期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
Quantitative studies on charcoalification:Physical and chemical changes of charring wood
1
作者 Gang Li Linlin Gao +2 位作者 Fengwen Liu Menghan Qiu Guanghui Dong 《Fundamental Research》 CAS CSCD 2024年第1期113-122,共10页
Charcoal is commonly preserved in both natural and artificial sediments,and is intensively used in paleontological,paleoenvironmental,and archaeological studies due to the abundant bio-information it contains.The bioc... Charcoal is commonly preserved in both natural and artificial sediments,and is intensively used in paleontological,paleoenvironmental,and archaeological studies due to the abundant bio-information it contains.The biochemical properties of charcoal are also used for paleoclimatic reconstruction;however,the reliability of this approach has been challenged due to a lack of clarity on how physicochemical properties change during the charring process,as well as the temperatures required for charcoalification.To address this lack,in this study,Qinghai spruce and Chinese pine wood samples from the northeastern Tibetan Plateau were heated at different temperatures and for different lengths of time under restricted oxygen conditions.The reflectance;carbon,nitrogen,and oxygen content;and tracheid morphology were quantified before and after heating to assess changes related to the charring process.Archaeological charcoal remains were then evaluated to determine the charcoalification temperatures by comparing with the experimental results.The minimum temperature required for wood charcoalification was∼300℃,while temperatures recorded by archaeological charcoal were concentrated at 400-500℃.During the charring experiments,the tracheid cell walls gradually homogenized,and tracheid cell wall thickness and lumen area decreased by∼20%.On average,50%mass losses were observed;the carbon and oxygen content(%wt.)approximately changed from 47%to 60%and 48%to 35%respectively,while the nitrogen content(%wt.)fluctuated around 0.2%.The reflectance increased slightly from 0%to 0.5%.We propose that the charcoalification of wood tissue refers to charring(in restricted air)and carbonization(in the almost absence of air)when the wood is exposed to a heat source,which then finally transforms into a black,inert solid.This quantitative study provided valuable data and a thorough assessment of the process of wood charcoalification,as well as accurately estimated the feasibility of using charcoal physicochemical properties in paleoclimatic research. 展开更多
关键词 Charcoalification Quantitative study Charcoal formation Archaeological charcoal Tracheid cell wall thickness Reflectance
原文传递
Refined chronology of prehistoric cultures and its implication for re-evaluating human-environment relations in the Hexi Corridor,northwest China 被引量:5
2
作者 Yishi YANG Shanjia ZHANG +8 位作者 Chris OLDKNOW Menghan QIU Tingting CHEN Haiming LI Yifu CUI Lele REN Guoke CHEN Hui WANG Guanghui DONG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2019年第10期1578-1590,共13页
The reconstruction of high-resolution chronologies for prehistoric cultures is a prerequisite for understanding the history of human evolution and its relationship with environmental change, and is valuable for explor... The reconstruction of high-resolution chronologies for prehistoric cultures is a prerequisite for understanding the history of human evolution and its relationship with environmental change, and is valuable for exploring the trajectory of transcontinental cultural exchanges in prehistoric time. The Hexi Corridor of northwest China was one of the earliest centers for long-distance culture exchange in the prehistoric world. The timing and sequence of cultural changes in this area remains poorly understood resulting from the lack of radiometric age control. This paper presents a refined radiocarbon(14 C) chronology to resolve the timing of human occupation and cultural evolution in the Hexi Corridor. Radiocarbon dating of crop remains, which have an annual life cycle, has the advantage of eliminating problems such as the carbon stored in ‘old wood’. As a result,14C dates from crop remains are used to test the validity of the14C dates derived from charcoal, bone and plant remains. The resultant database of ages is modelled using the Bayesian approach. The updated chronology presented in this paper shows generally good agreement with the original dates used to constrain cultural evolution in the Hexi Corridor. However, the occupation of the corridor by the Shajing and Shanma Late Bronze Age-Early Iron Age cultures appears to have taken place ~300 years later than previously thought. On the basis of comparing this updated chronology of cultural evolution with palaeoclimatic and historical records, it is proposed that the collapse of the Shajing and Shanma cultures occurred as a result of geopolitical impact rather than climate change. 展开更多
关键词 Bayesian modelling Radiocarbon DATING NEOLITHIC and BRONZE Age CHRONOLOGY Geopolitical situation Climate change Hexi CORRIDOR
原文传递
Detecting anthropogenic impact on forest succession from the perspective of wood exploitation on the northeast Tibetan Plateau during the late prehistoric period 被引量:3
3
作者 Fengwen LIU Shanjia ZHANG +1 位作者 Hucai ZHANG Guanghui DONG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2022年第11期2068-2082,共15页
Human activities are usually considered to have had impacts on forest degradation and/or changes of forest composition in the past.The Tibetan Plateau,an environmentally sensitive area,has witnessed a high intensity o... Human activities are usually considered to have had impacts on forest degradation and/or changes of forest composition in the past.The Tibetan Plateau,an environmentally sensitive area,has witnessed a high intensity of human activities since the late Neolithic,but the evidence is still incomplete concerning how human activities affected the environment,especially vegetation changes.This may result,in part,from the fact that research on prehistoric wood utilization by humans in the northeast Tibetan Plateau(NETP)is scarce,especially from the perspective of charcoal analysis,which is an archaeological index directly related to human activities.To fill this gap,we report new data here concerning charcoal analysis from 24 archaeological sites