Air Pollution Affects Pattern of Photosynthesis in Parmelia sulcata, a Corticolous Lichen.

Lichen disks kept in flasks contaminated with sulfur dioxide showed morphologic and photosynthetic abnormalities similar to those of lichens from an industrial center in Sweden, but lichens dried out for 4(1/2) to 6 months in the laboratory showed neither. Thus some kinds of lichens may be absent from city environments because of atmospheric pollutants which destroy chlorophyll.