SO2 :: Orange-fruited elm-lichen

Latin name: 
Caloplaca luteoalba

Impact Type: Direct exposure to pollutant

Key Concerns:

The Orange-fruited elm-lichen (Caloplaca luteoalba) used to be relatively widespread in the UK, but has suffered a severe decline in the last century. It is now largely confined to the dry bark of mature elm trees (Biodiversity Steering Group 1995). It is probably sensitive to SO2, however there is no published research as to the effects of air pollution on this species.

Additional Comments:

None 

Critical Load/level: 
Habitat/ Ecosystem Type Critical Load/ Level Status Reliability Indication of exceedance Reference
Forests and semi-natural vegetation

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

UNECE, 2004 quite reliable i.e. the results of some studies are comparable

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).

809
References: 
Group, Biodiversity Steering 1995 Biodiversity: the UK Steering Group report Action Plans 2
Species group: