Dynamics of fungal community composition, decomposition and resulting deadwood properties in logs of Fagus sylvatica, Picea abies and Pinus sylvestris

Higher forest management intensity had a negative effect on deadwood volume and in consequence on fungal species richness (sporocarps), but hardly to other analyzed variables. Furthermore, there were significant differences between the tree species for the concentrations of wood constituents and most nutrients as well as the activities of oxidative enzymes, although their course during decomposition was mostly similar among the tree species. We found that molecular species richness increased with the period of decomposition in contrast to the number of fruiting species, which was highest in the intermediate stage of decomposition. Both types of species richness increased with increasing volume of the CWD logs. Regarding the entire period of decomposition, white-rot fungi (WRF), based on identification of sporocarps, were the most abundant group of wood-decaying fungi in all three tree species. This corresponds well with the overall presence of laccase and peroxidases and the concomitant substantial loss of lignin, which points to the importance of these enzymes in deadwood decomposition. We found a continuous decomposition and decline of volume-related concentrations in wood constituents and nutrients with time of decomposition. Contrary to volume-related concentrations, the concentrations related to dry mass frequently increased.