The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphologica...The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphological mappingby Landsat- and Corona-Images as well as SRTM-topographic data, combined with field-surveys and geophysicalinvestigation provides evidence for tectonic impact on sedimentary processes during the Late Quaternary.Analyses of SRTM-Data and Landsat-Images reveal a system of up to 20m high inverted channels developed on theinactive eastern part of the large Hei river drainage delta south of the ancient lake Juyanze. The complex evolution of theselandforms requires a relative lowering of the lake basin at least two times since the last 40ka. A 26m high cliff section ofgravel-covered lake sediments within the Juyanze paleolake indicates a strong subsidence of the lake bottom of 10m/1000yrssince 18kaB. P.North of Ejina river oasis a distinct north-south striking scarp up to 13m high constitutes the eastern margin of theGaxun Nur. Palaeodrainage channels derived from the Gobi Altay. They display a sinistral offset of some decametres alonga set of WE-trending faults. The rhombic shape of the modern dry Gaxun Nur, fossil cliffs,well preserved beach ridges alongthe margins of the palaeolake system as well as gravel covered topsets of lacustrine sediments indicate local displacements ofmorphological features. The displacements of lake sediments at the southern margin of the modern Gaxun Nur Basin imply asubsidence of at least 0.81m/1000 yrs since 25kaB. P. as a result of a pull-apart development due to the left stepping faultsin a sinistral system.展开更多
Recently local government and environmental protection authorities in China have turned to the water hyacinth, one of the world’s worst aquatic weeds, to reduce nutrient concentrations in highly eutrophic lake waters...Recently local government and environmental protection authorities in China have turned to the water hyacinth, one of the world’s worst aquatic weeds, to reduce nutrient concentrations in highly eutrophic lake waters, especially in Lake Dian in southwestern China’s Yunnan Province. Although we do not reject using water hyacinth to reduce lake eutrophication, it is not a complete solution. In our view, a more complete solution requires a holistic consideration of watershed or drainage characteristics, and a solid understanding of the limnological features of individual lakes. Before the bio-geochemistry and toxicological effects of water hyacinth be thoroughly understood, applying it widely to lake restoration and overstating its practical value is not only irresponsible but also dangerous.展开更多
Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown ...Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown and has puzzled doctors for many years.A preliminary study on heavy metals and symptoms indicated that arsenic might pose the greatest threat to the health of local residents.Here,to explore the sources of and factors influencing arsenic enrichment in DV,whose residents exhibit signs of arsenic poisoning,the As contents in soil,water,and plants were systematically measured.The results indicated high As contents in plant and soil samples obtained from the area,and the source of As may be linked to the weathering of black shale rock.Ingestion of soil and consumption of plants were the two main As exposure pathways among children and adults,respectively,and children exhibited a higher health risk than adults.We presume and emphasize that when extreme drought events occur,humans might face unusual risks resulting from exposure to toxic elements and the direct consumption of highly polluted water.Our study provides a new perspective and sheds light on the environmental geochemistry and health links of this disease.展开更多
