Document Type
Article
Publication Date
1-28-2022
Department
Michigan Tech Research Institute
Abstract
Forest characteristics, structure, and dynamics within the North American boreal region are heavily influenced by wildfire intensity, severity, and frequency. Increasing temperatures are likely to result in drier conditions and longer fire seasons, potentially leading to more intense and frequent fires. However, an increase in deciduous forest cover is also predicted across the region, potentially decreasing flammability. In this study, we use an individual tree-based forest model to test bottom-up (i.e. fuels) vs top-down (i.e. climate) controls on fire activity and project future forest and wildfire dynamics. The University of Virginia Forest Model Enhanced is an individual tree-based forest model that has been successfully updated and validated within the North American boreal zone. We updated the model to better characterize fire ignition and behavior in relation to litter and fire weather conditions, allowing for further interactions between vegetation, soils, fire, and climate. Model output following updates showed good agreement with combustion observations at individual sites within boreal Alaska and western Canada. We then applied the updated model at sites within interior Alaska and the Northwest Territories to simulate wildfire and forest response to climate change under moderate (RCP 4.5) and extreme (RCP 8.5) scenarios. Results suggest that changing climate will act to decrease biomass and increase deciduous fraction in many regions of boreal North America. These changes are accompanied by decreases in fire probability and average fire intensity, despite fuel drying, indicating a negative feedback of fuel loading on wildfire. These simulations demonstrate the importance of dynamic fuels and dynamic vegetation in predicting future forest and wildfire conditions. The vegetation and wildfire changes predicted here have implications for large-scale changes in vegetation composition, biomass, and wildfire severity across boreal North America, potentially resulting in further feedbacks to regional and even global climate and carbon cycling.
Publication Title
Environmental Research Letters
Recommended Citation
Foster, A.,
Shuman, J.,
Rogers, B.,
Walker, X.,
Mack, M.,
Bourgeau-Chavez, L.,
Veraverbeke, S.,
&
Goetz, S.
(2022).
Bottom-up drivers of future fire regimes in western boreal North America.
Environmental Research Letters,
17(2).
http://doi.org/10.1088/1748-9326/ac4c1e
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/15848
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© 2022 The Author(s). Published by IOP Publishing Ltd. Publisher’s version of record: https://doi.org/10.1088/1748-9326/ac4c1e