA)and individual product data,although the DBMA-fused precipitation data were slightly lower than the best precipitation product(CMFD),the overall performance of DBMA was more robust.The error analysis between DBMA-fused precipitation dataset and the more advanced Integrated Multi-satellite Retrievals for Global Pre
文摘Soil respiration in wetlands surrounding lakes is a vital component of the soil carbon cycle in arid regions. However, information remains limited on the soil respiration around highly saline lakes during the plant growing season. Here, we aimed to evaluate diurnal and seasonal variation in soil respiration to elucidate the controlling factors in the wetland of Ebinur Lake, Xinjiang Uygur Autonomous Region, western China. We used a soil carbon flux automatic analyzer （LI-840A） to measure soil respiration rates during the growing season （April to November） in two fields covered by reeds and tamarisk and one field with no vegetation （bare soil） from 2015 to 2016. The results showed a single peak in the diurnal pattern of soil respiration from 11：00 to 17：00 for plots covered in reeds, tamarisk, and bare soil, with minimum values being detected from 03：00 to 07：00. During the growing season, the soil respiration of reeds and tamarisk peaked during the thriving period （4.16 and 3.75 μmol.m-2.s-1, respectively）, while that of bare soil peaked during the intermediate growth period （0.74 pmol-m-2-s-1）. The soil respiration in all three plots was lowest during the wintering period （0.08, 0.09, and -0.87 μmol.m-2.s-1, respectively）. Air temperature and relative humidity significantly influenced soil respiration. A significant linear relationship was detected between soil respiration and soil temperature for reeds, tamarisk, and bare soil. The average Q10 of reeds and tamarisk were larger than that of bare soil. However, soil moisture content was not the main factor controlling soil respiration. Soil respiration was negatively correlated with soil pH and soil salinity in all three plot types. In contrast, soil respiration was positively correlated with organic carbon. Overall,CO2 emissions and greenhouse gases had a relatively weak effect on the wetlands surrounding the highly saline Ebinur Lake.
基金funded by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0103)Basic Research Program of Shenzhen(20220811173316001)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2020A1515111142)Key Laboratory of Spatial Data Mining&Information Sharing of Ministry of Education,Fuzhou University(2022LSDMIS05)Supported by a grant from State Key Laboratory of Resources and Environmental Information System.
文摘Under the background of global warming and excessive human activities,much surface water in drylands is experiencing rapid degradation or shrinkage in recent years.The shrinkage of surface water,especially the degradation of lakes and their adjacent wetlands in drylands,may lead to the emergence of new salt dust storm hotspots,which causes greater danger.In this paper,based on high spatial resolution global surface water(GSW)and multiangle implementation of atmospheric correction(MAIAC)AOD data,we systematically analyze the dynamic characteristics of surface water and aerosols in typical drylands(Central Asia,CA)between 2000 and 2018.Simultaneously,combined with auxiliary environment variables,we explore the driving mechanisms of surface water on the regional salt/sand aerosols on different spatial scales.The results show that the seasonal surface water features an increasing trend,especially a more dramatic increase after 2015,and the permanent surface water indicates an overall decrease,with nearly 54.367%at risk of receding and drying up.In typical lakes(Aral Sea and Ebinur Lake),the interannual change feature of the surface water area(WA)is that a continuous decrease during the study period occurs in Aral Sea area,yet a significant improvement has occurred in Ebinur Lake after 2015,and the degradation of Ebinur Lake takes place later and its recovery earlier than Aral Sea.The aerosol optical depth(AOD)in CA shows obvious seasonal variation,with the largest in spring(0.192±0173),next in summer(0.169±0.106),and the smallest in autumn(0.123±0.065).The interannual variation of AOD exhibits an increase from 2000 to 2018 in CA,with high AOD areas mainly concentrated in the Taklamakan Desert and some lake beds resulting from lake degradation,including Aral Sea and Ebinur Lake.The AOD holds a similar trend between Aral Sea and Ebinur Lake on an interannual scale.And the AOD over Ebinur Lake is lower than that over Aral Sea in magnitude and lags behind in reaching the peak compared with Aral Sea.The WA change can s
文摘On the basis of lacustrine sedimentary profile of Ebinur Lake,sequences of evolution of paleoclimate and paleoenvironment in Ebinur Lake area have been rebuilt by analysing the sedimentary stratigraphy,bio-stratigraphy and gepochemistry as well as the chronological records.The results show that,during the last 10 ha years,the general change trends of the paleoclimate in Ebinur Lake area can be divided into three stages: (1) 10. 2-8.3 ka B. P., a warm-cool dry climate stage;(2) 8.3-3.5 ka B.P.,a warmer moist climate stage (specially,7.3-6. 4 ka B. P.,a relatively stable humid temperate stage);(3) 3. 5 ka B. P.-present, adraught temperate climate stage,similar to the present climate. In addition,there existed clearly several times of secondary undulations of dry-humid climate,i.e. 8.3 ka and 7.3 ka for dry climate
