The aim of this study was to examine long-term, cumulative, ozone concentrations in relation to the onset and development of visible foliar injury on several forest, shrub and herb species in southern Switzerland.

The aims were (amongst others):
- to assess the sensitivity to ozone of different plant species and determination of dose-response relationship
to determine, assess and validate visible and non-visible ozone symptoms

Figure 1 shows typical damage on plant leaves

to assess experimentally determined symptoms in the field and to develop a regionalized risk assessment on the basis of ozone monitoring and modelling data.

A low cost method (passive ozone monitoring) for determining integrated ambient ozone exposures was used on 16 out of 17 plots across Switzerland for dose-plant response relationship under natural field conditions.

Figure 2 shows a forestial monitoring site with diffusive samplers.

Reference:
http://www.wsl.ch/projects/ozone_ch/