SO2-sensitivity of plant communities in a beech forest.

The ground vegetation of a beech forest was fumigated discontinuously for 4 h per week in transportable open-top chambers with 300 microg SO(2)m(-3), representing the SO(2) peaks in ambient air. This fumigation did not lead to visible injuries, but caused a decrease of productivity and leaf area indices for several of the species occurring. During the fumigation, transpiration and photosynthesis were depressed. The recovery time after the stress was shorter for those species with a lower susceptibility to SO(2).