Tree-ring structure and climatic effects in young Eucalyptus globulus Labill. grown at two Portuguese sites: preliminary results

Abstract

Summary Dendrochronological analyses of Eucalyptus are generally rare and mostly restricted to Australia. This work reports an attempt to identify annual ring patterns in young blue gum trees (Eucalyptus globulus Labil) grown in Europe through studying the radial variation of vessel characteristics. Common radial trends were seen such as increasing vessel areas, decreasing vessel abundances and a cyclic variability of vessel characteristics associated to the seasons. Low water availability was related to reduced ring widths in combination with more and smaller vessels. Even with the given juvenility of the investigated eucalypt trees the pith to bark trends of vessel parameters might be useful in dendroecological studies, particularly with respect to drought scenarios. The employed method of using vessel parameters to identify rings seem to be the only accurate way of identifying annual rings in E. globulus.