Effect of Deadwood on Ectomycorrhizal Colonisation of Old-Growth Oak Forests

Although the importance of coarse woody debris (CWD) for species diversity is recognized, the effects of coarse woody debris decay class on species composition have received little attention. We examined how the species composition of ectomycorrhizal fungi (ECM) changes with CWD decay. We describe ectomycorrhizal root tips and the diversity of mycorrhizal fungal species at three English oak (Quercus robur L.) sites. DNA barcoding revealed a total of 17 ECM fungal species. The highest degree of mycorrhizal colonization was found in CWDadvanced (27.2%) and CWDearly (27.1%). Based on exploration types, ectomycorrhizae were classified with respect to ecologically relevant soil features. The short distance type was significantly correlated with soil P2O5, while the contact type was correlated with soil C/N. The lowest mean content of soil C-org was found in the CWDabsent site. The difference in total soil N between sites decreased with increasing CWD decomposition, whereas total C/N increased correspondingly. In this study we confirmed that soil CWD stimulates ectomycorrhizal fungi, representing contact or short-distance exploration types of mycelium.