The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average a...The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.展开更多
The migration speed of a typical barchan on the border of Minqin oasis,Gansu Province,northwestern China,was estimated by means of two methods.One is on the basis of a simple physical model and short-term field measur...The migration speed of a typical barchan on the border of Minqin oasis,Gansu Province,northwestern China,was estimated by means of two methods.One is on the basis of a simple physical model and short-term field measurements.The other comes from the combination of the barchan internal structure detected by ground-penetrating radar and optical/radiocarbon dating techniques.The upper limit of migration speed given by conventional C-14 dating is 3.42 m/yr.The optically stimulated luminescence dating indicates that the time-average migration speed of the studied barchan was 1.78 m/yr in 28 years prior to 2007.The physical estimation further suggests that the annual migration speed has increased in recent years.展开更多
The domestication of livestock from their wild progenitors was essential in the process of the Neolithic Revolution.Aurochs(Bos primigenius)are considered to be the ancestors of modern cattle(B.taurus).They were once ...The domestication of livestock from their wild progenitors was essential in the process of the Neolithic Revolution.Aurochs(Bos primigenius)are considered to be the ancestors of modern cattle(B.taurus).They were once widespread across Eurasia and North Africa but became extinct approximately 400 years ago[1].展开更多
Proxy-based reconstructions and climate model simulations of Holocene global annual mean temperatures exhibit divergent trends,leading to the well-known“Holocene temperature conundrum(HTC)”.This discrepancy is most ...Proxy-based reconstructions and climate model simulations of Holocene global annual mean temperatures exhibit divergent trends,leading to the well-known“Holocene temperature conundrum(HTC)”.This discrepancy is most pronounced in the mid-to-high latitudes of the Northern Hemisphere(NH)and has been attributed to either proxy seasonal bias or deficiencies in climate models.Paleoclimate data assimilation(PDA),which integrates proxy records with climate model simulations,provides an advanced method for generating global seasonal temperature reanalysis datasets for the mid-Holocene(MH).Assimilated results indicate that MH Eurasian temperatures are largely independent of the choice of model priors and exhibit significant spatial heterogeneity.Compared to the pre-industrial(PI)period,the MH is characterized by winter and annual mean warming in Europe and high-latitude Eurasia,while the rest of Eurasia experiences cooling.However,this spatial heterogeneity is not well represented in model simulations due to a pronounced winter cooling bias at high latitudes,likely resulting from inadequate representations of vegetation and sea ice feedback mechanisms.As Eurasian proxy records are predominantly concentrated in Europe,this regional imbalance introduces a warm bias in reconstructed winter and annual temperatures intended to represent broader Eurasian temperature changes.These results suggest that the HTC may stem from both the uneven spatial distribution of proxy records and the incomplete representation of internal climate feedbacks in current models.展开更多
The southeastern Tibetan Plateau(SETP)is the preeminent summer heavy precipitation region within the Tibetan Plateau(TP).However,the large-scale circulation types and dynamics driving summer heavy precipitation in the...The southeastern Tibetan Plateau(SETP)is the preeminent summer heavy precipitation region within the Tibetan Plateau(TP).However,the large-scale circulation types and dynamics driving summer heavy precipitation in the SETP remain inadequately elucidated.Using the hierarchical clustering method,two distinctive atmospheric circulation patterns associated with heavy precipitation were identified:the Tibetan Plateau vortex type(TPVT,constituting 56.6%of the events)and the mid-latitude trough type(MLTT,43.4%).A comprehensive examination of the two atmospheric circulation patterns reveals a clear nexus between the occurrences of summer heavy precipitation and positive vorticity anomalies,moisture convergence,as well as the southeastward displacement of the westerly jet core.Specifically,TPVT events are characterized by the eastward and dry-to-wet potential vorticity progression processes,while MLTT events are linked to the intrusion of a deep extratropical trough into the SETP.This study advances our understanding of the complex mechanisms governing the summer heavy precipitation in the SETP,shedding light on critical meteorological processes in the region.展开更多
Central Asia(CA)faces a severe water crisis exemplified by the shrinking Aral Sea.However,little is known about the entire region,particularly the numerous small water bodies that are vulnerable to climate change yet ...Central Asia(CA)faces a severe water crisis exemplified by the shrinking Aral Sea.However,little is known about the entire region,particularly the numerous small water bodies that are vulnerable to climate change yet vital for regional sustainability.We examined water bodies as small as 0.0045 km^(2)across CA from 1992 to 2020,identifying 66,215 water bodies in 2020,82.2%of which were previously unstudied.In contrast to the well-documented decline of the Aral Sea,other water bodies have expanded by 10.7%(8714.3 km^(2)),with a net gain of 15,831 lakes since 1992.These findings challenge the perception of a drying CA and provide evidence of a warm-wet climate trend,which is redistributing water resources and creating opportunities for transforming water management to address the long-standing water crisis in CA.展开更多
