2023 年 131 巻 1 号 p. 45-53
The Spatio-temporal distribution of prehistoric sites and the response of human activities to climate change are important considerations in studies of human–Earth relationships. The Jiaodong Peninsula in Shandong Province is an ideal place to study the relationship between Holocene environmental evolution and human adaptability. In this study, GIS software was used to study the elevation, slope, and riverside adjacency of Holocene settlement sites in the Jiaodong Peninsula. By analyzing trends in the spatiotemporal distribution of settlements in combination with climate and sea-level changes in the Jiaodong Peninsula we were able to explore the relationship between the spatiotemporal distribution and environmental evolution of the sites. The results showed that the prehistoric sites were mainly located in low-altitude areas with elevations of 0–60 m and sun-facing (i.e. south-, southeast-, and southwest-facing) slopes of 0°–5°. The number of Houli-Beixin sites (8500–6300 a BP) were relatively fewer than the number in other areas in China due to the impact of the early Holocene transgression. Continental sites in the Jiaodong Peninsula were substantially affected by climate change and began to increase during the Dawenkou stage (6300–4600 a BP) and reached a maximum during the Longshan stage (4600–4000 a BP). With the advent of the dry and cold 4.2 ka event, the number of continental sites decreased during the Yueshi stage (4000–3500 a BP). The number of coastal sites fluctuated slightly from the Longshan to the Yueshi stage (4000–3500 a BP) because of climate change. Compared with other areas in China, the reduction rate of sites from the Longshan (4000–3500 a BP) to the Yueshi culture (4000–3500 a BP) was relatively low, likely because fishing was the main livelihood. These results could help improve our understanding of the relationship between climate change and human activities.
The Holocene is known for both its periods of stable climate and millennial-scale climatic perturbations. The Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) showed that modern climate change caused by climatic warming has directly affected human lifestyles today (Intergovernmental Panel on Climate Change Working Group III, 2014). Thus, several studies have sought to predict the progression of climate change and its impact on human society by investigating Holocene climate change and its sociocultural influences (Kajita et al., 2018; Xie et al., 2019; Wu et al., 2019; Leng et al., 2019; Nakatuska et al., 2020). The adaptations of human civilizations to Holocene environmental evolution may point to broad trends that have continued relevance (Chen et al., 2015; Wu et al., 2016; Dong et al., 2017; Huang et al., 2017; Sun et al., 2021). High-resolution interdisciplinary studies on the linkages between human civilization and Holocene environmental evolution have received interest in recent years (Redman et al., 2004; Li et al., 2013; Xie et al., 2019; Xu et al., 2019). Discussions on the relationships between prehistoric human sites and Holocene environmental evolution have mainly focused on ecological and socioeconomic interaction systems, and their linkage with global/regional/local-scale climatic and environmental settings (Adger et al., 2013; Chapman, 2018; Stančikaitė et al., 2019; Zhang et al., 2021). Previous studies have indicated that Holocene environmental evolution was the most important factor determining the development of prehistoric culture, such as the rise of Mongolia (Pederson et al., 2014), the collapse of Neolithic cultures in China (Sun et al., 2019), the decline of the Mayan civilization in Mesoamerica (Haug et al., 2003), and the demise of Angkor in Southeast Asia (Buckley et al., 2010).
Haidai culture was an important early form of Chinese civilization (Figure 1a). This prehistoric civilization was advanced and culturally rich, and, broadly speaking, Haidai culture extended over 8000 years (Gao and Shao, 1984). Shandong Province comprises the main region of the Haidai cultural area and is rich in cultural relics (Figure 1b). The prehistoric cultural sequence in Shandong is complete. Scientific and technological analysis of the relics of the prehistoric sites has clearly distinguished the characteristics of sites from different periods. Thus, there was no influence of chronological ranges and time trends for the prehistoric sites (Gao and Shao, 1984). The Jiaodong Peninsula is located in the eastern part of Shandong Province. This peninsula is within the sea–land transition zone of the eastern monsoon region. From the Beixin to the Yueshi culture, the Jiaodong Peninsula was one of the most important sites of Haidai cultural activities in Shandong Province (Figure 1c). Due to the sensitivity of the natural environment of the transitional zone between sea and land and the long-term accumulation of prehistoric cultural relics, the Jiaodong Peninsula is an ideal site to study the relationship between Holocene environmental evolution and human adaptations. The earliest prehistoric culture of the Jiaodong Peninsula was the Houli culture (8500–7500 a BP), followed by the Beixin culture (7500–6300 a BP) (State Administration of Cultural Heritage, 2007). During the Houli–Beixin cultural period, early agriculture appeared in Shandong. People planted millet and raised pigs, dogs, and other domestic animals, and practiced hunting, fishing, and gathering. With this degree of economic foundation, productivity increased and society developed a matriarchal structure. The Dawenkou culture (6300–4600 a BP) extended from the Beixin culture. During this period, the warm and wet climate led to prosperity and the further development of agriculture. Fishing and hunting activities also continued. The Dawenkou culture reached new levels of social and transitioned from a matriarchal to a patriarchal structure (He, 2004). The subsequent Longshan culture (4600–4000 a BP) continued to prosper, and the means of production continually advanced. The social economy was dominated by agriculture, and a handicrafts industry emerged and developed. A substantial portion of the population participated in livestock and poultry production (He, 2004; Wu et al., 2013). The Yueshi culture (4000–3500 a BP) displayed socioeconomic characteristics similar to those of the Longshan culture, although the importance of fishing, hunting, and animal breeding increased (Zhang and Lu, 2004).
(a) Map of six Neolithic cultural areas in China proposed by Su (2011). (b) Map of Shandong Province. (c) Map of the Jiaodong Peninsula.
To evaluate the effect of the Holocene environmental evolution on human activity in the Jiaodong Peninsula, we investigated the spatiotemporal distribution patterns of Holocene settlements to analyze their relationship with environmental evolution. Further, the mechanisms of human–environmental interactions in the Jiaodong Peninsula are discussed in the context of reconstructed paleoenvironmental records.
The Jiaodong Peninsula (35°35′–38°N, 119°30′–122°43′E) is located at the confluence of China’s Bohai Rim Marine Economic Zone and Asia’s Yellow Sea Economic Zone. The Jiaodong Peninsula’s major cities include Qingdao, Yantai, and Weihai (Figure 1c). The peninsula is surrounded by the water, including the Bohai Sea and Yellow Sea, on three sides and has a total area of 2.98 × 104 km2. The Jiaodong Peninsula is situated in a warm temperate monsoon semi-humid continental climate zone. Its climate is regulated by the ocean, with four distinct seasons and a mild climate. The mean annual temperature is a moderate 12.3°C. The mean annual precipitation between 1956 and 2009 was 718.8 mm. The Peninsula’s rivers originate from the central mountainous areas, and most flow into the sea. These rivers are characterized by wide beds and rapid currents. River runoff shows obvious seasonal variation, with 70–80% of the annual runoff concentrated in the flood season. Three geomorphological types dominate the study area, namely tectonic erosion landforms, tectonic denudation landforms, and accumulation landforms. The terrain generally increases in height with increased distance inland (Liu et al., 2020).
Information about 207 archaeological settlements was mainly collected from published documents (Zhao, 1992; State Administration of Cultural Heritage, 2007). The chronology of these settlements can be classified into four stages based on their cultural characteristics and chronology. Due to the small number of known settlements and their relatively similar cultural characteristics, the Houli and Beixin cultures were unified into one stage. A 30 m × 30 m SRTM digital elevation model (DEM) and topographical and drainage maps were used to obtain spatial data for the cultural site distribution maps. The dataset was provided by the International Scientific Data Service Platform of the Computer Network Information Center, Chinese Academy of Sciences. Based on relevant archaeological data and materials, the prehistoric cultural sites of the Jiaodong Peninsula were plotted on a relief map using ArcGIS software. The slope and riverside adjacency were calculated based on the slope and river buffer zone determined by ArcGIS. We identified trends in the spatiotemporal distribution of archaeological settlements during different cultural periods to elucidate the relationship between Holocene environmental evolution and human adaptation.
The number of prehistoric sites generally presented an upward followed by a downward temporal trend, showing an inverted-V shape. The number of prehistoric sites increased from 12 during the Houli-Beixin period to 64 in the Dawenkou period, representing 5.8% to 30.98% of the 207 total sites, respectively. The number (83 sites) and proportion (40.1%) of sites reached a maximum in the Longshan cultural period, after which both the number (48) and proportion (23.19%) of sites decreased during the Yueshi period (Figure 2a).
Distribution (a), elevation (b), slope gradient (c), and slope direction (d) of prehistoric sites in the Jiaodong Peninsula.
The elevation distribution of prehistoric sites on the Jiaodong Peninsula was consistent, with most sites located in low-altitude areas. The proportion of prehistoric sites located between 0 and 60 m ranged from 68.7% to 91.67% during the four periods. Eleven Yueshi sites were located at elevations of >60 m, accounting for 22.92% of the total sites in that period. Longshan sites at elevations >60 m accounted for 31.32% of the total, the largest proportion. Compared with the proportion during other cultural periods, the relative number of Longshan and Yueshi sites at elevations >60 m was practically higher, which may reflect enhanced human adaptation to environmental evolution (Figure 2b, Figure 3).
Spatial distribution of the prehistoric sites in the Jiaodong Peninsula.
The prehistoric sites in the Jiaodong Peninsula were mainly distributed in relatively flat areas with gentle slopes of 0°–5° (71.98% of total settlements). Such slopes not only displace excess water when precipitation is high, but also keep water and soil from being lost. Thus, they were suitable for farming and breeding purposes (Figure 2c). Figure 2d shows that north is comparable to southeast and south, and west does not look substantially different from south.
The buffer zones between the settlements and the rivers were classified as 0–0.5 km, 0.5–1.0 km, and 1.0–1.5 km and were analyzed with ArcGIS software. The number of sites situated within different buffer zones was calculated, and the influence of rivers on site selection was analyzed. The prehistoric sites were mostly distributed in the 1–1.5 km buffer zone, indicating that the sites were mainly distributed near but not directly on the river. This evidence points to the dependence of these civilizations on the rivers (Figure 4).
Distribution of prehistoric sites within river buffer zones in the Jiaodong Peninsula.
The Jiaodong Peninsula is located in the eastern coastal zone of the East Asian monsoon region, which is one of the most sensitive regions to climate change in the world (Wang and Li, 1983; Han and Meng, 1986; Zhao, 1992; Zhou et al., 2008).
Based on a multi-proxy vegetation, pollen, clay mineral, and chemical element analysis of the Jiaodong Peninsula and adjacent areas, eight Holocene environmental evolution stages were identified (Figure 5). (1) Before 6500 a BP, the climate was warm and humid, and the landscape was dominated by deciduous broad-leaved forests. (2) During 6500–5000 a BP, the climate remained warm and humid, and the vegetation was dominated by broad-leaved forest with a small amount of subtropical plants and pines. The moisture and temperature conditions were more conducive to than those before 6500 BP, making this the suitable climate period. (3) From 5000 to 4500 a BP, the climate was mild and humid. Compared with the 6500–5000 a BP stage, hydrothermal activity decreased slightly. (4) Between 4500 and 3600 a BP, the climate was warm and slightly dry. The temperature was warmer than that during 5000–4500 a BP, and the precipitation was lower, leading to the development of grassland vegetation and the early paleosoil. (5) During 3600–2500 a BP, the climate was cool and slightly dry. The first paleoaeolian dunes developed in the early stage of this period, and the hydrothermal conditions improved in the late stage. (6) From 2500 to 1600 a BP, the hydrothermal conditions were slightly stronger than those during 3600–2500 a BP. The latter part of this period was drier, and the second stage of the paleoaeolian dunes developed. (7) Between 1600 and 800 a BP, the climate became relatively warm and humid, and the late paleosoil developed intensively. (8) Over the past 800 years, the climate has turned slightly warmer and drier, gradually approaching modern conditions.
Comprehensive comparison of Holocene vegetation, climate, deposition, and sea-level change in the Jiaodong Peninsula (modified from Zhao, 1992).
