In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial w...In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial wetlands,due to dramatic environmental changes induced by anthropogenic activities.Exploring the effects of these changes on the temporal dynamics of the waterbird communities can help understand how waterbirds adapt to environmental changes and thus formulate effective management and conservation plans.In this study,we carried out field surveys on waterbirds and environmental factors across 20 subsidence wetlands created by underground coal mining in the Huainan coal mining area in the breeding seasons of 2016 and 2021.We predicted that the waterbird assemblages(i.e.,number of individuals,species richness,Shannon-Wiener diversity,Pielou evenness and species composition) differed between the two years,and that these differences were correlated with the temporal changes in environmental factors.Across the surveyed wetlands,we recorded 26 waterbird species in 2016 and 23 in 2021.For individual wetlands,the number of waterbird individuals and species richness increased by 71.6% and 20.1%,respectively,over the five years,with no changes in Shannon-Wiener diversity and Pielou evenness.The overall increase in the number of bird individuals was mainly caused by an increase in vegetation gleaners and gulls that adapt well to anthropogenic activities.The species composition was significantly different between the two years,which was mainly caused by changes in the number of individuals of dominant species under influence of changes in human activities.For most wetlands,the temporal pairwiseβ-diversities could be explained by species turnover rather than nestedness,probably due to high mobility of waterbird species and dramatic changes in local environments.Our study suggests that waterbird communities could respond to environmental changes in subsidence wetlands,providing important implications for waterbird conservation in human-dominated artificial wetlands.展开更多
Neolithic culture series in the Yishu River Basin developed in the order of Beixin culture-Dawenkou culture-Longshan culture-Yueshi culture. During the early and middle stage of Longshan culture (4600-4300 cal. yr BP...Neolithic culture series in the Yishu River Basin developed in the order of Beixin culture-Dawenkou culture-Longshan culture-Yueshi culture. During the early and middle stage of Longshan culture (4600-4300 cal. yr BP), the climate in the Yishu River Basin was warm and wet. Paddy-oriented agriculture planted paddy was very developed. The society was flourishing with great amount of archaeological sites. The cooling starting in 4200 cal. yr BP made the paddies shortfall in output or even no seeds were gathered. This situation intensified the discrepancy between population and resource. The scarcity in natural resource led to substantial decrease in population and subsequent drop in archaeological sites. About 4000 cal. yr BP Longshan culture was displaced by Yueshi culture which was relatively un- derdeveloped, simple and unsophisticated.展开更多
Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exis...Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon 14C(AMS14C) and optically stimulated luminescence(OSL) ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of marine isotopic stage 7(MIS7), the last interglacial period(MIS5) and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the foraminifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.展开更多
At about 173 ka BP of the late period of mid-Pleistocene, the second terrace of the river had been formed as a result of uplift happening in Shangshan area because of the climate, sea level change and tectonic action....At about 173 ka BP of the late period of mid-Pleistocene, the second terrace of the river had been formed as a result of uplift happening in Shangshan area because of the climate, sea level change and tectonic action. Between 173-75 ka BP, aeolian deposited on the terrace, a layer of reticulate red clayey soil about 80-100 cm thick deposited and developed under the warmer and higher temperature. In the last glacial period, the drop of the temperature and the decrease of the precipitation induced the dust-storms increased, A layer of Xiashu loess about 1.0-1.5 m thick accumulated on Shangshan terrace in the last glacial, which has the reticulate red clayey soil buried. At the beginning of the Holocene (11500 a BP-), temperature went higher gradually and precipitation got more, the pre-persons moved on the Shangshan terrace (11,400-8600 a BP), which is one of the most important archaeological sites, and can connect the paleolithic culture with Neolithic culture. It could be assumed from the results that the lower reaches of the Yangtze River are the home of rice cultivation, too. The lower place to the west of the Shangshan site experienced the two cycles process of the fluvial facies and the lacustrine facies, indicating that the water source of the pre-historical Shangshan is the river water or lake water. Two AMS 14C age proved the water source disappeared more than 1000 years ago.展开更多
