Identifying superior oak provenances: Performance analysis under five varied climatic conditions in Austria

Adapting forests to climate change requires understanding intraspecific variations in tree growth and harnessing genetic diversity for sustainable forestry. We evaluated the growth performance of 21 provenances of Quercus robur and Quercus petraea planted at five climatically distinct Austrian sites. Tree heights were measured at 15 years to assess growth responses and provenance-environment interactions. Results showed that Q. robur was superior across more humid sites, while Q. petraea performed better in drier sites, reflecting their ecological niches. Provenances from different climatic clusters exhibited similar growth under mild conditions. However, under stressful environments, Q. robur and Q. petraea provenances from southern climatic clusters demonstrated greater resilience. We classified provenances into generalists , with consistent growth regardless of the environment, and specialists , with variable growth responses across different conditions. For Q. robur , Austrian provenances generally provided high and stable growth. In contrast, for Q. petraea , provenances from neighboring countries outperformed the Austrian ones. Future climate projections for Austria indicate a shift towards drier and warmer conditions, enhancing the value of stress-adapted provenances. These findings highlight the need to consider both current adaptations and future climate scenarios when selecting provenances for resilient, productive forests. • The growth of 15-year-old trees from 21 provenances of Q. robur and Q. petraea are evaluated across five Austrian sites. • Q. robur thrived in humid sites, while Q. petraea catches up in drier sites. • Mild site conditions yielded similar growth; stress favored provenances south of Austria. • Austrian Q. robur showed stable growth, while non-Austrian Q. petraea outperformed locals. • Future trends favor stress-adapted provenances for resilient forests.