A COMBINED POLLEN AND PHYTOLITH RECORD FOR 14,000 YEARS OF VEGETATIONCHANGE IN NORTHEASTERN THAILAND

Pollen and phytolith analyses of a 6.18 m core (3KUM) extracted from L ake Kumphawapi, northeastern Thailand provide the oldest continuous se quence of vegetation change for continental Southeast Asia. The combin ed microbotanical data suggest human/environment interaction from at l east the Early Holocene to the present. An amelioration of arid Late P leistocene environments in this region is indicated by the development of herbaceous swamp and swamp forest communities at the core site. Ea rly Holocene vegetation changes reflect the rapid expansion and divers ification of mixed-deciduous forests, which may also have been disturb ed by anthropogenic burning. The Late Holocene reduction in dry-land f orest and the subsequent establishment of secondary-growth forests, su ggests a further change to burning regimes. Changes in both human subs istence strategies as well as climate occurred during this period, inc luding the critical transition to rice agriculture. These changing sub sistence patterns are reflected in the Kumphawapi record by evidence o f shifting burning regimes, including indirect evidence of agricultura l activities in the Middle Holocene. The timing and nature of agricult ural development indicated by the archaeological data for northeastern Thailand needs to be re-evaluated in order to account for the burning regimes and vegetation changes evident in the 3KUM microfossil record . (C) 1998 Elsevier Science B.V. All rights reserved.