Mountains harbour disproportionately high biodiversity, including rare and endangered species, but are in general poorly protected. Yet, climate is currently warming at a rapid pace, especially in mountain environments, forcing species to shift their distributions to higher elevations to track the conditions they are adapted to. These shifts to higher elevations have become a global phenomenon with important consequences for ecosystems and human well-being. However, our knowledge about responses of mountain biota to environmental change is still lacking in many respects. The majority of research has so far focussed on species’ responses at their upper, expanding elevational limits and little is known about the dynamics at the lower, retracting limits of species’ distributions or about changes of species’ abundances. Yet, the balance between the two opposing range limits determines whether species ranges expand or contract, and therefore co-determine species’ extinction risk in the future. Furthermore, delayed responses at both lower and upper range limits might cause disequilibria between species’ distributions and climatic conditions that will have to be paid off in the future. In my talk, I will give a global overview of elevational range dynamics of mountain biota with a special emphasis on lower elevational range limits, plant species and case studies from the European Alps.