Browsing by Author "Sun, N"

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    Early agricultural development and environmental effects in the Neolithic Longdong basin (East Gansu)
    (Springer Nature, 2011-03-01) Zhou, XY; Li, XQ; Zhao, KL; Dodson, JR; Sun, N; Yang, Q
    Neolithic agricultural development and environmental effects in the Longdong area were reconstructed using a synthetic approach, investigating pollen, charcoal, and seed remains for two cultural layer sections and five flotation sites. Results show that Neolithic agriculture in the Longdong area had a simple organization and was dominated by the production of common millet, especially in the early and middle Yangshao age. After the late Yangshao age, Neolithic agriculture developed into a more complex structure, dominated by both common and foxtail millet and the cultivation of rice and soybeans. The production of foxtail millet gradually increased through the Neolithic period, reaching its highest point during the Qijia culture. Soybeans were first cultivated during the late Yangshao culture, approximately 5000 cal a BP. Rice production began no later than 4800 cal a BP, and continued to exist in the Qijia culture, approximately 4000 cal a BP. Agricultural production in Neolithic Longdong, specifically in the "Yuan" area of the loess plateau, developed as a shrub and grass dominated landscape. Vegetation in the river valleys was partly covered with Picea, Tusga, and Quercus coniferous and broadleaf mixed forests. Agricultural activity during the Neolithic period caused an increase in farmland on the loess tableland and a decrease in the abundance of shrub and grassland in the Longdong area. When farmlands were abandoned, vegetation recovered with Hippophae-, Rosaceae-, Ephedra-, and Leguminosae-dominated shrublands and Artemisia-dominated grasslands. © The Author(s) 2011.
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    The early agriculture and its impact on landscape in NW China
    (Australian Geosciences Council, 2012-08-05) Li, XQ; Dodson, JR; Zhou, XY; Zhou, KL; Sun, N
    The agriculture, as one of the most important events, appeared in the early Holocene and developed rapidly, which is the most important economic activity and the base of the forming and development of civilization. Millet and rice based agriculture originated in the Yellow and Yangtze valleys in the early Holocene respectively. Wild wheat strains were first used in the Fertile Crescent of Southwest Asia in the late-glacial and domesticated wheat was widespread in that region by 10500 BP. The early agriculture development included population growth, the expansions of material cultures, and its impacts on the landscape. The Northwestern China lies between the heartlands of wheat, rice and rain-fed agriculture and is also crossed by the famous ‘Silk Road’. The early agriculture and its impact were reconstructed based on the records of pollen, charcoal, seeds, phytolith, together with the high resolution AMS 14C dating. Neolithic agriculture in NW China had a simple organization and was dominated by the production of common millet in the early-middle Yangshao Culture (7000–5000 BP). After the late Yangshao age, the agriculture were dominated by both common and foxtail millet. Approximately 5000 cal BP ago, the rice and soybeans have been cultivated and continued to exist in the Qijia culture (4000–3800 BP). The agriculture developed into a more complex structure. The earliest wheat ages cluster around 4100 to 3800 cal BP in northern China’s Hexi corridor of Gansu Province and the likely route of wheat into China was via Russia and Mongolia. Wheat was added as a new crop to the existing millet and rice based agricultural systems. Eight crop types of foxtail millet, broomcorn millet, rice, wheat, barley, oats, soybean and buckwheat appeared and covered the main crop types of the two origin centers of East and West Asia around 4000 cal BP, which suggest the earliest complexity agriculture in Neolithic China. The land use and fire activity by early farmers are much different from the hunting-gathering society. The vegetation and environment were affected greatly by agricultural activity. Prehistoric farmers needed cultivated land and plants to live and caused an increase in farmland and influence on the vegetation during the Neolithic. Land degradation is probably the main cause for decreased agricultural activity and settlement abandonment in arid area. Agriculture induced soil fertility loss and land salinization contributed to the process of land degradation. The intensity and scale that prehistoric farmers impact on the landscape were much greater than previously thought during the Neolithic in NW China.