The intensification of millet agriculture facilitated the development of ancient civilization in northern China.In Inner Mongolia and the Central Plains,the intensification of millet farming was relatively continuous....The intensification of millet agriculture facilitated the development of ancient civilization in northern China.In Inner Mongolia and the Central Plains,the intensification of millet farming was relatively continuous.However,prior evidence from the western Loess Plateau(WLP)has suggested an indistinct sequence of millet cultivation and a time lag between the initial intensification of millet agriculture and subsequent expansion of millet farming.We report on new stable isotopic data and radiocarbon dates from the Gedachuan site which challenge that interpretation.Our results indicate a gradual intensification and expansion of millet agriculture across the whole WLP.They attest to intensive broomcorn millet-based farming underpinning the emergence and development of the agrarian society in the WLP during the early-middle Yangshao period(∼6300-5500 BP),and to an intensification of the higher-yielding foxtail millet-based farming leading to the rapid growth of population in the WLP and expansion of millet cultivation after 5300 BP.展开更多
Inland lakes in arid Central Asia are particularly susceptible to the impact of climate change and human activities.Ebinur Lake,the largest salt inland lake in Xinjiang,Northwest China,has experienced rapid shrinkage,...Inland lakes in arid Central Asia are particularly susceptible to the impact of climate change and human activities.Ebinur Lake,the largest salt inland lake in Xinjiang,Northwest China,has experienced rapid shrinkage,with human activities identified as the primary influencing factor.However,it remains unclear how human water use in different sectors,such as irrigation,husbandry,and industry,is responsible for the long-term change and seasonal variability of the lake area under changing climate.This study aims to address this knowledge gap by developing an integrated hydrological-socioeconomic-lake model that simulates the changes in the Ebinur Lake area during the period of 1950–2020.The simulated lake area changes under different model experiments were then compared with separate the impacts of climate change and human water use of different sectors.The results indicate that climate change,irrigation,husbandry,and industry water uses have contributed+5%,-79%,-25%,and-1%of the long-term change in the lake area,respectively.Despite climate change alone increasing the lake area,the increase in human water use has resulted in the persistent decline of Ebinur Lake.Notably,husbandry water use emerges as a significant contributor to lake shrinkage,accounting for approximately one-third of the impact of irrigation.Furthermore,irrigation water use has contributed to the enhanced seasonal variability,as indicated by the difference between the maximum and minimum monthly lake area in a year.This difference has increased from 120 km2in the 1950s to 183 km2in the 2010s.展开更多
The spheres of the Earth—specifically the lithosphere,hydrosphere,atmosphere,and biosphere—are intricately connected and interact through the fluxes of matter and energy,forming a complex and ever-evolving Earth sys...The spheres of the Earth—specifically the lithosphere,hydrosphere,atmosphere,and biosphere—are intricately connected and interact through the fluxes of matter and energy,forming a complex and ever-evolving Earth system.Understanding the dynamic linkages between these spheres during different types of forcings or events is essential for predicting changes and securing a sustainable future for living organisms,particularly humans.However,uncovering these linkages is challenging due to the need for suitable proxies that can demonstrate how these systems or spheres change across diverse temporal and spatial scales.展开更多
Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine period.How...Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine period.However,the role climate and environmental changes may have played in this pivotal event in Chinese history remains unclear.Here,we provide tree-ring evidence of persistent megadroughts from1576 to 1593 CE and from 1628 to 1644 CE in northern China,which coincided with exceptionally cold summers just before the fall of Beijing.Our analysis reveals that these regional hydroclimatic extremes are part of a series of megadroughts along the Pacific Rim,which not only impacted the ecology and society of monsoonal northern China,but likely also exacerbated external geopolitical and economic pressures.This finding is corroborated by last millennium reanalysis data and numerical climate model simulations revealing internally driven Pacific sea surface temperature variations and the predominance of decadal scale La Ni?a-like conditions to be responsible for precipitation decreases over northern China,as well as extensive monsoon regions in the Americas.These teleconnection patterns provide a mechanistic explanation for reoccurring drought spells during the late Ming Dynasty and the environmental framework fostering the fall of Beijing in 1644 CE,and the subsequent demise of the Ming Dynasty.展开更多
