Mushrooms on forest fires

Forest fires have always been ignited by natural causes such as lightning and volcanic activity, but in recent times the frequency of such events has increased worldwide - not least due to human activity - including in Saxony (e.g. in Saxon Switzerland). The resulting burn sites are usually recolonized in rapid succession by different groups of organisms and integrated into the existing ecosystems. However, there are still many uncertainties regarding the course of such successions, especially with regard to the role of fungi and mosses.

Two deciduous mosses in particular are emerging as new colonizers in our region: the purple-stemmed horntooth moss(Ceratodon purpureus) and the weather-indicating rotary moss(Funaria hygrometrica). Both species are undemanding and normally colonize ruderal areas. They are therefore not specially adapted to burnt areas, but use them as opportunistic initial colonizers (pioneer plants) and then quickly form larger light green areas in the middle of the still charred areas. The second group of pioneer organisms are fungi. In contrast to the mosses, here we find species that are particularly adapted to fires and forest fires and even require them for their existence. Among the first fungal colonizers are representatives of the burnt-spot cup fungi(Anthracobia spp., see Fig. 7) and the fire cup fungi(Pyronema spp.).

After the devastating fire in the Saxon Switzerland National Park (NP) and the neighboring Bohemian Switzerland NP in the Czech Republic in the summer of 2022, employees of the chair were able to visit the burn sites for the first time in the following September to document fungi (see Figure 7). A second area that we were able to investigate was located in the Gohrischheide (North Saxony), where there was also a large-scale fire in the summer of 2022. The primary objective was to record the Funga as completely as possible at the species level at an early stage of succession. The investigations revealed several as yet undescribed fungal species, two of which we have recently described in the journal Mycological Progress (Karich, A., Jarling, R., Ullrich, R. et al. Two new Agaricomycetes related to post-fire mosses. Mycol Progress 23, 28 (2024). https://doi.org/10.1007/s11557-024-01965-1.