Abstract: The paper deals with the vegetation history of the southern Loess Plateau, central China, for the last 100 ka based on palynological records from Weinan section. The pollen diagram of the loess-paleosol sequence at Weinan, southern part of the Plateau (109~30rE, 34°24′N), displays a predominence of arid shrubs or herbs (Arternisia, Chenopodiaceae) alternating with the abundance of mesic herbs (Cyperaceae, Ranuculaceae, Liliaceae etc. ) indicating a succession of steppe and meadow-steppe in turn during the last 100 ka BP. Forest vegetation developed only in some comparatively short time intervals e. g. Ulmus forest at ca. 95.1～90.0 ka BP (9. 50～9.32 m); Corylus woodland at ca. 25.0～21.1 ka BP (4.00～3.48 m) and Tsuga stand at ca. 13.7～11.8 ka BP (2.20～1.80 m). So far plant ecologists assinged the southern Loess Plateau to temperate broadleaf deciduous forest zone. Actually there are no forests on. the Plateau surfaces today. The lack of forest from the Plateau surface today is explained as being due to human interferences by plant ecologists. However, in the context of the last 100 ka BP it seems that there has been some nonhuman factors responsible for the treelessness of the Plateau, such as the free-draining nature of loess, which deserves greater consideration.

Key words: Loess Plaeteau, Palynology, Vegetation history, Late Pleistocene