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Located in the transitional region between northern and southern China, the middle Han River valley is of pivotal significance for current debates on rice domestication and the formation of mixed farming in early China. Based on phytoliths and macro-plant remains from 10 sites, along with radiocarbon dating, this study has narrowed the 2000-year gap in early rice utilization by 700 years in the middle Han River valley, and demonstrated the continuous development of rice agriculture in this region. This new evidence also reveals that as early as 7000 cal. BP, mixed farming emerged in this region and facilitated the further southward dispersal of foxtail millet and broomcorn millet into southern China and beyond. In addition, a sample-by-sample comparison of our results with phytoliths and macro-plant remains highlighted the potential biases inherent in these methods. This work emphasized the importance of multi-index archaeobotanical analysis to reconstruct ancient crop assemblages.

Rice is among the world’s most important and ancient domesticated crops. However, the spatial and temporal pattern of the early rice domestication process remains unclear due to the lack of systematic study of wild/domesticated rice remains and corresponding dates during the early Holocene. Here, we collected 248 samples from five typical Shangshan cultural sites in the lower Yangtze region where is the most likely origin place of rice for phytolith analysis. The results showed the following. (1) Rice bulliform phytoliths from the five sites all present domestication traits, suggesting that the rice domestication process had begun across the region by the early stage of the Holocene. (2) The relative domestication rates reflected by the rice bulliform phytoliths were different between sites, the sites with higher domestication rates were distributed closer to the mainstream river. (3) The rice domestication process revealed by bulliform phytoliths can be divided into three periods during the early Holocene: from 10 to 9 ka, rice domestication began and stayed at a low level under 35%; from 9 to 8.5 ka, rice domestication level increased to 50%; and from 8.5 to 8 ka, rice domestication level was in a fluctuating state. (4) By 9 ka BP, rice double-peaked phytoliths from glume cells are present in most of the studied sites, which imply the presence of crop dehusking processing. This study reconstructed the spatial and temporal patterns of rice domestication during the early Holocene, which will improve our knowledge of early crop domestication and enhance our understanding of changes in rice status.

This study presents new archaeobotanical evidence for agricultural production in the middle Yellow River region during the Yangshao culture period. Phytolith analyses, together with radiocarbon dating of samples from 10 sites in Zhengzhou, showed that common millet and foxtail millet were cultivated with rice in the region around 4000–3000 cal BC. The ratio of crop remains revealed that common millet was dominant in the crop structure. Rice cultivation was no longer confined to large sites situated in the lowlands and began to spread into the hilly lands and small sites. Furthermore, both dryland and wetland systems may have been used for rice cultivation. This pattern of crop production may have been mainly influenced by social background and artificial selection, which overcame the limitation of environmental factors. Such development of Yangshao agriculture facilitated the establishment of an agricultural society during the fourth millennium BC. It also has implications for understanding the reason why the middle Yellow River region (Central Plain) became known as ‘the cradle of Chinese civilization’.

Human activity on arid lands has been related to oases evolution. The ancient Loulan, an important transportation hub of the ancient Silk Road, developed on an ancient oasis on the west bank of the lake Lop Nur in Xinjiang, China. Previous studies and historical documents suggest that the region has experienced dramatic natural environmental and human activity–related changes over time, transitioning from a particularly prosperous oasis to a depopulated zone with harsh environment after about 1500 a BP (before present, where present = AD 1950). Based on systematic radiocarbon (14C) dating for natural plant remains and archeological sites in the Loulan area, it was revealed that the region re-experienced oasis environment from 1260 to 1450 cal. AD, corresponding to the Yuan–Ming Dynasties, which is the climate transition stage from the ‘Medieval Warm Period’ to the ‘Little Ice Age’, encompassing a series of pulse-like flood events which cannot be identified from lacustrine deposition due to the limits of sampling resolution and dating. It was found that humans re-occupied the Loulan area and built canals to irrigate farmlands during the period. The more habitable hydrological conditions that resulted from these environmental changes present one major reason for the re-emergence of human activities in the Loulan area.