基金supported by the Scientific Research Foundation for High-Level Talents of Shihezi University(RCZK2018C41,CXRC201801,RCZK2018C22)the National Natural Science Foundation of China(41661040,U1803244)the Scientific and Technological Research Projects of Xinjiang Production and Construction Corps,China(2021AB021)。
文摘Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the
基金supported by Science Supporting Project of National Ministry of Science and Technology (2008BAC39B04)National Natural Science Foundation of China (30470262,30970340)
文摘The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter grounds are unclear.This research focused on distribution sites,habitat,behavior,population size and seasonal changes of Relict Gull.Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake.The result showed Relict Gull was summer visitor to Xinjiang,Western China.Population curve with a single peak was obtained.This gull appeared in early April and was 63 individuals(1% of the global population).The number remained stable from May to July in 2009.The discovery of fledglings indi-cates that Relict Gull may breed here.They left Ebinur Lake in August.Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation,which was the most westerly record in China.
基金supported by the National Natural Science Foundation of China(Grant Nos.41971121&41572331)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19050103)the Basic Research Foundation of Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences(Grant No.SK202012).
文摘Airborne pollen is indicative of vegetation and climatic conditions.This study investigates airborne pollen trapping in the Betula microphylla-dominated wetland of Ebinur Lake in Northwestern China from September 2012 to August 2015 using Pearson correlation analysis and the Hybrid Single-particle Lagrangian Integrated Trajectory model.Higher temperatures and moderate precipitation during the flowering period facilitated an increase in birch pollen with more exotic spruce pollen carried from the Tianshan Mountains by airflows,leading to the highest arbor pollen concentrations from September 2012 to August 2013.Peak pollen concentrations from September 2013 to August 2014 were possibly due to an increase in herbaceous pollen resulting from higher temperatures,lower precipitation and more exotic pollen from the desert of southwest Ebinur Lake and Central Asia in summer and autumn.Between September 2014 and August 2015,unfavorable climate conditions in summer and autumn decreased the pollen dispersal of xerophytes such as Artemisia and Chenopodiaceae,with little pollen transported from the Kazakh hilly area in late summer,resulting in the lowest pollen concentrations.Climatic parameters and air mass movements both greatly affected the atmospheric pollen concentration.The results provide information concerning the dispersion and distribution of birch pollen,paleoenvironmental reconstruction and wetland conservation.
基金This work was supported by the Key Laboratory Opening Project of Xinjiang Uygur Autonomous Region,China(Grant No.2016D03007)the Key Subject Project of the 13th Five-year Plan of Xinjiang Normal University(Grant No.17SDKD0708)the National Natural Science Foundation of China(Grant No.41761113).
文摘Based on soil under seven vegetation types,the carbon sequestration potential in the Ebinur Lake wetland was estimated using the maximum value method,the saturation value method,and the classification and grading method.Results indicated that:1)Soil carbon sequestration results for the top 20 cm soil layer were about 1.88 Mt using the maximum value method;the middle level standard of the classification and grading method result was 1.71 Mt.2)Soil carbon sequestration potential in the top 20 cm layer under different vegetation types,evaluated using the saturation value method and the classificationgrading method,ranged from 0.45 to 0.67 Mt,accounting for about 5/16 of the ideal carbon sequestration potential.3)Carbon sequestration potential calculated using the saturation method and the classification method(middle level standard),combining the soil organic carbon increment under different vegetation types in Ebinur Lake wetland,recorded an average growth rate of soil organic carbon around 0.7-1 kg/(hm^2·a).Time required to reach its carbon sequestration potential was 41 to 144 a.These results indicate that soil organic carbon content dynamically changes,and different forms of land use affect soil organic carbon content.The potential and ability of soil carbon sequestration and its mechanism of dynamic change are investigated,providing a scientific basis for understanding regional carbon cycle and climate change in wetlands.
