The phenology of wilderness use: Backcountry recreation in a changing climate

AbstractPhenology studies are a critical tool for identifying the ways that changing climate affects species and ecosystems. Here, a phenological framework was used to assess the sensitivity of human behavior to temperature and hydroclimate variables that are likely to change as temperatures warm under twenty-first-century climate change. The timing of visitation to wilderness areas of the Sierra Nevada was used as a case study. Visitation timing was assessed using a backcountry permit database and data collected from weblogs or blogs. Mean, earliest, and latest visitation dates were regressed against temperature, streamflow, and snowpack variables: seasonally averaged air temperatures, snow water equivalent (SWE) in spring months, center of timing (CT), and total annual flow. Mean visitation was sensitive to CT, total annual flow, April and May SWE, and spring and summer temperatures, with visitors advancing 0.20–0.28 days for each day advance in CT and 3.7 to 5.7 days for each degree Celsius increase in...