Post-harvest intensification in Late Pleistocene Southwest Asia: plant food processing as a critical variable in Epipalaeolithic subsistence and subsistence change.

The objective of this dissertation is to investigate how developments in post-harvest systems may have influenced hunter-gatherer subsistence change during the Epipalaeolithic (23,970-11,990 14C yr BP cal) of Southwest Asia. The term post-harvest system, as it is used here, refers to the knowledge, technology and co-ordination of labour that are necessary to convert raw plants into edible products and/or storable yields. It is argued that post-harvest systems promote increased abundance in four ways: i) permitting a wider variety of plants or plant parts to be added to the diet ii) transforming a single plant part into several forms of food iii) producing physical or chemical changes that improve the nutrient value and iv) reducing spoilage and/or transforming seasonally available resources into to year-round staple foods. Moreover, it is argued that the development of post-harvest systems entailed more than simple increase: that it transformed hunter-gatherer productive systems. A schematic model is presented to illustrate how developments in post-harvest systems would be expected to transform hunter-gatherer production systems. The links between food processing intensification and resource selection, during periods of resource scarcity and of resource abundance, are also considered. This study is multidisciplinary, bringing together the archaeological and ethnographic records and data from food science and botany. A case study was carried out on the harvesting, processing and nutrient analyses of the mature tubers of sea club-rush Bolhoschoenus maritimus (L.) Palla. Sea club-rush was selected, from among plants recovered from Epipalaeolithic contexts, because it is widespread at early sites, its occurrence has significant archaeological time depth and no previous research of this type has been undertaken on this plant. The results of the case study show that the potential yields and nutrient values of sea club-rush tubers are comparable with those reported for other wild root foods. Like many other wild and domesticated edible roots, the tubers were found to require extensive processing to make them edible. A model is presented which suggests the technological and environmental conditions in which the intensification of sea club-rush tubers is tenable