Post-fire peatland vegetation recovery: a case study in open rich fens of the Canadian boreal forest

Abstract

Fire plays a major role in structuring and the functioning of boreal ecosystems. As peatlands are important components of boreal forests, the impact of fire upon these wetter ecosystems is increasingly studied, but with the main focus on treed peatlands and Sphagnum-dominated bogs so far. Important fires occurring more frequently in the past decade in southern Northwest Territories (Canada) provide the opportunity to assess early post-fire vegetation regeneration in open rich fens (1, 2 and 5-years post-fire) and to better understand early recovery succession. We aimed to 1) evaluate whether and how open rich fens are affected by fire 2) describe short-term vegetation regeneration, for both bryophytes and vascular species. A shift was observed between pioneer bryophytes and brown mosses between the second and fifth-year post-fire. Vascular plants, especially slow-growing species and the ones reproducing mainly by seeds, recovered partially. The first bryophyte species recovering were pioneer species adapted to colonize burned environment such as Marchantia polymorpha or Ceratodon purpureus. For vascular plant species, the ones previously present and capable to regrowth rapidly from unburned plant structures (base of tussocks, rhizomes, roots) were represented by species like Betula glandulosa or Carex aquatilis. The wetter conditions and lower fuel availability of fen depressional biotopes were important factors controlling the resistance and regeneration of species associated with them.

Shortening fire return interval predisposes west‐central Canadian boreal peatlands to more rapid vegetation growth and transition to forest cover

“…However, this declined as the proportional area of forests surrounding peatlands increases (Figure 8b). This is somewhat counterintuitive, given the potential for the expansion of aspen suckers into peatlands; however, the first 8 years represent only the early phase of post‐fire regeneration, and the influence of the remaining seedbed in peatlands following fire may yet manifest (Ellison & Bedford, 1995; Guêné‐Nanchen et al., 2022; Langdon et al., 2020).…”

“…(2022), and Guêné‐Nanchen et al. (2022) observed post‐fire proliferation of short‐statured shrubs, such as Labrador tea ( R. groenlandicum ) in a sample of measured peatlands.…”

Establishing peat‐forming plant communities: A comparison of wetland reclamation methods in Alberta's oil sands region

“…The most common bryophyte to establish was P. pseudotriquetrum , a slender, erect, moss that is widespread in fens and on wet soil over rock (Flora of North America Editorial Committee, 2014). It is not known as a peat‐forming species, but can be a key pioneer in recently burned peatlands (Guêné‐Nanchen et al, 2022; Rowe et al, 2017). Its abundance is consistent with the early seral stage of reclaimed wetlands and may help create the foundation for other mosses to colonize.…”