Relationship between the Surface Pollen and Vegetation in Shiyang River Drainage, Northwest China

Abstract

In order to investigate the surface pollen and its significance in indicating the surrounding vegetation, surface soil samples collected from 76 sites in different vegetation zones in the Shiyang River drainage were analyzed, and then the pollen assemblages of every zone were obtained. It is found that the relationship between the surface pollen and surrounding vegetation is very complex, and the representation of certain pollen is different in different vegetation zones. Picea, Pinus, Compositae and fern spores are over-representative. Sabina, Betula, Ericaceae, Rosaceae, Leguminosae, Gramineae and Polygonum are under-representative in the vegetation zone where their matrix plants dominate, and their representation differs from other vegetation zones in the drainage. Nitraria is well representative. Artimisia is well representation in the mountains and over-representation in the lower reaches of the Shiyang River. Chenopodiaceae is well representation in mountains, over-representation in grass and desert grass vegetation zones and under-representation in other zones. Picea pollen in the forest zone and the atmospheric circumfluence in the drainage are the main factors, which influence the relationship between the surface pollen and surrounding vegetation.