燕山南部花粉散布特征

燕山南部花９粉用布特性研究表明，空气中的花粉反映的是植物花期的季节性变化，表 粉是植物多年花粉散布的混合，冲积物花粉与空气中和表土花粉显著不同，是取样点上游表土花粉的混合，与取样点周围植被关系较小。因此，根据冲积物花粉恢复古植被，反映的是整个流域的植被面貌，而不是某一点的植被特征。

MODERN POLLEN DISPERSIONS IN THE SOUTH YANSHAN MOUNTAINS

Study on air pollen, surface pollen and fluvial pollen in south part of the Yanshan Mountains indicates that pollen abundance in air changes with seasons in plants flowering times, while pollen deposition in surface soil varies in several years, and pollen in fluvial sediments are different from air pollen and surface pollen which are mixed with surface pollen from upper river reaches and less well related with growing plants around the sampling site. Reconstructing the ancient vegetation based on fluvial pollen records can reveal the general features of the plants, but are different from the local trees in the sampling site.