Tree species diversity facilitates conservation efforts of European yew

European yew (Taxus baccata) is an endangered long-lived tree species. The species is facing a regeneration failure in a large part of its natural distribution, likely due to interplay of climate change and browsing by herbivores. Forest management approaches that support inter-specific complementarity can help the species mitigate these negative effects. However, a lack of long-term records has prevented an adequate answer to the facilitation hypothesis. Therefore, we compiled unique data from eleven long-term plots established on three sites in the western Carpathian Mountains in 1972, 1989 and 1995. During the past 30–50 years, forest stands were treated by various management alternatives, and the development of stands and regeneration were monitored in 5–12-year intervals. In this study, we tested the hypothesis that an increase in tree species diversity positively correlates with abundance of yew regeneration. Additionally, we compared the relationships between management and no-management alternatives. Our results revealed the positive correlation of tree species diversity and the quantity of yew regeneration. Moreover, an increase in the proportion of maple seedling at the expense of beech supported the establishment of yew seedlings at increased abundance. However, recently (since 1982) the growth of yew saplings did not exceed 20 cm in height, mostly because of heavy damage caused by deer browsing. We conclude that forest managers and conservationists can support the regeneration of yew using the treatments that increase tree species diversity.