During the past 3000 years,cattle on the Qinghai-Xizang Plateau have developed adaptive phenotypes under the selective pressure of hypoxia,ultraviolet(UV)radiation,and extreme cold.The genetic mechanism underlying thi...During the past 3000 years,cattle on the Qinghai-Xizang Plateau have developed adaptive phenotypes under the selective pressure of hypoxia,ultraviolet(UV)radiation,and extreme cold.The genetic mechanism underlying this rapid adaptation is not yet well understood.Here,we present whole-genome resequencing data for 258 cattle from 32 cattle breeds/populations,including 89 Tibetan cattle representing eight populations distributed at altitudes ranging from 3400 m to 4300 m.Our genomic analysis revealed that Tibetan cattle exhibited a continuous phylogeographic cline from the East Asian taurine to the South Asian indicine ancestries.We found that recently selected genes in Tibetan cattle were related to body size(HMGA2 and NCAPG)and energy expenditure(DUOXA2).We identified signals of sympatric introgression from yak into Tibetan cattle at different altitudes,covering 0.64%–3.26%of their genomes,which included introgressed genes responsible for hypoxia response(EGLN1),cold adaptation(LRP11),DNA damage repair(LATS1),and UV radiation resistance(GNPAT).We observed that introgressed yak alleles were associated with noncoding variants,including those in present EGLN1.In Tibetan cattle,three yak introgressed SNPs in the EGLN1 promoter region reduced the expression of EGLN1,suggesting that these genomic variants enhance hypoxia tolerance.Taken together,our results indicated complex adaptation processes in Tibetan cattle,where recently selected genes and introgressed yak alleles jointly facilitated rapid adaptation to high-altitude environments.展开更多
Aurochs(Bos primigenius),once widely distributed in Afro-Eurasia,became extinct in the early 1600 s.However,their phylogeography and relative contributions to domestic cattle remain unknown.In this study,we analyzed 1...Aurochs(Bos primigenius),once widely distributed in Afro-Eurasia,became extinct in the early 1600 s.However,their phylogeography and relative contributions to domestic cattle remain unknown.In this study,we analyzed 16 genomes of ancient aurochs and three mitogenomes of ancient bison(Bison priscus)excavated in East Asia,dating from 43,000 to 3,590 years ago.These newly generated data with previously published genomic information on aurochs as well as ancient/extant domestic cattle worldwide through genome analysis.Ourfindings revealed significant genetic divergence between East Asian aurochs and their European,Near Eastern,and African counterparts on the basis of both mitochondrial and nuclear genomic data.Furthermore,we identified evidence of geneflow from East Asian aurochs into ancient and present-day taurine cattle,suggesting their potential role in facilitating the environmental adaptation of domestic cattle.展开更多
The presence of organic matter in lakes profoundly impacts drinking water supplies,yet treatment processes involving coagulants and disinfectants can yield carcinogenic disinfection by-products.Traditional assessments...The presence of organic matter in lakes profoundly impacts drinking water supplies,yet treatment processes involving coagulants and disinfectants can yield carcinogenic disinfection by-products.Traditional assessments of organic matter,such as chemical oxygen demand(COD_(Mn))and biochemical oxygen demand(BOD_(5)),are often time-consuming.Alternatively,optical measurements of dissolved organic matter(DOM)offer a rapid and reliable means of obtaining organic matter composition data.Here we employed DOM optical measurements in conjunction with parallel factor analysis to scrutinize COD_(Mn)and BOD_(5)variability.Validation was performed using an independent dataset encompassing six lakes on the Yungui Plateau from 2014 to 2016(n=256).Leveraging multiple linear regressions(MLRs)applied to DOM absorbance at 254 nm(a254)and fluorescence components C1-C5,we successfully traced COD_(Mn)and BOD_(5)variations across the entire plateau(68 lakes,n=271,R^(2)>0.8,P<0.0001).Notably,DOM optical indices yielded superior estimates(higher R^(2))of COD_(Mn)and BOD_(5)during the rainy season compared to the dry season and demonstrated increased accuracy(R^(2)>0.9)in mesotrophic lakes compared to oligotrophic and eutrophic lakes.This study underscores the utility of MLR-based DOM indices for inferring COD_(Mn)and BOD_(5)variability in plateau lakes and highlights the potential of integrating in situ and remote sensing platforms for water pollution early warning.展开更多
The authors regret that the following statements in the original article were wrong and have been corrected.The authors would like to apologise for any inconvenience caused.
The authors regret that the following statements in the original article were wrong and have been corrected.The authors would like to apologise for any inconvenience caused.
Human activities are usually considered to have had impacts on forest degradation and/or changes of forest composition in the past.The Tibetan Plateau,an environmentally sensitive area,has witnessed a high intensity o...Human activities are usually considered to have had impacts on forest degradation and/or changes of forest composition in the past.The Tibetan Plateau,an environmentally sensitive area,has witnessed a high intensity of human activities since the late Neolithic,but the evidence is still incomplete concerning how human activities affected the environment,especially vegetation changes.This may result,in part,from the fact that research on prehistoric wood utilization by humans in the northeast Tibetan Plateau(NETP)is scarce,especially from the perspective of charcoal analysis,which is an archaeological index directly related to human activities.To fill this gap,we report new data here concerning charcoal analysis from 24 archaeological sites dated 5200–2300 a BP in the NETP,where this period saw remarkable environmental and social changes.By coupling the results with published paleoenvironment records(especially pollen),we aim to explore the utilization of wood and its spatial-temporal changes,as well as the anthropogenic impacts on past forest dynamics in the NETP.The results suggest that the wood resources collected by humans were mainly needleleaf trees(Picea L.and Pinus L.),broadleaved trees(Populus L.,Salix L.,and Betula)as well as shrubs(Hippophae L.and Tamarix L.),and that these were distributed around the human habitation areas.There was a clear spatial difference in the woody assemblage collected by humans in the period 3600–2300 a BP.This was likely related to the diversity of natural environments in local areas,but there was an abnormal spatial pattern of forest composition with broadleaved trees dominant above 2500 masl caused not by climate change,but by the rapid increase of human settlement and wood collection in high altitude areas of the NETP since 3600 a BP.展开更多
Electrochemical techniques have shown advantages for the removal of low-concentration nitrate.Here,copper oxide nanosheets were grown on self-supporting nickel foam(NF)to prepare electrodes(CuO/NF),which realized the ...Electrochemical techniques have shown advantages for the removal of low-concentration nitrate.Here,copper oxide nanosheets were grown on self-supporting nickel foam(NF)to prepare electrodes(CuO/NF),which realized the rapid and highly selective conversion of nitrate pollutants in sewage into nontoxic and harmless N_(2).The CuO/NF afforded 100%NO_(3)^(-)removal within 100 min and 99.53%selectivity for N_(2)at-50 mA without producing a lot of by-products(NO_(2)-,NH_(4)^(+),and N_(2)H_(4)).Furthermore,81.8%of NO_(3)^(-)was removed under the given conditions after six experimental repetitions.These results suggest that the cat-alyst has excellent electrochemical stability.The performance of CuO/NF for the electrocatalytic removal of NO_(3)^(-)in simulated wastewater(which contained Cl^(-) and SO_(4)^(2-))was almost unaffected.Because of the high efficiency,high stability,and low cost of CuO/NF,this catalyst is practical for the removal of nitrate for wastewater purification.展开更多
Excess phosphorus(P)in water can lead to eutrophication and upset ecological balance.In this study,biochar with ultrathin two-dimensional nanosheets from the natural mesocarp of shaddock was chosen as the carrier.The ...Excess phosphorus(P)in water can lead to eutrophication and upset ecological balance.In this study,biochar with ultrathin two-dimensional nanosheets from the natural mesocarp of shaddock was chosen as the carrier.The highly dispersed and small particle size of La(OH)_(3) on the surface of the nanosheets(MSBL3)was successfully achieved using chemical impregnation for the adsorption of P in aqueous solution,and the maximum adsorption capacity was 260.0 mg P g^(−1)[La].The differences in surface crystallization of La(OH)_(3) on biochar at different La loadings were analyzed using the high-precision characterization methods.After six adsorption-desorption cycles,MSBL3 retained 76.7%of its initial performance in terms of the P adsorption capacity.The preparation of 1 g of MSBL3 costs about RMB 1,and it could reduce the P concentration in 2.6 ton of Laoyu River water to below the eutrophication threshold;and the inhibitory effect of MSBL3 on the eutrophication of water bodies was confirmed by the growth state of water hyacinth.Furthermore,0.1 M MSBL3 could inhibit Escherichia coli and Staphylococcus aureus up to 98.7%and 85.0%,respectively,which indicates that MSBL3 can be used to recover P from water and also to improve water quality.In addition,the growth of the maize seedlings verified that the P-absorbed MSBL3 waste is a good soil fertilizer and can solve the problem of post-treatment of the adsorbent.In conclusion,MSBL3 prepared in this study is a promising P sorbent for application.展开更多
Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River rema...Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River remains poorly understood.Here,we reconstruct the geographic and ecological history of an endemic clade of East Asian fishes based on the mitochondrial phylogenomics analysis of Cyprinidae using 15 fossil calibrations.We estimate an ancestral condition of benthic spawning with demersal or adhesive eggs in southern East Asia before23 Ma and a derived condition of riverine spawning with semibuoyant eggs in the Yangtze by18 Ma.These results imply the formation of Yangtze riverine ecosystems around the Oligocene-Miocene boundary in response to plateau uplift and monsoon strengthening.Some of these cyprinids reverted to benthic spawning with adhesive eggs by15 Ma,a time of rising to peak net diversification rates,indicating the formation of potamo-lacustrine ecosystems by the mid-Miocene during a strong East Asian summer monsoon.Our study provides increased spatiotemporal resolution for the co-evolutionary histories of the Yangtze River and its biodiversity and highlights biological evidence concerning the geomorphological dynamics of the Yangtze River.展开更多
