The vegetation characteristics of the ‘ Yuan’ area at Yaoxian on the Loess Plateau in China over the last 12 000 years

Abstract

Vegetation history is a valuable tool to assist understanding of environmental changes, ecological restoration and human impact on the environment. This study discusses the pollen analysis of the Yaoxian section on the southern margin of the Loess Plateau in China. Based on the pollen diagram, the vegetation of Yaoxian shows four episodes of change, i.e. from steppe to humid-grassland, to steppe, to humid-grassland, and then to grassland, over the last 12 000 years. The vegetation of the ‘ Yuan’ region (the large flat surfaces of the Loess Plateau) was herb and shrubland, even in sub-humid regions. Previously published pollen records from Weinan, Luochuan and Fuxian in the ‘ Yuan’ area, using organic carbon isotopes (δ 13C) and phytolith analysis, all similarly indicate that the vegetation was dominated by shrubs and herbs. Thus, steppe and grassland were the dominant vegetation types and there was no natural forest in the ‘ Yuan’ region of the Loess Plateau during the Holocene, even not at the Holocene optimum.