Prescribed burning in spring or autumn did not affect the soil fungal community in Mediterranean Pinus nigra natural forests

Abstract

In the context of global change, wildfires are not only a threat but are also increasing in their severity in forest ecosystems worldwide, affecting and modifying vegetation, wildlife, and fungal dynamics. Mediterranean ecosystems are frequently affected by fire and prescribed burning is being increasingly used as a tool to reduce the risk and severity of wildfires. Although some of the effects of prescribed burning have been studied, the best moment to perform a prescribed burn to reduce the impact of fire on fungal communities has not been fully investigated. In this study, we analysed the effect of prescribed burning in two different seasons (spring and autumn) on soil fungi associated with natural Pinus nigra forests. Four years after prescribed burning was applied, our analyses showed that the total fungal richness and the composition of fungal communities in spring-burned, autumn-burned, and unburned control plots did not differ significantly. However, analyses of specific phyla and functional trophic groups did reveal some significant differences between spring- or autumn-burned plots and unburned control plots. Valuable edible fungi, which were not affected by the prescribed burning, were also found in the study area. Thus, our results suggest that prescribed burning is not only an interesting tool that could be used to reduce the risk of wildfire but also is compatible with the conservation of fungal communities, and could even promote specific valuable edible species, generating complementary incomes for the rural population. Although further studies are needed, our analyses suggest that the season (spring or autumn) in which prescribed burning is performed does not affect fungal conservation and, therefore, does not need to be one of the factors taken into consideration when selecting the most appropriate time to perform a prescribed burning.