Journal of Archaeological Science 1979, 6, 21 I-233 Ban Chiang and Northeast Thailand; the Palaeoenvironment and Economy Charles Higham” and Amphan Kijngam” Beginning with a detailed presentation of the fauna1 spectra from Ban Chiang and related sites in Northeast Thailand, this essay reconstructs the palaeoenvironment during the period 3500 BC to the end of the prehistoric period. The evidence from the freshwater molluscsfound in prehistoric layers suggests that the first occupantsof Ban Chiang encountereda habitat with permanentlakes and clear, slow moving streams. Since the lakes contracted in the dry season, there were ideal conditions for practising wet swidden agriculture. From c. 1600 BC, the presence of water buffalo and associated changes in the fauna1 spectrumsuggests the inception of wet rice cultivation. Such agricultural intensification, it is held, follows population pressure and accounts for subsequent settlementin the more arid plains of Thailand. Keywords: THAILAND, CAMBODIA, BAN CHIANG, NON NOK THA, PREHISTORIC, KHMER, ZOOLOGY, BIEOS, BUBALUS, GASTROPODS, GROWTH RINGS, PLOUGHING, POPULATION PRESSURE, SWIDDEN- ING, OSTEOLOGY, BONE STRESS. Introduction Excavations in the Sakon Nakhon Basin of Northeast Thailand have provided much environmental and economic data for the period from c. 3500 BC to the present (Figure 1). The objective of this paper is to summarize the fauna1 spectra from Ban Chiang and three related sites, and then to consider their implications for culture history in mainland Southeast Asia. Ban Chiang, Udon Thani Province, is a mound of as yet undetermined extent located at the confluence of three small tributaries of the Songkhram River. Like all other known contemporary sites in the Sakon Nakhon Basin, its location gives it accessto water and extensive, relatively flat low lying soils suitable for cultivation of rice under the inundation system (Higham, 1975a; Schauffler, 1978). Excavations undertaken there in 1974/5 document a six-phaseprehistoric sequence followed by a series of historic occupation layers (Gorman & Charoenwongsa, 1976). The mound was used for both occupation and a cemetery. As was the case at the culturally related site of Non Nok Tha, the occupants placed grave goods with the inhumed dead (Bayard, 1972). These offerings provide much data on ritual, technology and economy. Unlike Non Nok Tha, however, there is also much material from occupation contexts, including shell middens. The fine screening and flotation methods of data recovery have provided biological samples of unrivalled richness from a lowland site in Southeast Asia. Excavations by Schauffler (1976) at Ban Tong, Ban Phak Top and Don Khlang have ‘Department of Anthropology,University of Otago, New Zealand. bFine Arts Department, Bangkok, Thailand. 211 0305-4403/79/03021 I f23 $02.00/O c;‘ 1979 Academic Press Inc. (London) Limited