Hostname: page-component-745bb68f8f-l4dxg Total loading time: 0 Render date: 2025-02-05T23:00:29.421Z Has data issue: false hasContentIssue false
  • English
  • Français

Charcoal evidence for environmental change ca. 3.5 ka and its influence on ancient people in the West Liao River Basin of northeastern China

Published online by Cambridge University Press:  05 February 2021

Xin Jia Open the ORCID record for Xin Jia [Opens in a new window] ,
Shuzhi Wang ,
Yonggang Sun ,
Yiyin Li ,
Yanjing Jiao ,
Zhijun Zhao  and
Harry F. Lee
Xin Jia*
Affiliation:
Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing, 210023, China Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing, 210023, China School of Geography, Nanjing Normal University, Nanjing, 210023, China
Shuzhi Wang*
Affiliation:
Institute of Archaeology, Chinese Academy of Social Sciences, Beijing, 100710, China
Yonggang Sun
Affiliation:
School of History and Culture, Chifeng University, Chifeng, 024000, China
Yiyin Li
Affiliation:
College of Environmental Sciences, Peking University, Beijing, 100871, China
Yanjing Jiao
Affiliation:
Institute of Archaeology, Chinese Academy of Social Sciences, Beijing, 100710, China
Zhijun Zhao
Affiliation:
Institute of Archaeology, Chinese Academy of Social Sciences, Beijing, 100710, China
Harry F. Lee
Affiliation:
Department of Geography and Resource Management, The Chinese University of Hong Kong, Hong Kong, SAR, China
*
*Corresponding authors’ email addresses: jiaxin@njnu.edu.cn, szwang@cass.org.cn
*Corresponding authors’ email addresses: jiaxin@njnu.edu.cn, szwang@cass.org.cn
Rights & Permissions [Opens in a new window]

Abstract

Fossil charcoals from archaeological sites provide direct evidence for the relationship between environmental change and ancient peoples’ livelihoods in the past. Our identification of 5811 fossil charcoal fragments from 84 samples suggested temperate deciduous and mixed conifer-broadleaved forests as the dominant vegetation at the Erdaojingzi site in northeastern China ca. 3500 cal yr BP; the major representative taxa were Quercus, Pinus, and Ulmus. Four woody plants probably supplied humans with food resources at the Erdaojingzi site, including Quercus, Ulmus, Amygdalus/Armeniaca, and Ziziphus. The nuts of Quercus were utilized as staple foods because of their rich starch content. The leaves of Ulmus may have been used by humans because of their massive dietary fibre. Amygdalus/Armeniaca and Ziziphus probably provided fruits for humans. Based on the coexistence approach (CA) used on the fossil charcoals, we found that the MAT anomaly was 7.9 ± 5.9°C at ca. 3500 cal yr BP, which is almost the same as the modern one (7.8°C), while the MAP was halved from 772 ± 301 mm at ca. 3500 cal yr BP to 370 mm currently. The wet climate might have facilitated significant development of rain-fed agriculture, promoted the emergence of large settlements, and eventually facilitated the birth of civilization.

Keywords

ArchaeobotanyCivilization originSubsistence strategyVegetationFruitQuercusXiajiadian
Type
Research Article
Information
Quaternary Research , Volume 102 , July 2021 , pp. 142 - 152
Check for updates
Copyright
Copyright © University of Washington. Published by Cambridge University Press, 2021

INTRODUCTION

Exploring the relationship between environmental change and human adaptation during the Holocene is crucial to a better understanding of ancient human-environment interactions (Butzer, Reference Butzer2012; Hsiang et al., Reference Hsiang, Burke and Miguel2013). The rapid climatic deterioration ca. 4200 cal yr BP has been termed the “Holocene Event 3” (Perry and Hsu, Reference Perry and Hsu2000), and its significant effect on ancient civilizations has gained worldwide attention (Weiss et al., Reference Weiss, Courty, Wetterstrom, Guichard, Senior, Meadow and Curnow1993; Cullen et al., Reference Cullen, Demenocal, Hemming, Hemming, Brown, Guilderson and Sirocko2000; deMenocal, Reference deMenocal2001; Staubwasser et al., Reference Staubwasser, Sirocko, Grootes and Segl2003; Wu and Liu, Reference Wu and Liu2004; Lawler, Reference Lawler2007; Sun et al., Reference Sun, Liu, Wünnemann, Peng, Jiang, Deng, Chen, Li and Chen2019). Almost all prehistoric archaeological cultures in border regions in China declined during this climate event (Wang, Reference Wang2004; Wu and Liu, Reference Wu and Liu2004; An et al., Reference An, Tang, Barton and Chen2005; Chen et al., Reference Chen, Wang, Schneiderman, Tao and Cai2005; Wu et al., Reference Wu, Zhu, Zheng, Li, Wang, Li and Sun2014; Jia et al., Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017; Xu et al., Reference Xu, Liu, Sun, Chen, Cheng and Chen2017; Guo et al., Reference Guo, Xiong., Ding, Jin, Wu and Ye2018a; Sun et al., Reference Sun, Liu, Wünnemann, Peng, Jiang, Deng, Chen, Li and Chen2019). However, three dominant civilization centers emerged after the “Holocene Event 3” in northern China (Zhang, Reference Zhang1997), including the Erlitou Culture in the Central Plain (3800–3500 cal yr BP) (Zhang et al., Reference Zhang, Pollard, Rawson, Huan, Liu and Tang2019), the Yueshi Culture in the Haidai region (3800–3450 cal yr BP) (Fang, Reference Fang1998), and the Lower Xiajiadian Culture in the West Liao River Basin (4000–3500 cal yr BP) (Shelach, Reference Shelach1994; Shelach et al., Reference Shelach, Raphael and Jaffe2011).

The West Liao River Basin was one of the centers of the origin of Chinese civilization. The site of Xinglongwa is considered to be one of the earliest broomcorn millet cultivation sites (7800 cal yr BP) (Jones and Liu, Reference Jones and Liu2009; Zhao Reference Zhao2014). The finely carved jades that were excavated from the Hongshan Culture Niuheliang site first appeared ca. 5500 yr BP (Lawler, Reference Lawler2009). Ultimately, an advanced society was founded during the Lower Xiajiadian period, defined by the construction of stone cities such as the Sanzuodian site (Shelach, Reference Shelach1994; Shelach et al., Reference Shelach, Raphael and Jaffe2011). Previous research has shown that there was a 500 year cycle of human activity intensity, which was driven by climate changes in northeastern China during the Neolithic and Bronze ages (Xu et al., Reference Xu, Lu, Chu, Liu, Shen, Li, Wang and Wu2019). The warm and wet climate facilitated cultural prosperity and population growth, including the Xinglongwa, Hongshan, and Lower Xiajiadian cultures (Xia et al., Reference Xia, Deng and Wu2000; Jin and Liu, Reference Jin and Liu2001; Q. Xu et al., Reference Xu, Yang, Cui, Yang and Liang2002; Li et al., Reference Li, Wilis, Zhou and Cui2006; Jia et al., Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017; D. Xu et al., Reference Xu, Lu, Chu, Liu, Shen, Li, Wang and Wu2019). The prosperity of the Lower Xiajiadian Culture has been attributed to the development of millet agriculture in the warm and wet climate (Jia et al., Reference Jia, Sun, Wang, Sun, Zhao, Lee, Huang, Wu and Lu2016a, Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017). Nevertheless, in the West Liao River Basin, only scattered qualitative paleoclimate records exist that cover the Lower Xiajiadian period (Xu et al., Reference Xu, Yang, Cui, Yang and Liang2002; Li et al., Reference Li, Wilis, Zhou and Cui2006; Mu et al., Reference Mu, Qin, Zhang and Xu2016; Guo et al., Reference Guo, Xiong, Yang, Ye, Jin, Wu and Zhao2018b; Zhao et al., Reference Zhao, Xia, Jin, Jia and Liu2018), and these are inadequate for us to explore the ancient human-environment relationships in the region.

