HOLOCENE FIRE HISTORY RECONSTRUCTION OF LILY LAKE, WYOMING

Fire is a vital component of ecosystem functioning within boreal ecosystems. Reconstructing shifts in fire dynamics can provide information about changing climate as well as anthropogenic effects. This study integrates dendrochronology, sedimentary charcoal, and fossil diatoms to reconstruct fire history and functions as an assessment of the effectiveness of combining multiple proxies on various temporal scales. Lily Lake, an alpine lake of glacial origin, is located in the Greater Yellowstone Ecosystem at an elevation of 2,342 meters. Lily Lake has a maximum water depth of 16 meters. It is highly transparent with a deep chlorophyll maximum and, thus, is ideally suited for investigating the relationships between paleolimnological tools to reconstruct fire and mixing depth.

Preliminary diatom assemblage counts were used to create a diatom-inferred stratification index to reconstruct changes in lake stratification patterns over the Holocene. This stratification index was compared to dendrochronology and sedimentary charcoal fire history records of nearby sites to assess whether mixing depth changes were correlated with terrestrial fire events. Preliminary results suggest that these paleolimnological indicators show substantial changes throughout the Holocene and provide greater context for other regional records of fire history.