Mixed millet and rice agriculture is a unique agricultural style of China, and is distributed in a broad band between the Yangtze and Yellow River basin. However, the development of this style during the Neolithic-Bronze Age has not been comprehensively clarified, owing to limited archaeobotanical data and imprecise chronology for most of the regions. Here, the Central Plain, a location where mixed agriculture may have first appeared, was selected as the area for research. Phytolith and macrofossil analyses from the Zhuzhai site, together with the accelerator mass spectrometer (AMS) radiocarbon dating of samples, reveal information about the temporal changes of mixed agriculture as well as the domestication and cultivation of crops in this region. The results indicate that mixed millet and rice agriculture formed in the Central Plain about 8000 years ago. Common millet was the principal crop in the Peiligang and Yangshao periods, with the domestication process beginning in the Peiligang period and continuing up to the Shang period, at which time it was replaced by foxtail millet. Foxtail millet may have gone through a significant degree of domestication by ca. 6000 cal. BC, but its domestication process was still unclear. Rice had appeared since the Peiligang period, but its proportions were always low. Rice assigned to the Peiligang and Yangshao Cultures was the domesticated japonica, and its cultivation was always performed in dry field systems through the Neolithic-Bronze time. Within the subsistence economy, mixed agriculture was a minor component during the Peiligang period, but has been dominant since the Yangshao period.

This study presents the first direct evidence of millet cultivation in Neolithic southeast coastal China. Macroscopic plant remains and phytoliths, together with direct accelerator mass spectrometr...

Compared with the monistic structure of crop agriculture in Southwest Asia and Mesoamerica, agriculture in ancient China reflects the characteristics of a dualistic structure with millet in the north and rice in the south. It is argued that the rice and millet farming modes were mutually exchanged during their development and formed a vast region of mixed farming. However, the time and place of its origin, the routes of dissemination, and the development patterns and possible influence factors of mixed farming remain unclear. This study systematically collected information from 804 sites with millet and rice records and detailed floatation results from 78 mixed farming sites in prehistoric China. Three north–south communication corridors are identified between the upper, middle and lower Yellow and Yangtze River Valleys that began around 5500 BP, 8400 BP and 4600 BP, respectively. Cultural communication accompanied by human migration and the unique natural environment of loess and East Asia monsoons facilitated the interaction between millet and rice farming through these corridors. As a comprehensive reflection of the interaction between millet and rice farming, the crop structure of the four core mixed farming regions is in a continual process of adjustment, with the selection of foxtail millet in the southward spread of millet agriculture and temperate Oryza japonica in the northern spread of rice agriculture.

To better understand the long-term changes of the East Asian summer monsoon precipitation ( Pjja), quantitative reconstructions and model simulations are needed. Here, we develop continental-scale pollen-based transfer functions for Pjja with weighted averaging–partial least squares (WA-PLS) regression and a Bayesian multinomial regression method. We apply these transfer functions to a set of fossil pollen data from monsoonal China for quantitatively reconstructing the Pjja changes over the last 9500 years. We compare the reconstructions with Pjja simulations from a coupled atmosphere–ocean–sea ice general circulation model (the Kiel Climate Model, KCM). The results of cross-validation tests for the transfer functions show that both the WA-PLS model ( r2 = 0.83, root mean square error of prediction (RMSEP) = 112.11 mm) and the Bayesian model ( r2 = 0.86, RMSEP = 107.67 mm) exhibit good predictive performance. We stack all Pjja reconstructions from northern China to a summary curve. The stacked record reveals that Pjja increased since 9500 cal. yr BP, attained its highest level during the Holocene summer monsoon maximum (HSMM) at ~7000–4000 cal. yr BP and declined to present. The KCM output and the reconstructions differ in the early-Holocene (~9500–7000 cal. yr BP) where the model suggests higher Pjja than the reconstructions. Moreover, during the HSMM, the amplitude of the Pjja changes (~20–60 mm above present) in simulations is lower than the reconstructed changes (~70–110 mm above present). The rising (declining) Pjja patterns in reconstructions before (after) the HSMM are more pronounced and fluctuating than in simulations. Other palaeohydrological data such as lake-level reconstructions indicate substantial monsoon precipitation changes throughout the Holocene. Our results therefore show that the KCM underestimates the overall amplitude of the Holocene monsoon precipitation changes.