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    Human activity and its impact on the landscape at the Xishanping site in the western Loess Plateau during 4800-4300 cal yr BP based on the fossil charcoal record
    (Elsevier Science Ltd, 2012-10-01) Li, XQ; Sun, N; Dodson, JR; Zhou, XY
    The taxonomic identification of fossil charcoal can be a useful archaeobotanical tool, as it can reveal information about prehistoric humans' use of plant resources and other factors. In this study, we quantify the fossil charcoal in a cultural sequence from Xishanping in the western Loess Plateau of China representing 4800-4300 cal yr BP to consider aspects of humans' impact on this landscape. The fossil charcoal assemblages reveal that the relative abundances of Picea, Betula, Acer, Ulmus and Quercus decreased markedly after 4600 cal yr BP. This suggests a marked decline in the mixed coniferous-broadleaved forest after this time. Concurrently, an increasing abundance of Bambusoideae charcoal has been suggested to reflect the expansion of the bamboo forest. The marked changes in the vegetation after 4600 cal yr BP were not obviously influenced by climate; they may be a better reflection of the results of human activity. Furthermore, other genera that provide important resources to humans also increased after 4600 cal yr BP, including Castanea, Cerasus, Padus and Diospyros. It is nearly certain that nuts and berries were an important food resource and that fruit trees were managed by prehistoric humans in the late Neolithic. This work suggests that the scale of prehistoric human impact on the western Loess Plateau landscape during the late Neolithic was much greater than was previously believed. © 2012, Elsevier Ltd.
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    The impact of early smelting on the environment of Huoshiliang in Hexi Corridor, NW China, as recorded by fossil charcoal and chemical elements
    (Elsevier, 2011-05-15) Li, XQ; Sun, N; Dodson, JR; Ji, M; Zhao, KL; Zhou, XY
    Recent research has greatly increased our knowledge of early human impacts on the environment. Records of fossil charcoal and chemical elements from a bronze smelting site at Huoshiliang, in the Hexi corridor of northwest China, provide material with which to estimate the extent of smelting activity and its impact on the environment. Analysis of the microstructure of wood fossil charcoal is used to identify the types of charred wood and to reconstruct the local vegetation present during the period of smelting. Four wood types were used as firewood for smelting: Tamarix, Populus, Salix, and Polygonaceae. The assemblages of fossil charcoal showed that Tamarix was the most dominant shrub and was widely used as firewood, as a percentage of charcoal it increased from 89% to 97% over the smelting period. Populus. Polygonaceae and Salix were much less common and finally disappeared completely. When the trees and shrubs were used as fuel, the vegetation cover was reduced and erosion rates increased. This erosion increase was recorded in the higher values of the Rb/Sr ratio in the lacustrine sediment of Tiaohu lake, located near the Huoshiliang site. The deforestation caused by smelting activity sharply reduced the vegetation coverage and had serious impacts on the environment. When the available fuel wood ceased to meet the needs of smelting and human settlement, the Huoshiliang site was eventually abandoned in about 1860 BC. (C) 2011 Elsevier B.V.
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    Origin and spread of wheat in China
    (Elsevier, 2013-07-15) Dodson, JR; Li, XQ; Zhou, XY; Zhao, KL; Sun, N; Atahan, P
    Wheat was added as a new crop to the existing millet and rice based agricultural systems of China. Here we present 35 radiocarbon ages from wheat seeds collected from 18 sites between western (Xinjiang Province) and eastern (Henan Province) China. The earliest wheat ages cluster around 2100–1800 BCE in northern China's Hexi corridor of Gansu Province, where millet was already a well-established crop. Wheat first appears in Xinjiang and Henan about 300–400 years later, and perhaps a little earlier than this in Xinjiang, and we hypothesize that the likely route of wheat into China was via Russia through Gansu. © 2013, Elsevier Ltd.
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    Plant diversity of the Tianshui Basin in the western Loess Plateau during the mid-holocene - charcoal records from archaeological sites
    (Elsevier, 2013-10-02) Sun, N; Li, XQ; Dodson, JR; Zhou, XY; Zhao, KL; Yang, Q
    Assessing the potential impact of increased temperature needs examination of robust palaeorecords that contain analogues. The fossil charcoal (anthracological) records from the mid-Holocene archaeological sites can provide palaeo-analogues on the impacts of climate change. The Xishanping and Dadiwan sites were continuously developed during the Neolithic Culture in the Tianshui Basin, western Loess Plateau. A total of 24 samples of were recovered using a floatation method. At least 100 fragments were examined from each sample, and these fragments were identified following standard procedures, and the results were used to reconstruct the vegetation and plant diversity between 5200 and 4300 cal BP, which was a warm period for the region. The charcoal evidence from the Xishanping and Dadiwan sites confirm that woody plants were widely available, including temperate taxa such as Betula, Ulmus, Quercus, Carpinus, Acer, Corylus and Padus, and typical subtropical taxa such as Bambusoideae, Liquidambar formosana, Castanopsis, Pseudotsuga sinensis, and Eucommia ulmoides. The assemblages of fossil charcoal show that mixed forests of north-subtropical evergreen and deciduous broadleaved trees existed. This is a broader range of woody plants than at present in the Tianshui Basin. This leads to the conclusion that the warmer and increasing monsoon precipitation resulted in a northward shift in the southern vegetation zones. And that the natural botanical diversity between 5200 and 4300 cal BP was also greater than at present in the Tianshui Basin, western Loess Plateau. © 2013, Elsevier Ltd and INQUA.
