To disappear or to hold on – the fate of Europe's mountain flora in a warming world

Abstract

Europe's largest mountain ranges are hotspots of climate change with potentially profound consequences for its rich and unique flora. Recent evidence is pointing towards strong compositional changes in mountain plant assemblages and the loss of cold‐adapted species. Yet, other studies demonstrate remarkable resilience in these communities owing to their specialised life histories, long generation times and evolutionary history as well as nearby microrefugia brought about by complex terrain and topography. To help solve this apparent ambiguity, we here review how recent climate change is locally impacting mountain floral composition and diversity across Europe. Our review includes different autotrophic taxa ranging from shrubs and ferns to herbaceous species as well as lichens and bryophytes. Particular attention is paid to the importance of microclimates and changing snow conditions in shaping mountain plant community dynamics as well as species‐specific responses to a changing abiotic and biotic context. We show that climate‐change impacts on European mountain flora are multifaceted and highly context dependent. Indirect effects of vegetation changes and novel biotic interactions due to lowland species colonisations and shrubification are likely to dominate at lower elevations, while at higher elevations, demographic inertia and microclimatic heterogeneity can, at least to some extent, buffer the climate‐driven loss of native mountain flora. Synthesis – by linking and comparing insights from mountains across Europe, our review provides a critical perspective on mountain flora's sensitivity to climate change, thus supporting more informed conservation strategies for mountain biodiversity.