Many oak stands (Quercus spp.) have been managed as coppices for firewood production for centuries in the Mediterranean area. After the abandonment of firewood production during the 1980s, current management practices attempt to convert coppices into coppices-with-standards through thinning and promoting forest regeneration via sexual reproduction. In this work, we used long-term data from repeated forest inventories and dendrometers in a thinning trial to assess the effects of thinning and climate on the intra- and inter-annual growth dynamics of Quercus pyrenaica Willd. coppices. Our results revealed that thinning favored the growth of Q. pyrenaica trees, especially when the stand density reduction was high (ca. 50% of the basal area extracted). Unthinned plots displayed more natural mortality i.e., self-thinning. Growth was enhanced with low vapor pressure deficit. Intense thinning treatments displayed higher intra-annual growth rates and interacted positively with rainfall to induce higher growth. We conclude that thinning, especially intensive thinning, may alleviate the negative effects of dry years and thus could provide a potential measure to adapt these stands to the different climatic scenarios with higher temperatures and less precipitation within the framework of sustainable forest management.

This study has been funded through the Agreement EG17-042 between the Ministry of Agriculture and INIA. DMF was supported by Juan de la Cierva Formación Post-Doctoral program (FJC2018-037870-I) and DMB was funded by projects AGL2015-73190-JIN and RYC-2017-23389 from the Spanish Ministry of Science and Innovation. We also thank two anonymous reviewers for their helpful comments, which improved the quality of the work.

11 Pág. Instituto de Ciencias Forestales (ICIFOR)

Peer reviewed