The resistance and short‐term resilience of a restored extracted peatland ecosystems post‐fire: an opportunistic study after a wildfire

Abstract

Bogs are known to be relatively resistant and resilient to fire, due to the dominance of wet Sphagnum mosses. Indeed, Sphagnum mosses by holding water, ensure bog resistance, and by regenerating from any fragments left post‐fire, ensure bog resilience. The return of several ecological attributes has been reported in the literature post‐restoration. However, the resistance and resilience have not yet been evaluated in restored peatlands. A fire affecting an extracted peatland restored 10 years ago provided the opportunity to (1) evaluate the losses post‐fire, in terms of phytobiomass and plant cover and (2) assess early vegetation recovery after one growing season post‐fire. The fire response of the restored peatland, in terms of resistance and short‐term resilience, differed between the main plant communities. Sphagnum Lawn communities (Sphagnum species from the Acutifolia subgenus and Eriophorum vaginatum) showed greater resistance to fire losing proportionally less phytobiomass (17%) than Wet Hollow communities (44%) (Sphagnum species from the Cuspidata subgenus and Scirpus cyperinus). Greater resistance of the Sphagnum Lawn likely comes from the Acutifolia Sphagnum species growing in dense carpets with good water retention, along with the E. vaginatum tussocks being able to retain humidity below the tussocks, whereas the looser growth habit of Cuspidata Sphagnum species do not have good capillary rise capacity and Scirpus produced litter that can produce a good fuel. This study reinforces the idea that a peatland restoration approach using reintroduction material dominated by Acutifolia Sphagnum species and tussock cottongrass provides a better resistance and short‐term resilience of restored peatlands.

Initial ecological change in plant and arthropod community composition after wildfires in designated areas of upland peatlands

“…However, we found that following wildfires on sites of conservation interest with relatively high plant diversity, the species composition shifts toward common, pioneer species and away from characteristic upland species. Wildfires similarly may affect communities in “wet hollows” more than those forming a dense “lawn” due to the latter's better water retention (Blier‐Langdeau et al, 2022 ).…”

Ecological resilience of restored peatlands to climate change

“…In August 2014, an accidental fire burned nine hectares of the restored site; seven hectares remained intact, allowing for comparison between burnt and intact areas. Lawn-adapted species Sphagnum Acutifolia and Eriophorum sedges lost less biomass than their wetter hollow counterparts, which were dominated by Sphagnum Cuspidata and Scirpus sedges 73 . With that said, all sites-including the hollows-rapidly recovered.…”

“…We also present evidence that biodiversity, hydrological regime, and peat structure may not be fully restored or maintained, or may take decades to return (if at all), which is why the resilience of restored peatlands is put into question 72 . Still, it has been argued that restoration actions provide some resilience when compared to degraded sites 73 .…”

Post‐fire peatland recovery by peat moss inoculation depends on water table depth

“…Considering ongoing increases in atmospheric carbon and rising global temperatures, a rapid return of typical peatland vegetation is crucial to minimise the loss of previously locked‐up carbon (Nugent et al, 2019). The restoration of peatland vegetation and subsequent ecohydrological processes can also enhance the resistance and resilience of restored peatlands and minimise carbon loss to future extreme climatic events (Blier‐Langdeau et al, 2022; Loisel & Gallego‐Sala, 2022). Consequently, additional restoration action may be necessary along with rewetting to push restored peatlands towards pre‐disturbed states and ensure the long‐term stability of restored peatlands (Granath et al, 2016).…”