Visible leaf injury in young trees of Fagus sylvatica L. and Quercus robur L. in relation to ozone uptake and ozone exposure. An Open-Top Chambers experiment in South Alpine environmental conditions
2008
Gerosa, G. | Marzuoli, R. | Desotgiu, R. | Bussotti, F. | Ballarin-Denti, A.
An Open-Top Chambers experiment on Fagus sylvatica and Quercus robur seedlings was conducted in order to compare the performance of an exposure-based (AOT40) and a flux-based approaches in predicting the appearance of ozone visible injuries on leaves. Three different ozone treatments (charcoal-filtered; non-filtered; and open plots) and two soil moisture treatments (watered and non-watered plots) were performed. A Jarvisian stomatal conductance model was drawn up and parameterised for both species and typical South Alpine environmental conditions, thus allowing the calculation of ozone stomatal fluxes for every treatment. A critical ozone flux level for the onset of leaf visible injury in beech was clearly identified between 32.6 and 33.6 mmol O3m-2. In contrast, it was not possible to identify an exposure critical level using the AOT40 index. Water stress delayed the onset of the leaf visible injuries, but the flux-based approach was able to take it into account accurately. Ozone fluxes are more accurate than AOT40 exposure index in predicting ozone visible foliar injury onset on beech seedlings in South Alpine environmental conditions.
显示更多 [+] 显示较少 [-]