新疆表土松科花粉分布的探讨

THE DISCOSSION ON THE POLLEN OF PINE FAMILYIN SURFACE SOIL IN XINJIANG

根据新疆94个表土中松科(包括云杉属和松属,下同)花粉含量讨论其散布规律。在远离林区的荒漠、荒漠草原表土中、松科花粉普遍出现,含量较稳定。小于5%。在沙漠荒漠中,松科花粉的百分含量不稳定。在距林地10～0.5km处,松科花粉含量随近林地而明显增长。平原河谷林及低地草甸中松科花粉含量变幅较大、在高山、亚高山草甸中含量偏高,主因流水作用和地形风作用。

The distribution characteristics of pollen content of pine family are discussed based on 94 samples of surface soil in Xinjiang. (1) Almost all of the samples contain pollen of pine family in the various vegetation belts in Xinjiang. Which shows that the pollen distribution of pine family is very extensive. (2) If the distance is over 10 km from confferous forest, the pollen content of pine family is less than 5%; 10—0.5 km,it increases obviously with nearing the forest;under 5 km, it will be more than 10%. (3) The pollen content of pine family is lower than 5%. and 2—4% in most of the cases in the deserts and desert—steppe. (4) The change range of pollen content of pine family is large in the plain valley forests and the lwand meadows where the content is slightly higher than that in daserts and desert—stoppe due to the alluvial effectivity. (5) Because of airflow action,the pollen content of pine family is higher in the surface soil of upper meadow than that of lower meadow with the same distance from the mountainous forest.