As the key component of biodiversity, plant diversity plays a vital role in the conservation and sustainable growth of habitats around the world (Wilson and Ehrlich, Reference Wilson and Ehrlich1991; Pimm et al., Reference Pimm, Russell, Gittleman and Brooks1995; Thomas et al., Reference Thomas, Cameron, Green, Bakkenes, Beaumont, Collingham and Erasmus2004). Based on plant microfossils (pollen, phytoliths, starch granules), plant macrofossils (seeds, charcoal, wood), and biomarkers (aromatic hydrocarbons), it is possible to reconstruct the past vegetation composition, ancient agricultural evolution, and climate change (Piperno, Reference Piperno1988; Birks and Line, Reference Birks and Line1992; Shackleton and Prins, Reference Shackleton and Prins1992, Wang and Lu, Reference Wang and Lu1993; Piperno and Pearsall, Reference Piperno and Pearsall1998; Odgaard, Reference Odgaard1999; Jérémy et al., Reference Jérémy, Disnar, Arnaud, Chapron, Debret, Lallier, Desmet and Revel2008; Zhao, Reference Zhao2014; Matthias et al., Reference Matthias, Semmler and Giesecke2015; Chen et al., Reference Chen, Xu, Chen, Birks, Liu, Zhang and Jin2015a, Reference Chen, Dong, Zhang, Liu, Jia, An and Mab; Li et al., Reference Li, Gaillard, Cao, Herzschuh, Sugita, Tarasov and Wagner2020; Zhou et al., Reference Zhou, Yu, Spengler, Shen, Zhao, Ge and Bao2020). The investigation of ancient human-environment relationships requires a precise chronology of paleoclimate changes and human activities. However, there are often inconsistencies between the paleoclimate records obtained from sediments and the human activity records obtained from archaeological sites. For example, the lake and loess sediment records provide a large number of quantitative paleoclimate reconstructions (Chen et al., Reference Chen, Xu, Chen, Birks, Liu, Zhang and Jin2015a; Cao et al., Reference Cao, Tian, Telford, Ni, Xu, Chen, Liu, Stebich, Zhao and Herzschuh2017; Herzschuh et al., Reference Herzschuh, Cao, Laepple, Dallmeyer, Telford, Ni, Chen, Kong, Liu and Liu2019; Zhang et al., Reference Zhang, Li, Li, Xu, Zhang, Ge, Li, Deng, Li and Zhang2020), but due to the reservoir effect, it is difficult to obtain accurate chronological frameworks (Geyh et al., Reference Geyh, Schotterer and Grosjean1997; Christine et al., Reference Christine, Pessenda, Lang and Paterne2001; Stein et al., Reference Stein, Lazar and Goldstein2013, Long et al., Reference Long, Shen, Wang, Gao and Frechen2015).

First-hand paleoclimate records reconstructed from materials in archaeological sites are likely to help solve the age non-correspondence problems. Fortunately, since humans have been able to manipulate fire, large amounts of fossil charcoals remain in archaeological sites. Owing to the incomplete combustion of wood (McGinnes et al., Reference McGinnes, Szopa and Phelps1974), plenty of fossil charcoals that have retained their anatomical characteristics can be retrieved from the archaeological sites. In addition, reconstructions based on fossil charcoals are more responsive to local environmental conditions, owing to the immobility of large pieces of charcoal (Blackford, Reference Blackford2000). Furthermore, in prehistoric periods, human activities were likely confined to 5 km or 1 hour walking distance from the settlement (Shackleton and Prins, Reference Shackleton and Prins1992; Rodríguez, Reference Rodríguez2004; Fontenari et al., Reference Fontenari, Franceschetti, Sorrentino, Mussi, Pasolli, Napolitano and Flor2005; Li et al., Reference Li, Sun, Dodson, Zhou and Zhao2013). This also ensures that fossil charcoal, the by-product of human activities, reflects local scales of human-environment interactions (Vita-Finzi, Reference Vita-Finzi, Cooke and Johnson1969). Therefore, the fossil charcoals from archaeological sites were ideal materials for local vegetation reconstruction. They provide ideal materials for revealing paleo-vegetation, paleoclimate, and past human activities (Figueiral and Mosbrugger, Reference Figueiral and Mosbrugger2000; Cui et al., Reference Cui, Li, Hu, Yao and Li2002; Asouti and Austin, Reference Asouti and Austin2005; Asouti and Fuller, Reference Asouti and Fuller2008; Sun and Li, Reference Sun and Li2012; X. Li et al., Reference Li, Sun, Dodson, Zhou and Zhao2013; An et al., Reference An, Li, Dong, Chen, Zhao and Shi2014; Wang et al., Reference Wang, Wang, Wang, Liang, Qi and Ren2016; H. Li et al., Reference Li, An, Dong, Hu, Wang, Zhao, Yang and Yang2017; Liu et al., Reference Liu, Li, Cui, Yang, Lee, Ding, Hou and Dong2019a, Reference Liu, Yang, Shi, Storozum and Dongb). However, there have been only four cases of quantitative reconstructions of paleoclimate from fossil charcoals in western China (Sun and Li, Reference Sun and Li2012; Li et al., Reference Li, Sun, Dodson, Zhou and Zhao2013; N. Sun et al., Reference Sun, Li, Shang, Zhou and Dodson2014, Reference Sun N., Dodson J, Zhou and Yang2016; Wang et al., Reference Wang, Wang, Wang, Liang, Qi and Ren2016), and none located in eastern China, particularly in places where Chinese civilization originated, such as the Central Plain, the Haidai Region, and the West Liao River Basin.

The use of paleoenvironmental reconstructions based on fossil charcoal obtained from archaeological sites in the pivotal areas and periods of civilization origin is of great significance for exploring the environmental background and its influence on civilization. In this study, we reconstructed the vegetation and paleoclimate at the Erdaojingzi site using fossil charcoals. Combined with other archaeological materials unearthed from this site, we explored the ancient human-environment interactions in the West Liao River Basin (i.e., the eastern part of the agricultural-pastoral zone in northern China) during the Lower Xiajiadian period.

STUDY AREA

The Erdaojingzi site (119.08°N, 42.17°E, 617 m above sea level [a.s.l.]) is located in the Hongshan District to the southeast of Chifeng City, Inner Mongolia (Figure 1). Five thousand two hundred square meters were uncovered, and 305 archaeological features were unearthed, including city walls, surrounding ditches (moats), courtyards, house foundations, paths, cellars, ash pits and burials. In addition, the site contained 1000 excavated items filled with pottery wares, stone and bone implements, jades, and other artifacts (Cao et al., Reference Cao, Sun. and Dang2010). The excavation at the Erdaojingzi site provided sufficient materials to examine the human-environment relationships during a crucial stage of the origin of civilization.

Figure 1. (color online) Location of the Erdaojingzi site in Chifeng, Inner Mongolia, northeast China. (a) Map of China; (b) location of the Erdaojingzi site; (c) landscape of the Erdaojingzi site.

Chifeng is located in the southeast portion of Inner Mongolia, the eastern part of the farming-pastoral zone, in northeast China. This area also contains extensive loess accumulations, with loess tableland, hills, valleys, and other landform types. The West Liao River joins the upper branches of the Xar Moron River and the Laoha River (Figure 1), and feeds into the Liao River, ultimately flowing into the Bohai Sea. Uplift of the Great Khingan Mountains resulted in higher topography west of the West Liao River Basin. The average elevation ranges from 2833 m a.s.l. in the west to 280 m a.s.l. in the east, with mountains gradually giving way to hills and eventually to plains. The precipitation diminishes from the southeast (500 mm) to northwest (200 mm) owing to the characteristics of the East Asian monsoon, which likewise lessens from southeast to northwest (An et al., Reference An, Porter, Kutzbach, Wu, Wang, Liu, Li and Zhou2000). According to the meteorological data provided by the Chifeng Weather Station (http://data.cma.cn/), the average annual temperature is 7.8°C (with an annual extreme maximum and minimum temperature of 40.4 and −27.8°C, respectively), the average annual precipitation is 370 mm, and the average annual relative humidity is 50%. The temperate semi-humid and semi-arid continental monsoon climate promotes the vegetation of the temperate grassland in this area.

