Early-mid Holocene vegetation and diversity evolution on the Ningshao Plain, eastern China

• Published in: Catena (Giessen) 2024-11, Vol.246, p.108446, Article 108446
• Main Authors: Li, Zhen, Ma, Chunmei, Ni, Yufan, Liu, Zeyu, Wang, Bingling, Hu, Zhujun, Sun, Guoping, Wang, Yonglei, Meadows, Michael, Zheng, Hongbo
• Format: Article
• Language: English
• Subjects: Climate change; Hill number; Human activities; Pollen; Sea level; Vegetation diversity
• ISSN: 0341-8162
• DOI: 10.1016/j.catena.2024.108446

•Pollen based diversity reconstruction on the Ningshao Plain during early-mid Holocene.•Vegetation composition, biodiversity, and driving mechanisms were evaluated.•At 7.5 ka BP, vegetation composition changed greatly and the diversity decreased.•Human impacts caused alteration in vegetation composition and loss in biodiversity. The study of Holocene vegetation diversity changes and mechanisms in the Ningshao Plain is of great significance for understanding their responses to the coupled relationship between climate, sea level, and human activities. In this study, we analyzed pollen and charcoal from the Tianluoshan and Jingtoushan sites (TLS1402 and JTS1501) to represent the regional vegetation history, particularly changes in vegetation diversity during the early to mid-Holocene. The findings show that after 7.5 cal kyr BP, arboreal pollen (AP) declined significantly and that subtropical evergreen deciduous broad-leaved mixed forest replaced deciduous broad-leaved forest as the predominant vegetation type. The increase in Poaceae (>38 μm) and charcoal corresponds well with the decrease of AP (mainly manifested as deciduous species), suggesting that vegetation change may be related to human activities and that coniferous taxa (mainly Pinus) are more sensitive to fire response. Vegetation diversity based on the Hill numbers (N0, N1, N2 and Evenness) is shown to decline three times, viz. at 8.5, 8.2, and 7.5 cal kyr BP, among which the decrease around 8.5 and 7.5 cal kyr BP corresponds to two regional sea level rise events. The decrease in Jingtoushan diversity at 8.2 cal kyr BP may have superimposed signals of human interference beyond the influence of climate. The development of the Jingtoushan Culture commenced after the first sea level rise events (around 8.3–7.8 cal kyr BP), but was then interrupted by the second sea level transgression. Thereafter, the sea level became relatively stable, and the emergence of fire-assisted agriculture marked a new stage in the relationship between humans and the environment. Changes in vegetation diversity are closely related to regional fires and human activities. In addition, during the Jingtoushan and Hemudu cultures, the impact of human activities on AP diversity was significantly greater than that on non-arboreal pollen (NAP) taxa.