Do cork oak trees grow in the dry, hot summer of the mediterranean climate?

Abstract Monitoring stem radial intra-annual growth dynamics is a useful approach for characterising tree growth responses to climate change. In the Mediterranean there have been only a few studies reporting growth responses of cork oak ( Quercus suber L.) to seasonal water shortages. In this study, we focused on direct monitoring of intra-annual radial growth of mature cork oaks over nine complete years, under a 10-year cork harvesting cycle. Band dendrometers were used to assess growth seasonality in two contrasting sites regarding dryness. We hypothesised that summer dormancy and growth bimodality could vary between sites as they are strongly dependent on environmental conditions. Also, we hypothesised that within sites, growth bimodality intensity might vary over the years following cork harvesting disturbance. Our results revealed that growth bimodality was dominant at the drier site, with trees experiencing growth constraints under high temperatures and lower precipitation at short timescales. In contrast, trees at the wetter site exhibited a consistent summer growth, with high plasticity and responsiveness in their growth phenology, revealing the ability to acclimate in longer timescales. The coupling effects of cork harvesting and growth patterns enhanced the trees’ site-dependent growth strategies. At drier site, trees´ complacent radial growth responses maintain constant growth phenological phases, e.g., timings, and achieve higher peaks with higher growth rates, mainly in the spring (yearly growth range between 9.2 mm.yr − 1 and 4.4 mm.yr − 1 ). At the wetter site, tree’s growth drastic responses are due to varying growth timings and highly sensitive growth peaks and rates (yearly growths ranged between 17.5 mm.yr − 1 and 5.2 mm.yr − 1 ).