Soil fungal communities and succession following wildfire in Ethiopian dry Afromontane forests, a highly diverse underexplored ecosystem

Abstract

Ethiopian dry Afromontane forests are complex ecosystems that have important economic and ecological roles. However, recurrent fire has been a source of disturbance for these forests. We assessed the effect of fire on soil fungal communities in a remnant dry Afromontane forest in Wondo Genet, southern Ethiopia, by analysing soil samples collected from unburned stands and from stands one and ten years after fire using DNA metabarcoding of the ITS2 rDNA. The analysis indicated that the soil fungal community was most diverse soon after a fire disturbance and declined over time. Fungal community composition also differed among stands. Our results also indicated that differences in fungal diversity were stand dependent rather than due to the chronology of the fire history in this forest system. We found higher numbers of mycorrhizal species in burned stands, suggesting that these fungal symbionts could compensate for the effects of nutrient stress caused by fire in these areas. Fungal community composition was also significantly correlated with organic matter content, potassium and magnesium in soil. This work could be considered as a case study since the plots were established in a single stand for each treatment in the dry Afromontane forests of Ethiopia. Thus, we recommend further studies and conclusions regarding other stands need to be taken with caution.