Late holocene vegetation succession and climate change in the Central Plains of China: Evidence from a high-resolution pollen record

Changes in the East Asian summer monsoon precipitation will have a significant impact on China’s politics, economy, and social development. To explore the controls and drivers of the Late Holocene (∼3350–2560 cal. yr. BP) vegetation succession and East Asian summer monsoon precipitation changes in the Central Plains of China, we conducted pollen analysis of the Pu Tian core collected from Zhengzhou, China. The results showed three periods of vegetation and East Asian summer monsoon variation: coniferous and broad-leaved mixed forest between ∼3350–3025 cal. yr. BP, increasing forest vegetation dominated by broadleaf Betula between ∼3025–2930 cal. yr. BP, decreasing forest vegetation and increasing herbaceous plants dominated by Artemisia and Poaceae between ∼2930–2560 cal. yr. BP. Weighted Averaging Partial Least Squares Regression was used to quantitatively reconstruct the average annual precipitation variation in the Central Plains of China. Our precipitation reconstruction and its comparison to other reconstructions and forcing show that it was influenced by internal (intertropical convergence zone and El Niño-Southern Oscillation) and external (Northern Hemisphere Summer Insolation) forcing. Specifically, average annual precipitation decreased significantly between ∼2980–2680 cal. yr. BP, and tree pollen (such as Betula) also decreased significantly during this period, possibly related to the “2.8 ka” event (a weak monsoon event in the Holocene). Our comparison of the published climate and environmental records of the East Asian monsoon region suggests that the 2.8 ka event exhibiting a “W” structure of “dry-wet-dry” and may have been caused by the weakening of solar activity, which affected the climate of the East Asian monsoon region through oceanic and terrestrial atmospheric circulation such as El Niño-Southern Oscillation.