Warmer winter-spring conditions enhance European yew radial increment more than hot-dry summers hinder it near the species southernmost distribution limit

The European yew ( Taxus baccata ) is a relict, protected tree species. Aridification could threaten its persistence near the xeric, southernmost distribution limit of the species. However, there are still no studies on how yew’s long-term radial increment is constrained by drought, and how the drought-increment coupling interacts with land-use changes. To fill this research gap, we used dendrochronology to estimate ages and radial increment rates in six Spanish yew populations subjected to different site aridity levels. Then, climate variables and increment indices were correlated. We also reconstructed releases, which we attributed to the thinning of competing tree species. Most sampled yew trees (84 %) were recruited after the 1960s, when massive rural abandonment lead to the drastic reduction of logging and grazing in the study area. We detected releases linked to a previous thinning during the 2000s of competing pine in a dry site, and releases positively correlated with annual precipitation in the wettest site. Yew radial increment was constrained by cold winter−spring and warm−dry summer conditions (short droughts) in the driest sites. At regional level, drought−increment relationships weakened after the 1990s, when the site−to−site coherence of increment increased. Such drought−increment uncoupling and the positive increment trends observed in several yew populations, confirm that regional aridification is not negatively impacting yew performance. The decreasing influence of drought and the positive responses to warmer winter−spring conditions could be mediated by the topoclimate (shady aspect with wet−cool conditions) of the studied populations. According to radial increment data, southern yew populations inhabiting mountain climate refuges, characterized by wet−cool conditions, tolerate current aridification and their radial increment is boosted by warmer winters and springs. • How European yew ( Taxus baccata ) responds to drought near its rear edge? • Six stands of different aridity were sampled and correlated with climate variables. • Positive radial-increment trends were observed in several yew populations. • Yew increment was constrained by summer drought and by cold winter-spring conditions. • Drought-increment relationships weakened after the 1990s.