The influence of SO2 on CO2 uptake and peroxidase activity

This study confirms that CO₂ uptake of European conifers increases during needle maturation. Extensive investigations with grafts of several species show that this increase may even mask a deleterious effect of a weak SO₂ stress. In plants which are not dependent on air-borne SO₂ for S nutrition CO₂ uptake was not favored by SO₂. Peroxidase activity of tree foliage may be a valuable stress indication, particularly in areas with light air pollution. It is, however, not specific for air pollution and seems to be most suitable for “active” monitoring.