Dendrochronology of Quercus ilex L. and its potential use for climate reconstruction in the Mediterranean region

TitleDendrochronology of Quercus ilex L. and its potential use for climate reconstruction in the Mediterranean region
Publication TypeJournal Article
Year of Publication2009
AuthorsCampelo, F., Nabais C., García-González I., Cherubini P., GUTIÉRREZ E., & Freitas H.
JournalCanadian Journal of Forest Research
Volume39
Issue12
Pagination2486 - 2493
Date Published2009///
Keywordsclimate reconstruction (PG), Dendrochronology, dendroclimatology, Quercus ilex
Abstract

Holm oak (Quercus ilex L.) is a long-lived species widely distributed across the Mediterranean Basin, with potential value for dendrochronology and dendroclimatology. However, tree-ring dating in Q. ilex is a complex task that has limited the number of dendrochronological studies using this evergreen species. In the present work, it was investigated if old Q. ilex trees showed annual tree rings and whether they can be used as climate proxies. A long tree-ring chronology (126 years) of Q. ilex was developed using cross sections of 20 trees from the Guadiana river basin (Portugal). The high correlation among tree-ring series suggested that tree growth was controlled mainly by climate. Response function analysis showed a positive correlation between tree-ring width and precipitation from October(t–1) of the previous year to January(t) of the current year and in May(t). Tree-ring width was negatively correlated with the North Atlantic oscillation that exerts a strong influence on the precipitation over Iberia. Negative pointer years were triggered by dry years and became more frequent during the last decade of the 20th century. In conclusion, it is possible to accurately date old Q. ilex trees, and their tree rings could be used for climate reconstructions across the Mediterranean.

URLhttp://dx.doi.org/10.1139/X09-163