Using Seismic Line Disturbance to Gain New Insights into Peatland Restoration and Wildfire Management Treatments

Abstract:

Treed peatlands are becoming increasingly vulnerable to severe burning across the Boreal. Smouldering combustion of peat leads to extensive carbon emission and smoke pollution, contributing to potentially hazardous air quality. Traditional wildfire management treatments have been found to be ineffective at reducing surface carbon losses and rate of spread in black spruce dominated peatlands, hence novel treatments must be developed to protect the wildland society interface. We analysed the effect of seismic line disturbance in treed peatlands, where above-ground fuels are removed by heavy machinery, concurrently compressing the ground surface and minimising microtopography. We found that seismic lines intersecting treed peatlands maintained significantly greater canopy openness, and minimal above-ground fuels for at least 55 years post-disturbance. Moreover, the disturbance supported a shift from groundcover dominated by feather mosses to Sphagnum mosses. In-situ measures found that seismic lines had significantly greater near-surface moisture contents that led to lower smouldering potential at the surface, despite greater near-surface bulk density. All seismic line plots had a smouldering potential of less than one, suggesting ignition would not occur. A drying experiment found that after >50 days of successive drying Sphagnum mosses maintained a smouldering potential below one whereas feather moss smouldering potential was as high as eight. An “open and compress” strategy based on insights from seismic line disturbance is now being tested in collaboration with Sphagnum transplants to both restore treed peatlands post-fire, and as a peatland wildfire management treatment to reduce smouldering combustion vulnerability, particularly at the wildland society interface.