The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimenta...The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimentary total organic carbon(TOC), total nitrogen(TN), the stable carbon(δ13C) and nitrogen(δ15 N) isotopic composition to obtain the comprehensive understanding of the source and composition of sedimentary organic matter and further shed light on the environmental changes of the Jiaozhou Bay on a centennial time scale.Results suggest that the TOC and TN concentrations increase in the upper core, having indicated a probable eutrophication process since the 1920 s in the inner bay and the 2000 s in the bay mouth. The TOC and TN concentrations outside the bay have also changed since 1916 owing to the variation of terrigenous input.Considering TOC/TN ratio, δ13 C and δ15 N, it can be concluded there is a mixture of terrigenous and marine organic matter sources in the study area. A simple two end-member(terrigenous and marine) mixing model usingδ13 C indicats that 45%–79% of TOC in the Jiaozhou Bay is from the marine source. The environmental changes of the Jiaozhou Bay are recorded by geochemical proxies, which are influenced by the intensive anthropogenic activities(e.g., extensive use of fertilizers, and discharge of sewage) and climate changes(e.g., rainfall).展开更多
The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of ...The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of Chinese civilization. Using the field archaeological data and the sporo-pollens and the age data of the drilling cores, we analysed Neolithic cultural development and environmental evolution in the Huaihe River basin of Anhui. According to the combination of some research results in archaeology with environmental evolution research, this paper discusses the relationship between culture and environment in the Huaihe River basin of Anhui. The Neolithic cultural development was strongly impacted by the environmental change. The primitive culture (Shishanzi) was developed in the beginning of the Holocene Megathermal Period with distinct regional feature of the culture. From 6.5 kaBP to 5.5 kaBP, the climate changed warmer and wetter. The frequent occurrence of flood and waterlog due to such a climate regime and high sea level caused the earth's surface environment deteriorated in the Huaihe River basin of Anhui and the interruption of the Neolithic cultural development, hence a lack of archaeological sites. From 5.5 kaBP to 4.0 kaBP, the climate changed from wet to dry, the natural environment was propitious to human survival. Dawenkou Culture and Longshan Culture flourished in this period. The Neolithic cultural development, the number of the sites and their distribution characteristics of the sites in the study area differed apparently from those in Central China and Shandong Province.展开更多
Based on analysis of parameters of cores taken from Gaoyou Lake, including magnetic susceptibility, grain-size characteristics and sedimentary rate, environmental changes during the modern period were examined with th...Based on analysis of parameters of cores taken from Gaoyou Lake, including magnetic susceptibility, grain-size characteristics and sedimentary rate, environmental changes during the modern period were examined with the assistance of historical records and Gaoyou Lake water level materials. It is concluded that during the modern period a higher value of magnetic susceptibility and a lower sediment grain size coincided with a wet climate, while a lower value of magnetic susceptibility and a higher grain size were related with a dry climate. The results indicate that the climate in the 123 years period from 1880 to 2003AD can be divided into four stages: two low water level stages (1880-1915AD, 1948-1981AD) and two high water level stages (1915-1948AD, 1981-2003AD). It appears that the regional climate generally underwent a dry-wet-dry-wet pattern in 30-year cycles. At present, it is at the end of a wet period, so the regional climate is expected to become dry in the near future. This conclusion corresponds with the climate records in the historical literature of the Gaoyou area, and it also matches with the climatic changes in North Jiangsu area.展开更多
This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in...This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in relation to demographic transition and process of industrialization. It concludesthat a major way of improving environmental quality is to intensify pollution decreasing technical factorsand that control of population growth will also reduce the pressure on the environment.展开更多
The environmental change in the wetlands in the southern Mongolian Plateau has important impacts on the environment of North China and even the entire Northeast Asia,from which the global climate change can be underst...The environmental change in the wetlands in the southern Mongolian Plateau has important impacts on the environment of North China and even the entire Northeast Asia,from which the global climate change can be understood on a large scale,especially the climate change in the Mongolian Plateau.This study extracted the information on the wetlands from three stages of remote sensing images(also referred to as RS images)of the study area,including Enhanced Thematic Mapper Plus(ETM+)images of 2000,TM images of 2010,and Landsat 8 Operational Land Imager(OLI)images of 2018.As indicated by the extraction results,the area of wetlands decreased from 796.90 km^(2) of 2000 to 666.24 km^(2) of 2018 at a rate of 7.26 km^(2)/a.The reduced area is 130.66 km^(2),which is about 16.4%reduction.And the patch number of wetlands decreased from 731 of 2000 to 316 of 2018 in the study area,approximately 56.8%reduction(415 patches),and the decrease in the area of the wetlands mainly occurred in the northwest endorheic region.In terms of wetland types,the change of the wetlands was dominated by the decrease of lacustrine wetlands,of which the area and patch number decreased by 106.2 km^(2) and 242,respectively.Furthermore,the area of the lacustrine wetlands decreased at the highest rate of 8.70 km^(2)/a in 2010‒2018.From the perspective of spatial distribution,the wetlands in the western part shrunk more notably than those in the eastern part as a whole in the study area.According to local meteorological data,the precipitation gently decreased and the temperature increased(about 1.7℃)from 1975-2018.Overall,the decrease in the area of the wetlands and the temperature rises in the study area were mainly driven by the Mongolian monsoon climate,reduction in precipitation,and human activities.展开更多
