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### 黑河中游现代孢粉传播过程研究

1. 兰州大学资源环境学院西部环境教育部重点实验室,甘肃 兰州 730000
• 收稿日期:2016-12-14 修回日期:2017-02-24 出版日期:2017-12-20 发布日期:2017-12-20
• 作者简介:

作者简介：常婧(1993-),女,山西朔州人,博士研究生,主要从事气候变化研究。E-mail:changj16@lzu.edu.cn

• 基金资助:
国家自然科学基金面上项目(41571003),国家自然科学基金重大研究计划-重点支持项目(91125008),国家自然科学基金项目(41301216)资助

### Modern Pollen Transportation Process in the Middle Reach of the Heihe River

Jing Chang(), Zhengchuang Hui(), Haopeng Geng, Xiaofei Hu, Baotian Pan

1. Key Laboratory of Western China's Environmental Systems, Ministry of Education, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, Gansu, China
• Received:2016-12-14 Revised:2017-02-24 Online:2017-12-20 Published:2017-12-20
• Supported by:
National Natural Science Foundation of China(41571003), the Key Project of the Major Research Plan of the NSFC (91125008), National Natural Science Foundation of China (41301216).

Abstract:

Modern pollen assemblages in the arid regions and consequently the fossil ones, considerably differ from the modern vegetation and palaeo-vegetation caused by various dispersal agents, depending on the sampled location and the geographical conditions. Fluvial flow and wind are the main agents to influence the pollen transportation in the arid regions. Exotic pollen carried by these two dispersal agents could interrupt the relationship between the pollen and vegetation. Therefore, the influences of these two dispersal agents on the pollen transportation must be taken into account as reconstructing the palaeo-vegetation and the palaeo-environment via fossil pollen data. Moreover, a distinction should be made between the local pollen, which indicate the conditions around the sapling sites; and the exotic pollen, that rather represent far away vegetation, together with the energy and possibilities of the dispersal agents. To do this, we collected 8 riverbed samples and 7 surface soil samples for pollen analysis across the middle reach of Heihe River, located in the Hexi Corridor. The results showed that wind affects the pollen transportation relatively weak, percentages of exotic pollen transported by wind are usually under 10%. The surface soil pollen assemblages can reflect the distribution of local vegetation. While fluvial flow could carry more pollen from the upland to the study area and strongly affect the pollen transportation. Notably, the percentages of exotic pollen transported by fluvial flow reach up to 39.4%, and exotic pollen becomes the dominance of the pollen assemblages, leading an inaccurate relationship between the pollen assemblages and the local vegetation. The pollen assemblages of fluvial sediments mirror the distribution of upland vegetation and local vegetation.

• P534.63