Today, shrub meadow dominates the vegetation around the Erdaojingzi site, which is situated in the Loess hills and lower hilly areas of southeastern Chifeng. The main shrubs include Lespedeza bicolor Turcz., Vitex negundo Linn., Ziziphus jujube var. spinose (Bunge) Hu, Hoppophae Linn., Armeniaca sibirica (Linn.) Lam., among others. Some sporadic trees are distributed on the shrub grassland, including Pinus tabularformis Carr., Ulmus pumila Linn., Sophora japonica Linn., and Populus Linn. (Local History Compilation Committee of Chifeng, 1996).

METHODS

Radiocarbon dating

Two carbonized seed samples collected from the archaeological sites were dated with accelerator mass spectrometry (AMS) by Beta Analytic in Miami, Florida, USA. The IntCal20 curve (Reimer et al., Reference Reimer, Austin, Bard, Bayliss, Blackwell, Bronk Ramsey and Butzin2020) and the Libby half-life of 5568 years were used in calculating all ages, with the calibration performed using the OxCal 4.4 program (https://c14.arch.ox.ac.uk/oxcal/OxCal.html). All ages reported are relative to AD 1950 (referred to as “cal yr BP”).

Plant flotation and fossil charcoal identification

The application of flotation and the identification of plant remains have greatly promoted the study of the subsistence strategies of prehistoric societies in recent years (Zhao, Reference Zhao2010). Eighty-four soil samples with a total volume of 405 liters were collected for flotation. Carbonized plant remains were obtained using a sieve with #80 mesh (aperture size of 0.2 mm) and then dried in the shade and sorted. Five thousand eight hundred eleven fossil charcoals were collected with a sieve with an aperture size of 2 mm. A metallographic microscope (Nikon LV150) was employed to identify the microstructure of the fossil charcoals using the cross, radial, and tangential sections, and the plant taxa were identified based on wood anatomy atlases (Cheng et al., Reference Cheng, Yang and Liu1992; Yao, Reference Yao1988). The fossil charcoals with obvious morphological characteristics were adhered to an aluminum sample stage and were overgilded on the sample surface by an ion-sputtering instrument. Then, they were scanned by a Quanta 650 electron microscope. Based on the results of the identification of the fossil charcoals, the percent abundance ratio and frequency of each taxon were calculated. All samples were identified in the Archaeobotany Laboratory, Institute of Archaeology, Chinese Academy of Social Sciences.

Quantitative reconstruction of the paleoclimate

The coexistence approach (CA) is based on the assumption that fossil plants have similar climatic requirements as their nearest living relative species. The CA provides a quantitative estimate of past climate by setting out the climatic tolerances of individual species, and then identifying the range of climatic conditions under which all species in a fossil assemblage could co-exist today (Mosbrugger and Utescher, Reference Mosbrugger and Utescher1997). The coexistence approach (CA) was employed to quantitatively reconstruct the paleoclimate in the Erdaojingzi site associated with the Lower Xiajiadian Culture. Based on the similar living environment of modern plants, the climatic tolerance ranges of every taxon of the fossil charcoals were derived from Fang et al. (Reference Fang, Wang and Tang2009), including the maximum and minimum of the mean annual temperature (MAT), mean annual precipitation (MAP), and index of moisture content in the soil (IM) (Fang and Yoda, Reference Fang and Yoda1990), respectively.

RESULTS

Radiocarbon dating

Systematic archaeological excavation confirmed that the Erdaojingzi site is an archaeological site that belongs in the Lower Xiajiadian period, and no remains indicate that it fits other periods (Cao et al., Reference Cao, Sun. and Dang2010). The age range of Lower Xiajiadian Culture is 3900–2800 cal yr BP, based on 32 radiocarbon dates in the West Liao River Basin (Jia et al., Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017). The two calibrated 14C ages of the Erdaojingzi site are within the range of 3600–3500 cal yr BP. The calibrated 14C ages from charcoals collected in the Erdaojingzi site are shown in Table 1.

Table 1. 14C dates from the Erdaojingzi site.

Fossil charcoals

Five thousand eight hundred eleven charcoal fragments were identified, and 21 different taxa were identified in 84 samples from the Erdaojingzi site (Fig. 2, Table 2). The three most abundant types of fossil charcoals made up 75.03% of the total, including Quercus (2031, 34.95%), Pinus (1477, 25.42%), and Ulmus (852, 14.66%). There were also seven types of fossil charcoals with more than 100 pieces, including Tilia (271, 4.66%), Populus (270, 4.65%), Betula (191, 3.29%), Amygdalus/Armeniaca (190, 3.27%), Phellodendron (159, 2.74%), Cotoneaster (128, 2.20%), and Salix (102, 1.76%). There were also seven types that appeared sporadically, including Acer (23, 0.40%), Ziziphus (19, 0.33%), Alnus (9, 0.15%), Koelreuteria (3, 0.05%), Rhamnus (3, 0.05%), Fraxinus (2, 0.03%), and Ostrya (1, 0.02%). Four different types of fossil charcoals could not be identified.

Figure 2. Microstructures of charcoal from the Erdaojingzi site; (g) and (n) are tangential sections, others are cross-sections. (a) Acer sp.; (b, c) Amygdalus sp./Armeniaca sp.; (d) Betula sp.; (e) Cotoneaster sp.; (f) Ostrya sp.; (g) Phellodendron sp.; (h) Pinus sp.; (i) Populus sp.; (j, k) Quercus sp.; (l) Salix sp.; (m) Ulmus sp.; (n) Ziziphus sp.; (o) unknown 4.

Table 2. The fossil charcoal assemblages from the Erdaojingzi site.

With the exception of Pinus, a temperate evergreen conifer, most of the woody plants in China are broad-leaved deciduous taxa, including Quercus, Ulmus, Tilia, Populus, Betula, Amygdalus, Armeniaca, Phellodendron, Cotoneaster, Salix, Acer, Ziziphus, Alnus, Koelreuteria, Rhamnus, Fraxinus, and Ostrya (Wu, Reference Wu1980). Thus, the fossil charcoal assemblage at Erdaojingzi indicates the presence of temperate deciduous and mixed conifer-broadleaved forests ca. 3500 cal yr BP, distinct from the shrub meadow vegetation found there today.

Quantitative reconstruction of paleoclimate

The climatic factors were obtained by applying CA based on 21 fossil charcoal taxa from the Erdaojingzi site (Table 3). The results indicated that MAT was 2.0–13.8°C, MAP was 471–1073 mm, and IM was -28.7–74.1 (Fig. 3).

Figure 3. Coexistence intervals for the Erdaojingzi site (shadow represents the overlapping climate range, dotted line represents the modern climate in the areas).

Table 3. The climate ranges (from Fang et al., Reference Fang, Wang and Tang2009) of individual plant taxa in the Erdaojingzi site.

