Decades of warming have relaxed cold-temperature constraints on mountain plant distribution and increased species numbers on mountaintops. An international research team led by scientists from the University of Vienna, together with BOKU University and the Austrian Academy of Sciences, now shows that these changes also create a rising number of losers. The disappearance of plants from summits can take decades but has accelerated over the past 20 years. Rising biodiversity is therefore only part of the story and neglects an important aspect of recent summit vegetation dynamics.