Weimiao Dong

A high-resolution record of Holocene environmental and climatic changes from Lake Balikun (Xinjiang, China): Implications for central Asia

A high-resolution record of Holocene environmental and climatic change in the Balikun area was reconstructed from a sediment core from the Lake Balikun. Multiproxy data show that the climate was extremely arid during the early Holocene (before 8.6 cal. ka BP). Moisture began to increase after 8.6 cal. ka BP and the climate was humid between 7.9 and 4.3 cal. ka BP. A significant dry event occurred around 4.3–3.8 cal. ka BP. The climate became generally wet during the late Holocene (after 3.8 cal. ka BP). The Holocene pollen and geophysical records do not indicate a wet early Holocene, making it evident that there was no early-Holocene humid period associated with peak Asian monsoon strength. Regional comparisons indicate that this region has a different pattern of Holocene environmental and climatic change from the Asian monsoonal area and south Siberia.

How prehistoric humans use plant resources to adapt to environmental change: A case study in the western Chinese Loess Plateau during Qijia Period:

Fossilized charcoals can document how prehistoric humans used wood resources. Here, we present a quantitative result of charcoal fossil records, compiled with archaeobotanical data of Qijia Culture (4.3–3.8 cal. kyr BP) in the western Chinese Loess Plateau, to study how prehistoric people used plant resources and adapted to their environment. The charcoal records showed that Quercus, Ulmus, Pyrus, Acer, Picea, Prunus, and Bambusoideae were abundant during the Qijia Period, implying a warmer and wetter environment at that time. It also clearly showed that Qijia people had a strong preference to select woods in their daily life. Quercus was the most favorable wood, and thus, it was found in all samples. Many fruit trees planted in the Chinese Loess Plateau today were found in charcoal records. These fruit trees were, during the Qijia Period, at least in the process of being domesticated. Qijia people expanded the scope of using plant resources, and many new crops appeared during that time. These results provide a new insight into economic management and human adaption strategies in the Neolithic Age.

Stable Isotopic Detection of Manual Intervention Among the Faunal Assemblage from a Majiayao Site in NW China

Faunal remains from Shannashuzha in Minxian County, Gansu Province, China were isotopically analyzed to understand animal husbandry, and thus human subsistence strategy, during the Majiayao culture (5200-4800 cal yr BP) period. Stable carbon isotopic results reveal that only two pig samples clearly show a C-4-dominated diet with a mean delta C-13 value of -8.5%, which possibly indicated controlled feeding practices by human beings. No other significant manual intervention can be observed among the remaining samples, suggesting that both wild and domesticated meat sources were used at Shannashuzha. Statistically, Bos are indistinguishable from Cervidae based solely on isotopic results, suggesting that Bos may have remained in wild form during the Majiayao culture period. The presence of hare/rabbit, bamboo rat, and badger reflects the diversified food exploitation behavior.

Population history and its relationship with climate change on the Chinese Loess Plateau during the past 10,000 years

Based on compilation of a large number of archaeological and palaeosol 14C-ages, the Summed Probability Method is used to reconstruct population history and climatic patterns on the Chinese Loess Plateau during the period 8.5–3.5 cal. ka BP. During this period, the population experienced two major expansion periods and several climatic fluctuations. The first population expansion began at around 7.8 cal. ka BP, and the second at around 5.8 cal. ka BP. During the first period, although already in combination with cultivation of broomcorn millet the population growth was supported mainly by hunting and gathering. With the switch from broomcorn millet to foxtail millet, plant cultivation became the major factor promoting a second population increase. In this paper, we demonstrate that, initially, suitable climate and agriculture both can facilitate population growth and climate events had a significant influence on demographic fluctuations. However, when reaching the threshold of land capacity, population became increasingly more sensitive towards climate fluctuations.

Woodland vegetation composition and prehistoric human fuel collection strategy at the Shannashuzha site, Gansu Province, northwest China, during the middle Holocene

Charcoal analysis is a useful tool to gather information about the diversity of vegetation as well as human behaviour towards the environment and the diversified management of natural plant resources. Here we present the taxonomic identification of charcoal and calculate the percentage of each diameter class of the pieces excavated from the Shannashuzha archaeological site, Gansu Province. We discuss the implications of the data for the composition of the past woodland vegetation and prehistoric human fuel collection strategy. Twenty-two taxa were identified from 2,241 charcoal fragments with a further 50 fragments unidentified. Picea, Pinus, Bambusoideae, Salix, Populus, Quercus and Betula were abundant in many samples, although Bambusoideae is probably over-represented due to its high chance of being preserved. The vegetation around the Shannashuzha site had a typical mountain character and the main vegetation types reflected by the charcoal records included conifer woods, mixed broadleaved/conifer woods and riverbank broadleaved woods. This vegetation is similar to the modern vegetation and therefore the climate at that time is deemed to have been similar to or slightly warmer than today. Abundance was probably an important factor in the fuel collection strategy of the people. Collection of wood with a small diameter was a purposeful choice by prehistoric people, probably because it was less time-consuming in the study area, which was rich in wood resources. We conclude that in this region, prehistoric people selected firewood depending not on its type, but rather on its size (diameter). Charcoal from fruit trees found at this site and at many others nearby indicates that there was a common and long history of fruit utilization by prehistoric people in the western Loess Plateau. These results provide valuable information and a new insight into the interaction between human activities and plant resources in the Neolithic period.