Evaluation of the ozone-related risk for Austrian forests

Tokyo

2006

S. 53-61

Artikel aus einer ZeitschriftUnselbständiges Werk

200130891

Forest ecosystems are particularly affected by the impact of stress factors. Apart from natural stressors, there are also anthropogenic ones such as air pollutants. Ozone is considered to be the most phytotoxic air pollutant in Austria on a regional scale. In the past decade, concentrations in forested areas have increased significantly by up to 1.6 ppb per year. In order to assess the ozone impact on forests, a nationwide mapping of the AOT 40 for the forested area of Austria was done with the objective to take the ozone Critical Level as defined by the UN-ECE as the basic concept and to develop a threshold value with the help of three approaches. The adaptation of trees to the pre-industrial ozone levels, the parameters affecting stomatal uptake such as light intensity and water vapour saturation deficit, and the hemeroby (altered and natural) of the forest stands were taken into consideration. 61% of the forest area showed a level of more than 10.000 ppb.h. Lower altitude areas with predominantly altered stands were affected more heavily.