Climate change is speeding up changes in mountain forests in the Alps. By studying forests in Germany's Berchtesgaden National Park over 28 years, researchers found that the forests are getting denser, more complex, and richer in species. The changes are happening faster since the 1980s, with factors like past disturbances and climate playing key roles. Despite warming temperatures, older forest stages slow down the changes. This acceleration in forest dynamics could have big impacts on biodiversity and ecosystem processes.