In Europe, ambient ozone levels are high enough to cause visible injury in native species. Assessment of visible injury is a feasible way to detect the impacts of this pollutant in forest plants and to identify potential risk areas. Ozone-induced visible injury has been incorporated in monitoring programmes, and it is surveyed at a pan-European scale under the protocols of ICP-Forests.

This Web Site is an initiative of Fundación CEAM, in connection with the activities of the Working Group on Ambient Air Quality of ICP-Forests to provide support for the recognition of ozone symptoms. It contains  photodocumentation on ozone-induced visible and microscopic injury in forest plants. Symptoms have been either observed in the field or reproduced experimentally by fumigating plants with enhanced ozone levels in Open Top Chambers.