Wild aurochs(Bos primigenius)were once widespread across Eurasia and North Africa but became extinct around the 17th century[1].Aurochs are considered the ancestor of modern taurine(B.taurus taurus)and indicine(B.t.in...Wild aurochs(Bos primigenius)were once widespread across Eurasia and North Africa but became extinct around the 17th century[1].Aurochs are considered the ancestor of modern taurine(B.taurus taurus)and indicine(B.t.indicus)cattle,which were independently domesticated within regions restricted to Southwest Asia and South Asia,respectively[2,3].Extensive gene flow from local aurochs to domestic cattle has been well documented in Southwest Asia,Europe,and Africa[3,4],raising questions about the mechanisms underlying both the domestication and dispersal of early cattle.展开更多
The Tibetan Plateau(TP)is an important link between the South Asian monsoon(SAM)region,the East Asian monsoon region,and the drylands of Central Asia.Climate changes within these regions are dominated by both the mons...The Tibetan Plateau(TP)is an important link between the South Asian monsoon(SAM)region,the East Asian monsoon region,and the drylands of Central Asia.Climate changes within these regions are dominated by both the monsoon and the westerlies.This has prompted the scientific community to adopt a broad spatial perspective,proposing concepts such as the"Pan-Third Poleoor"Asian summer precipitationo,to better understand the regional climate dynamics,their driving mechanisms,and the resulting major ecological and environmental impacts.展开更多
The origin and spread of agriculture facilitated a decline in human mobility and eventually led to a predominantly sedentary lifestyle globally,including on the Tibetan Plateau.Previous studies have proposed an evolut...The origin and spread of agriculture facilitated a decline in human mobility and eventually led to a predominantly sedentary lifestyle globally,including on the Tibetan Plateau.Previous studies have proposed an evolution of prehistoric agriculture,from millet-based to barley-based farming.However,details regarding the process are vague.Here,we present diachronic changes in cropping structure from Xizang on the basis of a quantitative analysis of archaeobotanical remains from 12 sites located in southeastern Xizang.The advent of agriculture in Xizang began in the southeastern region around 4800 cal a BP and resulted in a quick spread of millet agriculture from the Hengduan Mountains to the Yarlung Zangbo River region.Subsequently,the introduction of barley and wheat to Xizang led to the transformation of millet-based farming into mixed farming after 3600 cal a BP.Eventually,around 3000 cal a BP,barley and wheat dominated across the entire Xizang with declining occurrences of millet.It took more than 600 years for barley and wheat to dominate in the Tibetan cropping system,which may reflect the time required for these exotic species to adapt physiologically to their new niche.In addition to the diachronic changes in crop farming,the ratio of barley to wheat and foxtail millet to broomcorn millet also varied at different elevations possibly due to local environmental variations and the crops’physiological requirements.展开更多
The term“Holocene temperature conundrum”refers to the inconsistencies between proxy-based reconstructions and transient model simulations,and it challenges our understanding of global temperature evolution during th...The term“Holocene temperature conundrum”refers to the inconsistencies between proxy-based reconstructions and transient model simulations,and it challenges our understanding of global temperature evolution during the Holocene.Climate reconstructions indicate a cooling trend following the Holocene Thermal Maximum,while model simulations indicate a consistent warming trend due to icesheet retreat and rising greenhouse gas concentrations.Various factors,such as seasonal biases and overlooked feedback processes,have been proposed as potential causes for this discrepancy.In this study,we examined the impact of vegetation-climate feedback on the temperature anomaly patterns in East Asia during the mid-Holocene(~6 ka).By utilizing the fully coupled Earth system model EC-Earth and performing simulations with and without coupled dynamic vegetation,our objective was to isolate the influence of vegetation changes on regional temperature patterns.Our findings reveal that vegetation-climate feedback contributed to warming across most of East Asia,resulting in spatially diverse temperature changes during the mid-Holocene and significantly improved model-data agreement.These results high-light the crucial role of vegetation-climate feedback in addressing the Holocene temperature conundrum and emphasize its importance for simulating accurate climate scenarios.展开更多
Millet agriculture,which originated in northern China,alongside rice agriculture,have nurtured the Chinese civilization.Prehistoric manuring practices likely promoted and maintained sustainable millet agricultural pro...Millet agriculture,which originated in northern China,alongside rice agriculture,have nurtured the Chinese civilization.Prehistoric manuring practices likely promoted and maintained sustainable millet agricultural production in the loess area of northern China.However,ongoing controversy exists regarding the indicators of prehistoric manuring intensity of foxtail millet(Setaria italica)and common millet(Panicum miliaceum).Here,we present the results of pot and field fertilization experiments on two millet types.Our findings suggest that manuring can significantly increase the δ^(15)N values of foxtail millet,and its δ^(15)N values increase with increasing manuring levels.The δ^(15)N values of foxtail millet leaves are systematically greater than those of grains by approximately 1.6‰.Manuring could have a long-term residual impact on increasing the δ^(15)N values of soil and millet crops.Combined with previous crop fertilization experiment results,we propose that the impact of manuring on the δ^(15)N values of non-nitrogen-fixing crops is roughly consistent.The δ^(15)N value and amount of manure are key factors determining the extent of change in plant δ^(15)N values.The millet grain δ^(15)N values can serve as reliable indicators of manuring practices.Finally,we provide an interpretive framework for assessing the correlation between manuring levels and the δ^(15)N values of archaeological millet remains.The δ^(15)N values of ancient millet grains suggest widespread and intensive manuring practices in prehistoric millet agriculture in northern China,spanning from the early Yangshao period to the Longshan period.展开更多