Numerous studies support that biodiversity predict most to ecosystem functioning,but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied.We i...Numerous studies support that biodiversity predict most to ecosystem functioning,but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied.We investigated 398 samples of the phytoplankton phosphorus resource use efficiency(RUE_(P)=chlorophyll-a concentration/dissolved phosphate)across two seasons in nine plateau lakes in Yunnan Province,China.We identified the main contributors to phytoplankton RUEP and analyzed their potential influences on RUEP at different lake trophic states.The results showed that total nitrogen(TN)contributed the most to RUEP among the nine lakes,whereas community turnover(measured as community dissimilarity)explained the most to RUEP variation across the two seasons.Moreover,TN also influenced RUEP by affecting biodiversity.Species richness(SR),functional attribute diversity(FAD2),and dendrogram-based functional diversity(FDc)were positively correlated with RUEP in both seasons,while evenness was negatively correlated with RUEP at the end of the rainy season.We also found that the effects of biodiversity and turnover on RUEP depended on the lake trophic states.SR and FAD2 were positively correlated with RUEP in all three trophic states.Evenness showed a negative correlation with RUEP at the eutrophic and oligotrophic levels,but a positive correlation at themesotrophic level.Turnover had a negative influence on RUEP at the eutrophic level,but a positive influence at the mesotrophic and oligotrophic levels.Overall,our results suggested that multiple factors and nutrient states need to be considered when the ecosystem functioning predictors and the biodiversityecosystem functioning relationships are investigated.展开更多
Zige Tangco is a meromictic saline lake located on the central Tibetan Plateau.Two parallel cores(ZGTC A-1 and ZGTC A-2)were collected from the lake at a water depth of 25 m during summer 2006.The chronology of core A...Zige Tangco is a meromictic saline lake located on the central Tibetan Plateau.Two parallel cores(ZGTC A-1 and ZGTC A-2)were collected from the lake at a water depth of 25 m during summer 2006.The chronology of core A-1 was reconstructed based on the Constant Initial Concentration(CIC)model of 210Pb and three accelerator mass spectrometry(AMS)ages from the chitin fragments.The hard water effect calibration of the sediment ^(14)C age showed that the reservoir effect ranged from 1655 yr at 1950 AD to 1540 yr at 1610 AD.The hydrological variation in Zige Tangco during the past 800 yr was reconstructed using multi-proxies,including organic and carbonate content,stable isotopes of fine-grained carbonate minerals(<38.5μm)and grain-size distribution of the lake sediments.Our results show that there were strong fluctuations in the lake level between 1200 and 1820 AD,and at least three dry periods were recorded between 1235 and 1315 AD,1410 and 1580 AD,and 1660 and 1720 AD characterized by high carbonate content,abrupt positive shifts of stable isotopes,and high sand content.The low-lake-level periods during the Little Ice Age(LIA)in Zige Tangco correspond to the lower δ^(18)O values in the Guliya ice core and the lower precipitation reconstructed from tree rings in Delingha.This demonstrated that the summer monsoon on the central Tibetan Plateau weakened during the dry and cold periods,whereas the winter monsoon strengthened.Relatively wetter periods or higher lake levels in Zige Tangco occurred at 1580-1650 AD and 1820-1900 AD.Negative shifts in stable isotopes were related to increased lake levels between 1800 and 1820 AD.Our results also showed that the summer monsoon precipitation on the central Tibetan Plateau was mainly controlled by solar activity during the past 800 yr.展开更多
基金supported by DFG (PA 131 16/1-4)NSFC(40871096 & 40371117)
文摘The Ejina( Gaxun Nur) Basin-enclosed by the Tibetan Plateau in the south and the Gobi Altay in the north hascontinuously evolved as a strong continental endorheic depositional environment. Medium scale geomorphological mappingby Landsat- and Corona-Images as well as SRTM-topographic data, combined with field-surveys and geophysicalinvestigation provides evidence for tectonic impact on sedimentary processes during the Late Quaternary.Analyses of SRTM-Data and Landsat-Images reveal a system of up to 20m high inverted channels developed on theinactive eastern part of the large Hei river drainage delta south of the ancient lake Juyanze. The complex evolution of theselandforms requires a relative lowering of the lake basin at least two times since the last 40ka. A 26m high cliff section ofgravel-covered lake sediments within the Juyanze paleolake indicates a strong subsidence of the lake bottom of 10m/1000yrssince 18kaB. P.North of Ejina river oasis a distinct north-south striking scarp up to 13m high constitutes the eastern margin of theGaxun Nur. Palaeodrainage channels derived from the Gobi Altay. They display a sinistral offset of some decametres alonga set of WE-trending faults. The rhombic shape of the modern dry Gaxun Nur, fossil cliffs,well preserved beach ridges alongthe margins of the palaeolake system as well as gravel covered topsets of lacustrine sediments indicate local displacements ofmorphological features. The displacements of lake sediments at the southern margin of the modern Gaxun Nur Basin imply asubsidence of at least 0.81m/1000 yrs since 25kaB. P. as a result of a pull-apart development due to the left stepping faultsin a sinistral system.
文摘Recently local government and environmental protection authorities in China have turned to the water hyacinth, one of the world’s worst aquatic weeds, to reduce nutrient concentrations in highly eutrophic lake waters, especially in Lake Dian in southwestern China’s Yunnan Province. Although we do not reject using water hyacinth to reduce lake eutrophication, it is not a complete solution. In our view, a more complete solution requires a holistic consideration of watershed or drainage characteristics, and a solid understanding of the limnological features of individual lakes. Before the bio-geochemistry and toxicological effects of water hyacinth be thoroughly understood, applying it widely to lake restoration and overstating its practical value is not only irresponsible but also dangerous.
基金supported by the National Natural Science Foundation of China(Nos.41820104008 and U2202207)the Special Project for Social Development of Yunnan Province(No.202103AC100001)。
文摘Many cases of an unknown disease exhibiting the clinical features of limb gangrene,blisters,ulceration,and exfoliation have been reported in Daping village(DV)in southwestern China.However,the pathogenesis is unknown and has puzzled doctors for many years.A preliminary study on heavy metals and symptoms indicated that arsenic might pose the greatest threat to the health of local residents.Here,to explore the sources of and factors influencing arsenic enrichment in DV,whose residents exhibit signs of arsenic poisoning,the As contents in soil,water,and plants were systematically measured.The results indicated high As contents in plant and soil samples obtained from the area,and the source of As may be linked to the weathering of black shale rock.Ingestion of soil and consumption of plants were the two main As exposure pathways among children and adults,respectively,and children exhibited a higher health risk than adults.We presume and emphasize that when extreme drought events occur,humans might face unusual risks resulting from exposure to toxic elements and the direct consumption of highly polluted water.Our study provides a new perspective and sheds light on the environmental geochemistry and health links of this disease.
基金supported by the National Key R&D Program of China(2021YFD1200400 and 2021YFF1001000)the National Natural Science Foundation of China(32102523,32372854,31861143014,32260823,and 32172706)+5 种基金the Key Research and Development Program of Xizang Autonomous Region of China(XZ202301ZY0008N)the Yunnan Expert Workstations(202305AF150156),the China Agriculture Research System of MOF and MARA(CARS-37)the Postdoctoral Fellowship Program of CPSF(GZC20232149)the Program of Yunling Scholar and Yunling Cattle Special Program of Yunnan Joint Laboratory of Seeds and Seeding Industry(202205AR070001)the Construction of Yunling Cattle Technology Innovation Center and Industrialization of Achievements(2019ZG007)Finally,we thank the High-Performance Computing(HPC)Center of Northwest A&F University(NWAFU)and Hefei Advanced Computing Center for providing computing resources.
文摘During the past 3000 years,cattle on the Qinghai-Xizang Plateau have developed adaptive phenotypes under the selective pressure of hypoxia,ultraviolet(UV)radiation,and extreme cold.The genetic mechanism underlying this rapid adaptation is not yet well understood.Here,we present whole-genome resequencing data for 258 cattle from 32 cattle breeds/populations,including 89 Tibetan cattle representing eight populations distributed at altitudes ranging from 3400 m to 4300 m.Our genomic analysis revealed that Tibetan cattle exhibited a continuous phylogeographic cline from the East Asian taurine to the South Asian indicine ancestries.We found that recently selected genes in Tibetan cattle were related to body size(HMGA2 and NCAPG)and energy expenditure(DUOXA2).We identified signals of sympatric introgression from yak into Tibetan cattle at different altitudes,covering 0.64%–3.26%of their genomes,which included introgressed genes responsible for hypoxia response(EGLN1),cold adaptation(LRP11),DNA damage repair(LATS1),and UV radiation resistance(GNPAT).We observed that introgressed yak alleles were associated with noncoding variants,including those in present EGLN1.In Tibetan cattle,three yak introgressed SNPs in the EGLN1 promoter region reduced the expression of EGLN1,suggesting that these genomic variants enhance hypoxia tolerance.Taken together,our results indicated complex adaptation processes in Tibetan cattle,where recently selected genes and introgressed yak alleles jointly facilitated rapid adaptation to high-altitude environments.
