NOx :: Stairstep Moss

Latin name: 

Hylocomium splendens

Impact Type: Direct exposure to pollutant

Key Concerns:

Exposure to raised levels of nitrogen oxides can interfere with the plant's metabolism which has the effect of reducing photosynthetic activity and therefore growth (Angold 1997). Morgan et al. (1992) have shown that Hylocomium splendens is susceptible to disruption of its metabolism when exposed to high rates dry nitrogen deposition (35 nl l-1 NO2). However, plants can recover normal rates of metabolism after a pollution free period (Morgan et al. 1992).

Additional Comments:

None 

Critical Load/level: 

Habitat/ Ecosystem Type Critical Load/ Level Status Reliability Indication of exceedance Reference
all vegetation categories

30 µg NOX (as NO2) m-3 annual mean; 75 µg NOX (as NO2 ) m-3 24-hour mean

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

The concentration units are referenced as if all the NOX were in the form of NO2. (see Unit Conversion). The level for NOX should only be applied where levels of SO2 and O3 are close to their critical levels.

809

References: 

Morgan, S.M.; Lee, J.A.; Ashenden, T.W. 1992 Effects of Nitrogen-Oxides on Nitrate Assimilation in Bryophytes New Phytologist 120 89-97

Species group: 

Pollutant: