High-resolution quantitative vegetation reconstruction in the North China Plain during the early-to-middle Holocene using the REVEALS model

Understanding the process and pattern of vegetation succession during the early-to-middle Holocene can yield valuable information for better predicting future vegetation evolution. In this study, we investigated the humidity evolution pattern in the North China Plain (NCP) during the early-to-middle Holocene by employing principal component analysis on 93 fossil spectra. Furthermore, by integrating the Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model, we quantitatively reconstructed the process of vegetation succession and discussed vegetation response to climate change events. Our results indicate that the sample scores of the first principal component axis (PCA axis 1) exhibited a consistent negative bias, implying a gradual rise in regional humidity. The quantitatively reconstructed tree coverage was found to be lower than the uncorrected pollen proportions, while the coverage of herb plants showed a significant increase compared to their respective pollen percentages. In the early and middle Holocene, the vegetation of the NCP succeeded from meadow steppe (10,000 - 8,100 cal yr B.P.) to meadow steppe with pine woodland patches (8,100 - 7,100 cal yr B.P.), then to pine forest (7,100 - 5,300 cal yr B.P.). The quantitatively reconstructed vegetation exhibited the most pronounced response to 8.2 ka climate event, with Asteraceae emerging as the dominant taxa. Furthermore, we conducted a comprehensive analysis of the impact of the 8.2 ka climate event on vegetation in northern China, identifying four distinct types of vegetation feedback: (1) negligible alterations in vegetation, (2) expansion of steppe or desert steppe, (3) proliferation of temperate tree species, and (4) augmentation of meadow steppe.