Vegetation and Climate During the Late Pleistocene in Fu County, Shaanxi

With the intention to comprehend the evolution characteristics of the prehistoric climate of the late Pleistocene in the middle area of loess plateau,we divided the sporopollen diagram into three different zones according to the geological investigation,intensive samples chosen and sporopollen analysis to fifty-four samples of the cross section in Shaanxi-Fu County.The three zones represented S_(1)、L_(1) and S_(0) sedimentary periods respectively.The first zone is combinatorial zone of Corylue-Compositae-Artemisia,with the characteristic that herbaceous plant pollen is predominant and the arbor plant pollen is of high content.The second zone is combinatorial zone of Compositae-Artemisia,with the characteristic that herbaceous plant pollen is predominant and the decrease of arbor plant pollen.The third which is named combinatorial zone of Pinus-Chenopodiaceae-Selaginella tamariscina is marked by the increase of Pinus、Chenopodiaceae、Selaginella tamariscina pollen and the increase of arbor pollen.The result indicated that the vegetation of S_(1) sedimentary periods was savannah forest grassland,climate was warm and weter;The vegetation of L_(1)sedimentary periods was dry grasslands,climate was cold and dry;The vegetation of S_(0) sedimentary periods was forest grassland.climate was warmer,cool and droughty.