[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmenta...[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmental change and ecological security for a river basin, DPSIR model as framework, the basic framework, principle and related method of index system of the environmental change and ecological security for a river basin under influence of the multi-level development were put forward. [ ]Result] Index system of the environmental change and ecological se- curity for a river basin based on DPSIR model included driving force indicator, pressure indicator, state indicator, influence indicator and response indicator. Each indicator type also had many sub-indicators. [ Conclusion] The research provided theoretical support and method reference for as- sessment of the ecological security and execution of the ecological environment management for a river basin in China.展开更多
Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the Yangtze River Delta in China, is most vulner...Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the Yangtze River Delta in China, is most vulnerable to sea level rise and exacerbating coastal hazards. This paper develops the method of delimiting vulnerable scope and assessing coastal vulnerability through field observations and sampling and by applying remote sensing and GIS, which are suitable for great river delta and coastal plains with large area, relative complex micro-geomorphology and the protection of seawall. Applying this method, the coastal vulnerability of the Jiangsu coastal plain to relative sea level rise (approximately 50 cm up to the year 2050) and exacerbating storm surges have been assessed. The results show that, up to the year 2050, the Jiangsu coastal plain will probably lose 12.8 % of tidal flats (about 5.8x104 hm2) and 7.9 % of cultivated land (about 7.2x104 hm2). Meanwhile, 2.0 % of population, 3.8 % of original value of fixed assets, 3.2% of GDP (Gross Domestic Product), 40.3 % of salt industry and 5.8 % of aquiculture respectively will be affected due to coastal environmental change.展开更多
Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1864 m above sea level. Formative ages of the Huangshan and its granite,process of mo...Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1864 m above sea level. Formative ages of the Huangshan and its granite,process of mountain geomorphic evolution from the Eocene to Quaternary,environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and the questionable 'Pleistocene glaciation' was also discussed in this paper.展开更多
Arctic environmental change research and Antarctic studies have mutual benefits for increasing understanding of climate and environmental change in the polar regions. Two examples of bipolar environmental research que...Arctic environmental change research and Antarctic studies have mutual benefits for increasing understanding of climate and environmental change in the polar regions. Two examples of bipolar environmental research questions with mutual benefit are presented here. First, climate change and climatically significant cryospheric changes are introduced, and then the roles of albedo feedback mechanism and light absorbing impurities are discussed. Second, the challenge of polar stratospheric ozone depletion is discussed in connection with the increase in the harmful ultraviolet solar irradiance reaching the Earth.展开更多
A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation o...A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation of the droughs and drough disasters are introduced briefly, and the main causes resulting 1i drought disasters are analysed in the paper. The lack of rainfall is one of the factors producing the drough disasters in Africa, but it is not the real one. From environmental viewpoints, the drough disasters in Africa resulted from unsuitable land use and management by man, and in essence they are the results of man-made environmental disturbance. Finally, the strategy for preventing drought disasters in Africa is suggested.展开更多
The Bashang region is a typical vulnerable eco-environmental zone. Our analysis of paleodunes, paleosol profiles, and lake changes taking place during last ten thousands years indicated that: (1) 10 - 6.9 ka B. P. was...The Bashang region is a typical vulnerable eco-environmental zone. Our analysis of paleodunes, paleosol profiles, and lake changes taking place during last ten thousands years indicated that: (1) 10 - 6.9 ka B. P. was a post-glacial temperature-increasing stage, in which lakes had their high water level; (2) 6.9 - 3.0 ka B. P. was a large warm stage, during which four paleosol layers were developed and climate fluctuation has assumed 4 - 5 small cold-humid and cold-dry alternations. Since 5.4 ka B. P, the lakes tended to gradually shrink; and by 2.1 ka B. P., water level has fallen by 2.7 m; (3) since 3.0 ka B. P. a general trend of the region was to change into a dry, warm-dry and cold-dry environment.展开更多
Security environment is both an objective reality and a subjective consciousness. Here so-called "objective reality" mainly refers to the inherent law of the changes in international security situation. To a...Security environment is both an objective reality and a subjective consciousness. Here so-called "objective reality" mainly refers to the inherent law of the changes in international security situation. To a great extent, the subjective consciousness of the objective reality depends on the position and strategic choices of a nation in the international展开更多
Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Th...Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula; 4800-4400 aB. P. , 3600-3350 aB. P. ,2100 - 1800 aB. P. and 900 aB. P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope (δC01213 ) which could be the substitute indicators of environmental temperature.展开更多
Environmental conditions change in the Southwest of Cote d’Ivoire has been a major issue in development debates over the last decades. Using remote sensing based on land cover change analysis, climatic data, national...Environmental conditions change in the Southwest of Cote d’Ivoire has been a major issue in development debates over the last decades. Using remote sensing based on land cover change analysis, climatic data, national statistical data, we analyzed the drivers of environmental change in Southwestern of Cote d’Ivoire. Being part of the perennial crops basin, Southwestern of Cote d’Ivoire has witnessed rapid degradation of environmental conditions caused by the conversion of forest areas to agricultural land during the last 20 - 30 years and by a combination of decline in precipitation, soil degradation, a diversity of policies with little concern for the environment and population pressure. We concluded that while climate variability has influenced environmental change in the area of Sassandra, various types of anthropogenic and State interventions in agriculture appear to have been the main underlying causes of environmental degradation.展开更多
Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time.Often,a change in behavior is the frst response to changing conditions.Behavioral fexibility can poten...Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time.Often,a change in behavior is the frst response to changing conditions.Behavioral fexibility can potentially improve an organism’s chances to survive and reproduce.Currently,we lack an understanding on the time-scale such behavioral adjustments need,how they actually affect reproduction and survival and whether behavioral adjustments are suffcient in keeping up with changing conditions.We used house mice(Mus musculus)to test whether personality and life-history traits can adjust to an experimentally induced food-switch fexibly in adulthood or by intergenerational plasticity,that is,adjustments only becoming visible in the offspring generation.Mice lived in 6 experimental populations of semi-natural environments either on high or standard quality food for 4 generations.We showed previously that high-quality food induced better conditions and a less risk-prone personality.Here,we tested whether the speed and/or magnitude of adjustment shows condition-dependency and whether adjustments incur ftness effects.Life-history but not personality traits reacted fexibly to a food-switch,primarily by a direct reduction of reproduction and sloweddown growth.Offspring whose parents received a food-switch developed a more active stress-coping personality and gained weight at a slower rate compared with their respective controls.Furthermore,the modulation of most traits was condition-dependent,with animals previously fed with high-quality food showing stronger responses.Our study highlights that life-history and personality traits adjust at different speed toward environmental change,thus,highlighting the importance of the environment and the mode of response for evolutionary models.展开更多
基金the National Natural Science Foundation of China(grant 31970500 and 31770571)the Excellent Youth Project of the Anhui Natural Science Foundation(grant 2108085Y09)。
文摘In the context of global degradation and loss of natural wetlands,waterbirds have been increasingly using artificial wetlands as alternative habitats.However,waterbirds are facing various threats in these artificial wetlands,due to dramatic environmental changes induced by anthropogenic activities.Exploring the effects of these changes on the temporal dynamics of the waterbird communities can help understand how waterbirds adapt to environmental changes and thus formulate effective management and conservation plans.In this study,we carried out field surveys on waterbirds and environmental factors across 20 subsidence wetlands created by underground coal mining in the Huainan coal mining area in the breeding seasons of 2016 and 2021.We predicted that the waterbird assemblages(i.e.,number of individuals,species richness,Shannon-Wiener diversity,Pielou evenness and species composition) differed between the two years,and that these differences were correlated with the temporal changes in environmental factors.Across the surveyed wetlands,we recorded 26 waterbird species in 2016 and 23 in 2021.For individual wetlands,the number of waterbird individuals and species richness increased by 71.6% and 20.1%,respectively,over the five years,with no changes in Shannon-Wiener diversity and Pielou evenness.The overall increase in the number of bird individuals was mainly caused by an increase in vegetation gleaners and gulls that adapt well to anthropogenic activities.The species composition was significantly different between the two years,which was mainly caused by changes in the number of individuals of dominant species under influence of changes in human activities.For most wetlands,the temporal pairwiseβ-diversities could be explained by species turnover rather than nestedness,probably due to high mobility of waterbird species and dramatic changes in local environments.Our study suggests that waterbird communities could respond to environmental changes in subsidence wetlands,providing important implications for waterbird conservation in human-dominated artificial wetlands.
基金National Natural Science Foundation of China, No.40271103 Subject Construction of Physical Geography during "985" and Testing Fund of Nanjing University
文摘Neolithic culture series in the Yishu River Basin developed in the order of Beixin culture-Dawenkou culture-Longshan culture-Yueshi culture. During the early and middle stage of Longshan culture (4600-4300 cal. yr BP), the climate in the Yishu River Basin was warm and wet. Paddy-oriented agriculture planted paddy was very developed. The society was flourishing with great amount of archaeological sites. The cooling starting in 4200 cal. yr BP made the paddies shortfall in output or even no seeds were gathered. This situation intensified the discrepancy between population and resource. The scarcity in natural resource led to substantial decrease in population and subsequent drop in archaeological sites. About 4000 cal. yr BP Longshan culture was displaced by Yueshi culture which was relatively un- derdeveloped, simple and unsophisticated.
基金The National Basic Research Program of China(973 Program)under contract No.2010CB951200the Marine Public Service Specific Research under contract No.201105020
文摘Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon 14C(AMS14C) and optically stimulated luminescence(OSL) ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of marine isotopic stage 7(MIS7), the last interglacial period(MIS5) and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the foraminifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.
基金National Science and Technology Support Program, No.2006BAK21B02 National Basic Research Program of China, No.2003CB415201 National Natural Science Foundation of China, No.40671016
文摘At about 173 ka BP of the late period of mid-Pleistocene, the second terrace of the river had been formed as a result of uplift happening in Shangshan area because of the climate, sea level change and tectonic action. Between 173-75 ka BP, aeolian deposited on the terrace, a layer of reticulate red clayey soil about 80-100 cm thick deposited and developed under the warmer and higher temperature. In the last glacial period, the drop of the temperature and the decrease of the precipitation induced the dust-storms increased, A layer of Xiashu loess about 1.0-1.5 m thick accumulated on Shangshan terrace in the last glacial, which has the reticulate red clayey soil buried. At the beginning of the Holocene (11500 a BP-), temperature went higher gradually and precipitation got more, the pre-persons moved on the Shangshan terrace (11,400-8600 a BP), which is one of the most important archaeological sites, and can connect the paleolithic culture with Neolithic culture. It could be assumed from the results that the lower reaches of the Yangtze River are the home of rice cultivation, too. The lower place to the west of the Shangshan site experienced the two cycles process of the fluvial facies and the lacustrine facies, indicating that the water source of the pre-historical Shangshan is the river water or lake water. Two AMS 14C age proved the water source disappeared more than 1000 years ago.
基金The Joint Fund between Natural Science Foundation of China and Shandong Province under contract No.U1606404the National Basic Research Program(973 Program)of China under contract Nos 2015CB452901 and 2015CB452902+1 种基金the National Key Research and Development Plan Sino-Australian Centre for Healthy Coasts under contract No.2016YFE0101500the Program for Aoshan Excellent Scholars of Qingdao National Laboratory for Marine Science and Technology of China under contract No.2015ASTP-OS13
文摘The Jiaozhou Bay is characterized by heavy eutrophication that is associated with intensive anthropogenic activities. Four core sediments from the Jiaozhou Bay are analyzed using bulk technologies, including sedimentary total organic carbon(TOC), total nitrogen(TN), the stable carbon(δ13C) and nitrogen(δ15 N) isotopic composition to obtain the comprehensive understanding of the source and composition of sedimentary organic matter and further shed light on the environmental changes of the Jiaozhou Bay on a centennial time scale.Results suggest that the TOC and TN concentrations increase in the upper core, having indicated a probable eutrophication process since the 1920 s in the inner bay and the 2000 s in the bay mouth. The TOC and TN concentrations outside the bay have also changed since 1916 owing to the variation of terrigenous input.Considering TOC/TN ratio, δ13 C and δ15 N, it can be concluded there is a mixture of terrigenous and marine organic matter sources in the study area. A simple two end-member(terrigenous and marine) mixing model usingδ13 C indicats that 45%–79% of TOC in the Jiaozhou Bay is from the marine source. The environmental changes of the Jiaozhou Bay are recorded by geochemical proxies, which are influenced by the intensive anthropogenic activities(e.g., extensive use of fertilizers, and discharge of sewage) and climate changes(e.g., rainfall).
基金National Natural Science Foundation of China, No.40271103 Natural Science Foundation of Anhui Provincial Education Department, No.2005KJ202/021
文摘The Huaihe River basin of Anhui is not only a transitional zone of physical geography, but also a convergent area of many cultures in China. It is one of the sensitive ecotones to global changes and the birthplace of Chinese civilization. Using the field archaeological data and the sporo-pollens and the age data of the drilling cores, we analysed Neolithic cultural development and environmental evolution in the Huaihe River basin of Anhui. According to the combination of some research results in archaeology with environmental evolution research, this paper discusses the relationship between culture and environment in the Huaihe River basin of Anhui. The Neolithic cultural development was strongly impacted by the environmental change. The primitive culture (Shishanzi) was developed in the beginning of the Holocene Megathermal Period with distinct regional feature of the culture. From 6.5 kaBP to 5.5 kaBP, the climate changed warmer and wetter. The frequent occurrence of flood and waterlog due to such a climate regime and high sea level caused the earth's surface environment deteriorated in the Huaihe River basin of Anhui and the interruption of the Neolithic cultural development, hence a lack of archaeological sites. From 5.5 kaBP to 4.0 kaBP, the climate changed from wet to dry, the natural environment was propitious to human survival. Dawenkou Culture and Longshan Culture flourished in this period. The Neolithic cultural development, the number of the sites and their distribution characteristics of the sites in the study area differed apparently from those in Central China and Shandong Province.
基金Foundation: National Natural Science Foundation of China, No.40271004Acknowledgements: We wish to thank Professor Wang Ying for her supervision during fieldwork and paper writing, Professor Bruce Mitchell, Associate Provost of University of Waterloo, for reviewing the paper, Shi Xiaodong and Luo Weiwei for making ^210pb dating measurements, and Ding Haiyan for participating in grain size and magnetic susceptibility measurements.
文摘Based on analysis of parameters of cores taken from Gaoyou Lake, including magnetic susceptibility, grain-size characteristics and sedimentary rate, environmental changes during the modern period were examined with the assistance of historical records and Gaoyou Lake water level materials. It is concluded that during the modern period a higher value of magnetic susceptibility and a lower sediment grain size coincided with a wet climate, while a lower value of magnetic susceptibility and a higher grain size were related with a dry climate. The results indicate that the climate in the 123 years period from 1880 to 2003AD can be divided into four stages: two low water level stages (1880-1915AD, 1948-1981AD) and two high water level stages (1915-1948AD, 1981-2003AD). It appears that the regional climate generally underwent a dry-wet-dry-wet pattern in 30-year cycles. At present, it is at the end of a wet period, so the regional climate is expected to become dry in the near future. This conclusion corresponds with the climate records in the historical literature of the Gaoyou area, and it also matches with the climatic changes in North Jiangsu area.
文摘This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in relation to demographic transition and process of industrialization. It concludesthat a major way of improving environmental quality is to intensify pollution decreasing technical factorsand that control of population growth will also reduce the pressure on the environment.
基金This study was funded by the project initiated by the China Geological Survey entitled “Remote Sensing Geological Survey of National Key Earth Zones”(DD20190536).
