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Vegetation composition has been greatly modified by human activity since Neolithic times, providing valuable insights into the evolution of human-landscape relationships. In this paper, we integrated 26 pollen records from the Zhejiang Province of China where a Neolithic culture of rice farming existed at an early date, to examine the dynamics of agricultural development and its impact on vegetation. Firstly, we synthesized the relative abundance of Oryza pollen and charcoal (Cpeak) using generalized additive models, to produce a record of agricultural development and the intensity of human activities. We found that changes in Oryza abundance and Cpeak were positively correlated, and identified three phases as follows: agricultural initiation before 8000 cal yr BP, agricultural development between 8000 and 6000 cal yr BP and the onset of intensive rice farming after 6000 cal yr BP. Pearson correlation between each pollen taxon and Oryza indicates that arboreal taxa exhibit an overall negative correlation with Oryza , but terrestrial herbs and ferns show a positive correlation, indicating that deforestation accompanied agricultural development. Rosaceae, Castanea , Fagus and Typha display positive correlation with Oryza during the earliest stage dominated by hunter-gathering, reflecting the protection and cultivation of food-producing vegetation. During the intensive farming stage, the Liangzhu ancestors reclaimed more farmland and began to pay attention on farmland management including clearing the fields of weeds. This is the main reason for the enhanced negative correlation between Artemisia , Chenopodiaceae, Brassicaceae, Asteraceae and Lamiaceae with Oryza at 6000–5000 cal yr BP. Finally, we confirm the potential of integrated Oryza abundance in pollen records as a human-impact index in the Zhejiang region, and emphasize that temporal dynamics in vegetation and human activities should be critically pre-examined when applying relevant human-impact indices. • Integrated charcoal and Oryza pollen reveal Neolithic human intensity and rice farming history. • Food-providing plants were protected during the hunter-gatherer stage. • During the intensive agriculture phase, weed taxa exhibited a strengthened negative correlation with Oryza correlation. • The application of anthropogenic pollen necessitates a critical evaluation of its temporal dynamics. [ABSTRACT FROM AUTHOR]

The 4.2 ka event was a period of global drought and climate cooling linked to the widespread disruption of Neolithic culture. However, the detailed climatic changes during this period are not completely understood. In this paper, we report a high-resolution pollen record for the Dayanghu wetland in the Zhejiang region of southeastern China, which we use to infer mean annual precipitation (MAP) fluctuations during the period spanning 4600–4000 calendar years before present (cal. yr BP). There was a long-term trend of decreasing MAP during this interval, consistent with weakening of the East Asian Summer Monsoon since the mid-Holocene. This trend was punctuated by episodes of relatively high MAP at 4350–4320, ca. 4260, and 4220–4200 cal. yr BP, and extreme droughts at 4200 and 4150 cal. yr BP. We propose that solar activity promoted El Niño events and contributed to dramatic MAP fluctuations in the Dayanghu wetland. La Niña events and negative-phase intervals of the Pacific Decadal Oscillation may have been responsible for the extreme drought at 4200–4150 cal. yr BP. In summary, we propose a close relationship between MAP and solar forcing, with short-term enhanced solar activity increasing the intensity of the East Asian Summer Monsoon and contributing to increasing decadal variability in the inner tropical Pacific, which ultimately leads to increased precipitation variability in southeast China. The results improve our understanding of the detailed climatic features of the 4.2 ka event. • High-resolution pollen record for ca. 4.2 ka for the Zhejiang region, China. • Pollen-based mean annual precipitation was quantitatively reconstructed. • Long-term droughts tended to occur during 4600–4000 cal. yr BP. • La Niña-dominated ENSO contributed to a catastrophic drought at 4200–4150 cal. yr BP. [ABSTRACT FROM AUTHOR]