Human Activities And Plant-animal Utilization From Paleolithic To Bronze Age In Northwest Yunnan Province

The study about peopling and the driving mechanism of human inhabitation on the Tibetan Plateau is a widely-concerned issue,which has been intensively studied in recent years.Based on systematic archaeological survey,dating and archaeobotanical studies on the Tibetan Plateau,it can be concluded that human extensively settled the area below 2500 m in the Tibetan Plateau after 5200BP(years Before Present),and the permanently settled above 3000 m since 3600 BP.The introduction and utilization of cold-tolerant barely and wheat to the Tibetan Plateau facilitated human year-round settlement on the high-altitude areas of the Tibetan Plateau.However,these works mostly focused on the human occupation and subsistence strategies during Neolithic and Bronze Age in the northeast Tibetan Plateau,human activities and livelihoods transition in other parts of the Tibetan Plateau during prehistoric times has not been well understood.Southeast Tibetan Plateau,with numerous big rivers and huge mountains crisscrossing in this area,is another important passageway for human migration during both prehistoric and historical times,and key study area for exploring human and agricultural diffusion to the high Plateau.The region is the junction area of Yunnan,Sichuan and Tibet,and the important part of Tibetan-Yi Corridor.Large numbers of Paleolithic,Neolithic and Bronze sites distribute in this area.However,the history about human settlement and utilization of agriculture resource in northwest Yunnan province is still unclear,due to the absence of reliable dating,archaeobotanical and zooarchaeological studies,and isotopic analysis from prehistoric sites in the area,which are the research contents of this paper.This paper focus on the study of chronology and subsistence strategy from investigated and excavated sites in middle Nujiang River valley,one of the most V important areas for archaeological sites distribution in Yunnan province.Totally 18 sites have been found in field work of this study.A 160 cm deep section has been cleared in the excavated pit of the Yushuiping site,6 radiocarbon dating samples and 2 OSL samples were collected for dating in the site.Another 5 radiocarbon dating samples and 15 soil samples were collected from 5 investigated sites for dating and archaeobotanical studies including macrofossil and phytolith analysis.Moreover,we participate in the excavation and studies of Shilinggang Bronze Age site in the study area,totally 84 flotation samples,15 soil samples and 6 human teeth samples were collected to do macro-and micro-plant remains analysis,and 6 samples were collected for radiocarbon dating.Meanwhile,we collected and identified 1033 animal bones,and selected 48 human bones and 58 animal bones to do carbon and nitrogen stable isotope analysis.Based on these works,and the comparison to previous studies in Yunnan-Guizhou Plateau,we discuss the history of human activities from Palaeolithic to Bronze Age in northwest Yunnan Province and adjacent areas,and explore the strategies of plant and animal utilization during Neolithic and Bronze periods.Furthermore,we discuss the possible links between prehistoric agriculture development and climate change.The main conclusions and highlights of this study are listed as below.(1)Paleolithic groups occupied margin area of southeast Tibetan Plateau during 39000-31000 cal yr BP,about 20000 years older than previous estimation.(2)Human cultivated rice and millet in Shilinggang site before 2500 BP.People mainly consumed C3 plants(very likely rice and tubers),and part of people might also have consumed a small amount of C4 plants(probably foxtail millet)in that site.(3)Human also fed and hunted animals in Shilinggang site before 2500 BP.Domesticated animals include dog,cattle,buffalo,horse,sheep,goat,and pig,and the wild animals hunted include deer,badger,ericius,bamboo rat,monkey,bear,fish,pheasant and birds.(4)Agriculture development during Neolithic to Bronze in Yunnan-Guizhou Plateau can be mainly divided to three phases.Human cultivated rice during 4800-3900 BP,rice and millet crops during 3900-3400 BP,then rice,millet crops and wheat barley during 3400-2300 BP.(5)Human activities had been affected by climate change during Paleolithic in northwest Yunnan province.However,human settlements in northwest Yunnan Province might have not been obviously influenced by climate change,but agriculture development in the area since Neolithic period.In addition,we argue that to determine the ages of archaeological sites only by characteristics of tool remains in the Nujiang River valley may be unreliable,systematic dating from excavated prehistoric sites in the area are needed.Due to the poor preservation of macro plant-fossils in the acid soils widely distributed in Yunnan Province,the combination of macro-and micro-fossil analysis,as well as carbon and nitrogen isotope analysis of human bones,is necessary for the comprehensive studies of human subsistence strategy during prehistoric times.This study provide valuable new dataset for exploring prehistoric human inhabitation on the Tibetan Plateau,subsistence strategy for adaptation to high-cold environments,and agriculture development in Yunnan-Guizhou Plateau during Neolithic and Bronze periods.There are also some deficiencies in this studies,due to the limitation of archaeological excavation in the study area,which should be strengthened in future.