Critical tropospheric ozone levels: Preliminary results of ozone fumigation of trees
Faculty of Sciences. Biology
Dordrecht :Springer, 1998
International Conference on Impacts of Global Change on Tree Physiology, and Forest Ecosystems, Nov. 26-29, 1996, Wageningen, Netherlands
University of Antwerp
The response of four tree species -i.e. Populus nigra cv. Wolterson (poplar), Fagus sylvatica (beech), Quercus robur (oak) and Pinus sylvestris (Scots pine) to tropospheric ozone was studied in controlled environment growth chambers during one growing season. With the aim to contribute to the evaluation of critical ozone levels, concentrations were set at: 0 ppb ozone, 40 ppb, 80 ppb (with AOT40 of 10 ppm.h, the proposed critical level) and 100 ppb (with AOT40 of 15 ppm.h). Preliminary results show negative effects of 80 ppb and 100 ppb ozone treatments on stem biomass, stem diameter, leaf abscission rate as well as visible leaf injury. Effects were most pronounced in poplar.