Effekter av naturvårdsbränning på markskiktet i boreal skog: Täckningsgrad och återhämtning hos tre artgrupper

Sammanfattning

Natural wildfires have historically constituted a central ecological disturbance in boreal forests, but the reduced fire frequency during the twentieth century has negatively affected ground‑layer vegetation and several fire‑adapted species. Prescribed burning is therefore used as a restoration method to reintroduce fire-related ecological processes. The aim of this study was to examine how bryophytes, lichens, and ericaceous shrubs respond to prescribed burning and how their early successional development progresses following fire. Surveys were conducted in five burned areas and five unburned reference sites within the Lappland Nature Reserve in Västmanland County. In each plot, the cover of the three species groups and the presence of exposed mineral soil were recorded. Differences between treatments were analysed using independent t-tests and Mann-Whitney tests, and temporal changes were assessed using linear regression. Bryophytes and lichens exhibited significantly lower cover in burned areas compared to unburned reference sites, whereas ericaceous shrubs did not differ significantly between treatments. Only ericaceous shrubs showed a significant positive relationship between cover and time since fire. Bryophytes and lichens displayed no statistically detectable recovery during the study period. Field observations indicated that bryophytes primarily occurred in moist microhabitats within burned areas, suggesting that soil moisture may locally mitigate fire effects. The study demonstrates that ground–layer species groups respond differently to prescribed burning and recover at varying rates. In combination with previous research, the findings highlight the need for long-term studies to clarify how variation in fire intensity, microhabitat conditions, and dispersal strategies influence successional trajectories. Such knowledge is essential for optimizing prescribed burning within restoration initiatives such as Life2Taiga.