Fungi associated with Vitality loss of European beech in central Germany

Abstract Vitality loss of beech is a complex disease of European beech that has been occurring all across central Germany since the summer of 2018, leading to growth loss and causing damage to affected trees. Using a culture-based method, 13 matured European beech trees affected to varying degrees by Vitality loss of beech in central Germany were sampled. The isolation of fungi from each test tree was conducted in a standardised manner, with subsequent culturing, morphotyping and identification of filamentous species. All in all, 181 morphotypes were isolated from twigs, branches and trunks of symptomatic and asymptomatic tissue and identified. Fifteen different orders of Ascomycota and four orders of Basidiomycota were detected. Isolated species and corresponding orders differed greatly depending on the test tree, the sampled tree compartment and the tissue type. However, it could not be shown that the vitality status of the host tree had an effect on the fungal community in asymptomatic tissue, possibly because the effect was superimposed by the site or individual tree characteristics. While, depending on the individual tree, a large number of different fungal species probably contributed to the damage caused by Vitality loss of beech, Biscogniauxia nummularia and Neonectria coccinea were present throughout the whole study area, confirming their high relevance in Vitality loss of beech. Biscogniauxia nummularia was isolated more frequently from the asymptomatic tissue of damaged trees than from the asymptomatic tissue of undamaged trees and is therefore possibly suitable as a bioindicator for the beech vitality.