Natural durability of important European wood species against wood decay fungi. Part 2: Field tests and fungal community

The durability classes (DC) of heartwood from Sessile oak (Quercus petraea) and European larch (Larix decidua) were investigated by in-ground field tests according to EN 350 and EN 252. Tests were performed at five different European field sites. The performance of larch and oak was equal at all fields, resulting in the same average lifetime and DC values at each location. However, basidiomycete lab tests provided completely different durability values, for instance DC 1 for oak and DC 5 for larch. Additionally, the spectrum of fungi was analyzed at pine and beech stakes every half year, over a period of three years, using morphological methods and DNA analysis. The decay was mainly caused by white and soft rot fungi at all five test fields. The mycoflora was influenced by the wood species and the analyzed areas of the exposed specimens. The highest number of fungal species was found in the earth/air transition zone. A total of 98 fungi from 77 genera were detected, whereby not all of them were previously classified as wood degrading fungi.