The macromycete flora in roadside verges planted with trees in comparison with related forest types

The results of mycocoenological research in different types of roadside verges with planted Quercus robur and Fagus sylvaticus in Drenthe, northeastern Netherlands, are compared with studies in forest types of the same tree species in the same area. The roadside verges were investigated in the years 1986-1988. Three types of roadside verges with Quercus and two with Fagus were distinguished on the basis of their communities of green plants. Three types of oak forests were studied in the period 1972-1979 by Jansen and IJpelaar (Jansen, 1984). Two types of beech forest were studied by Van Steenis (1991) and Opdam (1991). Forests and roadside verges that were included in this study are situated on sandy soils. A comparison is made between the presence-degrees of macromycete species in these types. The differences between roadside verges with trees and forest communities are described and discussed, emphasizing the different patterns for ectomycorrhizal and saprotrophic fungi. Differences between Quercus and Fagus plots are outlined and discussed. In addition, the data are compared with results of mycocoenological research from other parts of Europe. Efforts are made to explain the occurrence of many characteristic ectomycorrhizal species in roadside verges. The significance of different types of roadside verges and forests for threatened macrofungi is evaluated.