文摘The environmental change in the wetlands in the southern Mongolian Plateau has important impacts on the environment of North China and even the entire Northeast Asia,from which the global climate change can be understood on a large scale,especially the climate change in the Mongolian Plateau.This study extracted the information on the wetlands from three stages of remote sensing images(also referred to as RS images)of the study area,including Enhanced Thematic Mapper Plus(ETM+)images of 2000,TM images of 2010,and Landsat 8 Operational Land Imager(OLI)images of 2018.As indicated by the extraction results,the area of wetlands decreased from 796.90 km^(2) of 2000 to 666.24 km^(2) of 2018 at a rate of 7.26 km^(2)/a.The reduced area is 130.66 km^(2),which is about 16.4%reduction.And the patch number of wetlands decreased from 731 of 2000 to 316 of 2018 in the study area,approximately 56.8%reduction(415 patches),and the decrease in the area of the wetlands mainly occurred in the northwest endorheic region.In terms of wetland types,the change of the wetlands was dominated by the decrease of lacustrine wetlands,of which the area and patch number decreased by 106.2 km^(2) and 242,respectively.Furthermore,the area of the lacustrine wetlands decreased at the highest rate of 8.70 km^(2)/a in 2010‒2018.From the perspective of spatial distribution,the wetlands in the western part shrunk more notably than those in the eastern part as a whole in the study area.According to local meteorological data,the precipitation gently decreased and the temperature increased(about 1.7℃)from 1975-2018.Overall,the decrease in the area of the wetlands and the temperature rises in the study area were mainly driven by the Mongolian monsoon climate,reduction in precipitation,and human activities.
文摘[ Objective] The research aimed to study index system of the environmental change and ecological security for a river basin based on DPSIR model. [Method] Based on considering each influence factor of the environmental change and ecological security for a river basin, DPSIR model as framework, the basic framework, principle and related method of index system of the environmental change and ecological security for a river basin under influence of the multi-level development were put forward. [ ]Result] Index system of the environmental change and ecological se- curity for a river basin based on DPSIR model included driving force indicator, pressure indicator, state indicator, influence indicator and response indicator. Each indicator type also had many sub-indicators. [ Conclusion] The research provided theoretical support and method reference for as- sessment of the ecological security and execution of the ecological environment management for a river basin in China.
基金National Natural Science Foundation of China, No.49871076 Excellent Doctoral Thesis Foundation of Chinese Academy of Sciences
文摘Assessment of coastal vulnerability to future environmental change has been emphasized in coastal nations or regions. The Jiangsu coastal plain, located to the north of the Yangtze River Delta in China, is most vulnerable to sea level rise and exacerbating coastal hazards. This paper develops the method of delimiting vulnerable scope and assessing coastal vulnerability through field observations and sampling and by applying remote sensing and GIS, which are suitable for great river delta and coastal plains with large area, relative complex micro-geomorphology and the protection of seawall. Applying this method, the coastal vulnerability of the Jiangsu coastal plain to relative sea level rise (approximately 50 cm up to the year 2050) and exacerbating storm surges have been assessed. The results show that, up to the year 2050, the Jiangsu coastal plain will probably lose 12.8 % of tidal flats (about 5.8x104 hm2) and 7.9 % of cultivated land (about 7.2x104 hm2). Meanwhile, 2.0 % of population, 3.8 % of original value of fixed assets, 3.2% of GDP (Gross Domestic Product), 40.3 % of salt industry and 5.8 % of aquiculture respectively will be affected due to coastal environmental change.
文摘Huangshan (Yellow Mountain) is located in southern part of the lower reaches of the Yangtze River. The highest Lotus Flower peak is 1864 m above sea level. Formative ages of the Huangshan and its granite,process of mountain geomorphic evolution from the Eocene to Quaternary,environmental changes of Quaternary, formative origin of beautiful peaks and fascinating rocks were studied and the questionable 'Pleistocene glaciation' was also discussed in this paper.
基金Academy of Finland(Arctic projects No.296302 and No.272041Antarctic projects of FARPOCC and SAARA)+1 种基金Ministry for Foreign Affairs of Finland(IBA-project No.PC0TQ4BT-25)Interact International Network for Terrestrial Research and Monitoring in the Arctic(EU-Interact H2020 Grant Agreement No.730938)。
文摘Arctic environmental change research and Antarctic studies have mutual benefits for increasing understanding of climate and environmental change in the polar regions. Two examples of bipolar environmental research questions with mutual benefit are presented here. First, climate change and climatically significant cryospheric changes are introduced, and then the roles of albedo feedback mechanism and light absorbing impurities are discussed. Second, the challenge of polar stratospheric ozone depletion is discussed in connection with the increase in the harmful ultraviolet solar irradiance reaching the Earth.
文摘A number of very serious drough disasters occurred in many regions of Aftica during past 30 years. It is commonly considered that they are among the most serious disasters after the World War II. The basic situation of the droughs and drough disasters are introduced briefly, and the main causes resulting 1i drought disasters are analysed in the paper. The lack of rainfall is one of the factors producing the drough disasters in Africa, but it is not the real one. From environmental viewpoints, the drough disasters in Africa resulted from unsuitable land use and management by man, and in essence they are the results of man-made environmental disturbance. Finally, the strategy for preventing drought disasters in Africa is suggested.
基金The National Natural Science Foundation of China(No.49872094andNo.40072097)
文摘The Bashang region is a typical vulnerable eco-environmental zone. Our analysis of paleodunes, paleosol profiles, and lake changes taking place during last ten thousands years indicated that: (1) 10 - 6.9 ka B. P. was a post-glacial temperature-increasing stage, in which lakes had their high water level; (2) 6.9 - 3.0 ka B. P. was a large warm stage, during which four paleosol layers were developed and climate fluctuation has assumed 4 - 5 small cold-humid and cold-dry alternations. Since 5.4 ka B. P, the lakes tended to gradually shrink; and by 2.1 ka B. P., water level has fallen by 2.7 m; (3) since 3.0 ka B. P. a general trend of the region was to change into a dry, warm-dry and cold-dry environment.
文摘Security environment is both an objective reality and a subjective consciousness. Here so-called "objective reality" mainly refers to the inherent law of the changes in international security situation. To a great extent, the subjective consciousness of the objective reality depends on the position and strategic choices of a nation in the international
文摘Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core( GA7) , 9.28 meters long , was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula; 4800-4400 aB. P. , 3600-3350 aB. P. ,2100 - 1800 aB. P. and 900 aB. P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope (δC01213 ) which could be the substitute indicators of environmental temperature.
文摘Environmental conditions change in the Southwest of Cote d’Ivoire has been a major issue in development debates over the last decades. Using remote sensing based on land cover change analysis, climatic data, national statistical data, we analyzed the drivers of environmental change in Southwestern of Cote d’Ivoire. Being part of the perennial crops basin, Southwestern of Cote d’Ivoire has witnessed rapid degradation of environmental conditions caused by the conversion of forest areas to agricultural land during the last 20 - 30 years and by a combination of decline in precipitation, soil degradation, a diversity of policies with little concern for the environment and population pressure. We concluded that while climate variability has influenced environmental change in the area of Sassandra, various types of anthropogenic and State interventions in agriculture appear to have been the main underlying causes of environmental degradation.
文摘Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time.Often,a change in behavior is the frst response to changing conditions.Behavioral fexibility can potentially improve an organism’s chances to survive and reproduce.Currently,we lack an understanding on the time-scale such behavioral adjustments need,how they actually affect reproduction and survival and whether behavioral adjustments are suffcient in keeping up with changing conditions.We used house mice(Mus musculus)to test whether personality and life-history traits can adjust to an experimentally induced food-switch fexibly in adulthood or by intergenerational plasticity,that is,adjustments only becoming visible in the offspring generation.Mice lived in 6 experimental populations of semi-natural environments either on high or standard quality food for 4 generations.We showed previously that high-quality food induced better conditions and a less risk-prone personality.Here,we tested whether the speed and/or magnitude of adjustment shows condition-dependency and whether adjustments incur ftness effects.Life-history but not personality traits reacted fexibly to a food-switch,primarily by a direct reduction of reproduction and sloweddown growth.Offspring whose parents received a food-switch developed a more active stress-coping personality and gained weight at a slower rate compared with their respective controls.Furthermore,the modulation of most traits was condition-dependent,with animals previously fed with high-quality food showing stronger responses.Our study highlights that life-history and personality traits adjust at different speed toward environmental change,thus,highlighting the importance of the environment and the mode of response for evolutionary models.