Deserts are the most distinctive landscapes in the arid zones of midlatitude Asia,producing over 600 Tg of dust annually and serving as primary sources of mineral dust for the Northern Hemisphere.This dust is carried ...Deserts are the most distinctive landscapes in the arid zones of midlatitude Asia,producing over 600 Tg of dust annually and serving as primary sources of mineral dust for the Northern Hemisphere.This dust is carried by the westerlies and the East Asian winter monsoon to downwind regions including East Asia,the northern Pacific Ocean,and even Greenland,influencing the global climate,global biogeochemical cycles,ocean productivity,Northern Hemisphere glaciations,and human health.展开更多
China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of...China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of the carbon sink in China’s terrestrial ecosystems to mitigate anthropogenic carbon emissions has attracted unprecedented attention from scientific communities,policy makers and the public.Here,we reviewed the assessments on China’s terrestrial ecosystem carbon sink,with focus on the principles,frameworks and methods of terrestrial ecosystem carbon sink estimates,as well as the recent progress and existing problems.Looking forward,we identified critical issues for improving the accuracy and precision of China’s terrestrial ecosystem carbon sink,in order to serve the more realistic policy making in pathways to achieve carbon neutrality for China.展开更多
The natural environment provides material essentials for human survival and development. The characteristics,processes, regional differentiation and forcing mechanisms of the elements of the natural environment(e.g. g...The natural environment provides material essentials for human survival and development. The characteristics,processes, regional differentiation and forcing mechanisms of the elements of the natural environment(e.g. geomorphology,climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective.展开更多
The Tibetan Plateau,the world's "Third Pole",has an average elevation above 4,000 masl (meters above sea level)and an area of over 500×10^4km^2,It is the highest and largest plateau on earth and is ...The Tibetan Plateau,the world's "Third Pole",has an average elevation above 4,000 masl (meters above sea level)and an area of over 500×10^4km^2,It is the highest and largest plateau on earth and is very sensitive to global climate change [1,2].The cold,dry and hypoxic high-altitude environment of the plateau presents a major challenge to human survival.Therefore,the history and mechanisms of prehistoric human history on the Tibetan Plateau-from brief hunting expeditions to seasonal hunting-gathering and finally to permanent settlements-has attracted both general interest and substantial scientific debates [3-6].Archaeological studies indicate that humans probably first explored the plateau at the end of the late Pleistocene.They practiced intensive seasonal hunting-gathering from 15 ka BP [6],and permanently settled regions above 3,000 masl after 3.6 ka BP,which was facilitated by the development of an agropastoral economy [3].However, the early part of the human history of the Tibetan Plateau is still poorly documented,due to the lack of well-preserved archaeological sites and reliable dating results (Fig.la).展开更多
基金supported by the National Natural Science Foundation of China(No.42072211)the National Natural Science Foundation of China(No.42401048)the Third Xinjiang Scientific Expedition and Research Program(No.2021xjkk0302)。
文摘The Taklimakan Desert,located in the heart of central Asia,covers approximately 330000 km^(2),making it China's largest desert and the world's second-largest shifting desert(Dong et al.,2024).With an average annual precipitation of less than 100 mm and evaporation rates ranging from 2000 to 3000 mm(Yang et al.,2020),it is recognized as one of the driest regions on Earth,often referred to as the“sea of death”.
基金supported by 973 project No. 2000048700NSFC projects No. 40601053 and 40872108Ministry of Science and Technology of China project No. 2006FY110800
文摘The migration speed of a typical barchan on the border of Minqin oasis,Gansu Province,northwestern China,was estimated by means of two methods.One is on the basis of a simple physical model and short-term field measurements.The other comes from the combination of the barchan internal structure detected by ground-penetrating radar and optical/radiocarbon dating techniques.The upper limit of migration speed given by conventional C-14 dating is 3.42 m/yr.The optically stimulated luminescence dating indicates that the time-average migration speed of the studied barchan was 1.78 m/yr in 28 years prior to 2007.The physical estimation further suggests that the annual migration speed has increased in recent years.
