Extensive and Long-Term Specialization: Hohokam Ceramic Production in the Phoenix Basin, Arizona

The ceramic evidence from 10 sites in the lower Salt River valley, Arizona, represents the entire temporal interval defined as the pre-Classic era of Hohokam prehistory. These data indicate that nearly all of the clay pots consumed in the valley over a period lasting six centuries were manufactured by just a few potter groups. The uninterrupted duration, high volume, and the large variety of vessel forms and wares produced for exchange may have been unparalleled in the prehistoric Southwest. A temporally comprehensive model of pottery manufacture in the Phoenix basin is presented, its implications for the origins of specialization, and the influence of intensive irrigation are discussed. In addition, the implications are considered for a previously published model of the Hohokam economy centered on marketplace transactions (Abbott, Smith, and Gallaga 2007).

Streamflow and Population Change in the Lower Salt River Valley of Central Arizona, ca. A.D. 775 to 1450

Floods and droughts and their effects on Hohokam canal systems and irrigation agriculture play a prominent role in many cultural-historical interpretations of the Hohokam trajectory in the lower Salt River valley (modern-day Phoenix, Arizona metropolitan area). Catastrophic floods and associated geomorphic stream channel changes may have contributed to settlement and population changes and the substantial depopulation of the lower Salt River valley ca. A.D. 1450 or later. In this study, archaeological data on Hohokam domestic architecture is used to infer changes in prehistoric population growth rates from ca. A.D. 775 through 1450 in the most thoroughly documented canal system in the Salt River valley. Changes in growth rates are compared to the retrodictions of annual streamflow discharge volumes derived from tree-ring records. Contrary to expectations, population growth rates increased as the frequency, magnitude, and duration of inferred flooding, drought, and variability increased. These results challenge existing assumptions regarding the relationship among floods and droughts, conditions for irrigation agriculture, and population change in the lower Salt River valley.