Wood lots and horticultural intensification in Prehistoric Tucson, B.C. 2,100-A.D. 500

Abstract

This study presents the results of a long-term, large-data set paleoethnobotanical study of wood use along the Santa Cruz River floodplain, near Tucson, Arizona. Over the interval from 2,100BCE to A.D.50, local villagers depleted regional saltbush stocks by overharvesting them for fuel. At the same time, they became increasingly reliant on mesquite. We explore the implications of the reduction of saltbush, and the dependence on mesquite. We combine information from ancient wood charcoal assemblages, an ancient pollen assemblage, estimates of likely per capita fuelwood consumption rates, and estimates of mesquite and saltbush productivity. We show that vast amounts of land had to be set aside for sustainable mesquite harvesting. We suggest that the need for mesquite management for fuel emerged coevally with agricultural intensification prior to A.D. 50. Thereafter, additional demands for fuel during the Agua Caliente phase further escalated the need for managing wood lots. This study is germane for scholars of the prehistoric American Southwest, and also for people studying pre-pottery early agricultural societies or prehistoric community resource ownership worldwide.