基金supported by the National Natural Science Foundation of China(41820104008,U2202207,U23A20161,T2222030 and 32102523)the earmarked fund for the China Agriculture Research System of MOF and MARA(CARS-37)+1 种基金the Chinese Universities Scientific Fund(2452021153)the Independent Research Fund Denmark(8028-00005B).
文摘Aurochs(Bos primigenius),once widely distributed in Afro-Eurasia,became extinct in the early 1600 s.However,their phylogeography and relative contributions to domestic cattle remain unknown.In this study,we analyzed 16 genomes of ancient aurochs and three mitogenomes of ancient bison(Bison priscus)excavated in East Asia,dating from 43,000 to 3,590 years ago.These newly generated data with previously published genomic information on aurochs as well as ancient/extant domestic cattle worldwide through genome analysis.Ourfindings revealed significant genetic divergence between East Asian aurochs and their European,Near Eastern,and African counterparts on the basis of both mitochondrial and nuclear genomic data.Furthermore,we identified evidence of geneflow from East Asian aurochs into ancient and present-day taurine cattle,suggesting their potential role in facilitating the environmental adaptation of domestic cattle.
基金the support of the Science and Technology Project of Yunnan Province(No.202103AC100001)the National Natural Science Foundation of China(Nos.42322104 and 42071131)+3 种基金the National Key Research and Development Programof China(No.2017YFA0605202)the Youth Innovation Promotion Association CAS(No.2021312)the Provincial Natural Science Foundation of Jiangsu(No.BK20220162)the TÜBITAK program BIDEB2232(project 118C250).
文摘The presence of organic matter in lakes profoundly impacts drinking water supplies,yet treatment processes involving coagulants and disinfectants can yield carcinogenic disinfection by-products.Traditional assessments of organic matter,such as chemical oxygen demand(COD_(Mn))and biochemical oxygen demand(BOD_(5)),are often time-consuming.Alternatively,optical measurements of dissolved organic matter(DOM)offer a rapid and reliable means of obtaining organic matter composition data.Here we employed DOM optical measurements in conjunction with parallel factor analysis to scrutinize COD_(Mn)and BOD_(5)variability.Validation was performed using an independent dataset encompassing six lakes on the Yungui Plateau from 2014 to 2016(n=256).Leveraging multiple linear regressions(MLRs)applied to DOM absorbance at 254 nm(a254)and fluorescence components C1-C5,we successfully traced COD_(Mn)and BOD_(5)variations across the entire plateau(68 lakes,n=271,R^(2)>0.8,P<0.0001).Notably,DOM optical indices yielded superior estimates(higher R^(2))of COD_(Mn)and BOD_(5)during the rainy season compared to the dry season and demonstrated increased accuracy(R^(2)>0.9)in mesotrophic lakes compared to oligotrophic and eutrophic lakes.This study underscores the utility of MLR-based DOM indices for inferring COD_(Mn)and BOD_(5)variability in plateau lakes and highlights the potential of integrating in situ and remote sensing platforms for water pollution early warning.
文摘The authors regret that the following statements in the original article were wrong and have been corrected.The authors would like to apologise for any inconvenience caused.
文摘The authors regret that the following statements in the original article were wrong and have been corrected.The authors would like to apologise for any inconvenience caused.