The impacts of climate change on prehistoric human activity are generally indirect, but ultimately, humans must adjust to new environments. First, human civilizations must adapt to temperature and precipitation fluctuations (Kotova and Makhortykh, 2010; Zeng et al., 2016; Guo et al., 2018). Solar radiation, sufficient precipitation, and wild animal and plant resources contributed to the development of the Houli–Beixin culture before 6500 BP. The Houli–Beixin sites were concentrated on the low plain along the coast (Figure 2b, Figure 3). The climate during the Dawenkou period was humid and warm, and agriculture rapidly progressed, as indicated by various excavated agricultural implements, pits for cereal storage, and carbonated foxtail millet. The development of animal husbandry and winemaking also reflected agricultural progress (Zhang and Lu, 2004; He, 2004). Our results showed that the number of sites during the Dawenkou period increased to 64 (representing 30.91% of the total) (Figure 2a). Further, the number of inland sites also increased. After 5000 years, the climate became drier and colder, although it remained relatively warm. The climatic conditions were suitable for foxtail millet cultivation, and agriculture continued its rapid development, as indicated by excavated harvest implements and delicate production tools. Seed and millet were the main crops, and small-scale rice was cultivated (Zhao, 2004). The number of sites increased to 83 in the Longshan period (40.1% of the total) (Figure 2a). The number of inland sites increased substantially. After 4000 a BP, accompanied by a decrease in temperature and precipitation, the number of Yueshi sites decreased considerably (from 83 in the Longshan period to 48; Figure 2a). Socioeconomic conditions showed degradation in the study area. The decline in the Yueshi culture occurred around the time of the 4 ka BP dry/cold event. The abrupt climatic change around 4.2 ka BP may represent the dry/cold period in the study area since the Younger Dryas, with temperatures decreasing by 3–5°C (Wu and Liu, 2001; Wang et al., 2014; Zhang et al., 2020). This substantial cooling severely restricted the development of prehistoric agriculture and substantially reduced crop production. During the dry/cold period, the dependence of the Yueshi culture on water strengthened: the distance between settlements and rivers gradually shortened (Figure 4).
Relationship between prehistoric cultural sites and sea-level changeMost coastal areas in China were affected by the Holocene transgression, which threatened the survival of prehistoric civilizations (Zhang et al., 2005; Wu et al., 2014; Guo et al., 2013). The distribution of prehistoric cultural sites on the Jiaodong Peninsula was strongly influenced by sea-level changes (Figure 5). The Holocene transgression in the Jiaodong Peninsula began in approximately 11700 a BP. During this period, the last glaciation ended, and the temperature gradually began to increase, resulting in a rise in sea level. Large quantities of seawater invaded the land, which was reflected in the archaeological record in the form of primitive tools and pottery and other signs of low economic productivity. Compared with the Houli–Beixin cultural sites in other areas of Shandong Province (Guo et al., 2013; Niu et al., 2013), the number of prehistoric sites in the Jiaodong Peninsula was small due to the Holocene transgression.
During 6000–5000 a BP, the sea level reached its maximum, and the extent of the transgression was the greatest. However, the number of sites at distances of 0–20 km from the water’s edge during the Dawenkou phase was not substantially reduced (Figure 2b), which may be attributable to two factors. First, although the sea level reached a maximum around 6000 a BP, the sea level in the Jiaodong Peninsula did not rise to a large extent (Figure 5), which is consistent with the results of Li et al. (2002, 2014). Thus, the sea-level rise did not lead to a decline in the Dawenkou culture. Second, compared with the Houli–Beixin culture, the productivity of the Dawenkou culture was greatly improved. Some prehistoric human beings were able to migrate inland, and coastal Dawenkou communities transitioned from simple farming to a combination of farming and fishing.
