USING HISTORIC AND MODERN DATA TO UNTANGLE THE ROLE OF CLIMATE VERSUS MANAGEMENT IN DRIVING LARGE STAND-REPLACING FIRES IN HIGH ELEVATION FORESTS IN CENTRAL IDAHO

Studying fire regimes in the Frank Church Wilderness (FCW) provides an opportunity to understand the history of wildfires in a high elevation wilderness that has experienced little human influence. Studies of wildfire in the Western USA show a marked increase in the size and severity of large fires in high elevation forests; however, these fires are often attributed to both management and climate drivers.

The goal of this research is to better understand past fire regimes ( size, severity, and frequency) in an unmanaged wilderness. The study will include three parts: long term records (datasets extending over thousands of years from prior radiocarbon-based studies, and tree-ring based reconstructions that extend over the past ~500 years), historical records (fire lookout logs and other USFS data), and a modern- satellite era (1970’s to present) fire atlas. I will construct a longer-term record of the timing and estimated size of fires from previous studies to satellite era data to establish trends of fire regimes in the FCW. Future work will compare the archived Forest Service research dataset (Parks et al., 2015) with data on adjacent managed forests to understand if and how prior management (fire suppression, logging, etc.) influence the size, severity, and frequency of fires in high elevation mixed conifer forests. This will provide a relatively unmanaged site to compare with managed but otherwise similar forests of the Frank Church. This study will connect prior studies over a variety of temporal periods that have not been previously combined.

For long term records, I will incorporate, extract, and combine datasets from prior radiocarbon and tree-ring based studies that reconstruct records of fire. The second part of the study is to use historical records from fire lookout logbooks and from USFS and other management records. For the third part of the study, I will use a modern-satellite era beginning in 1972 to 2012 fire atlas that has about 300 fires for evaluation (Parks et al., 2015).

Preliminary data analysis shows a decadal increase in fire size and frequency from 1972-2012. The pilot study was successful at statistically measuring the changes in wildfire size and severity.