dated 5200–2300 a BP in the NETP,where this period saw remarkable environmental and social changes.By coupling the results with published paleoenvironment records(especially pollen),we aim to explore the utilization of wood and its spatial-temporal changes,as well as the anthropogenic impacts on past forest dynamics in the NETP.The results suggest that the wood resources collected by humans were mainly needleleaf trees(Picea L.and Pinus L.),broadleaved trees(Populus L.,Salix L.,and Betula)as well as shrubs(Hippophae L.and Tamarix L.),and that these were distributed around the human habitation areas.There was a clear spatial difference in the woody assemblage collected by humans in the period 3600–2300 a BP.This was likely related to the diversity of natural environments in local areas,but there was an abnormal spatial pattern of forest composition with broadleaved trees dominant above 2500 masl caused not by climate change,but by the rapid increase of human settlement and wood collection in high altitude areas of the NETP since 3600 a BP. 展开更多
关键词 Charcoal records Late prehistoric period Northeast Tibetan Plateau Climate change Anthropogenic impacts
原文传递
Spatiotemporal variation of agricultural patterns in different geomorphologic and climatic environments in the eastern Loess Plateau,north-central China during the late Neolithic and Bronze Ages 被引量:1
4
作者 Haiming LI Yifu CUI +5 位作者 Nathaniel JAMES Melissa RITCHEY Fengwen LIU Junna ZHANG Minmin MA Guanghui DONG 《Science China Earth Sciences》 SCIE EI CSCD 2022年第5期934-948,共15页
Human settlement and agricultural development are closely linked to local geomorphological and climatic environments.However,the variation in agricultural systems in different environmental and prehistoric contexts re... Human settlement and agricultural development are closely linked to local geomorphological and climatic environments.However,the variation in agricultural systems in different environmental and prehistoric contexts remains unknown.We report new archaeobotanical and radiocarbon dates from 34 Neolithic and Bronze Age sites in the Hutuo River Valley(HTRV)in north-central China and compare them with updated archaeobotanical studies in the Sushui River Valley(SSRV)and Henan Province(HNP),to explore the similarities and differences of agricultural patterns under different geomorphologic and climatic environments in north-central China.Our results reveal that humans consistently cultivated foxtail and broomcorn millet in the HTRV from the Miaodigou(6000–5700 cal.a BP)to the Shang-Zhou(3600–2256 cal.a BP)period,despite the introduction of wheat and barley into the area around 4000 a BP.Climate conditions and hilly landforms in the HTRV,SSRV and some parts of the HNP led people to develop foxtail and broomcorn millet dry land farming practices between 7000 and 3000 a BP.Alternatively,in other areas of the HNP,the climate conditions and alluvial plains enabled people to develop a mixed agriculture of millets,soybeans,and rice from 7000 to 4000 a BP,with the addition of wheat between 4000 and 3000 a BP.Farmers’different agricultural technologies and interactions with foreign cultures may have also influenced the formation of different agricultural patterns in the three regions between 7000 and 3000 a BP.Population growth during 7000–3000 a BP can explain the overall propensity of the higher-yield foxtail millet rather than broomcorn millet as the main cultivated crop.In the HTRV,however,higher proportions of broomcorn millet(as compared to the SSRV and HNP),may reflect the greater drought and heat tolerance of broomcorn millet,representing an adaptive agricultural strategy in the river valley. 展开更多
关键词 Archaeobotanical Agricultural patterns Climate conditions Hilly area Alluvial plains
原文传递
A brief history of wheat utilization in China 被引量:1
5
作者 Minxia LU Liang CHEN +4 位作者 Jinxiu WANG Ruiliang LIU Yang YANG Meng WEI Guanghui DONG 《Frontiers of Agricultural Science and Engineering》 2019年第3期288-295,共8页
Wheat is one of the most important crops in both China and the world, and its domestication can be traced back to ~10000 years ago.However, the history of its origin and utilization in China remains highly ambiguous.D... Wheat is one of the most important crops in both China and the world, and its domestication can be traced back to ~10000 years ago.However, the history of its origin and utilization in China remains highly ambiguous.Drawing upon the most recent results of taxonomic, genetic, archeological and textual studies focused on the wheat in prehistory, this paper argues that wheat was not domesticated but introduced into China in the late fifth millennium BP.In the subsequent centuries,this exotic crop was quickly utilized as a staple food in northwest China.In contrast, it was not adopted as a staple in the Central Plains until the Han Dynasty(202 BCE–220 CE), which was mainly as a consequence of the living environment, population and innovations in food processing technology. 展开更多
关键词 MULTIDISCIPLINARY evidence PREHISTORIC food GLOBALIZATION WHEAT CONSUMPTION WHEAT DOMESTICATION
原文传递
Human activities have altered fire-climate relations in arid Central Asia since~1000 a BP:evidence from a 4200-year-old sedimentary archive 被引量:3
6
作者 Shanjia Zhang Yiwen Lu +3 位作者 Wenyu Wei Menghan Qiu Guanghui Dong Xingqi Liu 《Science Bulletin》 SCIE EI CSCD 2021年第8期761-764,M0003,共5页
Fire has crucial effects on ecosystem succession,the carbon cycle,and atmospheric chemical composition[1-3].Previous studies have shown that fire dynamics are closely related to regional vegetation and climate.Arid Ce... Fire has crucial effects on ecosystem succession,the carbon cycle,and atmospheric chemical composition[1-3].Previous studies have shown that fire dynamics are closely related to regional vegetation and climate.Arid Central Asia(ACA)is sensitive to climate change,and grassland fires in ACA account for over 80%of the total burned area[4].In the face of intense global climate change,it is vital to understand how grassland burning responds long-term to climate and vegetation.Developing such an understanding would help predict fire activity and thus assist in the development of future fire management policies. 展开更多
关键词 草原火灾 晚全新世 卡拉库里湖 气候变化响应 长时间尺度 中亚地区 高分辨率
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部