Ash and ash dieback in the Czech Republic.
This paper establishes that the lack of restriction in the use of non-indigenous species in the urban environment is enhancing the ash replacement in Czech Republic. To preserve ash in urban environment, it is recommended to plant more resistant species and cultivars of ash, such as manna ash (Fraxinus ornus) or cultivars F. excelsior 'Nana', which seems to be more resistant. The use of some cultivars is limited by the absence of suitable resistant rootstock for grafting. Some non-native ashes like F. pennsylvanica should be also considered.