Changing patterns of natural dynamics in old-growth European beech (Fagus sylvatica L.) forests can inspire forest management in Central Europe.

• An unique database on dynamics of eleven beech-dominated old-growth forests in Central Europe since 1970 to 2019 utilised. • The radial increment of beech trees increased whereas the natural mortality decreased significantly during the study period. • European beech appears to be the most vital and competitive species from sub-mountain to mountain zones in Central Europe under ongoing climate change. • Admixture of other species can contribute to profitability of close-to-nature forest management based on European beech. European beech is the dominant native tree species in sub-mountain and mountain zones of the European continent and provides multiple ecosystem services to European society. However, the mountain zone is strongly affected by environmental change. Here, we explore the long-term natural dynamics of European beech-dominated old-growth forests in the Western Carpathians, Central Europe. We use fifty-year measurements of forest stand dynamics from eleven nature reserves strictly protected from any management (some of them included in the UNESCO natural heritage program). The study sites cover a typical range of natural conditions of the beech-dominated altitudinal zone in the Western Carpathians. The database includes long-term pair-wise non-destructive measurements of nearly 3.000 beeches from 1970 through 2019. We aim to investigate three crucial processes of beech forest dynamics: increment, ingrowth, and mortality of beech trees. The results, besides expected interactions, indicated a statistically significant change in radial increment and tree mortality during the study period. The radial increment increased, whereas tree mortality decreased during the past decades. Our findings indicate that European beech has strengthened the role of the most vital and competitive tree species in the elevational range from sub-mountain to mountain zone of Central European mountains during the last 50 years. The species increases the potential of enlarging its current distribution and outcompeting other species at the upper as well as lower elevational range edges. The assumed reasons for such development considering postglacial vegetation development in Europe and upcoming climate change are discussed. Possible implications and ways how to utilize the observed findings in close-to-nature forest management are suggested. [ABSTRACT FROM AUTHOR]