Many studies have focused on the physiological and morphological responses of Quercus suber to high temperatures and summer drought. Nevertheless, our understanding of the potential of this species to cope with climate change is incomplete. An increase in severity, length and frequency of summer droughts is expected in the Iberian Peninsula over the 21st century. We investigated the potential of cork oak to adapt to climate change in a 4-year study comparing seedling survival from thirteen Spanish populations in a common garden. Acorn size was evaluated as a possible adaptive trait enhancing stress resistance during establishment. Populations originating from sites with the driest summers exhibited the highest survival rates under dry conditions. These populations were characterized by bigger acorns, suggesting selection for this trait across sites experiencing drought. Our findings reveal that northern populations are not well adapted to cope with increasing drought but suggest that they might cope well with the moderate drought increase expected for these zones. However, continental populations are intermediately adapted to dry conditions, while drastic and fast increases in summer droughts are expected to occur in these regions. This extensive and quick change will provide scant chances to adapt making the populations of cork oak in these regions particularly vulnerable to the future climatic conditions.
Bibliographical noteFunding Information:
We are grateful to Pedro Fernández, Laura Castro, Regina Chambel, José María Climent, Pilar Jiménez and all people from the Forestry School of Madrid that collaborated in the setting up of the cork oak field trials under the EU concerted action on cork oak, FAIR I CT 95 0202. We would like also to thank to Salustiano Iglesias and the DGB for the maintenance of the essays and partial financial support. We thank to AEMET (Agencia estatal de Meteorología) for providing the climatic data. We thank to Hervé Bohbot, Christelle Fontaine and James Aronson for providing the map of the distribution of cork oak. Finally, we would like to thank to Matthew Robson for reviewing the English version and his valuable suggestions. This work was funded by the Spanish Ministry of Science (PLASTOFOR, AGL-00536/FOR), Spanish Ministry of Environment and DGB (Convenio UPM-DGB). This study was also supported by a MEC-FPI fellowship (BES-2005-7573) to J.A.R.V.
- Acorn size
- Climate change
- Quercus suber