Climate Change and Cultural Response in the Prehistoric American Southwest

Abstract

Comparison of regional tree-ring cutting-date distributions from the southern Colorado Plateau and the Rio Grande region with tree-ring-based reconstructions of the Palmer Drought Severity Index (PDSI) and with the timing of archaeological stage transitions indicates that Southwestern Native American cultures were periodically impacted by major climatic oscillations between A.D. 860 and 1600. Sitespecifi c information indicates that aggregation, abandonment, and out-migration from many archaeological regions occurred during several widespread megadroughts, including the well-documented middle-twelfth-and late-thirteenthcentury droughts. We suggest that the demographic response of southwestern Native Americans to climate variability primarily refl ects their dependence on an inordinately maize-based subsistence regimen within a region in which agriculture was highly sensitive to climate change. RESUMEN La comparación entre las distribuciones de anillos de árboles con fecha de corte de la zona sur de la Colorado Plateau y la región del Río Grande con reconstrucciones basadas en anillos de árboles del Índice Severo de Defi ciencia Palmer (PDSI, por sus siglas en Inglés) y con el momento del período de transición arqueológica, indica que las culturas Nativas

A 2,000-year reconstruction of the rain-fed maize agricultural niche in the US Southwest

“…GDD shows less yearto-year variation than does precipitation. Precipitation reconstructions for both study areas show general agreement with other regional reconstructions of drought 3,16 ; major pan-regional drought episodes occurred in the first half of the first century AD, the mid-AD 100s, mid-AD 700s, late AD 1200s and late AD 1500s. Several major droughts affect the VEPIIS area more strongly than the VEPIIN area, including those around AD 1000, the mid-AD 1100s and the late AD 1400s.…”

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

“…b Distribution of tree-ring dates for the period 900-1400·A.D. (data from Benson and Berry 2009). Black values indicate "death" dates and white values indicate "v" dates (dates that are a few years older than the death date).…”

Who provided maize to Chaco Canyon after the mid-12th-century drought?

“…While the rate of population increase in the Zuni region for the A.D. 1125-1225 period cannot be proven to have resulted from in-migration, megadrought characterized the southern Colorado Plateau between A.D. 1130 and 1177 ( Fig. 1; see, e.g., Benson and Berry, 2009) and it is doubtful that populations expanded during this time period by means other than in-migration.…”