Distribution of paleo-river channels and prehistoric cultural sites in the HoloceneThe water system of the Jiaodong Peninsula mainly included the Dagu River, Wulong River, Dagujia River, and other coastal rivers. The rivers were formed in the late period of the late Pleistocene. During the Holocene, the tectonic movement of Jiaodong Peninsula was dominated by differential uplift. The climate in this region was humid, the terrain was flat, and the river volume was sufficient. During the Dawenkou cultural period, the demand for agricultural water was small, and the river changed the course frequently (Chen et al., 2009; Zhang et al., 2020). Therefore, the cultural sites had little requirement for water sources, and most of the sites were not close to the rivers (Figure 4). During the Longshan cultural period, the demand for agricultural water increased substantially because of the rapid development of agriculture, and the distribution of cultural sites was obviously distributed along the river channels. The previous studies have shown that the paleo-rivers in this region during the Holocene have the characteristics of large volumes of water, wide channels, and rapid surges of flow (Zhao, 1992; Chen et al., 2009). The cultural sites of the Longshan cultural period were distributed along the river and at higher elevations to cope with sudden river diversion. All these showed that the ability of these ancient people to adapt to nature was increasing.
Comparison of the spatiotemporal distribution Jiaodong Peninsula sites with other areasThe Jiaodong Peninsula, a typical coastal area surrounded by the sea on three sides, experienced similar cultural development processes as did other regions in China, although some aspects were unique. The prehistoric sites in the Jiaodong Peninsula can be divided into continental and coastal sites (Zhao, 1992). Continental sites were mainly distributed in the inland plains near the river and river terraces. The number of continental sites was substantially influenced by climatic changes. During the Houli–Beixin cultural period, the number of continental sites was small. With the arrival of the Holocene Megathermal, the number of continental sites began to increase, reaching a maximum during the Longshan culture. With the rapid decline in monsoon precipitation intensity around 4200 BP, the number of continental sites decreased substantially. Many marine creatures and fishing tools have been found in the coastal sites of Jiaodong Peninsula. Due to the influence of the dry and cold 4.2 ka event, the number of continental Yueshi sites was fewer than that of coastal sites. Thus, the degradation experienced during the Yueshi period was lower in the Jiaodong Peninsula than in other parts of China. For example, the number of sites in northeast Shandong Province decreased from 593 sites in the Longshan period (4600–4000 a BP) to 138 sites in the Yueshi period (4000–3600 a BP), representing a reduction rate of 76.73% (Guo et al., 2013). In Henan Province, the number of Longshan sites (4600–4000 a BP) decreased from 1249 to 43 during the Erlitou period (3800–3600 a BP), representing a loss of 96.56% (Li et al., 2015). In the Yangtze River Delta, the 81 Liangzhu (5700–4100 a BP) sites decreased to six sites during the Maqiao cultural period (4100–3300 a BP), a reduction rate of 92.59% (Zhang et al., 2005). Compared with the above results, the sites in the Jiaodong Peninsula decreased from 83 during the Longshan period to 48 sites during the Yueshi period, representing a loss of only 42.17%. This difference is attributable to the different lifestyles in these regions; in the coastal Jiaodong Peninsula sites, fishing minimized the impact of climate change on the number of sites. Animal remains from inland were found in Yueshi cultural sites. In addition, there were a large number of marine animals such as shells, snails, and fish bones. Meanwhile, sea pebbles as handicrafts, fishing hooks, and other fishing tools have also been found in the prehistoric sites of the Peninsula, indicating that these prehistoric peoples used the sea as their home and food source (Zhao, 1992).
This research was supported financially by National Natural Science Foundation of China (No. 41702185, U1706220, 41901102), the Foundation of School and Land Integration Development in Yantai (No. 2021XDRHXMQT18), Humanity and Social Science Foundation of Ministry of Education of China (No. 19YJCZH171), the Natural Science Foundation of Shandong Province (No. ZR2019PD013), and was supported by the open foundation of State Key Laboratory of Lake Science and Environment (2022SKL005), the open foundation of CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, YICCAS (No. 2020KGJJ10), the open foundation of State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, CAS (No. SKLLQG2024), the Youth Innovation Team Project for Talent Introduction and Cultivation in Universities of Shandong Province, Key Project of Undergraduate Teaching Reform in Shandong Province (Z2021177), the Teaching Research Foundation of Ludong University (2020J140), Key Project of Research and Development program in Shandong Province (2021RKY07122).
