The Impacts of Climate Change on the Neolithic Cultures of Gansu-Qinghai Region During the Late Holocene Megathermal
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See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/225224713 The impacts of climate change on the Neolithic cultures of Gansu-Qinghai region during the late Holocene Megathermal ARTICLE in JOURNAL OF GEOGRAPHICAL SCIENCES · JUNE 2010 Impact Factor: 1.34 · DOI: 10.1007/s11442-010-0417-1 CITATIONS READS 12 31 6 AUTHORS, INCLUDING: Hou Guangliang Qinghai Normal University 14 PUBLICATIONS 40 CITATIONS SEE PROFILE Available from: Hou Guangliang Retrieved on: 02 December 2015 J. Geogr. Sci. 2010, 20(3): 417-430 DOI: 10.1007/s11442-010-0417-1 © 2010 Science China Press Springer-Verlag The impacts of climate change on the Neolithic cultures of Gansu-Qinghai region during the late Holocene Megathermal LIU Fenggui1,2,3, ZHANG Yili3, FENG Zhaodong4, HOU Guangliang2, ZHOU Qiang2, ZHANG Haifeng2 1. School of Geography, Beijing Normal University, Beijing 100875, China; 2. School of Life and Geographic Science, Qinghai Normal University, Xining 810008, China; 3. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China; 4. Key Laboratory of Western China's Environmental Systems (Ministry of Education), Lanzhou University, Lanzhou 730000, China Abstract: The Holocene Megathermal is divided into early, middle and late periods, each having different impacts on the Neolithic cultures due to their different climate changing trends. This study is based on a comparative analysis of the environmental evolution information recorded in the Qinghai Lake, the western edge of the Loess Plateau and Zoige and the spa- tial distribution of Neolithic sites of the Gansu-Qinghai region. Results show that the early and middle periods towards warm and humid promoted the development of Neolithic cultures with agriculture as the main sector in the Gansu-Qinghai region, furthermore a heyday of Yang- shao Culture prosperity emerged. The Holocene entered the late period after the cold climate event at 5.9 ka BP in the Gansu-Qinghai region. Later the climate began to turn cold. How- ever, at the 5.8–4.2 ka BP a relatively stable warm and humid climate created the conditions for the development of Majiayao Culture of the Neolithic Age in this region, thus the distribu- tion of its cultural heritage sites expanded towards high altitudes and high latitudes. From 4.2 ka BP onwards, the climate became cold and dry, which had a significant influence on the Neolithic cultures of the Gansu-Qinghai region, leading to a dramatic change in the cultural characters and spatial distribution of Qijia Culture around 4.2 ka BP. After a nearly 300 years of cold and dry period, the unified Neolithic farming culture completely collapsed. Afterwards an industrial division of animal husbandry and farming and regional multiple cultures formed, and ultimately led to the end of primitive society and the starting of a civilized society. Keywords: Gansu-Qinghai region; Neolithic cultures; climate change 1 Introduction The impact of environmental change on archaeological cultures is a major aspect in the re- search into the past man-land relationship. During the late period of Holocene Megathermal Received: 2009-08-10 Accepted: 2009-11-03 Foundation: National Natural Science Foundation of China, No.40771211; No.40261003; National Key Technology Re- search and Development Program, No.2007BAC03A11 Author: Liu Fenggui (1966–), Professor, specialized in regional geography related to the Tibetan Plateau. E-mail: [email protected] www.scichina.com www.springerlink.com 418 Journal of Geographical Sciences (Shi, 1992; Shi et al., 1992; Wang and Gong, 2000), a dramatic climate change produced far-reaching influence on the turning of Chinese Neolithic culture. A large number of re- search data show that the turning point of Chinese Neolithic culture was closely related to the 4.2 ka BP cold and dry event during the Holocene Megathermal (data used in this article are the corrected age) (Huang et al., 1991; Zhou et al., 1992; Mo et al., 1996; Zhu et al., 1996; Zhang et al., 1997; Fang and Sun, 1998; Wu and Liu, 2001; An et al., 2003; Liu et al., 2005). The Tibetan Plateau and northern China's farming-pastoral zone are considered to be sen- sitive to climate change (Zhang et al., 1997; Zheng and Yao, 2004), and therefore the study on the impacts of climate change events of these regions on Neolithic human activities have important theoretical and practical significances. The Gansu-Qinghai region, as a transitional zone between the Tibetan Plateau and the Loess Plateau and with an altitude of 1000–3500 m, is a sensitive and vulnerable area to the environmental changes in China, where envi- ronmental change information has been recorded in the rich lake sediments, loess accumula- tions and peat sediments. Besides, in the region studies on Neolithic archaeological culture are more comprehensive, Neolithic cultures are well developed and preserved with integral sequences, and the Neolithic cultural sites are densely distributed (Xie, 2002), which domi- nated development of early Chinese civilization (Yan, 1997). In the late Holocene Megathermal, affected by dramatic climate change, the Neolithic cultures had an important turning point (Mo et al., 1996; An et al., 2003; Hou and Liu, 2004), that is, animal hus- bandry and farming industries separated into the two major social divisions of labor, thus a unified farming culture went from rise to decline, and then disappeared. 