DISCUSSION

Paleovegetation and paleoclimate

Because plant species have particular climate tolerances (Thornthwaite, Reference Thornthwaite1948; Fang and Yoda, Reference Fang and Yoda1990; Wang, Reference Wang1992), plant composition from sedimentary records or archaeobotanical assemblages can indicate climate history (Piperno, Reference Piperno1988; Birks and Line, Reference Birks and Line1992; Shackleton and Prins, Reference Shackleton and Prins1992; Wang and Lu, Reference Wang and Lu1993; Odgaard, Reference Odgaard1999; Matthias et al., Reference Matthias, Semmler and Giesecke2015; Chen et al., Reference Chen, Xu, Chen, Birks, Liu, Zhang and Jin2015a; Cao et al., Reference Cao, Tian, Telford, Ni, Xu, Chen, Liu, Stebich, Zhao and Herzschuh2017; Xu et al., Reference Xu, Liu, Sun, Chen, Cheng and Chen2017; Li et al., Reference Li, Gaillard, Cao, Herzschuh, Sugita, Tarasov and Wagner2020). Pollen-based vegetation and climate reconstructions typically reflect the paleoenvironmental conditions in a wide area due to the long distance of pollen dispersion (Xu et al., Reference Xu, Li, Zhang, Zhang, Zhang and Lu2015). The pollen of herbaceous plants dominated the pollen assemblage (60–80%) from the Wangxianggou profile in this area during the Lower Xiajiadian period, including Artemisia, Chenopodiaceae, and Fagopyrum (Li et al., Reference Li, Wilis, Zhou and Cui2006). Furthermore, 30% of the area was covered with woody plants (Li et al., Reference Li, Gaillard, Cao, Herzschuh, Sugita, Tarasov and Wagner2020), including temperate broadleaved trees such as Quercus, Ulmus, Betula, Juglans, Alnus, Castanea, Celtis, Anacardiaceae, Pterocarya, Tilia, and Salix, and temperate coniferous trees such as Pinus (Li et al., Reference Li, Wilis, Zhou and Cui2006). However, there are some differences in pollen assemblage between the archaeological sites and the natural profiles. A large number of pollen specimens in the Dadianzi and Chengzishan sites in the Lower Xiajiadian period were identified as Pinus (Kong et al., Reference Kong, Du, Liu, Yang and Zhou1991; Zhao et al., Reference Zhao, Li, Shang, Zhou and Sun2009). Our pollen records, which were obtained from the natural sand-dune profiles in the West Liao River Basin, indicated that temperate grassland was the dominant vegetation in this area during the Lower Xiajiadian period (Jia et al., Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017). Such a difference may be attributable to secondary accumulation in the archaeological strata.

Fortunately, the woody plants that were completely recovered by the fossil charcoals obtained from the Erdaojingzi site can make up for the deficiency of pollen in grassland vegetation. There were 21 different woody plants growing near the Erdaojingzi site ca. 3500 cal yr BP, including Quercus, Pinus, Ulmus, Tilia, Populus, Betula, Phellodendron, Amygdalus/Armeniaca, Cotoneaster, Salix, Acer, Ziziphus, Alnus, Koelreuteria, Rhamnus, Fraxinus, Ostrya, and four unknown plants (Table 2). However, six species of woody plants that were found in this area 3500 cal yr BP are not distributed here today, including Phellodendron, Cotoneaster, Alnus, Koelreuteria, Fraxinus, and Ostrya. Three types of woody plants probably were the dominant species, including Quercus (34.95%), Pinus (25.42%), and Ulmus (14.66%). Seven other woody plants probably appeared around the site because their percent abundance ratio all exceed 1%, including Populus (4.65%), Amygdalus/Armeniaca (3.27%), Cotoneaster (2.20%), Betula (3.29%), Salix (1.76%), Tilia (4.66%), and Phellodendron (2.74%). Also, some woody plants appeared sporadically, as indicated by their small amount of charcoal remains, such as Acer (0.40%), Ziziphus (0.33%), Alnus (0.15%), Koelreuteria (0.05%), Rhamnus (0.05%), Fraxinus (0.03%), and Ostrya (0.02%). The unearthed percent ubiquity refers to the percentage of a specific taxon of charcoal in all samples. It was employed to reflect the combination of woody vegetation around the site in the corresponding period (Salisbury and Jane, Reference Salisbury and Jane1940). As reflected by both the percentage of absolute number and unearthed percent ubiquity, Quercus (34.95%, 86.3%) and Ulmus (14.66%, 64.38%) were likely to be the dominant woody plants distributed around the Erdaojingzi site ca. 3500 cal yr BP. Most woody plants are temperate broad-leaved deciduous taxa, except the evergreen coniferous plants of Pinus.

Therefore, the assemblages of fossil charcoal at the Erdaojingzi sites reflected that temperate deciduous and mixed conifer-broadleaved forests were found near the site ca. 3500 cal yr BP. Similar vegetation types occur in the middle and lower mountain areas in the Songnen Plain and the Liaohe Plain, as well as the low-elevation area of the Changbai Mountains in the east nowadays (Wu, Reference Wu1980).

Almost all climate records from soil/sand-dune profiles (Ren, Reference Ren1998; Xia et al., Reference Xia, Deng and Wu2000; Jin and Liu, Reference Jin and Liu2001; Xu et al., Reference Xu, Yang, Cui, Yang and Liang2002; Yang et al., Reference Yang, Wang, Zhou, Lai and Long2012; Zhao et al., Reference Zhao, Xia, Jin, Jia and Liu2018; Xue et al., Reference Xue, Jin, Liu, Sun and Liu2020), lakes (Li et al., Reference Li, Wilis, Zhou and Cui2006), and archaeological samples (Kong et al., Reference Kong, Du, Liu, Yang and Zhou1991) indicated a wet climate in the West Liao River Basin ca. 3500 BP. Because previous studies only qualitatively describe the climate in our study area, we made an attempt to use fossil charcoals obtained from the Erdaojingzi site to reconstruct the past climate. Based on CA, the MAT ca. 3500 cal yr BP was 7.9 ± 5.9°C, which is very similar to the present one (7.8°C), while MAP was almost halved, from 772 ± 301 mm at ca. 3500 cal yr BP to 370 mm currently (Fig. 3). Also, the moisture index reduced sharply from 22.7 ± 51.4 at ca. 3500 cal yr BP (Fig. 3) to −30 ± 10 nowadays (Fang et al., Reference Fang, Wang and Tang2009). The charcoal assemblage at the Erdaojingzi site indicated a relatively wetter climate for the temperate zone in the West Liao River Basin. This echoes previous results about the past climate in our study area (Ren, Reference Ren1998; Xia et al., Reference Xia, Deng and Wu2000; Jin and Liu, Reference Jin and Liu2001; Xu et al., Reference Xu, Yang, Cui, Yang and Liang2002; Li et al., Reference Li, Wilis, Zhou and Cui2006; Yang et al., Reference Yang, Wang, Zhou, Lai and Long2012; Zhao et al., Reference Zhao, Xia, Jin, Jia and Liu2018; Xue et al., Reference Xue, Jin, Liu, Sun and Liu2020). The past forest was dominated by temperate deciduous and mixed conifer-broadleaved species, such as Quercus, Pinus, and Ulmus.

Human utilization of wood resources

Timber is one of the main resources for humans and is closely related to human activities identified by archaeological remains (Shackleton and Prins, Reference Shackleton and Prins1992). There were four main purposes for human utilization of woody plant resources: building materials, making tools, fuelwood, and food. In addition to being used as firewood, almost all woody plants in the Erdaojingzi site could be utilized as construction and tool-making materials.

Archaeobotanical studies of carbonized seeds have shown that ancient people were engaged in dry farming of predominantly foxtail millet at the Erdaojingzi site (Y. Sun et al., Reference Sun, Zhao, Cao, Sun and Dang2014). Apart from agriculture, fossil charcoals indicate that local people may also have engaged in some gathering activities (Y. Sun et al., Reference Sun, Zhao, Cao, Sun and Dang2014). Four woody plants have also been used as food today, including Quercus, Ulmus, Amygdalus/Armeniaca, and Ziziphus. Quercus probably was dominant in the gathering, comprising the most fossil charcoals identified from the Erdaojingzi site (Table 2). Acorns, which are the nuts of Quercus, are considered to be an important component of gathering because they were often found in the archaeological sites of China (Zhao, Reference Zhao2006; Fuller et al., Reference Fuller, Harvey and Qin2007; Sun et al., Reference Sun, Huang and Zheng2007; Yang et al., Reference Yang, Yu, Lü, Cui, Guo and Ge2009; Fuller and Qin, Reference Fuller and Qin2010; Ma et al., Reference Ma, Yang, Zhang, Sun and Jia2016). The acorns also have been processed by humans since the Neolithic Age in the West Liao River Basin (Ma et al., Reference Ma, Yang, Zhang, Sun and Jia2016), and were probably chosen as a useful supplement for food resources in the Erdaojingzi site due to their rich starch content. The second-largest number of fossil charcoals comes from Ulmus. Owing to the edibility of the tender leaves, Ulmus could provide a certain amount of food resources in the spring when food is relatively scarce. Utilization of the leaves of Ulmus was also reflected by a clay pot discovered at the Shigu site in Henan (Xu, Reference Xu1996). Apart from serving as primary food resources, some fruit-bearing woody plants were selected as supplementary food sources in ancient times, such as Amygdalus/Armeniaca and Ziziphus (42.47% and 9.59% of the unearthed percent ubiquity, respectively).

