Impact Type: Direct exposure to pollutant
Key Concerns:
The virtual absence of Sphagnum species from the blanket bogs of the southern Pennines has been attributed to high SO2 pollution (Ferguson & Lee 1983a,b). Of the 18 species of Sphagnum reported in the area in 1913, only 5 were recorded in 1964 (Tallis 1964) and of those only S. recurvum is common today (Press et al. 1983).
Impact Type: Direct exposure to pollutant
Key Concerns:
Impact Type: Direct exposure to pollutant
Key Concerns:
Antitrichia curtipendula has been eliminated from much England and Southern Scotland, this is almost certainly due to SO2 (Adams & Preston 1992 , Fowler et al. 2001, Hill et al. 1994, Mulgrew & Williams 2000, Weibull 2000).
Additional Comments:
None
Impact Type: Direct exposure to pollutant
Key Concerns:
The magnitude of O3 impacts on bryophytes in the UK is currently very uncertain. The largest O3 concentrations occur at high altitude sites, and the most severe bryophyte impacts are therefore expected for species at Scottish mountain sites. However, with the exception of the experimental studies of Potter et al. (1996a,b) and others, there has been little demonstration of actual species responses in the field.
Impact Type: Direct exposure to pollutant
Key Concerns:
There have been a number of papers published on the effects of O3 on Sphagnum spp. (Gagnon & Karnosky 1992, Lee et al. 1998, Potter et al. 1996a,b). Most of these are based on fumigation experiments either in controlled-environment chambers or open-top chambers.
Impact Type: Direct exposure to pollutant
Key Concerns:
Impact Type: Direct exposure to pollutant
Key Concerns:
Polytrichum commune may be susceptible to damage by O3 in winter (Potter et al 1996b), if the exposure continues for more than four days (Lee et al. 1998). Potter et al. (1996b) observed no tissue death or visible damage, but there was significant reduction in growth and photosynthesis during winter O3 exposure (150 ppb).
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).
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 Pleurozium schreberi is susceptible to disruption of its metabolism when exposed to high NOX concentrations (35 nl l-1 NO2). However, plants can recover normal rates of metabolism after a pollution free period (Morgan et al. 1992).
Impact Type: Direct exposure to pollutant
Key Concerns:
