Climatic instability recorded by the mollusk assemblages from the late glacial loess deposits in China

The loess-paleosol sequence in China records abundant and valuable information on the global and regional climate changes. Biological record from the loess sequence is the most direct evidence on variation in pattern of paleo-atmospheric circulation and changes in winter and summer monsoon. A new record of climatic instability, which occurred in the Loess Plateau during the late glacial period, is presented. Through the study of terrestrial mollusks from three loess sequences, the authors intend to characterize the biological response process to rapid climate change and to learn the mechanisms driving the instable climate changes and the possible linkage in different regions. The result shows the striking consistent variability in the ratio records of three mollusk sequences of the late glacial, indicating apparent rapid climate fluctuations. Correlation of our three mollusk records with the oxygen isotopic records from Greenland ice cores and foraminiferal records from the Northeast Pacific Ocean

The spatial pattern of farming and factors influencing it during the Peiligang culture period in the middle Yellow River valley, China

The Peiligang culture （ca. 7000-5000 cal BC） is the earliest Neo- lithic culture in the middle Yellow River valley and represents the emergence of cereal farming in the region. It has long been considered representative of millet farming, which requires a dry field, a certain amount of rainfall, and minimal crop management, but new records reveal that mixed farming of millet and rice （Oryza so.） took place during this period.

Crossing of the Hu line by Neolithic population in response to seesaw precipitation changes in China

How various peoples crossed geographical barriers,were affected by climate change and human-made technologies comprise some of the most interesting quandaries in the history of cultures.This paper considers the Hu line,which is a major boundary between population centres and different environments in China.The boundary became evident approximately 11,400 years ago;however,evidence suggests that people crossed through at 5200,3800,and 2800 cal a BP,facilitating the increases of the trans-Eurasian exchange.The timings of the crossings correspond to the weakening of the East Asian summer monsoon that triggers seesaw changes of precipitation in western and eastern China.This analysis demonstrates that climate change on a millennial-to-centennial scale can have a profound influence on population distribution with long-term consequences.

Component and simulation of the 4,000-year-old noodles excavated from the archaeological site of Lajia in Qinghai,China

Noodles are a global food,but the periods when and places where they were made and originated,as well as their ingredients and the cooking methods used to manufacture them,have remained contentious.In the 2005 edition of the journal Nature,we wrote a summary of the millet noodle specimens found in the Late Neolithic Qijia cultural stratum of the Lajia archaeological site in Qinghai Province,China.However,how the ancient people made millet noodles remains controversial.This paper provides a systematic analysis of the remains of noodles found withinan earthenware bowl at the Lajia ‘‘noodle house'' in terms of their plant composition including phytoliths,starch and biomarkers.It provides evidence of how people used millet4,000 years ago and,most specifically,of the principal methods used for producing millet-based noodles.Further,we show how we used traditional hele tools to make hele millet noodles,with especial reference to the gelatinized hydrogel-forming method,to simulate morphology consistent with the composition and form of the unearthed millet noodles.The results of this study provide new evidence and new insights into the cultural characteristics of the prehistoric human diet.

Land-snail eggs as a proxy of abrupt climatic cooling events during the reproductive season

Seasonal abrupt climatic events severely impact ecosystems and human society.Knowledge of how seasonal abrupt climate events have evolved in the geological past is crucial for understanding seasonal climate change,because the long duration of geological records enables them to provide information unobtainable from modern observations.However,the lack of appropriate proxies has greatly limited our understanding of the long-term evolution of seasonal climate changes.

Eco-environmental changes in the Chinese Loess Plateau during low-eccentricity interglacial Marine Isotope Stage 19

Eco-environmental changes during interglacials with an astronomical background similar to that of the Holocene are potentially helpful for understanding the future climatic evolution.Marine oxygen isotope stage(MIS)19 is similar to the Holocene in astronomical background,both being characterized by a low eccentricity of the Earth’s orbit.However,MIS 19 has attracted research attention only recently and therefore less is known about eco-environmental changes during this interval,especially based on terrestrial records.In the Chinese Loess Plateau(CLP),the S7 paleosol can provide valuable terrestrial paleoclimatic and paleoenvironmental record for MIS 19.Here,high-resolution terrestrial snail records from the L8–L7 strata of the Huining,Xifeng and Luochuan sequences in the CLP were analyzed in order to characterize spatio-temporal changes in climate and eco-environment during MIS 20–18.The results show that in all three sections the late part of MIS 20 was dominated by abundant cold-aridiphilous mollusc species,indicating that cold and dry climatic conditions prevailed across the entire CLP,under the strong influence of the winter monsoon.The mollusc fauna of MIS 19 were dominated by warmth-loving and thermohumidiphilous species that enable the definition of two climatic stages.The early part of MIS 19(~790–778 ka)was marked by warm and humid conditions,as evidenced by high abundances of warmth-loving and thermo-humidiphilous species.This interval was slightly warmer than today and it lasted for^12 kyr.The climate of the later part of MIS 19(~778–761 ka)was more moderate,and increased proportions of cold-aridiphilous and warmth-loving species were recorded.The warmth of this period was similar to that of today,but the climatic fluctuations were stronger.During the early part of MIS 18(~761–745 ka),the Xifeng and Luochuan sections in the eastern CLP still maintained high abundances of warmth-loving and thermo-humidiphilous species,indicating that the moderate climatic conditions during late MIS 19 continued during early MIS 18,lasting for another^15 kyr,and that the influence of the summer monsoon remained strong in the eastern CLP during early MIS 18.However,in the western CLP,cold-aridiphilous species in the Huining section became dominant during early MIS 18,reflecting the prevalence of a cold and dry glacial climate,with the strong influence of the winter monsoon.These findings indicate that a steeper climatic gradient and a pronounced regional environmental difference existed between the eastern and western CLP during the early part of MIS 18.Comparison of our mollusc results with the variation of Earth orbital parameters suggested that climate changes in the CLP during MIS 20–18 were likely controlled mainly by insolation changes forced by the configuration of Earth orbital parameters.The unique orbital configuration during the low eccentricity interglacial-to-glacial transition could have strengthened the East Asian summer monsoon which favored the amelioration of the eco-environment in the CLP,especially in the eastern CLP where the summer monsoon exerted a strong influence.Thus we speculate that,under natural climatic conditions,the climate of the CLP may remain in a warm,humid state for another 30 kyr,although climatic instability and the seasonal differences between winter and summer could strengthen.