Implications for Lower Xiajiadian Culture

The relatively wet climate may represent a warm temperate humid climate in the West Liao River Basin ca. 3500 cal yr BP, which is significantly different from the middle temperate semi-humid and semi-arid climate today. Climate change has not only caused the transition of regional forest grassland vegetation ca. 3500 cal yr BP to today's retama bushland vegetation, but also facilitated the significant development of rain-fed agriculture. The main subsistence strategies transformed from a mixture of multiple survival patterns during the Neolithic Age (before 4000 cal yr BP) (Jia et al., Reference Jia, Lee, Zhang, Wang, Sun, Zhao, Yi, Huang and Lu2016b, Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017) to millet-dominated agriculture during the Lower Xiajiadian period (Zhao et al., Reference Zhao, Li, Shang, Zhou and Sun2009; Y. Sun et al., Reference Sun, Zhao, Cao, Sun and Dang2014; Jia et al., Reference Jia, Sun, Wang, Sun, Zhao, Lee, Huang, Wu and Lu2016a, Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017). Developed agriculture provided stable food resources for human beings, promoted the emergence of large settlements, such as Sanzuodian and Erdaojingzi (Cao et al., Reference Cao, Sun. and Dang2010; Shelach et al., Reference Shelach, Raphael and Jaffe2011), and further facilitated the birth of advanced civilization. However, good times did not last long: the 500 year cycle of climate deterioration destroyed the agricultural system in the West Liao River Basin after 3500 BP (Jia et al., Reference Jia, Sun, Wang, Sun, Zhao, Lee, Huang, Wu and Lu2016a, Reference Jia, Yi, Sun, Wu, Lee, Wang and Lu2017; Xu et al., Reference Xu, Lu, Chu, Liu, Shen, Li, Wang and Wu2019). Subject to the influence of the East Asian summer monsoon, the precipitation gradually decreased from the southeast to the northwest. The agricultural groups of the Lower Xiajiadian Culture probably followed the precipitation change and migrated southward to the North China Plain, then moved southward and integrated with the cultural system in central China.

CONCLUSION

The fossil charcoals indicate that temperate deciduous and mixed conifer-broadleaved forests were the dominant vegetation near the Erdaojingzi site at ca. 3500 cal yr BP. The three major woody plants discovered are Quercus, Pinus, and Ulmus, representative species of the warm temperate forest-steppe.

In addition to the use of woody plants for building materials, making tools, and fuel, there were four woody plants that probably supplied food for ancient humans in the Erdaojingzi site. The nuts of some woody plants such as Quercus were taken as staple foods because of their rich starch or cellulose content. The tender leaves of Ulmus might have served as supplementary food sources for humans in spring when food was relatively scarce. The other two woody plants, namely Amygdalus/Armeniaca and Ziziphus, probably provided fruits to humans.

The CA results of the quantitative reconstruction indicate that MAT was 7.9 ± 5.9°C and MAP was 772 ± 301 mm. The past environment was significantly wetter than that today. The wet climate facilitated significant development of rain-fed agriculture, the emergence of large settlements such as Sanzuodian and Erdaojingzi, and the birth of advanced civilization. Also, subject to the influence of the East Asian summer monsoon, precipitation change likely caused the agricultural groups of the Lower Xiajiadian Culture to migrate southward to the North China Plain, and then to move southward and integrate with the cultural system in central China.

ACKNOWLEDGMENTS

This research was supported by the National Social Science Foundation of China (Grant Nos. 17BKG031) and the National Natural Science Foundation of China (Grant Nos. 41771223).

References

REFERENCES

An, C.B., Li, H., Dong, W.M., Chen, Y.F., Zhao, Y.T., Shi, C., 2014. How prehistoric humans use plant resources to adapt to environmental change: a case study in the western Chinese Loess Plateau during Qijia Period. The Holocene 24, 512–517.CrossRefGoogle Scholar
An, C.B., Tang, L.Y., Barton, L., Chen, F.H., 2005. Climate change and cultural response around 4000 cal yr BP in the western part of Chinese Loess Plateau. Quaternary Research 63, 347–352.CrossRefGoogle Scholar
An, Z.S., Porter, S.C., Kutzbach, J.E., Wu, X.H., Wang, S.M., Liu, X.D., Li, X.Q., Zhou, W.J., 2000. Asynchronous Holocene optimum of the East Asian monsoon. Quaternary Science Reviews 19, 743–762.CrossRefGoogle Scholar
Asouti, E., Austin, P., 2005. Reconstructing woodland vegetation and its exploitation by past societies, based on the analysis and interpretation of archaeological wood charcoal macro-fossils. Environmental Archaeology 10, 1–18.CrossRefGoogle Scholar
Asouti, E., Fuller, D.Q., 2008. Trees and Woodlands of South India: Archaeological Perspectives. Left Coast Press, Walnut Creek, California.Google Scholar
Birks, H.J.B., Line, J.M., 1992. The use of Rarefaction Analysis for estimating palynological richness from Quaternary pollen-analytical data. The Holocene 2, 1–10.CrossRefGoogle Scholar
Blackford, J.J., 2000. Charcoal fragments in surface samples following a fire and the implications for interpretation of subfossil charcoal data. Palaeogeography, Palaeoclimatology, Palaeoecology, 164, 33–42.CrossRefGoogle Scholar
Butzer, K.W., 2012. Collapse, environment, and society. Proceedings of the National Academy of Sciences 109, 3632–3639.CrossRefGoogle ScholarPubMed
Cao, J.N., Sun., J.S., Dang, Y., 2010. Excavation on the Erdaojingzi site in Chifeng, Inner Mongolia. Archaeology, 103–105.Google Scholar
Cao, X., Tian, F., Telford, R.J., Ni, J., Xu, Q., Chen, F., Liu, X., Stebich, M., Zhao, Y., Herzschuh, U., 2017. Impacts of the spatial extent of pollen-climate calibration-set on the absolute values, range and trends of reconstructed Holocene precipitation. Quaternary Science Reviews 178, 37–53.CrossRefGoogle Scholar
Chen, F.H., Dong, G.H., Zhang, D.J., Liu, X.Y., Jia, X., An, C.B., Ma, M.M., et al. , 2015b. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P. Science 347, 248–250.CrossRefGoogle Scholar
Chen, F.H., Xu, Q.H., Chen, J.H., Birks, H.J.B., Liu, J.B., Zhang, S.R., Jin, L.Y., et al. ., 2015a. East Asian summer monsoon precipitation variability since the last deglaciation. Scientific Reports 5: 11186. https://doi.org/10.1038/srep11186.Google Scholar
Cheng, J.Q., Yang, J.J., Liu, P., 1992. China Timber Atlas. China Forest Publishing House, Beijing.Google Scholar
Chen, Z.Y., Wang, Z.H., Schneiderman, J., Tao, J., Cai, Y.L., 2005. Holocene climate fluctuations in the Yangtze delta of eastern China and the Neolithic response. The Holocene, 915–924.CrossRefGoogle Scholar
Christine, H., Pessenda, L., Lang, A., Paterne, M., 2001. Development of accurate and reliable 14C chronologies for loess deposits: application to the loess sequence of Nussloch (Rhine Valley, Germany). Radiocarbon 43, 611–618.Google Scholar
Cui, H.T., Li, Y.Y., Hu, J.M., Yao, X.S., Li, Y., 2002. Vegetation reconstruction of Bronze Age by using microscopic structure of charcoals. Chinese Science Bulletin 47, 2014–2017.CrossRefGoogle Scholar
Cullen, H.M., Demenocal, P.B., Hemming, S., Hemming, G., Brown, F.H., Guilderson, T., Sirocko, F., 2000. Climate change and the collapse of the Akkadian empire: evidence from the deep sea. Geology 28, 379–382.2.0.CO;2>CrossRefGoogle Scholar
deMenocal, P.B., 2001. Cultural responses to climate change during the Late Holocene. Science 292, 667–673.CrossRefGoogle ScholarPubMed
Fang, H., 1998. The stage and age of the Yueshi Culture. Archaeology, 343–359. [in Chinese]Google Scholar
Fang, J.Y., Wang, Z.H., Tang, Z.Y., 2009. Atlas of Woody Plants in China. Higher Education Press, Beijing. [in Chinese]Google Scholar
Fang, J.Y., Yoda, K., 1990. Climate and vegetation in China III water balance and distribution of vegetation. Ecological Research 5, 9–23.CrossRefGoogle Scholar
Figueiral, I., Mosbrugger, V., 2000. A review of charcoal analysis as a tool for assessing Quaternary and Tertiary environments: achievements and limits. Palaeogeography, Palaeoclimatology, Palaeoecology, 164, 397–407.CrossRefGoogle Scholar
Fontenari, S., Franceschetti, S., Sorrentino, D., Mussi, F., Pasolli, M., Napolitano, M., Flor, R., 2005. r. walk. GRASS GIS Computer Program. http://grass.fbk.eu/grass62/manuals/html62_user/r.walk.html.Google Scholar
Fuller, D.Q., Harvey, E., Qin, L., 2007. Presumed domestication? Evidence for wild rice cultivation and domestication in the fifth millennium BC of the Lower Yangzte region. Antiquity 81, 316–331.CrossRefGoogle Scholar
Fuller, D.Q., Qin, L., 2010. Declining oaks, increasing artistry, and cultivating rice: the environmental and social context of the emergence of farming in the Lower Yangtze Region. Environmental Archaeology 15, 139–159.CrossRefGoogle Scholar
Geyh, M.A., Schotterer, U., Grosjean, M., 1997. Temporal changes of the 14C reservoir effect in lakes. Radiocarbon 40, 921–931.CrossRefGoogle Scholar
Guo, L.C., Xiong., S.F., Ding, Z.L., Jin, G.Y., Wu, J.B., Ye, W., 2018a. Role of the mid-Holocene environmental transition in the decline of late Neolithic cultures in the deserts of NE China. Quaternary Science Reviews 190, 98–113.CrossRefGoogle Scholar
Guo, L.C., Xiong, S.F., Yang, P., Ye, W., Jin, G.W., Wu, W.W., Zhao, H., 2018b. Holocene environmental changes in the Horqin desert revealed by OSL dating and δ13C analyses of paleosols. Quaternary International 469, 11–19.CrossRefGoogle Scholar
Herzschuh, U., Cao, X., Laepple, T., Dallmeyer, A., Telford, R.J., Ni, J., Chen, F., Kong, Z., Liu, G., Liu, K.-B., 2019. Position and orientation of the westerly jet determined Holocene rainfall patterns in China. Nature Communications 10, 1–8.CrossRefGoogle ScholarPubMed
Hsiang, S.M., Burke, M., Miguel, E., 2013. Quantifying the influence of climate on human conflict. Science 341, 1235367. https://doi.org/10.1126/science.1235367.CrossRefGoogle ScholarPubMed
Jérémy, J., Disnar, J.R., Arnaud, F., Chapron, E., Debret, M., Lallier, V.E., Desmet, M., Revel, R.M., 2008. Millet cultivation history in the French Alps as evidenced by a sedimentary molecule. Journal of Archaeological Science 35, 814–820.Google Scholar
Jia, X., Lee, H.F., Zhang, W.C., Wang, L., Sun, Y.G., Zhao, Z.J., Yi, S.W., Huang, W.B., Lu, H.Y., 2016b. Human-environment interactions within the West Liao River Basin in Northeastern China during the Holocene Optimum. Quaternary International 426, 10–17.CrossRefGoogle Scholar
Jia, X., Sun, Y.G., Wang, L., Sun, W.F., Zhao, Z.J., Lee, H.F., Huang, W.B., Wu, S.Y., Lu, H.Y., 2016a. The transition of human subsistence strategies in relation to climate change during the Bronze Age in the West Liao River Basin, Northeast China. The Holocene 26, 781–789.CrossRefGoogle Scholar
Jia, X., Yi, S.W., Sun, Y.G., Wu, S.Y., Lee, H.F., Wang, L., Lu, H.Y., 2017. Spatial and temporal variations in prehistoric human settlement and their influencing factors on the south bank of the Xar Moron River, Northeastern China. Frontiers of Earth Science 11, 137–147.CrossRefGoogle Scholar
Jin, G.Y., Liu, T.S., 2001. Mid-Holocene climate change in North China, and the effect on cultural development. Chinese Science Bulletin 47, 408–413.CrossRefGoogle Scholar
Jones, M.K., Liu, X.Y., 2009. Origins of Agriculture in East Asia. Science 324, 730–731.CrossRefGoogle ScholarPubMed