基金supported by the National Natural Science Foundation of China(Grant Nos.41825001,41820104008)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0601)。
文摘Human activities are usually considered to have had impacts on forest degradation and/or changes of forest composition in the past.The Tibetan Plateau,an environmentally sensitive area,has witnessed a high intensity of human activities since the late Neolithic,but the evidence is still incomplete concerning how human activities affected the environment,especially vegetation changes.This may result,in part,from the fact that research on prehistoric wood utilization by humans in the northeast Tibetan Plateau(NETP)is scarce,especially from the perspective of charcoal analysis,which is an archaeological index directly related to human activities.To fill this gap,we report new data here concerning charcoal analysis from 24 archaeological sites dated 5200–2300 a BP in the NETP,where this period saw remarkable environmental and social changes.By coupling the results with published paleoenvironment records(especially pollen),we aim to explore the utilization of wood and its spatial-temporal changes,as well as the anthropogenic impacts on past forest dynamics in the NETP.The results suggest that the wood resources collected by humans were mainly needleleaf trees(Picea L.and Pinus L.),broadleaved trees(Populus L.,Salix L.,and Betula)as well as shrubs(Hippophae L.and Tamarix L.),and that these were distributed around the human habitation areas.There was a clear spatial difference in the woody assemblage collected by humans in the period 3600–2300 a BP.This was likely related to the diversity of natural environments in local areas,but there was an abnormal spatial pattern of forest composition with broadleaved trees dominant above 2500 masl caused not by climate change,but by the rapid increase of human settlement and wood collection in high altitude areas of the NETP since 3600 a BP.
基金This work was financially supported by the National Key R&D Program of China(No.2019YFC1804400)Special Project for Social Development of Yunnan Province(No.202103AC100001)+1 种基金Double Tops Joint Fund of the Yunnan Science and Technology Bureau and Yunnan University(No.2019FY003025)Double First Class University Plan(No.C176220100042).
文摘Electrochemical techniques have shown advantages for the removal of low-concentration nitrate.Here,copper oxide nanosheets were grown on self-supporting nickel foam(NF)to prepare electrodes(CuO/NF),which realized the rapid and highly selective conversion of nitrate pollutants in sewage into nontoxic and harmless N_(2).The CuO/NF afforded 100%NO_(3)^(-)removal within 100 min and 99.53%selectivity for N_(2)at-50 mA without producing a lot of by-products(NO_(2)-,NH_(4)^(+),and N_(2)H_(4)).Furthermore,81.8%of NO_(3)^(-)was removed under the given conditions after six experimental repetitions.These results suggest that the cat-alyst has excellent electrochemical stability.The performance of CuO/NF for the electrocatalytic removal of NO_(3)^(-)in simulated wastewater(which contained Cl^(-) and SO_(4)^(2-))was almost unaffected.Because of the high efficiency,high stability,and low cost of CuO/NF,this catalyst is practical for the removal of nitrate for wastewater purification.
基金Special Project for Social Development of Yunnan Province(202103AC100001)Double-First Class University Plan(C176220100042)+1 种基金Scientific Research Fund Project of Yunnan Provincial Department of Education(2023Y0210)Graduate Student Funding of School of Ecology and Environmental Science,Yunnan University(Y2000229).
文摘Excess phosphorus(P)in water can lead to eutrophication and upset ecological balance.In this study,biochar with ultrathin two-dimensional nanosheets from the natural mesocarp of shaddock was chosen as the carrier.The highly dispersed and small particle size of La(OH)_(3) on the surface of the nanosheets(MSBL3)was successfully achieved using chemical impregnation for the adsorption of P in aqueous solution,and the maximum adsorption capacity was 260.0 mg P g^(−1)[La].The differences in surface crystallization of La(OH)_(3) on biochar at different La loadings were analyzed using the high-precision characterization methods.After six adsorption-desorption cycles,MSBL3 retained 76.7%of its initial performance in terms of the P adsorption capacity.The preparation of 1 g of MSBL3 costs about RMB 1,and it could reduce the P concentration in 2.6 ton of Laoyu River water to below the eutrophication threshold;and the inhibitory effect of MSBL3 on the eutrophication of water bodies was confirmed by the growth state of water hyacinth.Furthermore,0.1 M MSBL3 could inhibit Escherichia coli and Staphylococcus aureus up to 98.7%and 85.0%,respectively,which indicates that MSBL3 can be used to recover P from water and also to improve water quality.In addition,the growth of the maize seedlings verified that the P-absorbed MSBL3 waste is a good soil fertilizer and can solve the problem of post-treatment of the adsorbent.In conclusion,MSBL3 prepared in this study is a promising P sorbent for application.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB31000000).