基金the National Natural Science Foundation of China(41873028,41501541)。
文摘There is a lack of research on soil microplastics in arid oases considering the rapid economic development of northwestern China.Here,we studied the occurrence and sources of microplastics in soil,as well as the relationships between microplastics and adsorbed heavy metals in the Ebinur Lake Basin,a typical arid oasis in China.Results showed that(1)the average microplastic content in all soil samples was 36.15(±3.27)mg/kg.The contents of microplastics at different sampling sites ranged from 3.89(±1.64)to 89.25(±2.98)mg/kg.Overall,the proportions of various microplastic shapes decreased in the following order:film(54.25%)>fiber(18.56%)>particle(15.07%)>fragment(8.66%)>foam(3.46%);(2)among all microplastic particles,white particles accounted for the largest proportion(52.93%),followed by green(24.15%),black(12.17%),transparent(7.16%),and yellow particles(3.59%).The proportions of microplastic particle size ranges across all soil samples decreased in the following order:1000-2000μm(40.88%)>500-1000μm(26.75%)>2000-5000μm(12.30%)>100-500μm(12.92%)>0-100μm(7.15%).FTIR(Fourier transform infrared)analyses showed that polyethylene terephthalate(PET),polypropylene(PP),polycarbonate(PC),polyethylene(PE),and polystyrene(PS)occurred in the studied soil;(3)random forest predictions showed that industrial and agricultural production activities and the discharge of domestic plastic waste were related to soil microplastic pollution,in which agricultural plastic film was the most important factor in soil pollution in the study area;and(4)seven heavy metals extracted from microplastics in the soil samples showed significant positive correlations with soil pH,EC,total salt,N,P,and K contents(P<0.01),indicating that these soil factors could significantly affect the contents of heavy metals carried by soil microplastics.This research demonstrated that the contents of soil microplastics are lower than other areas of the world,and they mainly come from industrial and agricultural activities of the Ebinur Lake Basin.
基金Natural Science Foundation of Xinjiang Uygur Autonomous Region,No.2021D01A118National Natural Science Foundation of China,No.U1803244Open Project of Xinjiang Laboratory of Lake Environment and Resources in Arid Area,No.XJNUSYS2019B18。
文摘In arid and semi-arid environments,desert vegetation plays an important role in preventing soil erosion by wind and helps maintain the stability of desert and oasis ecosystems.Four types of typical desert vegetation,namely Populus euphratica,Haloxylon ammodendron,Nitraria sibirica,and Halostachs caspica,corresponding to different habitats(i.e.,river bank,sand dune,desert,and salt marsh)were chosen as the model vegetation in this research.Theδ^(2)H andδ^(18)O for rainwater,soil water,and plant water were applied to identify the water sources and quantify the proportions of different water sources used over the entire plant growth period(from March to October).The results showed that the precipitationδ^(2)H andδ^(18)O in the Ebinur Lake basin varied from-142.5‰to-0.6‰and from-20.16‰to 1.20‰,respectively.The largestδ^(2)H andδ^(18)O values occurred in summer and the smallest in winter.The soil waterδ^(2)H andδ^(18)O of the four habitats decreased gradually with increasing depth.Theδ^(2)H andδ^(18)O values of water extracted from the stems of the four plants had similar variation trends,that is,the maximum was observed in spring and the minimum in summer.Among the four plants,H.caspica had the highest stable isotopic values in the stem water,followed by N.sibirica,H.ammodendron,and P.euphratica.The water sources and utilization ratios of desert vegetation varied across different growth stages.Throughout the growing period,H.ammodendron mainly used groundwater,whereas the water source proportions used by N.sibirica varied greatly throughout the growing season.In spring,plants mainly relied on surface soil water,with a contribution rate of 80%-94%.However,in summer,the proportion of deep soil water used was 31%-36%;and in autumn,the proportion of middle soil water used was 33%-36%.H.caspica mainly relied on topsoil water in spring and autumn,and the proportion of soil water in the middle layer slightly increased to 20%-36%in summer.P.euphratica mainly used intermediate soil water in spring with a util