基金supported by the National Natural Science Foundation of China Basic Science Center for Tibetan Plateau Earth System(41988101).
文摘The domestication of livestock from their wild progenitors was essential in the process of the Neolithic Revolution.Aurochs(Bos primigenius)are considered to be the ancestors of modern cattle(B.taurus).They were once widespread across Eurasia and North Africa but became extinct approximately 400 years ago[1].
基金supported by the Basic Science Center for Tibetan Plateau Earth System(BSCTPES,41988101)the National Key Research and Development Program of China(2023YFF0805200)the National Natural Science Foundation of China(42101148)。
文摘Proxy-based reconstructions and climate model simulations of Holocene global annual mean temperatures exhibit divergent trends,leading to the well-known“Holocene temperature conundrum(HTC)”.This discrepancy is most pronounced in the mid-to-high latitudes of the Northern Hemisphere(NH)and has been attributed to either proxy seasonal bias or deficiencies in climate models.Paleoclimate data assimilation(PDA),which integrates proxy records with climate model simulations,provides an advanced method for generating global seasonal temperature reanalysis datasets for the mid-Holocene(MH).Assimilated results indicate that MH Eurasian temperatures are largely independent of the choice of model priors and exhibit significant spatial heterogeneity.Compared to the pre-industrial(PI)period,the MH is characterized by winter and annual mean warming in Europe and high-latitude Eurasia,while the rest of Eurasia experiences cooling.However,this spatial heterogeneity is not well represented in model simulations due to a pronounced winter cooling bias at high latitudes,likely resulting from inadequate representations of vegetation and sea ice feedback mechanisms.As Eurasian proxy records are predominantly concentrated in Europe,this regional imbalance introduces a warm bias in reconstructed winter and annual temperatures intended to represent broader Eurasian temperature changes.These results suggest that the HTC may stem from both the uneven spatial distribution of proxy records and the incomplete representation of internal climate feedbacks in current models.
基金Second Tibetan Plateau Scientific Expedition,Research(STEP)Programme(2019QZKK0105)National Natural Science Foundation of China(U2442213,42122033,42475002 and 42075006).
文摘The southeastern Tibetan Plateau(SETP)is the preeminent summer heavy precipitation region within the Tibetan Plateau(TP).However,the large-scale circulation types and dynamics driving summer heavy precipitation in the SETP remain inadequately elucidated.Using the hierarchical clustering method,two distinctive atmospheric circulation patterns associated with heavy precipitation were identified:the Tibetan Plateau vortex type(TPVT,constituting 56.6%of the events)and the mid-latitude trough type(MLTT,43.4%).A comprehensive examination of the two atmospheric circulation patterns reveals a clear nexus between the occurrences of summer heavy precipitation and positive vorticity anomalies,moisture convergence,as well as the southeastward displacement of the westerly jet core.Specifically,TPVT events are characterized by the eastward and dry-to-wet potential vorticity progression processes,while MLTT events are linked to the intrusion of a deep extratropical trough into the SETP.This study advances our understanding of the complex mechanisms governing the summer heavy precipitation in the SETP,shedding light on critical meteorological processes in the region.
基金supported by the Excellent Research GroupProgram for Tibetan Plateau Earth System(42588201)the National Key Research and Development Program of China(2018YFA0606404)+2 种基金the State Key Laboratory of Tibetan PlateauEarth System,Environment and Resources(TPESER)Youth Innovation Key Program(TPESER-QNCX2022ZD-04)the National NaturalScience Foundation of China(42401048)the China Postdoctoral Innovation Program(GZC20241804).
文摘Central Asia(CA)faces a severe water crisis exemplified by the shrinking Aral Sea.However,little is known about the entire region,particularly the numerous small water bodies that are vulnerable to climate change yet vital for regional sustainability.We examined water bodies as small as 0.0045 km^(2)across CA from 1992 to 2020,identifying 66,215 water bodies in 2020,82.2%of which were previously unstudied.In contrast to the well-documented decline of the Aral Sea,other water bodies have expanded by 10.7%(8714.3 km^(2)),with a net gain of 15,831 lakes since 1992.These findings challenge the perception of a drying CA and provide evidence of a warm-wet climate trend,which is redistributing water resources and creating opportunities for transforming water management to address the long-standing water crisis in CA.
基金supported by the National Natural Science Foundation of China(41825001)the National Key R&D Program of China(2018YFA0606402)+2 种基金Fundamental Research Funds for the Central Universities(lzujbky-2021-77 and lzujbky-2021-ct03)National Social Science Fund of China(21CKG011)National Natural Science Foundation of China(42001073)and Academician and Expert Workstation of Yunnan Province(202305AF150183).