Kong, Z.C., Du, N.Q., Liu, G.M., Yang, H., 1991. A preliminary study on environmental archaeology in Inner Mongolia Autonomous Region from 8000–2400 BP. In: Zhou, K.S. (Ed.), Research on Environmental Archaeology (1st series). Science Press, Beijing, 112–119. [in Chinese]Google Scholar
Lawler, A., 2007. Climate spurred Later Indus decline. Science 316, 978–979.Google ScholarPubMed
Lawler, A., 2009. Beyond the Yellow River: how China became China. Science 325, 930–933, 935.CrossRefGoogle ScholarPubMed
Li, F.R., Gaillard, M.J., Cao, X.Y., Herzschuh, U., Sugita, S., Tarasov, P.E., Wagner, M., et al. ., 2020. Towards quantification of Holocene anthropogenic land-cover change in temperate China: a review in the light of pollen-based REVEALS reconstructions of regional plant cover. Earth-Science Reviews 203, 103119. https://doi.org/10.1016/j.earscirev.2020.103119.CrossRefGoogle Scholar
Li, H., An, C.B., Dong, W.M., Hu, W., Wang, Z.Y., Zhao, S.Z., Yang, X.Y., Yang, Y.S., 2017. Woodland vegetation composition and prehistoric human fuel collection strategy at the Shannashuzha site, Gansu Province, northwest China, during the middle Holocene. Vegetation History and Archaeobotany 26, 213–221.CrossRefGoogle Scholar
Liu, F.W., Li, H.M., Cui, Y.F., Yang, Y.S., Lee, H.F., Ding, D.T., Hou, Y.G., Dong, G.H., 2019a. Chronology and plant utilization from the earliest walled settlement in the Hexi Corridor, northwestern China. Radiocarbon 61, 971–989.CrossRefGoogle Scholar
Liu, F.W., Yang, Y.S., Shi, Z.L., Storozum, M.J., Dong, G.H., 2019b. Human settlement and wood utilization along the mainstream of Heihe River basin, northwest China in historical period. Quaternary International 516, 141–148.CrossRefGoogle Scholar
Li, X.Q., Sun, N., Dodson, J., Zhou, X.Y., and Zhao, K.L., 2013. The vegetation characteristics in the Western Loess Plateau during the mid-Holocene, based on charcoal fossils. Vegetation History and Archaeobotany 22, 61–70.CrossRefGoogle Scholar
Li, Y.Y., Wilis, K.J., Zhou, L.P., Cui, H.T., 2006. The impact of ancient civilization on the northeastern Chinese landscape: palaeoecological evidence from the Western Liaohe River Basin, Inner Mongolia. The Holocene 16, 1109–1121.CrossRefGoogle Scholar
Local History Compilation Committee of Chifeng, 1996. City Annals of Chifeng. People's Publishing House of Inner Mongolia, Hohhot 429. [in Chinese]Google Scholar
Long, H., Shen, J., Wang, Y., Gao, L., Frechen, M., 2015. High-resolution OSL dating of a late Quaternary sequence from Xingkai Lake (NE Asia): chronological challenge of the “MIS 3a Mega-paleolake” hypothesis in China. Earth and Planetary Science Letters 428, 281–292.CrossRefGoogle Scholar
Matthias, I., Semmler, M.S.S., Giesecke, T., 2015. Pollen diversity captures landscape structure and diversity. Journal of Ecology 103, 880–890.CrossRefGoogle Scholar
Ma, Z.K., Yang, X.Y., Zhang, C., Sun, Y.G., Jia, X. 2016. Early millet use in West Liaohe area during early-middle Holocene. Science China Earth Sciences 59(8), 1554–1561.CrossRefGoogle Scholar
McGinnes, E.A., Szopa, P.S., Phelps, J.E., 1974. Use of Scanning Electron Microscopy in Studies of Wood Charcoal Formation. Scanning Electron Microscopy/1974, Proceedings of the Workshop on Scanning Electron Microscope and the Plant Sciences. ITT Research Institute, Chicago, pp. 469–476.Google Scholar
Mosbrugger, V., Utescher, T., 1997. The coexistence approach-a method for quantitative reconstructions of Tertiary terrestrial palaeoclimate data using plant fossils. Palaeogeography, Palaeoclimatology, Palaeoecology 134, 61–86.CrossRefGoogle Scholar
Mu, Y., Qin, X., Zhang, L., Xu, B., 2016. Holocene climate change evidence from high-resolution loess/paleosol records and the linkage to fire-climate change-human activities in the Horqin dunefield in northern China. Journal of Asian Earth Sciences 121, 1–8.CrossRefGoogle Scholar
Odgaard, B.V., 1999. Fossil pollen as a record of past biodiversity. Journal of Biogeography 26, 7–17.CrossRefGoogle Scholar
Perry, C.A., Hsu, K.J., 2000. Geophysical, archaeological, and historical evidence support a solar-output model for climate change. Proceedings of the National Academy of Sciences 97, 12433–12438.CrossRefGoogle ScholarPubMed
Pimm, S.L., Russell, G.J., Gittleman, J.L., Brooks, T.M., 1995. The future of biodiversity. Science 269, 347–350.CrossRefGoogle ScholarPubMed
Piperno, D.R., 1988. Phytolith Analysis: An Archaeological and Geological Perspective. Academic Press, San Diego, 280 pp.Google Scholar
Piperno, D.R., Pearsall, D.M., 1998. The Origin of Agriculture in the Lowland Neotropics. Academic Press, San Diego, 400 pp.Google Scholar
Reimer, P.J., Austin, W.E.N., Bard, E., Bayliss, A., Blackwell, P.G., Bronk Ramsey, C., Butzin, M., et al. , 2020. The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0–55 kcal BP). Radiocarbon 62, 725–757.CrossRefGoogle Scholar
Ren, G.Y., 1998. Pollen evidence for increased summer rainfall in the medieval warm period at Maili, northeast China. Geophysical Research Letters 25, 1931–1934.CrossRefGoogle Scholar
Rodríguez, M.F., 2004. Woody plant resources in the southern Argentine Puna: Punta de la Pena 9 archaeological site. Journal of Archaeological Science 31, 1361–1372.CrossRefGoogle Scholar
Salisbury, E.J., Jane, F.W., 1940. Charcoals from Maiden Castle and their significance in relation to the vegetation and climatic conditions in prehistoric times. The Journal of Ecology 28, 310–325.CrossRefGoogle Scholar
Shackleton, C.M., Prins, F., 1992. Charcoal analysis and the “Principle of least effort”—a conceptual model. Journal of Archaeological Science 19, 631–637.CrossRefGoogle Scholar
Shelach, G., 1994. Social complexity in North China during the Early Bronze Age: a comparative study of the Erlitou and Lower Xiajiadian cultures. Asian Perspectives 33, 261–292.Google Scholar
Shelach, G., Raphael, K., Jaffe, Y., 2011. Sanzuodian: the structure, function and social significance of the earliest stone fortified sites in China. Antiquity 85, 11–26.CrossRefGoogle Scholar
Staubwasser, M., Sirocko, F., Grootes, P.M., Segl, M., 2003. Climate change at the 4.2 ka BP termination of the Indus valley civilization and Holocene South Asian monsoon variability. Geophysical Research Letters 30, 1425. https://doi.org/10.1029/2002GL016822.CrossRefGoogle Scholar
Stein, M., Lazar, B., Goldstein, S.L., 2013. Radiocarbon reservoir ages as freshwater-brine monitors in Lake Lisan, Dead Sea system. Radiocarbon 55, 1050–1057. https://doi.org/10.1017/S0033822200058185.CrossRefGoogle Scholar
Sun, G.P., Huang, W.J., Zheng, Y.F., 2007. Excavation report of the Neolithic Tianluoshan Site in Yuyao City, Zhejiang Province, in 2004. Cultural Relics, 5–24. [in Chinese]Google Scholar
Sun N., Li, Dodson J, X.Q.., Zhou, X.Y., Yang, Q., 2016. The quantitative reconstruction of temperature and precipitation in the Guanzhong Basin of the southern Loess Plateau between 6200 BP and 5600 BP. The Holocene 26, 1200–1207.CrossRefGoogle Scholar
Sun, N., Li, X.Q., 2012. The quantitative reconstruction of the palaeoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. Climate of the Past 8, 625–636.CrossRefGoogle Scholar
Sun, N., Li, X.Q., Shang, X., Zhou, X.Y., Dodson, J., 2014. Vegetation characteristics and palaeoclimate of Xiahe site in the southern Loess Plateau during the mid-Holocene based on fossil charcoal records. Quaternary Science 34, 27–34. [in Chinese, with English abstract]Google Scholar
Sun, Q.L., Liu, Y., Wünnemann, B., Peng, Y.J., Jiang, X.Z., Deng, L.J., Chen, J., Li, M.T., Chen, Z.Y., 2019. Climate as a factor for Neolithic cultural collapses approximately 4000 years BP in China. Earth-Science Reviews 197, 102915. https://doi.org/10.1016/j.earscirev.2019.102915.CrossRefGoogle Scholar
