Holocene Palaeoenvironmental Reconstruction Based on Microfossil Analysis of a Lake Sediment Core, Nong Han Kumphawapi, Udon Thani, Northeast Thailand

Abstract

Pollen, phytolith, and charcoal analyses are presented for a Holocene lake sediment core taken from Nong Han (Lake) Kumphawapi, Udon Thani, Northeast Thailand. Major changes appear in the record at approximately 6500 calibrated years B.P. with the establishment of permanent swamp or lake conditions at the core site and a decline in regional arboreal taxa. These changes are difficult to explain in simple climatic terms and are inconsistent with other climatic reconstructions for the region. A coincident increase in disturbance indicators in the microfossil record may reflect human activities, particularly changes to dryland vegetation through the use of fire. The technique appears to be insensitive to the development of intensive wet-rice agriculture, which almost certainly occurred during the period represented by the microfossil record. Despite this, the results indicate good potential for further detailed microfossil analyses at Nong Han Kumphawapi. KEYWORDS: palaeoenvironmental analysis, pollen, origins of rice, Thailand, Southeast Asia.