Format: ORAL

Veronica De Micco

University of Naples Federico II, Dept. Agricultura Sciences, via Università 100, I-80055 Portici, Naples, Italy

Ongoing climate change is a major challenge for forest productivity. Indeed, climate change impacts ecosystems directly, through a direct modification of plant growth and physiological behaviour, and indirectly due to the alteration in species composition, thus diversity. Tree vulnerability and forest die-back are rapidly increasing, serious, phenomena, which are attracting more and more attention due to impacts on ecological, social, and economic aspects. The aim of this communication is to highlight how, in the last years, the key role of quantitative wood anatomy in understanding tree acclimation has been more and more recognised, considering that the largest part of global vegetation biomass depends on a thin layer of cells, namely the vascular cambium, whose functioning determines the variability of wood traits. The latter have impact on tree eco-physiological behaviour, given that the limits of metabolic and physiological acclimation are ultimately regulated by the physics of the plants structure. A focus is dedicated to study cases conducted on tree and shrub species in Mediterranean ecosystems which are particularly vulnerable to climate change. The increase in the frequency of extreme events, such as severe and prolonged drought periods, will likely induce plastic adaptive responses in Mediterranean species, thus affecting plant growth, health, and productivity of forestry systems, with consequences on biogeochemical cycles and ecosystem services. Main findings are discussed regarding xylogenesis and anatomical traits of Mediterranean woods, both under natural and semi-controlled conditions, to unravel signals hidden in tree-rings, as intra-annual-density-fluctuations. Indeed, a correct functional interpretation of such signals must be guided by the study of xylogenesis, which helps relate intra-ring variation of traits with intra-seasonal environmental variations. Understanding how the plants have reacted to past environmental changes can help understanding their plasticity and forecasting their responses to future changes, to evaluate possible consequences on ecosystems.