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    Use of coal in the bronze age in China
    (Sage, 2014-03-03) Dodson, JR; Li, XQ; Sun, N; Atahan, P; Zhou, XY; Liu, HB; Zhao, KL; Hu, SM; Yang, ZM
    People in northern and western China were probably the first in the world to use coal as a source of energy in a consistent way. The ages cluster around 1900–2200 BC in modern day Inner Mongolia and Shanxi provinces. These are areas where near-surface coal is abundant today and woody vegetation was scant in the Bronze Age. Since coal is bulky to transport, it was probably not a cost-effective energy source in areas with abundant wood supply. The sites where coal was first used were probably occupied for a century to a few centuries at most and were associated with Bronze Age societies. The earliest age is about 3490 BC from a house site at Xiahe in Shaanxi Province; however, the coal is not securely tied to the radiocarbon ages and is assumed to have been used at this site sometime after 3490 BC. The elemental composition of modern mine and sedimentary coal in nearby archaeological contexts suggests that coal was used from local sources, and that elemental composition of coal may be a useful tool in identifying site origin of coal.
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    Vegetation characteristics in the western Loess plateau between 5200 and 4300 cal. B.P. based on fossil charcoal records
    (Springer, 2013-01-01) Li, XQ; Sun, N; Dodson, JR; Zhou, XY; Zhao, KL
    Understanding terrestrial vegetation dynamics is a crucial tool in global change research. The Loess Plateau, an important area for the study of Asian monsoons and early agriculture, poses a controversial question on the potential vegetation and its pattern. Fossil charcoal as direct evidence of wood provides precision in species identification and hence vegetation reconstruction. Charcoals from the Dadiwan and Xishanping sites suggest a great variety of plants between 5200 and 4300 cal. b.p. in the valley area of the western Loess Plateau. The deciduous broad-leaf wood from Quercus, Ulmus, Betula, Corylus and Acer is very frequent and makes up almost half the total abundance ratio of the represented taxa. Meanwhile, some typical subtropical taxa such as Liquidambar formosana, Eucommia ulmoides, Toxicodendron and Bambusoideae, are present at the two study sites. The high abundance of Picea appearing between 5200 and 4300 cal. b.p. suggests the development of Picea forests in the valley of the western Loess Plateau. The assemblages of charcoal indicate that the mixed forest of evergreen deciduous and conifer-deciduous broadleaved trees developed in the valley of the Loess Plateau during the Holocene optimum. Precipitation is the main controlling factor for forest development. The increasing precipitation is the probable reason for the appearance of north-subtropical forests between 5200 and 4300 cal. b.p. © 2013, Springer.
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    Zonal vegetation change in the Chinese Loess Plateau since MIS 3
    (Elsevier Science, 2014-06-15) Zhou, XY; Li, XQ; Dodson, JR; Yang, SL; Long, H; Zhao, KL; Sun, N; Yang, Q; Liu, HB
    Three pollen records from different regions of the Chinese Loess Plateau (CLP) show that the zonal differentiation of vegetation was not large in late MIS 3 time, all the areas were covered by warm semi-humid grass-shrub land, with some conifer-broad leaf mixed forest in the valleys. It appears that the zonal differentiation of vegetation nearly disappeared in the Last Glacial Maximum (LGM), while the semi-arid steppe expanded to the southern margin of the CLP. During the Holocene Thermal Maximum (HTM), the zonal differentiation became complex, with warm humid forest in the southeastern part and semi-arid steppe in the northern CLP. The zonal degree of vegetation differentiation of the CLP decreased again during the late Holocene as a result of climate change and increasing human influence on the landscape. In recent centuries, the transformation of the grass communities caused by land clearance for agriculture on the loess tablelands has been significant. © 2014, Elsevier Ltd.