Ancient Loulan, an important city on the Silk Road, disappeared about 1500 years ago. The environmental conditions associated with the vicissitude of ancient Loulan have been debated since the city was rediscovered in ad 1900. However, little paleobotanical evidence concerning vegetation and environment in this area has so far been available. In this study, phytoliths and diatoms extracted from 16 samples including two fossil camel coprolites from sites of Loulan and Milan indicate that the landscape of ancient Loulan was a typical oasis, where reeds, grasses of Paniceae and Pooideae probably grew along with some shrubs. Also, some typical brackish diatoms might live in some water bodies in the catchment of an ancient lake, Lop Nor. Our results also suggest that common millet as staple crop, and foxtail millet and possibly naked barley as non-staple crops were the main food source for ancient Loulan and Milan residents between ad 50 and 770.

The ancient kingdom of Loulan on China’s Silk Road has disappeared for about 1500 years. Historical records have documented widespread cultivation in Loulan which supported the kingdom’s prosperity for hundreds of years. However, no farmland ruins have been found although the ancient Loulan city was discovered more than 100 years ago. In this study, remotely sensed, geomorphic and geological observations of possible farmlands in Loulan were analyzed. A wide distribution of partly preserved plots with recognizable regular and straight boundaries, the existence of crossed canals, the occurrence of a gypseous incrustation layer (GIL) overlying on the surface of farmland-like blocks, and extracted large-sized pollen grains of cultivated grass from GIL samples provide new evidence for the ancient farmlands. Field observations revealed that the upper cultivated soil layer overlaid on GIL, i.e. soil horizon A, had been wind-eroded and GIL is the ruined soil horizon B. These new findings point to a well-developed agriculture of the ancient Loulan kingdom. The size and distribution of the farmlands and the thickness of the GIL suggests that irrigation for cultivation in this currently exceedingly arid area had lasted for a long time. Fluvial and lacustrine sediments in Loulan area deposited during the about 4 to ~ 8 ka BP period, revealing that the wet Holocene optimum and two arid events of about 4 and 8 ka BP occurred in the westerlies-dominated northwest China. The Loulan kingdom period was another wet stage when the ecological environment was the typical cultivated grass of oasis near wetland. The insufficiency of water during the late period of the Loulan kingdom led the decline of irrigation agriculture and finally the renunciation of the kingdom.

Fossil pollen from Nam Co and modern pollen from altitudinal vegetation belts around the lake are investigated to reveal alpine vegetation succession in response to climate changes during the Holocene in the central Tibetan Plateau. The discriminant analysis on 37 topsoil samples shows that pollen samples from alpine steppe at lower elevations (60%). Our result indicates that the pollen ratio of Artemisia to Cyperaceae (A/Cy) can be used as an indicator of the vertical shift of vegetation belts and temperature changes in the central Tibetan Plateau as suggested by previous studies. A history of the vertical shift of vegetation belts on the northern slope of Nyainqentanglha Mountains and climate changes since 8.4 kyr BP are thus recovered by 198 fossil pollen assemblages from a 332 cm core of Nam Co. Paleovegetation reconstructed from fossil pollen assemblages through discriminant analysis shows a general downward shift of altitudinal vegetation belts, suggesting a decline in the temperature trend since 8.4 kyr BP. This result is consistent with the reduction of A/Cy ratios. The fossil pollen record also reveals warm and wet climate during the early to mid Holocene, and cold and dry conditions during the late Holocene in the Nam Co area. A comparison of Holocene climatic reconstructions across the Plateau indicates that termination of maximum moisture at around 6–5.5 kyr BP in our record is associated with the southeastward retreat of the Southwest Monsoon.

The geochemistry of dated sediment cores from Lake Huguangyan (21°9′N, 110°17′E), tropical South China, reveals distinct stratigraphical patterns in total organic and inorganic carbon (TOC, TIC), biogenic silica (BS) and total nitrogen (TN) over the past 1400 years. In this hydrologically closed lake, TIC variations may re‘ ect changes in the precipitation/evaporation ratio, which controls the evaporative enrichment of carbonate. TOC, BS and TN in the sediment are proxy indicators of lake productivity and nutrient input, which we believe are linked to local precipitation. High TIC content correlates with low concentrations of TOC, BS and TN, and indicates two drought episodes dated to ad 670–760 and ad 880–1260 in the sediments of Lake Huguangyan. Local historical chronicles support these data, suggesting that the climate of tropical South China was dry during the ‘Mediaeval Warm Period’ (MWP) and wet during the ‘Little Ice Age’ (LIA). The detected MWP drought is temporally correlated with evidence for lower precipitation on the Guliya (China) and Quelccaya (Peru) ice caps, and with increased salinity in Moon Lake (US Great Plains).