Historic and paleo hydroclimate, fire, and human activity in the San Luis Valley, Colorado, USA

Keywords: San Luis Valley, drought, wildfire, tree rings, lake sediments
Session Type: Virtual Poster Abstract
Day: Sunday
Session Start / End Time: 2/27/2022 03:40 PM (Eastern Time (US & Canada)) - 2/27/2022 05:00 PM (Eastern Time (US & Canada))
Room: Virtual 27

Abstract

The trends of a hotter, drier, and more fire-prone southwestern United States have become even more pronounced over the past decade, stressing hydrologic and human systems and disrupting ecosystem services. The interplay of drought and human activities is believed to have impacted the timing and frequency of wildfires throughout the southwestern U.S. In the San Luis Valley (SLV), Colorado the current prolonged drought has raised the specter of future fires that will be outside of the scale and intensity observed in the historical record. But the SLV historical record is limited in time and spatial scale. Information contained in environmental proxies may help to constrain uncertainty about natural fire occurrence in the region. Paleo data may also be used to explain long-term patterns in the fire record that cannot be explained by changes in climate alone. However, the SLV lacks overlapping paleorecords of hydroclimate, natural fire, and human activity that provide a long-term context for recent drought and wildfire. In this study, we use instrumental data, gridded reanalysis products, historical documents, and aerial imagery to evaluate the SLV hydroclimatic setting, historic human use, and wildfire preconditioning in the past century, especially during the most recent decade of extended drought. We also examine the state of paleoenvironmental knowledge in the SLV over the Common Era in preparation for using updated, newly collected tree rings and lake sediments which will enhance data resolution and lengthen existing records during a period of important transition from indigenous occupation to colonial exploration and settlement.