Legacies of Prehistoric Agricultural Practices Within Plant and Soil Properties Across an Arid Ecosystem

Summary

Closely integrated research between archaeologists and ecologists provides a long-term view of human land use that is rare in the ecological literature,

allowing for investigation of activities that lead to enduring environmental outcomes. This extended temporal perspective is particularly important in

arid lands where succession occurs slowly and ecosystem processes are mediated by abiotic, geomorphic factors. Numerous studies show that impacts

from ancient human actions can persist, but few have explored the types of practices or mechanisms that lead to either transient or long-term environmental

change. We compared plant and soil properties and processes from a range of landscape patch types in the Sonoran Desert of the US Southwest that supported different, well-documented prehistoric farming practices from AD 750–

1300. Our results show that the types of ancient human activities that leave long-term ecological legacies in arid lands are those that fundamentally alter ‘‘slow variables’’ such as soil properties that regulate the timing and supply of water. Prehistoric Hohokam floodwater-irrigation practices, but not dryland farming techniques, substantially altered soil texture, which was strongly associated with

desert plant community and functional composition. However, prehistoric agriculture did not consistently alter long-term nutrient availability and thus had no impact on ‘‘fast variables’’ such as production of seasonal annual plants that are restricted to periods of ample rainfall. In this arid ecosystem, the inverse texture model explained patterns in plant functional composition at large

scales, but is less predictive of production of shortlived desert annuals that experience a more mesic precipitation regime.

This Resource is Part of the Following Collections

• Legacies on the Landscape

Keywords

Temporal Coverage

Calendar Date: 1200 to 1450

Spatial Coverage

Individual & Institutional Roles

Contributor(s): Arizona State University, Department of Anthropology

Landowner(s): Bureau of Land Management

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