Acta Geographica Sinica ›› 2013, Vol. 68 ›› Issue (3): 398-413.doi: 10.11821/xb201303011

Previous Articles     Next Articles

Relationship between surface pollen assemblage and the vegetation in Luonan Basin, eastern Qinling Mountains, Central China

ZHANG Wenchao1, LI Chunhai2, LU Huayu1, TIAN Xianhua3, ZHANG Hongyan1, LEI Fang1, TANG Lingyu4   

  1. 1. School of Geographic and Oceanographic Sciences, Institute for Climate and Global Change Research, Nanjing University, Nanjing 210093, China;
    2. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, CAS, Nanjing 210008, China;
    3. College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China;
    4. Nanjing Institute of Geology and Paleontology, CAS, Nanjing 210008, China
  • Received:2012-08-07 Revised:2012-12-07 Online:2013-03-20 Published:2013-05-10
  • Supported by:

    National Natural Science Foundation of China, No.41072122; No.40930103; No.41021002; The “Strategic Priority Research Program” of the CAS, No. XDA05120704, No. XDA05130201

Abstract: The catchment of South Luohe River in Central China is a major region for investigating modern pollen-environment relationship because it is an environment transitional zone which is sensitive to the climatic change. In this study, 40 surface sediment samples under 10 vegetation types in Luonan Basin, upper catchment of South Luohe River were taken to investigate the relationship between pollen assemblage and plant vegetation. The results show that the surface pollen compositions reflect the vegetation quite well, with unique features among different vegetation types. In the forest topsoils, the average of arboreal pollen percentage is greater than 40%, and the Selaginella sinensis spore content is higher. As to woodland shrubs and shrubs, the tree pollen average is 13.2% and 16.6% respectively, and the shrub pollen is higher than grass samples. And the grass and farmland topsoils are characterized by the low percentages of tree and shrub pollen (<10% and <1%), and high percentages of herb pollen (>80%). Pinus, Quercus and some other tree pollens can indicate the regional vegetation in terms of their dispersal ability. Quercus pollen is under-representative and so is to Pinus, which is quite different from general. Artemisia pollen is significantly over-represented, has poor correlation with plant coverage, and may reflect human disturbance. Gramineae can indicate plants quite well, but with low representation. High percentages of Chenopodiaceae component probably suggest human activities and predominant Selaginella sinensis may be a significant indication of forest environment. Cluster analysis (CA) and principal components analysis (PCA) can distinguish forest and non-forest vegetation well. The former one is better at separating pine and mixed forests, while the latter one at farmland and other non-forest and more stable than that of the cluster analysis. The first axis of PCA analysis is likely to mainly reflect the humidity. The average of surface pollen concentration in Luonan Basin is 1.42 × 105 grains/g. The pollen concentration does not correlate with vegetation coverage, but may help to distinguish vegetation types.

Key words: surface pollen, vegetation type, cluster analysis, PCA, Luonan Basin