Flammability of Boreal Landscapes

Increasing short-interval fires are leading to shifts in post-fire regeneration from conifer- to deciduous-dominated parklands or grasslands. Deciduous stands have been considered less flammable due to their wetter foliage than the resinous needles of their coniferous counterparts, and therefore are often considered a fuel-break in short timescales and a landscape-scale negative feedback to burning on longer timescales. It remains unclear whether the increased presence of deciduous species after reburning will enable lower subsequent burning: deciduous stands have been shown to burn within climatically extreme fire seasons, and the fuel structure of emerging post-reburned stands is unknown.

I recieved a Graduate Innovation Award from the Joint Fire Science Program, to examine an aspect of this puzzle: one, how do patterns of fuel in post-fire stands change with additional reburning? and two, do patterns of fuel in reburned stands enable subsequent novel fire behavior?

Methods

To answer those two questions, we worked with a combination of novel field and modeling tools. We’ve measured fuel abundance, dispersion, density, composition and connectivity using both traditional transect lines and newer 3D sampling frames. Our data on fuel patterns in reburned stands informed scenarios built for the physics-based fire behavior model Wildland Urban Interface Fire Dynamics Simulator (WFDS). We found that reburned stands only sustained consistent fire spread under scenarios of extreme fire weather conditions and moderate fuel availability.

More information

In 2022, we recieved an NSF collabrative research award to continue and expand this work. Award specifics here.

JFSP Grant details are here..

Results from this project have been shared at the annual meetings of the Association of Fire Ecology, the Great Plains and Rocky Mountain Geographers and the Alaska Fire Science Consortium.