THE EFFECTS OF BLACK SPRUCE FUEL MANAGEMENT ON SURFACE FUEL CONDITION AND PEAT BURN SEVERITY IN AN EXPERIMENTAL FIRE

In the boreal plains ecozone, black spruce (Picea mariana) peatlands can represent large parts of the expanding wildland-urban interface (WUI) and wildland-industry interface (WII). The boreal plains wildfire regime is predicted to increase in areal extent and intensity, amplifying the need for wildfire management to protect the WUI and WII. Forested peatland ecosystems can burn at high intensity and present challenges for wildfire managers such as severe smouldering combustion and large carbon loss. Fuel management techniques such as mulching treatments (converting surface and canopy fuel to a masticated fuelbed) can be applied to black spruce peatlands, yet the impact on fuel load, condition and peat burn severity is unclear. Using observations from an experimental fire we found that a mulch-thinning fuel-treatment could reduce peat depth of burn. However, where peat bulk density was increased by compaction, this led to an increased peat combustion carbon loss relative to the control. Furthermore, near-total combustion of the mulch layer resulted in significantly more surface fuel carbon emission from thinned and stripped fuel-treated areas compared to the control. We argue that while fuel-treatment may benefit smouldering combustion suppression efforts, surface fuel carbon loss should be considered before treatments are implemented on a large scale.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author