Peatland margins are a distinct ecotone especially vulnerable to deep smouldering in the Boreal Plains because they can experience greater water table drawdown during dry periods compared to peatland middles. Margin recovery trajectories have potentially important implications for wildfire behaviour as both the rate of vegetation recovery and community composition control fuel load and flammability. We compared peatland margin and middle vegetation trajectories using a chronosequence of time-since-fire in boreal Alberta, Canada. Margins had unique post-fire indicator species, with a higher broadleaf cover and limited Sphagnum moss colonization. Middles and margins became less distinct with greater time-since-fire, where both were dominated by feathermoss as canopy closure increased. High burn severity in margins can expose the seedbank in the underlying mineral soil to favourable conditions, causing rapid accumulation of broadleaf aboveground biomass and limiting Sphagnum establishment. The rapid accumulation of aboveground biomass increases potential fuel load, while exclusion of Sphagnum increases future smouldering potential given the dense peat in the margin ecotone. However, the dominance of deciduous vegetation for several decades post fire would serve to limit wildfire compared to a conifer-dominated system, particularly post leaf-out. Thus, peatland margins could represent a positive feedback to peat carbon loss for early season fires and a negative feedback for post leaf-out fires due to the interplay between fuel load, fire seasonality, and species flammability. Characterization of margins as distinct ecotones with a separate vegetation structure and species composition from peatland middles provides critical insight about wildfire vulnerability and carbon storage in the Boreal Plains.

泥炭地边缘是一个独特的生态交错带，特别容易受到北方平原深层闷烧的影响，因为与泥炭地中部相比，它们在干旱时期会经历更大的地下水位下降。边缘恢复轨迹对野火行为具有潜在的重要影响，因为植被恢复率和群落组成控制着燃料负荷和可燃性。我们使用加拿大阿尔伯塔省北部火灾发生后的时间序列比较了泥炭地边缘和中部植被轨迹。边缘地区有独特的火灾后指示物种，阔叶覆盖率较高， 泥炭藓 定殖有限。随着火灾发生后时间的延长，中部和边缘变得不那么明显，随着树冠闭合的增加，中部和边缘都以羽毛苔为主。边缘的严重烧伤会使下面的矿质土壤中的种子库暴露在有利的条件下，导致阔叶地上生物量的快速积累并限制 泥炭藓 的形成。地上生物量的快速积累增加了潜在的燃料负荷，而考虑到边缘生态交错带的致密泥炭，排除泥炭藓增加了未来阴燃​​的可能性。然而，与以针叶树为主的系统相比，火灾后数十年落叶植被的主导地位将有助于限制野火，特别是在落叶后。因此，由于燃料负荷、火灾季节性和物种可燃性之间的相互作用，泥炭地边际可能代表对早季火灾的泥炭碳损失的正反馈，以及对落叶后火灾的负反馈。将边缘描述为具有独立植被结构和泥炭地中部物种组成的独特生态交错带，为了解北方平原野火脆弱性和碳储存提供了重要见解。