Seedelings of Fagus sylvatica, Quercus robur and Fraxinus excelsior were exposed to ambient ozone air pollution during three years in an open-top chamber experiment at Curno conducted at the Curno facilities site (Northern Italy) (Lat. 45°41'00" N, Long. 9°37'00" E, elevation 245 m a.s.l.). The experiment included also Populus nigra cutlings but, because of their very fast growth, they were coppiced at the end of each year. The experimental set-up included well-watered and drought-stressed plots, in order to assess the role of drought in modifying the effects of ozone stress. At the end of the experiment all plants were cut and the aboveground biomass (dry weight) was determined. In addition, the radial growth was measured by tree-ring analysis. The ring-width data were analyzed jointly with the physiological parameters assessed through the lasting of the experiment, with special reference to the foliar content of chlorophyll, the chlorophyll a efficiency, the stomatal conductance (measured and modelled) and the ozone foliar uptake. The data-set was analyzed with ANOVA and multivariate statistical techniques. The results suggest that the growth of the seedlings in an ozone-rich environment follows species-specific patterns. Not always tree-ring width and biomass decreased. Beside, the response can vary over the years and it needs to plan long-term experiments need.
Biomass and tree-ring analysis in young trees from an open-top chambers study of the effects of tropospheric ozone / Pollastrini M.; Bussotti F.; Cherubini P.; Desotgiu R.; Gerosa G.; Marzuoli R.. - STAMPA. - (2006), pp. 85-85. (Intervento presentato al convegno Workshop IUFRO “Forests under Influence of Air Pollution, Climate Change and Urban Development tenutosi a Riverside, California (USA) nel 10-15 September 2006).