2 Climate changes of the Gansu-Qinghai region during Holocene Megathermal Holocene Megathermal refers to the warmest interglacial period after the last glacial period. It occurred at 8.5–3.0 ka BP in China (Shi, 1992; Shi et al., 1992). During the early period of 8.5–7.2 ka BP, the earth's climate fluctuated and the average global temperature became warmer. Temperature and precipitation presented a clear upward trend in the frequent fluc- tuations. In this period, agriculture-based Neolithic cultures developed rapidly. During the middle period of 7.2–6.0 ka BP, temperature and precipitation reached their maximum val- ues, and due to lush vegetation, the Yangshao Culture reached a peak in Neolithic prosperity. During the late period of 5.9–4 ka BP, the earth’s climate fluctuated with a downward trend of temperature and precipitation, of which 5–4.2 ka BP was a relatively stable stage during which the number of cultural sites soared. The end of the Holocene Megathermal at around 4.2 ka BP had a profound impact on the Chinese Neolithic cultures due to extreme climate instability. Environmental information for lake cores of Qinghai Lake in northeast of the Tibetan Plateau (3195 m asl) (Liu et al., 2002; Figure 1a), Sujiawan loess section of the western edge of the Loess Plateau (1950 m asl) (Feng et al., 2004, Figure 1b), and Zoige Hongyuan peat core section on the south-east edge of the Qinghai–Tibet Plateau (3466 m asl) (Hong et al., 2003; Figure 1c) can be extracted to better reflect the Gansu-Qinghai region (to be dis- cussed in this paper) in the Holocene climate and environmental changes. LIU Fenggui et al.: The impacts of climate change on the Neolithic cultures of Gansu-Qinghai region 419 Figure 1 Climate change of the Gansu-Qinghai region recorded in different environments during late Holocene Megathermal (after Liu Xingqi et al., 2002; Feng Zhaodong et al., 2004; Hong Yetang et al., 2003) The past records from the above three regions (Figure 1a-c) show that, since 10 ka BP, spruce, pine and other conifer pollen levels have significantly increased, while herbs pollen reduced. The entire region shifts from grasslands to forest or forest-grassland (Du et al., 1989; Kong et al., 1990; Liu et al., 2002; 2003; Shen et al., 2004; Feng et al., 2004; Sun et al., 2008; Zhou et al., 2001; Liu et al., 1994, 1995). Up to the early period of Holocene Megathermal, mixed coniferous and broad-leaved forests were well developed in the Qing- hai Lake region, with Betula a small amount of thermophilic Ulmus. Pinus, fir, spruce and iron Suginami could be found in the western edge of the Loess Plateau, with mixed conifer- ous and broad-leaved forests composed of Betula, Juglans, Ulmus, and Gramineae, As- teraceae, Artemisia (Sun et al., 2008). Spruce and fir were mainly distributed in Zoige re- gion, with mixed coniferous and broad-leaved forests consisting of oak, chestnut and roses, etc. (Wang et al., 1996). Seen from plants and sediments, the climate presented a warming trend in spite of frequent fluctuations of temperature and precipitation (Zhang et al., 1994; Chen et al., 1990; Feng et al., 2004; Wang et al., 1993). The salinity of the Qinghai Lake reached a low level around 6.3 ka BP (Zhang et al., 1994), and the lake surface was 40 m higher compared to the present (Wang and Wang, 1992). In this period, Picea purpurea and elm were found on the lakeshore, and a large amount of wet herbs in Sujiawan section. Be- sides the pollen concentrations of trees and shrubs went up to 80% of the peak (Sun et al., 2008). Both the Hongyuan’s peat gradation and total organic carbon content were the high- 420 Journal of Geographical Sciences est (Zhou et al., 2001). It can be inferred that the annual mean temperature was about 3℃ higher and the precipitation was increased by 240–300 mm compared to the modern times (Shi, 1992), which showed a heyday of the Holocene Megathermal. Temperature and precipitation began a turning point after 5.9 ka BP cooling event. The sediments of the Qinghai Lake have more particles with a grain size of <4 μm, while parti- cles of > 64 μm tend to be stabilized (Shen et al., 2004 ), indicating that precipitation tended to decrease, that larger amount of Artemisia increased significantly in lake area, and that pine and other tree pollen concentrations decreased significantly.