新疆夏尔希里自然保护区保持着较为原始的生态环境，是研究植被与环境变化的理想区域。通过在保护区内从海拔1 042~2 426 m的山地草原化荒漠带、山地干草原带和山地森林带采集的33个表土孢粉样品，结合对每个样点做的植被样方调查，根据孢粉数据进行有序聚类分析和冗余分析，探讨了表土孢粉组合特征与植被之间的对应关系。结果表明：3个孢粉组合带的特征与各垂直带植被总体上有较好的对应；藜科和麻黄属花粉含量与样方植物盖度无明显相关性，这两类孢粉呈现超代表性分布特征，应该是随气流从低海拔地带传播到山地高海拔地带的区域外花粉；桦属花粉和豆科花粉与对应的桦木林及锦鸡儿灌丛植被群落有较好的对应；A/C比值和孢粉总浓度大小在区分森林带与草原化荒漠植被带时有明显的指示意义；蕨类植物孢子与降水量和海拔高度正相关，豆科植物花粉与温度正相关。由于山地地形因素引起的土壤、水分及光照度差异，在相同海拔高度的阳坡与阴坡形成的森林植被和中山草甸植被交替的过渡植被，因此孢粉组合中出现较多的花粉混合，进而降低了云杉和桦属花粉与植被盖度的相关性，这类木本花粉与植被之间的数量关系较为复杂。该现象在植物生态学分析中具有普遍性，但对表土孢粉数据在植被与气候定量重建中的应用具有较大的影响。在运用山地表土孢粉数据进行植被与气候定量重建时，需要结合植被样方资料和沉积环境特征对表土孢粉数据进行校正和筛选。
Xiarxili Nature Reserve which maintains an original intact ecosystem is an ideal area for studying the relationship between vegetation and environmental change in Xinjiang,China. In this paper,we collected 33 surface pollen samples from the mountain steppe desert zone,mountain steppe zone to mountain forest zone in this nature reserve area covering the elevation from 1 042 m to 2 426 m,and each sampling site was surveyed.The clustering analysis (CA) and redundancy analysis (RDA) based on the palynology data were carried out,and the relationship among palynology characteristics of surface samples and vegetation survey was discussed.The results show that there was a good fit between the characteristics of the three surface pollen assemblage zones,which were accomplished according to the results of CA and RDA,and the modern vegetation zones.The pollen contents of Chenopodiaceae and Ephedra were not significantly associated with the vegetation coverage,thus Chenopodiaceae and Ephedra presented a super-representative distribution characteristic,indicating that the pollen was transmitted from the lowerelevation region to the higherelevation region with the airflow,and Chenopodiaceae and Ephedra were the exogenous-originated pollen. Betula and Leguminosae pollen had good correspondence with birch grove and Caragana bush. A/C ratio and pollen total concentration had important significance in distinguishing forest zone and steppe desert zone.The RDA results showed that fern spores were positively correlated with precipitation and elevation,and Leguminous pollen was positively correlated with temperature.Because of the difference of soil,moisture and illuminance caused by the variation of mountain topography, different type of vegetation zone formed on the sunny and shady slopes at the same elevation, the forest zone and meadow zone occurred alternately. Influenced by mountain airflow and waterflow, the pollen composition was mixed with things coming from the two vegetation zones, thus the correlation between the pollen content of Picea and Betula and the vegetation coverage was decreased. Therefore, the quantitative relation between pollen and vegetation became more complex, which is universal in the scope of phytoecology. But it has a great impact on the quantitative reconstruction of vegetation and climate when using the surface pollen data, though the mechanism should be further studied. Hence, when using the surface pollen data from the mountain region for quantitative reconstruction, it is necessary to investigate the vegetation status of sampling sites in detail and analyze the characteristics of sedimentary environment, and should correct and filter the surface pollen data.
