RELATIONSHIPS BETWEEN WOOD TRAITS AND DROUGHT RESISTANCE IN EUCALYPTUS spp: EVIDENCES AND OPEN QUESTIONS

Eucalyptus is one of the main forestry genus with more than 20 million ha. planted worldwide, in addition to the native forests in Oceania, formed by more than 700 species growing in very diverse environments.

Although there is broad knowledge about ecophysiological traits of eucalypts, response to silviculture (of the few planted species) and wood anatomy and technological properties related to industrial uses, we know very little about the relationships between wood anatomy and function in this genus, and their implications for drought resistance.

Moreover, the wood of eucalypts is complex, with mostly solitary vessels surrounded and connected to vasicentric tracheids, fiber tracheids and parenchyma cells, all immersed in a matrix of fibers. The hydraulic functioning of this tissue cannot be understood in terms of the current knowledge of wood hydraulic function developed mostly from conifers and broadleaves with grouped vessels. We present our results related to this topic developed from commercial eucalipt plantations in Argentina and Spain; we compare them to recent (and quite opposite) results from native forests in Australia, and we delineate some of the open questions we are exploring to contribute to the adaptive management and genetic improvement of this genus in a framework of climate change.