ABSTRACT Historic human–climate interactions have been of interest to scholars for a long time. H... more ABSTRACT Historic human–climate interactions have been of interest to scholars for a long time. However, exploring the long-term relation between prehistoric demography and climate change remains challenging because of the absence of an effective proxy for population reconstruction. Recently, the summed probability distribution of archaeological radiocarbon dates has been widely used as a proxy for human population levels, although researchers recognize that such usage must be cautious. This approach is rarely applied in China due to the lack of a comprehensive archaeological radiocarbon database, and thus the relation between human population and climate change in China remains ambiguous. Herein we systematically compile an archaeological 14C database (n = 4656) for China for the first time. Using the summed probability distributions of the radiocarbon dates alongside high-resolution palaeoclimatic records, we show that: 1) the commencement of major population expansion in China was at 9 ka cal BP, occurring after the appearance of agriculture and associated with the early Holocene climate amelioration; 2) the major periods of small population size and population decline, i.e., 46–43 ka cal BP, 41–38 ka cal BP, 31–28.6 ka cal BP, 25–23.5 ka cal BP, 18–15.2 ka cal BP, and 13–11.4 ka cal BP, correspond well with the dating of abrupt cold events in the Last Glacial (LG) such as the Heinrich and Younger Dryas (YD) events, while the major periods of high-level population in the Holocene, i.e., 8.5–7 ka cal BP, 6.5–5 ka cal BP and 4.3–2.8 ka cal BP, occur at the same times as warm-moist conditions and Neolithic cultural prosperity, suggesting that abrupt cooling in the climate profoundly limited population size and that mild climate episodes spurred a growth in prehistoric populations and advances in human cultures; and 3) populations in different regions experience different growth trajectories and that their responses to climate change are varied, due to both regional environmental diversity and the attainment of different levels of adaptive strategies.
Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great ... more Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great significance for our understanding of the southeastward dispersal of rice agriculture in the prehistoric period. Until now, quite limited archaeobotanical work has been done in this region. In eastern Taiwan, no archaeological evidence of rice agriculture has been obtained, probably owing to the poor preservation conditions for plant macroremains. Here, we report a new discovery of 4200-year-old domesticated rice remains at the Chaolaiqiao site, which for the first time in detail demonstrates the ancient practice of rice agriculture in this area. Based on a combination of factors that include a rice-based plant subsistence strategy, the mid-Holocene limits to available farmland and the fast-growing Taiwan Neolithic population from settlement pattern data, we infer that this contradiction in eastern Taiwan between land-dependent agriculture and limited suitable farmland encouraged a population movement out of Taiwan during the Middle Neolithic period.
Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fractio... more Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fraction is recognised as an ideal dating material because of its high resistance to decomposition and post-deposition contamination at the time of phytolith formation. However, the reliability of phytolith radiocarbon dating has recently been questioned. The development of a new extraction protocol for phytoliths, with paired dating between phytoliths and other materials from the same sediment, may provide further evidence for the reliability of phytolith dating. We present an improved method for extracting phytoliths from soils. We compared the dating of phytoliths and other materials (e.g., charcoal and plant seeds) recovered at the same depth from seven pits at six archaeological sites in China. The estimated ages of the phytoliths and other materials were generally consistent, except for one outlier. We attribute this inconsistency to the post-depositional processes of phytoliths in soil, rather than to the uptake of old carbon from the soil. Our results clearly show the potential for phytolith carbon dating at archaeological sites in the absence of other dating materials.
The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation... more The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation variability is traditionally considered as an East Asian summer monsoon (EASM) indicator, impedes our understanding of the behaviour and dynamics of the EASM. Here we present a well-dated, pollen-based, ~20-yr-resolution quantitative precipitation reconstruction (derived using a transfer function) from an alpine lake in North China, which provides for the first time a direct record of EASM evolution since 14.7 ka (ka = thousands of years before present, where the "present" is defined as the year AD 1950). Our record reveals a gradually intensifying monsoon from 14.7-7.0 ka, a maximum monsoon (30% higher precipitation than present) from ~7.8-5.3 ka, and a rapid decline since ~3.3 ka. These insolation-driven EASM trends were punctuated by two millennial-scale weakening events which occurred synchronously to the cold Younger Dryas and at ~9.5-8.5 ka, and by two centennial-scale i...
