Wildfire and post-fire management effects on early fungal succession in Pinus mugo plantations, located in Curonian Spit (Lithuania)

Abstract

The objective of this study was to evaluate the effects of wildfire and subsequent forest management on the diversity and functional community structure of fungi during early stage of succession in the coastal sand dunes of the Curonian Spit in Lithuania. 12 permanent study plots were established in multiple forest areas: burnt, not managed (B); burnt, clear-cut (C); burnt, clear-cut and reforested (R) and unburnt (U). During three years of the study, a total of 390 different fungal species were determined. The overall number of recorded species in studied post-fire variants comprised 52% (B), 41% (C) and 48% (R) of unburnt sites (U, 261 species). Significantly different species compositions were registered between C and B plots, while no difference was observed between C and R plots. Fungal communities of all burnt sites showed more significant differences stemming from annual changes rather than from types of forest management. Early succession of the post-fire fungal communities maintained the fungi from all defined taxonomical and functional groups. However, a certain alteration within some fungal life styles was observed. The wildfire has negatively impacted the lichens and the mycorrhizal species, as the percentages of these groups decreased from 15% and 12% in U plots to 10% and 3% in B plots. Wood saprobic fungi and soil saprobes were affected negatively by harvesting of the burnt trees that reduced their percentage from 38% and 8% in B plots to 27% and 4% in C plots. Soil-associated fungi were less affected both by fire and post-fire management than the fungi inhabiting above-ground substrates. The percentage of soil-associated fungi initially increased in the burnt sites, but two years after the fire it returned to the pre-fire level. No significant effect on soil-inhabiting fungi was noted for the differently managed post-fire sites.