In order to examine the precontact production system of Rarotonga beyond the limits of the archaeologically visible irrigated taro terraces, a model of potential productivity is created. The model is based on an assessment of the productive potential of soil types and an inventory of precontact crops on Rarotonga. It is used here to examine a number of factors related to production: temporal change in production; reliability of production; the perceived value of land; and settlement. There are a number of limitations to the model as it stands, but its main value lies in its use as a foil against which to examine these other, more interesting aspects of production. The model is based on environmental factors, but the Rarotongan production system is as much a product of history as of environment.
Archaeologists working on precontact horticulture (1) in Polynesia have been most interested in taro (Colocasia esculenta) production, and most of this interest has concentrated on irrigated taro. The reasons for this are simple enough: firstly because irrigated taro terraces survive as sites in ways that shifting or swamp cultivations do not; secondly these sites are large and impressive as well as being easily surveyed and mapped; and finally because, beginning with Wittfogel (1957), hydraulic agricultural systems have featured strongly in the debate on the role of production in the development of sociopolitical complexity (Kirch 1994:5). These factors were a significant contribution to the research design and field work on which this paper is based, and which is in part reported here (see also Campbell 2000, 2001). However taro terraces form only a minor part of precontact production--horticultural methods that leave no direct archaeological trace were more extensive and contributed more to precontact subsistence (see further below). Even without visible site remains, there are definite clues in the environment that enable us to talk about other aspects of production alongside irrigated taro, and to begin to examine an integrated production system, which is what this paper attempts for the island of Rarotonga in the Southern Cook group.
Rarotonga is a typical Polynesian high island. At roughly 11 x 6 km, with a maximum elevation of 653 m, its topography is characterised by deeply incised valleys surrounded by a continuous coastal plain generally about 1 km wide. Surrounding the island is a fringing reef enclosing a shallow lagoon up to 1 km in width. The tapere system of landholding develops out of this concentric resource pattern. Tapere are radial land units, each centred on a valley and containing mountain, coastal plain, lagoon and reef resources. Each tapere was governed by one or more chiefly mata'iapo, who was the (usually) senior (usually) male member of the ngati, or local descent group. Ariki were the highest chiefly grade and exercised vital ritual functions in society as well as heading cross-tapere alliances. Religious ritual was centred on marae, which while not as elaborate as similar structures elsewhere in East Polynesia, are robustly constructed of stone and so survive well as archaeological sites. Less robust house sites are not commonly recorded, particularly on the coastal plain, the zone of modern settlement.
With the arrival of the London Missionary Society in 1827 settlement patterns on Rarotonga changed dramatically. Those who wished to take advantage of the new opportunities of religion and literacy were obliged to relocate to coastal villages. This was followed by a dramatic depopulation due to introduced disease, with the result that inland horticulture and settlement were abandoned (Crocombe 1964:67, Lange 1982:148, Walter 1996:93). Taro production declined in general through the nineteenth century as draft animals and iron tools made dryland cropping easier, and crops that stored for long periods and could be traded to ships, such as kumara, were preferred (Crocombe 1964:86). …