石羊河流域表土孢粉与植被的关系

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

通过对石羊河流域不同植被带76个表土样的孢粉分析,研究了该流域各植被带的表土孢粉组合及主要植物花粉与其植物比例的关系.结果显示:石羊河流域各科属孢粉与植物之间的关系复杂,同一科属孢粉在不同植被带中的代表性也各有差异,所以某科属孢粉的代表性问题需要在不同植被带中分别讨论.森林带的云杉属花粉和流域自身的大气环流状况是影响流域表土孢粉组合及各科属花孢粉与植物关系的主要因素.

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.