文摘The intensification of millet agriculture facilitated the development of ancient civilization in northern China.In Inner Mongolia and the Central Plains,the intensification of millet farming was relatively continuous.However,prior evidence from the western Loess Plateau(WLP)has suggested an indistinct sequence of millet cultivation and a time lag between the initial intensification of millet agriculture and subsequent expansion of millet farming.We report on new stable isotopic data and radiocarbon dates from the Gedachuan site which challenge that interpretation.Our results indicate a gradual intensification and expansion of millet agriculture across the whole WLP.They attest to intensive broomcorn millet-based farming underpinning the emergence and development of the agrarian society in the WLP during the early-middle Yangshao period(∼6300-5500 BP),and to an intensification of the higher-yielding foxtail millet-based farming leading to the rapid growth of population in the WLP and expansion of millet cultivation after 5300 BP.
基金supported by the Third Xinjiang Scientific Expedition and Research(Grant No.2021xjkk0805)the National Natural Science Foundation of China(Grant No.41790424)NSFC-DFG Mobility(Grant No.M0468)。
文摘Inland lakes in arid Central Asia are particularly susceptible to the impact of climate change and human activities.Ebinur Lake,the largest salt inland lake in Xinjiang,Northwest China,has experienced rapid shrinkage,with human activities identified as the primary influencing factor.However,it remains unclear how human water use in different sectors,such as irrigation,husbandry,and industry,is responsible for the long-term change and seasonal variability of the lake area under changing climate.This study aims to address this knowledge gap by developing an integrated hydrological-socioeconomic-lake model that simulates the changes in the Ebinur Lake area during the period of 1950–2020.The simulated lake area changes under different model experiments were then compared with separate the impacts of climate change and human water use of different sectors.The results indicate that climate change,irrigation,husbandry,and industry water uses have contributed+5%,-79%,-25%,and-1%of the long-term change in the lake area,respectively.Despite climate change alone increasing the lake area,the increase in human water use has resulted in the persistent decline of Ebinur Lake.Notably,husbandry water use emerges as a significant contributor to lake shrinkage,accounting for approximately one-third of the impact of irrigation.Furthermore,irrigation water use has contributed to the enhanced seasonal variability,as indicated by the difference between the maximum and minimum monthly lake area in a year.This difference has increased from 120 km2in the 1950s to 183 km2in the 2010s.
基金supported by the National Natural Science Foundation of China(41988101)the International Partnership Program of Chinese Academy of Sciences for Future Network Project(162GJHZ2023053FN).
文摘The spheres of the Earth—specifically the lithosphere,hydrosphere,atmosphere,and biosphere—are intricately connected and interact through the fluxes of matter and energy,forming a complex and ever-evolving Earth system.Understanding the dynamic linkages between these spheres during different types of forcings or events is essential for predicting changes and securing a sustainable future for living organisms,particularly humans.However,uncovering these linkages is challenging due to the need for suitable proxies that can demonstrate how these systems or spheres change across diverse temporal and spatial scales.
基金supported by the Basic Science Center for Tibetan Plateau Earth System(BSCTPES,41988101)the National Natural Science Foundation of China(32061123008)+3 种基金Ulf Büntgen and Jan Esper were supported by the ERC Advanced Grant Monostar(Ad G 882727)the Czech Science Foundation(23-08049S,HYDRO8)Fredrik Charpentier Ljungqvist was supported by the Swedish Research Council(Vetenskapsr?det,2018-01272)the Marianne and Marcus Wallenberg Foundation(MMW 20220114)。
文摘Historical documents provide evidence for regional droughts preceding the political turmoil and fall of Beijing in 1644 CE,when more than 20 million people died in northern China during the late Ming famine period.However,the role climate and environmental changes may have played in this pivotal event in Chinese history remains unclear.Here,we provide tree-ring evidence of persistent megadroughts from1576 to 1593 CE and from 1628 to 1644 CE in northern China,which coincided with exceptionally cold summers just before the fall of Beijing.Our analysis reveals that these regional hydroclimatic extremes are part of a series of megadroughts along the Pacific Rim,which not only impacted the ecology and society of monsoonal northern China,but likely also exacerbated external geopolitical and economic pressures.This finding is corroborated by last millennium reanalysis data and numerical climate model simulations revealing internally driven Pacific sea surface temperature variations and the predominance of decadal scale La Ni?a-like conditions to be responsible for precipitation decreases over northern China,as well as extensive monsoon regions in the Americas.These teleconnection patterns provide a mechanistic explanation for reoccurring drought spells during the late Ming Dynasty and the environmental framework fostering the fall of Beijing in 1644 CE,and the subsequent demise of the Ming Dynasty.
