N deposition :: a liverwort

Latin name: 
Riccia fluitans

Impact Type: Deposition of pollutant

Key Concerns:

There is evidence that Riccia fluitans actually prefer increased nitrogen inputs. Locally intense nitrogen deposition may therefore favour this species at the expense of other bryophytes (Roelofs 1983).

Additional Comments:

Personal observations suggest liverworts may be more tolerant than their co-habiting mosses to enhanced N inputs. They tend to be more tolerant of shade and many naturally inhabit, grow 'within' other bryophytes. This type of habit may also mean their pollution exposure is substantially modified with their co-habiting plants filtering out much of the nitrogen. Since the genera is probably N limited, at low doses, N effects will probably be positive, enhancing growth and reproductive capacity. 

Critical Load/level: 
Critical Load/ Level

No comparable habitat with established critical load estimate available