摘要
This paper presents the pollen assemblages from 108 surface sediment samples from 4 lakes(the Lake Daihai,Lake Hongjiannao,Lake Hulunnao and Lake Duikounao) in the monsoon fringe area of China.The herb pollen taxa Artemisia,Chenopodiaceae,Poaceae and Compositae are the major components of pollen assemblages of the 4 lakes and Pinus,Betula,Quercus,Ulmus,Populus,Ostryopsis and Elaeagnaceae are frequently presented,which reflect regional and local vegetation well.The mean similarity coefficients for samples from the Lake Daihai,Lake Hongjiannao,Lake Hulunnao and Lake Duikounao are 0.66 ± 0.17,0.71 ± 0.11,0.73 ± 0.12 and 0.67 ± 0.12 respectively,so pollen assemblages are relatively consistent in each lake,which shows that focusing and mixing effects have occurred before and after pollen deposition.However,pollen assemblages do differ between sampling sites in each lake.The largest difference is seen in the Lake Daihai,followed by the Lake Duikounao,Lake Hulunnao and Lake Hongjiannao(The mean Euclidean distance is 20.09 ± 11.11,11.22 ± 3.64,10.67 ± 4.03 and 8.44 ± 4.51 respectively).These differences are possibly caused by the differences of focusing and mixing effects,pollen source areas,drainage areas and regional vegetation compositions.The Lake Daihai and Lake Hongjiannao have water deeper than 5 m and strong re-suspension,focusing and mixing effects occur in the lakeshore and shallow water areas,where pollen concentrations are lower than in deeper lake areas.In the Lake Hulunnao and Lake Duikounao,with depths less than 5 m,re-suspension and mixing effects are obvious across the whole lake area,so pollen assemblages and pollen concentra-tions are more consistent among sampling sites in each lake.Comparison between the lake samples and samples from the inflowing river reveals that wind is primary pollen transportation force in the Lake Hongjiannao,where the consistency of pollen assemblage is conspicuous,while there is greater variation in lakes where pollen input is dominated by waterborne sources.
This paper presents the pollen assemblages from 108 surface sediment samples from 4 lakes （the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao） in the monsoon fringe area of China. The herb pollen taxa Artemisia, Chenopodiaceae, Poaceae and Compositae are the major components of pollen assemblages of the 4 lakes and Pinus, Betula, Quercus, Ulmus, Populus, Ostryopsis and Elaeagnaceae are frequently presented, which reflect regional and local vegetation well. The mean similarity coefficients for samples from the Lake Daihai, Lake Hongjiannao, Lake Hulunnao and Lake Duikounao are 0.66±0.17, 0.71±0.11,0.73±0.12 and 0.67±0.12 respectively, so pollen assemblages are relatively consistent in each lake, which shows that focusing and mixing effects have occurred before and after pollen deposition. However, pollen assemblages do differ between sampling sites in each lake. The largest difference is seen in the Lake Daihai, followed by the Lake Duikounao, Lake Hulunnao and Lake Hongjiannao （The mean Euclidean distance is 20.09 ± 11.11, 11.22 ± 3.64, 10.67 ± 4.03 and 8.44 ± 4.51 respectively）. These differences are possibly caused by the differences of focusing and mixing effects, pollen source areas, drainage areas and regional vegetation compositions. The Lake Daihai and Lake Hongjiannao have water deeper than 5 m and strong re-suspension, focusing and mixing effects occur in the lakeshore and shallow water areas, where pollen concentrations are lower than in deeper lake areas. In the Lake Hulunnao and Lake Duikounao, with depths less than 5 m, re-suspension and mixing effects are obvious across the whole lake area, so pollen assemblages and pollen concentrations are more consistent among sampling sites in each lake. Comparison between the lake samples and samples from the inflowing river reveals that wind is primary pollen transportation force in the Lake Hongjiannao, where the consistency of pollen assemblage is conspicuous, while there is greater variation in lakes where pollen input is dominated by waterborne sources.
作者
TIAN Fang1,2,XU QingHai1,2,3,LI YueCong1,2,CAO XianYong1,2,WANG XueLi1,2 & ZHANG LiYan1,2 1 College of Resources and Environmental Sciences,Hebei Normal University,Shijiazhuang 050016,China
2 Hebei Key Laboratory of Environmental Change and Ecological Construction,Shijiazhuang 050016,China
3 Key Laboratory of Western China’s Environmental System(Ministry of Education),Lanzhou University,Lanzhou 730000,China
基金
the Preliminary Special Foundation for National Basic Research Pro- gram of China (Grant No.2003CCA01800)
the Major Program of National Natural Science Foundation of China (Grant No. 40730103)
National Natural Science Foundation of China (Grant Nos.40571166 and 40672107)
the Master Foundation Ministry of Education (Grant No.20050094004)
Hebei Special Foundation for Ph.D (Grant No.06547006-3)
Hebei Foundation for the Key Subject Construction of University
关键词
湖泊
花粉
相似系数
欧几里得
季风
lacustrine pollen, similarity coefficient, Euclidean distance, mixing effect