文摘Documenting the origins of megadiverse(sub)tropical aquatic ecosystems is an important goal for studies of evolution and ecology.Nonetheless,the geological and ecological establishment of the modern Yangtze River remains poorly understood.Here,we reconstruct the geographic and ecological history of an endemic clade of East Asian fishes based on the mitochondrial phylogenomics analysis of Cyprinidae using 15 fossil calibrations.We estimate an ancestral condition of benthic spawning with demersal or adhesive eggs in southern East Asia before23 Ma and a derived condition of riverine spawning with semibuoyant eggs in the Yangtze by18 Ma.These results imply the formation of Yangtze riverine ecosystems around the Oligocene-Miocene boundary in response to plateau uplift and monsoon strengthening.Some of these cyprinids reverted to benthic spawning with adhesive eggs by15 Ma,a time of rising to peak net diversification rates,indicating the formation of potamo-lacustrine ecosystems by the mid-Miocene during a strong East Asian summer monsoon.Our study provides increased spatiotemporal resolution for the co-evolutionary histories of the Yangtze River and its biodiversity and highlights biological evidence concerning the geomorphological dynamics of the Yangtze River.
基金supported by the National Natural Science Foundation of China (Nos.42001099, 42071131)the Special Project for Social Development of Yunnan Province (No.202103AC100001)the Yilong Lake Administration (No.FDZBHH2021039-1)
文摘Numerous studies support that biodiversity predict most to ecosystem functioning,but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied.We investigated 398 samples of the phytoplankton phosphorus resource use efficiency(RUE_(P)=chlorophyll-a concentration/dissolved phosphate)across two seasons in nine plateau lakes in Yunnan Province,China.We identified the main contributors to phytoplankton RUEP and analyzed their potential influences on RUEP at different lake trophic states.The results showed that total nitrogen(TN)contributed the most to RUEP among the nine lakes,whereas community turnover(measured as community dissimilarity)explained the most to RUEP variation across the two seasons.Moreover,TN also influenced RUEP by affecting biodiversity.Species richness(SR),functional attribute diversity(FAD2),and dendrogram-based functional diversity(FDc)were positively correlated with RUEP in both seasons,while evenness was negatively correlated with RUEP at the end of the rainy season.We also found that the effects of biodiversity and turnover on RUEP depended on the lake trophic states.SR and FAD2 were positively correlated with RUEP in all three trophic states.Evenness showed a negative correlation with RUEP at the eutrophic and oligotrophic levels,but a positive correlation at themesotrophic level.Turnover had a negative influence on RUEP at the eutrophic level,but a positive influence at the mesotrophic and oligotrophic levels.Overall,our results suggested that multiple factors and nutrient states need to be considered when the ecosystem functioning predictors and the biodiversityecosystem functioning relationships are investigated.
基金supported by the National Natural Science Foundation of China(Grant No.41971097).
文摘Zige Tangco is a meromictic saline lake located on the central Tibetan Plateau.Two parallel cores(ZGTC A-1 and ZGTC A-2)were collected from the lake at a water depth of 25 m during summer 2006.The chronology of core A-1 was reconstructed based on the Constant Initial Concentration(CIC)model of 210Pb and three accelerator mass spectrometry(AMS)ages from the chitin fragments.The hard water effect calibration of the sediment ^(14)C age showed that the reservoir effect ranged from 1655 yr at 1950 AD to 1540 yr at 1610 AD.The hydrological variation in Zige Tangco during the past 800 yr was reconstructed using multi-proxies,including organic and carbonate content,stable isotopes of fine-grained carbonate minerals(<38.5μm)and grain-size distribution of the lake sediments.Our results show that there were strong fluctuations in the lake level between 1200 and 1820 AD,and at least three dry periods were recorded between 1235 and 1315 AD,1410 and 1580 AD,and 1660 and 1720 AD characterized by high carbonate content,abrupt positive shifts of stable isotopes,and high sand content.The low-lake-level periods during the Little Ice Age(LIA)in Zige Tangco correspond to the lower δ^(18)O values in the Guliya ice core and the lower precipitation reconstructed from tree rings in Delingha.This demonstrated that the summer monsoon on the central Tibetan Plateau weakened during the dry and cold periods,whereas the winter monsoon strengthened.Relatively wetter periods or higher lake levels in Zige Tangco occurred at 1580-1650 AD and 1820-1900 AD.Negative shifts in stable isotopes were related to increased lake levels between 1800 and 1820 AD.Our results also showed that the summer monsoon precipitation on the central Tibetan Plateau was mainly controlled by solar activity during the past 800 yr.
