[Objective] The aim was to explore the relationship of pollen types and blooming plants,pollen fertility and meteorological factors during the falling process of pollen in the atmosphere.[Method] The falling record of pollen in Lanzhou University in spring in 2009 was obtained by 10 m platform natural falling method.The pollen falling number,duration,relationship among falling types and surrounding plants,as well as weather were discussed.[Result] Main pollen types included Populus L.,Salix,Paulownia and Platanaceae.Its pollen falling number,duration was consistent with the flowering period of corresponding plants in the garden;the classification and richness of falling of pollen was influenced by wind.The larger the wind was,the richer the variety become.There was basically no pollen from outside.The authors failed to observe the distinct changes of palynological assemblage in sandy storm weather.[Conclusion] The study could lay basis for the study of the modern progress of natural plants pollen.
三叠纪—侏罗纪之交(Triassic-Jurassic boundary,TJB)发生了三叠纪末的生物大灭绝(end-Triassic mass extinction,ETE),海洋和陆地生态系统都发生了不同程度的崩溃。而在陆地生态系统中,植物群首当其冲,但是该时段的植物群变化的详细数据还相对缺乏。本文在新疆准噶尔盆地南缘郝家沟剖面TJB地层系统采样研究,来揭示该过程的植物群响应。根据孢粉属种组成及含量变化划分了3个孢粉组合,对古气候进行了重建。结果表明,准噶尔盆地南缘TJB的气候演变经历了湿热—湿冷—干热的转换过程。同时对ETE和TJB两个重要界线及灭绝发生的期次关系进行了讨论,由孢粉数据结合前人植物大化石、有机碳同位素地层曲线、生物标志化合物和Hg/TOC全球对比的结果,指示ETE和TJB可能分别位于郝家沟组43层底附近和八道湾组49层底附近;并推测三叠纪末陆地植被的灭绝在高纬度的准噶尔盆地记录到3个期次。在ETE与TJB之间地层中发现了与全球多处记录到的孢子含量激增一致的现象,推测该时期陆地生态系统的波动具有全球性。
