Amy Hessl* - West Virginia University
Neil Pederson - LDEO Columbia University
Peter Brown - Rocky Mountain Tree Ring Lab
Baatarbileg Nachin - National University of Mongolia
Tom Saladyga - Concord University
Byambagerel Suran - Colorado State University
Fire is a global process affecting both the biosphere and the atmosphere. Consequently, measuring rates of change in wildland fire and understanding the mechanisms responsible for such changes are important research goals. A large body of modeling studies projects increases in wildfire activity in future decades, but few empirical studies have documented change in modern fire regimes. Identifying generalizable pathways through which climate change may alter fire regimes is a critical next step for understanding, measuring, and modeling fire under a changing climate. Here, I propose three pathways along which fire regimes might respond to climate change: changes in fuel condition, fuel volume, and ignitions. I then apply these pathways to the analysis of the last 200 years of fire activity and land use change in Mongolia using tree ring records of past fire. Increased temperatures in Mongolia have not lead to changes in fire frequency either because of intensive land use or increasing moisture in some regions. Changes in fire severity may be equally important for the earth system and require further attention. Critical research needs include next generation dynamic vegetation models (DGVMs) that consider changes in vegetation alongside changes in human activities, and long fire history records from a variety of vegetation types suitable for validating these DGVMs.