The history of tea is poorly known, mainly due to the questionable identification of decayed tea ... more The history of tea is poorly known, mainly due to the questionable identification of decayed tea plants in archaeological samples. This paper attempts to test the utility of calciphytoliths (calcium oxalate crystals) for the identification of tea in archaeological samples. It provides the first survey of the macropatterns of calciphytoliths in several species of Theaceae and common non-Theaceae plants. Crystals were extracted from 45 samples of tea, Theaceae and common non-Theaceae plants, and detected microscopically between crossed polarizers. In tea plants, druse and trichome base are the most distinctive crystals. Druses have the smallest diameter (11.65 ± 3.64 μm), and trichome bases have four distinctive straight and regular cracks, similar to a regular extinction cross. The results provide morphological criteria for distinguishing tea from other plants, specifically the presence of identifiable druses together with calcified trichome bases. The implications are significant fo...
Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake i... more Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus, and a temperature proxy, revealed ~500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ~500-year cyclic climate change occurred in EA during the mid-late Holocene and even the last 150 years dominated by anthropogenic forcing. It was almost in phase with a ~500-year periodic change in solar activity and Greenland temperature change, suggesting that ~500-year small variations in solar output played a prominent role in the mid-late Holocene climate dynamics in EA, linked to high latitude climate system. Its last warm phase might terminate in the next several decades to enter another ~250-year cool phase, and thus this future centennial cyclic temperature minimum could partially sl...
(1Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China; 2The Ge... more (1Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China; 2The Geological Analysis Center, Beijing, China; 3The Administrative Center for China's Agenda 21th Century, Beijing, China) ... Received 22 August 2001; revised manuscript ...
To understand the origin of the ultrafine pedogenic components responsible for the magnetic susce... more To understand the origin of the ultrafine pedogenic components responsible for the magnetic susceptibility (MS) enhancement remains a major challenging problem in linking magnetic signal with paleoclimate. Here we examine the effect of the natural fires on the MS signal of both plants and modern soils and in particular the MS difference between C3 and C4 plant ashes and their
Abstract The geographical distribution of dominant plant species in China was georeferenced and c... more Abstract The geographical distribution of dominant plant species in China was georeferenced and climatic variables were interpolated into all grids. Accordingly, the percentage distributions of principal pollen taxa based on 1860 surface pollen sites in China were selected and the related climate values were interpolated with the same method. The geographical and climatic comparison between the two datasets indicated that the climate threshold of most pollen taxa from surface pollen is coherent with plant distributions. The ...
ABSTRACT Historic human–climate interactions have been of interest to scholars for a long time. H... more ABSTRACT Historic human–climate interactions have been of interest to scholars for a long time. However, exploring the long-term relation between prehistoric demography and climate change remains challenging because of the absence of an effective proxy for population reconstruction. Recently, the summed probability distribution of archaeological radiocarbon dates has been widely used as a proxy for human population levels, although researchers recognize that such usage must be cautious. This approach is rarely applied in China due to the lack of a comprehensive archaeological radiocarbon database, and thus the relation between human population and climate change in China remains ambiguous. Herein we systematically compile an archaeological 14C database (n = 4656) for China for the first time. Using the summed probability distributions of the radiocarbon dates alongside high-resolution palaeoclimatic records, we show that: 1) the commencement of major population expansion in China was at 9 ka cal BP, occurring after the appearance of agriculture and associated with the early Holocene climate amelioration; 2) the major periods of small population size and population decline, i.e., 46–43 ka cal BP, 41–38 ka cal BP, 31–28.6 ka cal BP, 25–23.5 ka cal BP, 18–15.2 ka cal BP, and 13–11.4 ka cal BP, correspond well with the dating of abrupt cold events in the Last Glacial (LG) such as the Heinrich and Younger Dryas (YD) events, while the major periods of high-level population in the Holocene, i.e., 8.5–7 ka cal BP, 6.5–5 ka cal BP and 4.3–2.8 ka cal BP, occur at the same times as warm-moist conditions and Neolithic cultural prosperity, suggesting that abrupt cooling in the climate profoundly limited population size and that mild climate episodes spurred a growth in prehistoric populations and advances in human cultures; and 3) populations in different regions experience different growth trajectories and that their responses to climate change are varied, due to both regional environmental diversity and the attainment of different levels of adaptive strategies.
Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great ... more Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great significance for our understanding of the southeastward dispersal of rice agriculture in the prehistoric period. Until now, quite limited archaeobotanical work has been done in this region. In eastern Taiwan, no archaeological evidence of rice agriculture has been obtained, probably owing to the poor preservation conditions for plant macroremains. Here, we report a new discovery of 4200-year-old domesticated rice remains at the Chaolaiqiao site, which for the first time in detail demonstrates the ancient practice of rice agriculture in this area. Based on a combination of factors that include a rice-based plant subsistence strategy, the mid-Holocene limits to available farmland and the fast-growing Taiwan Neolithic population from settlement pattern data, we infer that this contradiction in eastern Taiwan between land-dependent agriculture and limited suitable farmland encouraged a population movement out of Taiwan during the Middle Neolithic period.
Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fractio... more Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fraction is recognised as an ideal dating material because of its high resistance to decomposition and post-deposition contamination at the time of phytolith formation. However, the reliability of phytolith radiocarbon dating has recently been questioned. The development of a new extraction protocol for phytoliths, with paired dating between phytoliths and other materials from the same sediment, may provide further evidence for the reliability of phytolith dating. We present an improved method for extracting phytoliths from soils. We compared the dating of phytoliths and other materials (e.g., charcoal and plant seeds) recovered at the same depth from seven pits at six archaeological sites in China. The estimated ages of the phytoliths and other materials were generally consistent, except for one outlier. We attribute this inconsistency to the post-depositional processes of phytoliths in soil, rather than to the uptake of old carbon from the soil. Our results clearly show the potential for phytolith carbon dating at archaeological sites in the absence of other dating materials.
The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation... more The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation variability is traditionally considered as an East Asian summer monsoon (EASM) indicator, impedes our understanding of the behaviour and dynamics of the EASM. Here we present a well-dated, pollen-based, ~20-yr-resolution quantitative precipitation reconstruction (derived using a transfer function) from an alpine lake in North China, which provides for the first time a direct record of EASM evolution since 14.7 ka (ka = thousands of years before present, where the "present" is defined as the year AD 1950). Our record reveals a gradually intensifying monsoon from 14.7-7.0 ka, a maximum monsoon (30% higher precipitation than present) from ~7.8-5.3 ka, and a rapid decline since ~3.3 ka. These insolation-driven EASM trends were punctuated by two millennial-scale weakening events which occurred synchronously to the cold Younger Dryas and at ~9.5-8.5 ka, and by two centennial-scale i...
The history of tea is poorly known, mainly due to the questionable identification of decayed tea ... more The history of tea is poorly known, mainly due to the questionable identification of decayed tea plants in archaeological samples. This paper attempts to test the utility of calciphytoliths (calcium oxalate crystals) for the identification of tea in archaeological samples. It provides the first survey of the macropatterns of calciphytoliths in several species of Theaceae and common non-Theaceae plants. Crystals were extracted from 45 samples of tea, Theaceae and common non-Theaceae plants, and detected microscopically between crossed polarizers. In tea plants, druse and trichome base are the most distinctive crystals. Druses have the smallest diameter (11.65 ± 3.64 μm), and trichome bases have four distinctive straight and regular cracks, similar to a regular extinction cross. The results provide morphological criteria for distinguishing tea from other plants, specifically the presence of identifiable druses together with calcified trichome bases. The implications are significant fo...
Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake i... more Here we presented a high-resolution 5350-year pollen record from a maar annually laminated lake in East Asia (EA). Pollen record reflected the dynamics of vertical vegetation zones and temperature change. Spectral analysis on pollen percentages/concentrations of Pinus and Quercus, and a temperature proxy, revealed ~500-year quasi-periodic cold-warm fluctuations during the past 5350 years. This ~500-year cyclic climate change occurred in EA during the mid-late Holocene and even the last 150 years dominated by anthropogenic forcing. It was almost in phase with a ~500-year periodic change in solar activity and Greenland temperature change, suggesting that ~500-year small variations in solar output played a prominent role in the mid-late Holocene climate dynamics in EA, linked to high latitude climate system. Its last warm phase might terminate in the next several decades to enter another ~250-year cool phase, and thus this future centennial cyclic temperature minimum could partially sl...
(1Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China; 2The Ge... more (1Institute of Geology and Geophysics, Chinese Academy of Science, Beijing 100029, China; 2The Geological Analysis Center, Beijing, China; 3The Administrative Center for China's Agenda 21th Century, Beijing, China) ... Received 22 August 2001; revised manuscript ...
To understand the origin of the ultrafine pedogenic components responsible for the magnetic susce... more To understand the origin of the ultrafine pedogenic components responsible for the magnetic susceptibility (MS) enhancement remains a major challenging problem in linking magnetic signal with paleoclimate. Here we examine the effect of the natural fires on the MS signal of both plants and modern soils and in particular the MS difference between C3 and C4 plant ashes and their
Abstract The geographical distribution of dominant plant species in China was georeferenced and c... more Abstract The geographical distribution of dominant plant species in China was georeferenced and climatic variables were interpolated into all grids. Accordingly, the percentage distributions of principal pollen taxa based on 1860 surface pollen sites in China were selected and the related climate values were interpolated with the same method. The geographical and climatic comparison between the two datasets indicated that the climate threshold of most pollen taxa from surface pollen is coherent with plant distributions. The ...
Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an,... more Phytoliths and biomolecular components extracted from ancient plant remains from Chang'an (Xi'an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang'an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE. Tea (Camellia sinensis L.) is one of the most popular nonalcoholic beverages, consumed by over two-thirds of the world's population for its refreshing taste, aroma, medicinal, and mildly stimulating qualities 1. The exact antiquity of tea is shrouded in Chinese myth 2. The first unambiguous textual reference to the consumption of tea as a beverage can be dated to 59 BCE during the Western Han Dynasty 2,3. However, its widespread popularity amongst both northern Chinese and people to the west such as Uighurs is generally attributed to the Tang Dynasty (7 th –8 th century CE) 4. Previously the oldest physical evidence of tea was from China's Northern Song Dynasty (960–1127 CE) 5. It has long been hypothesized that tea, silks and porcelain were key commodities exported from the ancient Chinese capital, Chang'an, to central Asia and beyond by caravans following several transport routes constituting the network commonly referred to as the Silk Road 6–10 , in use by the second century BCE. However, there are no records of tea having been carried along the Silk Road into Tibet, central Asia or southern Asia until the Tang Dynasty (618–907 CE) 6,7. The Tibetan Plateau was then closely linked eastwards to central China through trade of tea and horses for Tibetan furs and medicinal plants 6–10. Although trade of millets already connected the Tibetan Plateau to lowland China more than 4000 calibrated years before present (yr BP) 11 , and barley cultivation and pastoralism expanded after 3600 yr BP 12 , the emergence of historical patterns of commodity trade and habits of tea drinking along the Silk Road and in the Tibetan Plateau has remained poorly understood, due mainly to the poor preservation of plant leaves, and the challenge of identifying decayed tea remains in archeological samples 7,13. Here, we present evidence from calcium phytoliths (calcium oxalate plant crystals), chemical biomarkers and radiocarbon dating from dried plant bundles from two funerary sites: the Han Yangling Mausoleum 14 in Xi'an, Sha'anxi Province; and the Gurgyam Cemetery in Ngari district, western Tibet 15,16 (Fig. 1a). Large modern reference collections are used to compare and contrast microfossil morphology and biomolecular components of these ancient remains to modern standards of tea and related plant species 13. Our study reveals that tea was drunk by Han Dynasty emperors as early as 2100 yr BP and had been introduced into the Tibetan Plateau by 1800 yr BP. This indicates that one branch of the Silk Road passed through western Tibet at that time.
Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an,... more Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.
Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual ... more Rice (Oryza sativa) is regarded as the only grass that was selected for cultivation and eventual domestication in the Yangtze basin of China. Although both macro-fossils and micro-fossils of rice have been recovered from the Early Neolithic site of Shangshan, dating to more than 10,000 years before present (BP), we report evidence of phytolith and starch microfossils taken from stone tools, both for grinding and cutting, and cultural layers, that indicating barnyard grass (Echinochloa spp.) was a major subsistence resource, alongside smaller quantities of acorn starches (Lithocarpus/Quercus sensu lato) and water chestnuts (Trapa). This evidence suggests that early managed wetland environments were initially harvested for multiple grain species including barnyard grasses as well as rice, and indicate that the emergence of rice as the favoured cultivated grass and ultimately the key domesticate of the Yangtze basin was a protracted process.
Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great ... more Located in the key junction between mainland China and Island Southeast Asia, Taiwan is of great significance for our understanding of the southeastward dispersal of rice agriculture in the prehistoric period. Until now, quite limited archaeobotanical work has been done in this region. In eastern Taiwan, no archaeological evidence of rice agriculture has been obtained, probably owing to the poor preservation conditions for plant macroremains. Here, we report a new discovery of 4200-year-old domesticated rice remains at the Chaolaiqiao site, which for the first time in detail demonstrates the ancient practice of rice agriculture in this area. Based on a combination of factors that include a rice-based plant subsistence strategy, the mid-Holocene limits to available farmland and the fast-growing Taiwan Neolithic population from settlement pattern data, we infer that this contradiction in eastern Taiwan between land-dependent agriculture and limited suitable farmland encouraged a population movement out of Taiwan during the Middle Neolithic period.
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