Get access

Vegetation and fire history of a Chinese site in southern tropical Xishuangbanna derived from phytolith and charcoal records from Holocene sediments

Authors

  • Yansheng Gu,

    Corresponding author
    1. Key Laboratory of Biogeology and Environmental Geology (China University of Geosciences), Ministry of Education, Wuhan 430074, China
    2. Institute of Ecology and Environment, China University of Geosciences, Wuhan 430074, China
      *Yansheng Gu, Key Laboratory of Biogeology and Environmental Geology (China University of Geosciences), Ministry of Education, Wuhan 430074, China.
      E-mail: ysgu@cug.edu.cn
    Search for more papers by this author
  • Deborah M. Pearsall,

    1. Department of Anthropology, University of Missouri, Columbia, MO 65211, USA
    Search for more papers by this author
  • Shucheng Xie,

    1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China
    Search for more papers by this author
  • Jianxin Yu

    1. Key Laboratory of Biogeology and Environmental Geology (China University of Geosciences), Ministry of Education, Wuhan 430074, China
    Search for more papers by this author

*Yansheng Gu, Key Laboratory of Biogeology and Environmental Geology (China University of Geosciences), Ministry of Education, Wuhan 430074, China.
E-mail: ysgu@cug.edu.cn

Abstract

Aim  The aims of this paper are to reconstruct the vegetation and fire history over the past 2000 years in a well-preserved rain-forest area, to understand interactions between climate, fire, and vegetation, and to predict how rain forest responds to global warming and increased intensity of human activity.

Location  Xishuangbanna, south-west China, 21–22° N, 101–102° E.

Methods  Phytolith (plant opal silica bodies) morphotypes, assemblages, and indices were used to reconstruct palaeovegetation and palaeoclimate changes in detail. Micro-charcoal particles found in phytolith slides, together with burnt phytoliths and highly weathered bulliform cells, were employed to reconstruct a record of past fire occurrence. A survey of field sediments, lithology, and 14C dating were also employed.

Results  Phytoliths were divided into 11 groups and classified into 33 well-described morphotypes according to their shape under light microscopy and their presumed anatomical origins and ecological significance. The phytolith assemblages were divided into six significant zones that reveal a complete history of vegetation changes corresponding to climate variation and fire occurrence. Phytolith assemblages and indices show that the palaeoclimate in the study area is characterized by the alternation of warm–wet and cool–dry conditions. Phytolith and charcoal records reveal that 12 fire episodes occurred. Comparison of burnt phytoliths with an aridity index (Iph) shows that fire episodes have a strong relationship with drought events.

Main conclusions  Our results indicate that fire occurrence in the tropical rain forest of Xishuangbanna is predominantly under the control of natural climate variability (drought events). Nearly every fire episode is coupled with a climatic event and has triggered vegetation composition changes marked by a pronounced expansion of grasses. This indicates that drought interacts with fire to exert a strong influence on the ecological dynamics of the rain forest. However, the impact of human activity in recent centuries is also significant. Our results are important for understanding the interactions between climate, fire, and vegetation, and for predicting how rain forest responds to global warming and increased human activity.

Get access to the full text of this article

Ancillary