Does the presence of large down wood at the time of a forest fire impact soil recovery?

Abstract

Fire may remove or create dead wood aboveground, but it is less clear how high severity burning of soils affects belowground microbial communities and soil processes, and for how long. In this study, we investigated soil fungal and bacterial communities and biogeochemical responses of severely burned "red" soil and less severely burned "black" soil from a burned forest on the eastern slope of the Cascade Range in Oregon. Specifically, we examined the effects of burn severity on soil nutrients and microbial communities for 1-4 years after wildfire. Soil nutrients were significantly reduced in red soils. Soil fungi and bacteria, assessed with molecular methods, steadily colonized both burn severities and soil biodiversity increased throughout the study showing that microbial communities seem to have the capacity to quickly adjust to extreme disturbances. Although richness did not vary by soil type, the fungal and bacterial community compositions varied with burn severity. This difference was greatest in the early time points following the fire and decreased with time. However, nutrient-limited conditions of red soils were detected for four years after the wildfire and raise concern about soil productivity at these sites.

Wildfire severity reduces richness and alters composition of soil fungal communities in boreal forests of western Canada

“…We found the common fungi in the NWT were comparable to other boreal regions. Pezizomycetes are known to fruit after fire and includes our most common sequence, Calyptrozyma (Fujimura, Smith, Horton, Weber, & Spatafora, 2005;Smith et al, 2017). This was closely related to a sequence of fungus that colonized roots after fires in Alaska (Bent et al, 2011) but this genus is deemed not to be mycorrhizal according to FUNGuild.…”

Resilience to fire of phylogenetic diversity across biological domains

“…() reported this trend in soil ectomycorrhizal fungi as consequence of the predominance of Ascomycetes after fire, which we also detected when targeting the whole fungal community. Fire‐resistant Ascomycetes show rapid fruiting, stimulated growth and spore germination due to heating (Cairney & Bastias, ; Dix & Webster, ; Reazin, Morris, Smith, Cowan & Jumpponen, ; Smith et al., ), as well as lower sensitivity to dry conditions compared to Basidiomycetes (Rayner & Boddy, ; cited in Nordén, Götmark, Ryberg, Paltto & Allmér, ) making Ascomycetes more competitive under postfire conditions. Such a shift in the competitive hierarchies, together with the competition among postfire fungi (Dix & Webster, ), could explain the increase phylogenetic α diversity in the fungal community.…”

Comunidades fúngicas procedentes de sistemas forestales en Etiopía

“…Forest fires typically have both short-and long-term effects on fungal communities. As a short-term effect, fire causes a reduction in richness Oliver et al, 2015;Reazin et al, 2016) and as a long-term effect, fire also causes a shift in the presence or relative frequencies of fungal species in the forest system Smith et al, 2017). In this study, we also observed the least fungal taxa richness in the recently burned stand.…”

“…The diversity value in early stage of fire might be due to the typical effects of fire to limit the type and number of fungal species appearing in an area. Thus, only a few fungi establish early in post-fire conditions, appearing adapted to the environment created after fire (Hansen et al, 2013;Reazin et al, 2016;Smith et al, 2017). In the following successional stage, however, the diversity values showed non-significant differences with the unburned stand (Fig.…”