基金supported by the National Natural Science Foundation of China(41988101,32102523)。
文摘Wild aurochs(Bos primigenius)were once widespread across Eurasia and North Africa but became extinct around the 17th century[1].Aurochs are considered the ancestor of modern taurine(B.taurus taurus)and indicine(B.t.indicus)cattle,which were independently domesticated within regions restricted to Southwest Asia and South Asia,respectively[2,3].Extensive gene flow from local aurochs to domestic cattle has been well documented in Southwest Asia,Europe,and Africa[3,4],raising questions about the mechanisms underlying both the domestication and dispersal of early cattle.
基金National Natural Science Foundation of China project Basic Science Center for Tibetan Plateau Earth System(41988101)。
文摘The Tibetan Plateau(TP)is an important link between the South Asian monsoon(SAM)region,the East Asian monsoon region,and the drylands of Central Asia.Climate changes within these regions are dominated by both the monsoon and the westerlies.This has prompted the scientific community to adopt a broad spatial perspective,proposing concepts such as the"Pan-Third Poleoor"Asian summer precipitationo,to better understand the regional climate dynamics,their driving mechanisms,and the resulting major ecological and environmental impacts.
基金supported by the National Key R&D Program of China(2021YFC1523600)the National Natural Science Foundation of China(41930323&42371171)+2 种基金Basic Science Center for Tibetan Plateau Earth System(BSCTPES,41988101)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022068)National Cultural Heritage Conservation Special Fund from National Cultural Heritage Administration,China.
文摘The origin and spread of agriculture facilitated a decline in human mobility and eventually led to a predominantly sedentary lifestyle globally,including on the Tibetan Plateau.Previous studies have proposed an evolution of prehistoric agriculture,from millet-based to barley-based farming.However,details regarding the process are vague.Here,we present diachronic changes in cropping structure from Xizang on the basis of a quantitative analysis of archaeobotanical remains from 12 sites located in southeastern Xizang.The advent of agriculture in Xizang began in the southeastern region around 4800 cal a BP and resulted in a quick spread of millet agriculture from the Hengduan Mountains to the Yarlung Zangbo River region.Subsequently,the introduction of barley and wheat to Xizang led to the transformation of millet-based farming into mixed farming after 3600 cal a BP.Eventually,around 3000 cal a BP,barley and wheat dominated across the entire Xizang with declining occurrences of millet.It took more than 600 years for barley and wheat to dominate in the Tibetan cropping system,which may reflect the time required for these exotic species to adapt physiologically to their new niche.In addition to the diachronic changes in crop farming,the ratio of barley to wheat and foxtail millet to broomcorn millet also varied at different elevations possibly due to local environmental variations and the crops’physiological requirements.
基金supported by the National Natural Science Foundation of China(42101149)the China Postdoctoral Science Foundation(2022M711441)the Swedish Research Council(Vetenskapsr?det)(2017-04232,2022-03617)。
文摘The term“Holocene temperature conundrum”refers to the inconsistencies between proxy-based reconstructions and transient model simulations,and it challenges our understanding of global temperature evolution during the Holocene.Climate reconstructions indicate a cooling trend following the Holocene Thermal Maximum,while model simulations indicate a consistent warming trend due to icesheet retreat and rising greenhouse gas concentrations.Various factors,such as seasonal biases and overlooked feedback processes,have been proposed as potential causes for this discrepancy.In this study,we examined the impact of vegetation-climate feedback on the temperature anomaly patterns in East Asia during the mid-Holocene(~6 ka).By utilizing the fully coupled Earth system model EC-Earth and performing simulations with and without coupled dynamic vegetation,our objective was to isolate the influence of vegetation changes on regional temperature patterns.Our findings reveal that vegetation-climate feedback contributed to warming across most of East Asia,resulting in spatially diverse temperature changes during the mid-Holocene and significantly improved model-data agreement.These results high-light the crucial role of vegetation-climate feedback in addressing the Holocene temperature conundrum and emphasize its importance for simulating accurate climate scenarios.
基金supported by the National Natural Science Foundation of China(Grant No.41930323)。
文摘Millet agriculture,which originated in northern China,alongside rice agriculture,have nurtured the Chinese civilization.Prehistoric manuring practices likely promoted and maintained sustainable millet agricultural production in the loess area of northern China.However,ongoing controversy exists regarding the indicators of prehistoric manuring intensity of foxtail millet(Setaria italica)and common millet(Panicum miliaceum).Here,we present the results of pot and field fertilization experiments on two millet types.Our findings suggest that manuring can significantly increase the δ^(15)N values of foxtail millet,and its δ^(15)N values increase with increasing manuring levels.The δ^(15)N values of foxtail millet leaves are systematically greater than those of grains by approximately 1.6‰.Manuring could have a long-term residual impact on increasing the δ^(15)N values of soil and millet crops.Combined with previous crop fertilization experiment results,we propose that the impact of manuring on the δ^(15)N values of non-nitrogen-fixing crops is roughly consistent.The δ^(15)N value and amount of manure are key factors determining the extent of change in plant δ^(15)N values.The millet grain δ^(15)N values can serve as reliable indicators of manuring practices.Finally,we provide an interpretive framework for assessing the correlation between manuring levels and the δ^(15)N values of archaeological millet remains.The δ^(15)N values of ancient millet grains suggest widespread and intensive manuring practices in prehistoric millet agriculture in northern China,spanning from the early Yangshao period to the Longshan period.
