Characteristics of the modern pollen distribution and their relationship to vegetation in the Xinjiang region, northwestern China

In this study, we examined the modern pollen distribution and its relationship to vegetation communities in the Xinjiang region, an arid area of China, in an effort to provide guidance for reconstructing past vegetation types and climates. We collected 214 surface soil and dust flux pollen samples, from which we identified more than 100 pollen taxa. The geographical distribution of 12 pollen taxa adequately represented the distribution of the plants that produced the pollen. Vegetation formations such as coniferous forests, alpine meadows, halophytic meadows, temperate steppes, temperate deserts, and sandy deserts in the study area had well-defined pollen assemblages. The mean pollen concentrations per unit mass of soil in our samples decreased from coniferous forests to steppes, then to desert shrub communities, and finally to sandy deserts. Pollen concentrations did not appear to be linearly related to the vegetation cover. The results of cluster analysis and principal-components analysis produced vegetation groups that reflected the relationships among the pollen taxa, and provided a basis for subdividing xeromorphic pollen assemblages in arid areas.