How many, how far? Quantitative models of Neolithic land use for six wetland sites on the northern Alpine forelands between 4300 and 3700 bc

摘要

Dendrochronological studies demonstrate a highly dynamic settlement system in prehistoric wetland sites in the northern Alpine forelands. In this article, we apply an agent-based simulation model of the human-environment system to better understand possible causes of these dynamics. Therefore, we formulate a generic quantitative model of land use and calorie supply in Neolithic wetland sites ca. 4300-3700 bc. Archaeological, geographical and palaeoenvironmental data together with information from an agronomic crop yield model (MONICA) are used in an agent-based simulation of Neolithic land use (WELASSIMO model). We fit the generic model to specific conditions at six archaeological sites and their surrounding environments, using local data. In our simulations, annual crop yields fluctuate markedly around a long term mean which starts to decrease after a few years of crop production. Crop plants supply 60-90% of the annual calorie demand. As sources of readily available non-crop calories are needed to compensate potential low crop yields, we argue that Corylus avellana (hazelnuts) were especially important to provide these extra calories; the simulated importance of non-crop calories is 10-40%. Records of human-induced fires are interpreted as being indicative of a strategy to generally open up the woodland canopy and promote the growth of light-demanding hazel. The extent of the different land use methods is quantified and visualized in tiles of 8 km(2) around the six study sites. The specific vegetation cover, the importance of hunting and the number of livestock animals have a major effect on the total area required.