It is argued that the views put forward by Gardner and Willis are compatible with the opinions expressed in Küster (1997) if consideation is given to the distinctive aspects of the expansion of tree species in Central Europe and the different ecological conditions elsewhere.
Küster, H.1997: The role of farming in the postglacial expansion of beech and hornbeam in the oak woodlands of central Europe . The Holocene7, 239-242 .
