Sulphur dioxide :: All vegetation types

Critical Load/Level Values: 

20 µg SO2 m-3 annual mean and half-year(Oct-March) mean

Status: 
UNECE, 2004
Habitat/Ecosystem Type: 
Forests and semi-natural vegetation
Description: 

Low temperature appears to enhance the negative effects of SO2, and the lower critical level of 15 µg SO2 m-3 is used where the effective temperature sum (ETS) (i.e. the sum of temperatures) above 5oC is below 1000 degree days (d.d) (Ashmore et al., 1994).

Reliability: 
quite reliable i.e. the results of some studies are comparable
CL reference: 
Manual on methodologies and criteria for modelling and mapping critical loads and levels and air pollution effects risks, and trends,