Climate scenarios in the Mediterranean predict raising temperatures and more frequent and extreme drought. We focused on analysing the effect of drought on cork growth and chemical composition to evaluate if more frequent and severe forthcoming droughts will compromise the performance of cork as a sealant for wine bottles. A few species can produce cork in a significant proportion. We initiated this research on gathering the available information to put cork oak and its cork under this general panorama. We concluded that the cork from Quercus suber is presently the only raw-material with the characteristics necessary for production of solid cork products and focused our research on it. To study the response of cork-growth to drought and the effect of phellogen age we used a dendroecological methodology and a components resilience analysis, confirming that drought reduces growth and provided extra knowledge on this subject: cork oak is very tolerant and resilient to extreme droughts but more severe droughts correspond to higher decrease of growth and more trees affected although to greater recovery performance. Nevertheless, there are other factors involved in the response: site, tree and the age of the phellogen. Regarding chemical composition the research developed brings insights into the effect of drought on the proportion of its main components. Our results show that, in general, drought does not affect it, with some exceptions. Nevertheless, the variability associated to the tree is much more relevant than the effect of drought conditions and affects all the parameters analyzed. In practical terms, the potential increased occurrence of droughts arising from climatic changes will not compromise the performance of cork as a sealant for wine bottles but cork debarking rotations should be enlarged in order to have the necessary cork plank width, namely if the drought occurs in the first 2 years

Doutoramento em Engenharia Florestal e dos Recursos Naturais / Instituto Superior de Agronomia. Universidade de Lisboa

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