Sulphur dioxide :: Lichens

Critical Load/Level Values: 

10 µg SO2 m-3 annual mean

Status: 
UNECE, 2004
Habitat/Ecosystem Type: 
Cyanobacterial lichens
Description: 

SO2 dissolves in water to produce acidic ions which are readily absorbed through the lichen thalli disrupting photosynthesis. SO2 has also been shown to inhibit the activity of nitrogenase, which is used by cyanobacterial photobionts to fix atmospheric nitrogen.

Reference: Gries, C. (2008). Lichen sensitivity to air pollution, Chapter 13 in Nash, TH, III (ed.) Lichen Biology (2nd. ed.), Cambridge University Press, Cambridge.

Reliability: 
quite reliable i.e. the results of some studies are comparable