Sun, Y.G., Zhao, Z.J., Cao, J.E., Sun, J.S. Dang, Y., 2014. Report of the 2009 flotation results at Erdaojingzi site, Inner Mongolia. Agricultural Archaeology 34, 1–9. [in Chinese]Google Scholar
Thomas, C.D., Cameron, A., Green, R.E., Bakkenes, M., Beaumont, L.J., Collingham, Y.C., Erasmus, B.F.N., et al. , 2004. Extinction risk from climate change. Nature 427, 145–148.CrossRefGoogle ScholarPubMed
Thornthwaite, C.W., 1948. An approach toward a rational classification of climate. Geographical Review 38, 55–94.CrossRefGoogle Scholar
Vita-Finzi, F.C., 1969. Early man and environment. In: Cooke, R.U., Johnson, J.H. (Eds.), Trends in Geography—An Introductory Survey. Pergamon, Oxford, pp. 102–109.CrossRefGoogle Scholar
Wang, H.S., 1992. Floristic Plant Geography. Science Press, Beijing. [in Chinese]Google Scholar
Wang, S.Z., Wang, Q.Q., Wang, Z.X., Liang, G.J., Qi, W.U., Ren, X.Y., 2016. Timber utilization and ecological environment indicated by the charcoal remains in Jinchankou site during the mid-late period of the Qijia Period. Agricultural Archaeology 143, 19–25. [in Chinese]Google Scholar
Wang, W., 2004. A study on the causes of the wide range cultural changes in China around 2000 B.C. Archaeology, 67–77. [in Chinese]Google Scholar
Wang, Y.J., Lu, H.Y., 1993. The Study of Phytolith and Its Application. China Ocean Press, Beijing, 228 pp. [in Chinese]Google Scholar
Weiss, H., Courty, M.A., Wetterstrom, W., Guichard, F., Senior, L., Meadow, R., Curnow, A., 1993. The genesis and collapse of third millennium north Mesopotamian civilization. Science 261, 995–1004.CrossRefGoogle ScholarPubMed
Wilson, E.O., Ehrlich, P.R., 1991. Biodiversity studies: science and policy. Science 253, 758–762.Google Scholar
Wu, L., Zhu, C., Zheng, C.G., Li, F., Wang, X.H., Li, L., Sun, W., 2014. Holocene environmental change and its impacts on human settlement in the Shanghai Area, East China. Catena 114, 78–89.CrossRefGoogle Scholar
Wu, W.X., Liu, T.S., 2004. Possible role of the “Holocene Event 3” on the collapse of Neolithic cultures around the Central Plain of China. Quaternary International 117, 153–166.Google Scholar
Wu, Z., 1980. The Vegetation of China. Science Press, Beijing. [in Chinese]Google Scholar
Xia, Z.K., Deng, H., Wu, H.L., 2000. Geomorphologic background of the prehistoric culture evolution in the Xar Moron River Basin, Inner Mongolia. Acta Geographica Sinica 55, 329–336. [in Chinese with English abstract]Google Scholar
Xu, D.K., Lu, H.Y., Chu, G.Q., Liu, L., Shen, C.M., Li, F.J., Wang, C., Wu, N.Q., 2019. Synchronous 500-year oscillations of monsoon climate and human activity in Northeast Asia. Nature Communications 10, 1–10.CrossRefGoogle ScholarPubMed
Xu, L.C., Liu, Y., Sun, Q.L., Chen, J., Cheng, P., Chen, Z.Y., 2017. Climate change and human occupations in the Lake Daihai basin, north-central China over the last 4500 years: a geo-archeological perspective. Journal of Asian Earth Science 138, 367–377.CrossRefGoogle Scholar
Xu, Q.H., Li, M.Y., Zhang, S.R., Zhang, Y.H., Zhang, P.P., Lu, J.Y., 2015. Modern pollen processes of China: progress and problems. Scientia Sinica Terrae 58, 1661–1682. [in Chinese]Google Scholar
Xu, Q.H., Yang, Z.J., Cui, Z.J., Yang, X.L., Liang, W.D., 2002. A study on pollen analysis of Qiguoshan section and ancestor living environment in Chifeng area, Nei Mongol. Scientia Geographica Sinica 22, 453–457. [in Chinese with English abstract]Google Scholar
Xu, T.Z., 1996.The primitive agriculture during the Peiligfang period from the Shigu site in Changge, Henan. In: Institute of Cultural Relics and Archaeology in Henan Province (Eds.), Collection of Archaeological Studies on Cultural Relics in Henan Province. People's Publishing House of Henan, Zhengzhou, pp. 12–16. [in Chinese]Google Scholar
Xue, W.P., Jin, H.L., Liu, B., Sun, L.Y., Liu, Z.Y., 2020. History of moisture change indicated by aeolian deposit in the Horqin sandy land, northeastern China since the Last Glacial Maximum. Quaternary International 547, 50–62.CrossRefGoogle Scholar
Yang, L.H., Wang, T., Zhou, J., Lai, Z.P., Long, H., 2012. OSL chronology and possible forcing mechanisms of dune evolution in the Horqin dunefield in northern China since the Last Glacial Maximum. Quaternary Research 78, 185–196.CrossRefGoogle Scholar
Yang, X.Y., Yu, J.C., Lü, H.Y., Cui, T.X., Guo, J.N., Ge, Q.S., 2009. Starch grain analysis reveals function of grinding stone tools at Shangzhai site, Beijing. Science in China Series D: Earth Sciences 52, 1164–1171.CrossRefGoogle Scholar
Yao, X.S., 1988. Structure of Main Chinese Wood. China Forest Publishing House, Beijing. (in Chinese)Google Scholar
Zhang, C.L., 1997. Research on the relationship among the pre-Shang Culture, the Yueshi Cuture and the Lower Xiajiadian Culture. World of Antiquity, 34–51. [in Chinese]Google Scholar
Zhang, C., Pollard, A.M., Rawson, J., Huan, L.M., Liu, R.L., Tang, X.J., 2019. China's major Late Neolithic centres and the rise of Erlitou. Antiquity 93, 588–603.CrossRefGoogle Scholar
Zhang, Z., Li, Y.C., Li, C.Z., Xu, Q.H., Zhang, R.C., Ge, Y.W., Li, B., Deng, C.L., Li, Z.G., Zhang, L., 2020. Pollen evidence for the environmental context of the early Pleistocene Xiashagou fauna of the Nihewan Basin, north China. Quaternary Science Reviews 236, 106298. https://doi.org/10.1016/j.quascirev.2020.106298.CrossRefGoogle Scholar
Zhao, C.H., 2006. Donghulin prehistoric site in Mentougou District, Beijing. Archaeology, 3–8. [in Chinese]Google Scholar
Zhao, K.L., Li, X.Q., Shang, X., Zhou, X.Y., Sun, N., 2009. Agricultural characteristics of Middle-late Bronze Age in western Liaoning Province. Chinese Bulletin of Botany 44, 718–724. [in Chinese with English abstract]Google Scholar
Zhao, S., Xia, D.S., Jin, H.L, Jia, J., Liu, B., 2018. A multi-proxy late Holocene climate record from aeolian deposits of the Horqin sandy land, northeast China and its societal implications. Aeolian Research 35, 29–38.CrossRefGoogle Scholar
Zhao, Z.J., 2010. Paleoethnobotany: Theories, Methods and Practice. Science Press, Beijing. [in Chinese]Google Scholar
Zhao, Z.J., 2014. The process of origin of agriculture in China: archaeological evidence from flotation results. Quaternary Science 34, 73–84. [in Chinese with English abstract]Google Scholar
Zhou, X.Y., Yu, J.J., Spengler, R.N., Shen, H., Zhao, K.L., Ge, J.Y., Bao, Y.G., et al. , 2020. 5,200-year-old cereal grains from the eastern Altai Mountains redate the trans-Eurasian crop exchange. Nature Plants 6, 1–10.CrossRefGoogle ScholarPubMed
Figure 0

Figure 1. (color online) Location of the Erdaojingzi site in Chifeng, Inner Mongolia, northeast China. (a) Map of China; (b) location of the Erdaojingzi site; (c) landscape of the Erdaojingzi site.

Figure 1

Table 1. 14C dates from the Erdaojingzi site.

Figure 2

Figure 2. Microstructures of charcoal from the Erdaojingzi site; (g) and (n) are tangential sections, others are cross-sections. (a) Acer sp.; (b, c) Amygdalus sp./Armeniaca sp.; (d) Betula sp.; (e) Cotoneaster sp.; (f) Ostrya sp.; (g) Phellodendron sp.; (h) Pinus sp.; (i) Populus sp.; (j, k) Quercus sp.; (l) Salix sp.; (m) Ulmus sp.; (n) Ziziphus sp.; (o) unknown 4.

Figure 3

Table 2. The fossil charcoal assemblages from the Erdaojingzi site.

Figure 4

Figure 3. Coexistence intervals for the Erdaojingzi site (shadow represents the overlapping climate range, dotted line represents the modern climate in the areas).

Figure 5

Table 3. The climate ranges (from Fang et al., 2009) of individual plant taxa in the Erdaojingzi site.