Wildfire is the largest disturbance in Canada’s boreal region. Post-disturbance resilience of boreal ecosystems depends on the ecohydrological recovery and reestablishment of keystone species, such as mosses.

We examined post-fire moss accumulation and moss moisture stress (soil water tension, soil moisture) in triplicate burned and unburned Boreal Shield landscape units (Sphagnum moss in shallow peatlands, deep peatlands middles and margins, and upland Polytrichum moss mats) 5-years post-fire. Our measurements were compared to previously identified thresholds of moisture stress to inform how moss resiliency can be identified and prioritised in adaptive management strategies.

The greatest soil water tension was in upland Polytrichum mats in both burned and unburned landscapes, and the lowest tension was in deep peatlands middles, in both landscapes. We found no significant difference in the drought resilience between the burned and unburned landscapes 5-years post fire. Depth of burn, remnant post-fire soil depth, and post-fire soil accumulation did not show a significant relationship with the moss tension 5-years post fire. Rather, current soil depth best explained moss moisture stress in burned and unburned landscapes.

Our findings suggest that moss stress decreases with increasing soil depth (soil water storage), and that moss stress decreases with increased moss recovery. Ongoing research will determine the critical depth for greater moss resiliency through Hydrus-1D modelling with the aim to provide researchers and practitioners information to maximise ecosystem recovery in active post fire restoration.