A ∼8000 year fire history from an Arizona/Sonora borderland ciénega

Sediment cores from the San Bernardino Ciénega near Douglas, Arizona and Agua Prieta, Sonora, Mexico were examined to reconstruct the fire history of this region and inform restoration efforts. A ∼8000 year vegetation and fire history record was reconstructed from these sediments using fossil pollen and charcoal. Results from the fire reconstruction show an increase in fire activity coincident with the onset of ENSO, and an increase in fire frequency during the Medieval Climate Anomaly. Preliminary pollen data show taxa that reflect winter-dominated precipitation (Ephedra and Artemisia) correspond to times of greater fire activity. These fire data shed light on the long-term history of fire in desert environments that may be helpful in understanding what fire regimes may be expected with global warming and also how to best incorporate fire into management plans.