Riparian Oases and Environmental Variation during the Archaic Period in Southern Arizona, 4000 to 2000 BP

Summary

Late Archaic forager-farmers in the Sonoran Desert lived in a resource-rich but water-poor environment. Rivers that flowed through major valleys supported lush riparian habitat, creating linear oases bounded by foothills covered by desertscrub vegetation and “sky island” mountain ranges. Hunting and foraging in these diverse ecosystems supported small but stable populations throughout the region, and by 4000 BP low-level maize agriculture was incorporated into the subsistence diet. Irrigation-based agriculture on river floodplains was developed by 3500 BP, and became an integral though not central part of the subsistence economy. Rivers and their riparian corridors were vulnerable to climatic variation, in particular changes in precipitation regimes due to ENSO fluctuations. We present a reconstruction of the Santa Cruz River in southern Arizona as a case study of human response to local environmental variation. Geomorphic and archaeological data combined with proxy climatic measures based on tree ring records are used to infer potential effects of river regime on forager-farmer communities in the Tucson Basin. Chronological analyses reveal change in early agricultural settlement locations attributable to changes in river conditions. We conclude that the mixed foraging-farming economy minimized risk from local environmental variation, and remained a viable subsistence strategy for some 2000 years.

This Resource is Part of the Following Collections

• Society for American Archaeology 81st Annual Meeting, Orlando, FL (2016)   •
• Understanding the Nature and Timing of Human Responses to Environmental Change

Keywords

Spatial Coverage