Prehistoric agricultural intensification in the Society Islands, French Polynesia.

摘要

This thesis challenges the current notion that intensive agriculture was not central to the Society Island (Maohi) chiefdoms of French Polynesia. Based on a reanalysis of the ethnohistoric literature and archaeological survey and excavation program I tested a model of the combined effects of agricultural intensification, increasing social complexity, increasing population, increasing conflict, and human-induced landscape change.;I conducted archaeological research in the Opunohu and Niuroa Valleys (Mo'orea Island), and the Fa'aroa and Matorea Valleys (Raiatea Island). Whereas the large Opunohu and Fa'aroa Valleys are ideally suited for agriculture and habitation, arable and inhabitable land are at a premium in the smaller Niuroa and Matorea Valleys.;Archaeological evidence for a shift from swidden farming to more labor intensive terrace and barrage sites, an increase in number of agricultural sites, and the late settlement of areas with limited agricultural productivity, document agricultural intensification in late prehistory. The ethnohistoric information similarly documents a highly intensive cultivation system composed of six cultivation subsystems encompassing a wide range of cultigens and their varieties.;The synchronous appearance of elite structures and intensive agricultural sites in the 13th century highlight the close relationship between the development of Maohi social complexity and agricultural intensification. Increasing conflict appears to have played only an indirect role in agricultural intensification and was without economic motivation. Population pressure was a factor only in the smaller, more marginal windward valleys in the late period. Land tenure restrictions on productive land in larger valleys and social limits to population growth throughout the leeward islands may account for this.;Prehistoric human-induced landscape change was integral to agricultural intensification. Several lines of evidence from the Opunohu Valley document the association between early swidden farming and alluviation of the valley floor, the conversion of hillslope vegetation, and the degradation of soils. Such changes began after A.D. 600, but the alluviated valley floor was only used for agriculture after a population increase in the 13th century A.D.;Agricultural intensification is a pervasive feature of Maohi prehistory. No single factor accounts for this. Landscape change and increasing social complexity were the common factors in all areas studied. Population pressure and increasing social conflict were less important or only important locally.