基金supported by the Third Xinjiang Scientific Expedition and Research Program(2021xjkk0302)the National Natural Science Foundation of China project of the Basic Science Center for Tibetan Plateau Earth System(41988101)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0602)the National Natural Science Foundation of China(42072211)。
文摘Deserts are the most distinctive landscapes in the arid zones of midlatitude Asia,producing over 600 Tg of dust annually and serving as primary sources of mineral dust for the Northern Hemisphere.This dust is carried by the westerlies and the East Asian winter monsoon to downwind regions including East Asia,the northern Pacific Ocean,and even Greenland,influencing the global climate,global biogeochemical cycles,ocean productivity,Northern Hemisphere glaciations,and human health.
基金supported by the National Natural Science Foundation of China(Grant No.41988101)National Key R&D Program of China(Grant No.2019YFA0607304)。
文摘China announced its national goal to reach the peak of carbon emission by 2030 and achieve carbon neutrality by 2060,during the General Assembly of the United Nations in September 2020.In this context,the potential of the carbon sink in China’s terrestrial ecosystems to mitigate anthropogenic carbon emissions has attracted unprecedented attention from scientific communities,policy makers and the public.Here,we reviewed the assessments on China’s terrestrial ecosystem carbon sink,with focus on the principles,frameworks and methods of terrestrial ecosystem carbon sink estimates,as well as the recent progress and existing problems.Looking forward,we identified critical issues for improving the accuracy and precision of China’s terrestrial ecosystem carbon sink,in order to serve the more realistic policy making in pathways to achieve carbon neutrality for China.
基金supported by the National Natural Science Foundation of China (Grant No. 41842050)
文摘The natural environment provides material essentials for human survival and development. The characteristics,processes, regional differentiation and forcing mechanisms of the elements of the natural environment(e.g. geomorphology,climate, hydrology, soil, etc.) are the main objects of research in physical geography. China has a complex natural environment and huge regional differentiation and therefore it provides outstanding reserach opportunities in physical geography. This review summarizes the most important developments and the main contributions of research in the physical geography and human living environment in China during the past 70 years. The major topics addressed are the uplift of the Tibetan Plateau and the evolution of its cryosphere, the development of fluvial systems, the acidification of the vast arid region of the Asian interior, variations in the monsoon and westerly climate systems on multiple timescales, the development of lakes and wetlands, the watershed system model, soil erosion, past human-environment interactions, biogeography, and physical geographic zonality. After briefly introducing international research developments, we review the history of research in physical geography in China, focusing on the major achievements and major academic debates, and finally we summarize the status of current research and the future prospects. We propose that in the context of the national demand for the construction of an ecological civilization, we should make full use of the research findings of physical geography, and determine the patterns and mechanisms of natural environmental processes in order to continue to promote the continued contribution of physical geography to national development strategies, and to further contribute to the theory of physical geography from a global perspective.
基金supported by the National Natural Science Foundation of China (41771225 and 41620104007)the Fundamental Research Funds for the Central Universities (lzujbky-2018-146)
文摘The Tibetan Plateau,the world's "Third Pole",has an average elevation above 4,000 masl (meters above sea level)and an area of over 500×10^4km^2,It is the highest and largest plateau on earth and is very sensitive to global climate change [1,2].The cold,dry and hypoxic high-altitude environment of the plateau presents a major challenge to human survival.Therefore,the history and mechanisms of prehistoric human history on the Tibetan Plateau-from brief hunting expeditions to seasonal hunting-gathering and finally to permanent settlements-has attracted both general interest and substantial scientific debates [3-6].Archaeological studies indicate that humans probably first explored the plateau at the end of the late Pleistocene.They practiced intensive seasonal hunting-gathering from 15 ka BP [6],and permanently settled regions above 3,000 masl after 3.6 ka BP,which was facilitated by the development of an agropastoral economy [3].However, the early part of the human history of the Tibetan Plateau is still poorly documented,due to the lack of well-preserved archaeological sites and reliable dating results (Fig.la).
