Growing scattered broadleaved tree species in Europe in a changing climate: a review of risks and opportunities

Scattered broadleaved tree species such as ashes (Fraxinus excelsior L. and Fraxinus angustifolia Vahl.), black alder (Alnus glutinosa (L.) Gaertn.), birches (Betula pendula Roth. and Betula pubescens Ehrh.), elms (Ulmus glabra Huds., Ulmus laevis Pall. and Ulmus minor Mill.), limes (Tilia cordata Mill. and Tilia platyphyllos Scop.), maples (Acer campestre L., Acer platanoides L. and Acer pseudoplatanus L.), wild service tree (Sorbus domestica L. and Sorbus torminalis L. Crantz), walnuts (Juglans regia L., Juglans nigra L. and hybrids) and wild cherry (Prunus avium L.) are important components of European forests. Many species have high economic, environmental and social values. Their scattered distributions, exacerbated in many cases by human activity, may make them more vulnerable to climate change. They are likely to have less ability to reproduce or adapt to shifting climate space than more widespread species. The general impacts of climate change on these scattered species are reviewed. Some specific risks and opportunities are highlighted for each species, although there is considerable uncertainty and therefore, difficulty in quantifying many specific risks and/or impacts on scattered broadleaved tree species.