Nitrogen Deposition

N deposition :: Juniper

Impact Type: Deposition of pollutant

Key Concerns:

Juniper, Juniperus communis, is a member of the cupressaceae and is found on limestone heathland and moorland where it can be widespread but local (Biodiversity Steering Group 1995). It is not known to be sensitive to air pollution. Such sites are normally co N/P limited so that growth responses to N would be limited. Generally growth is slow.

Additional Comments:

N deposition :: Irish Lady's tresses

Impact Type: Deposition of pollutant

Key Concerns:

Irish Lady's tresses (Spiranthes romanzoffiana) is a rare orchid of boggy pastures and meadows which occurs particularly in Northern Ireland, the extreme west of Scotland and at one site in England in south Devon (Biodiversity Steering Group 1995). This UK BAP species has declined in intensive agricultural areas, probably due to eutrophication and habitat loss. Atmospheric N deposition is expected to be a contributing factor since it will increase competition from grasses and tall forbs.

N deposition :: Irish Hare

Impact Type: Deposition of pollutant

Key Concerns:

Current work at CEH Banchory on N deposition and mountain hares (Lepus timidus) suggests that N deposition leads to habitat change with a loss of Racomitrium heath. There is evidence to suggest this can have a negative impact on hare numbers, as an increase in grass species favours sheep over hares. Hare numbers then decline. The exact mechanisms are not known at present, however research is ongoing (van de Wal pers. comm.).

Additional Comments:

N deposition :: Freshwater Sponges

Impact Type: Deposition of pollutant

Key Concerns:

There is evidence from research work in Germany that increased nitrite concentrations have a detrimental effect on the growth and repoduction of freshwater sponges (Kahlert & Neumann 1997). However there is no published research available for Britain and Northern Ireland.

Additional Comments:

None

N deposition :: Filmy ferns

Impact Type: Deposition of pollutant

Key Concerns:

Filmy ferns (Hymenophyllum spp) are small ground or epiphytic ferns often associated with bryophyte communities. They are likely to be sensitive to nitrogen deposition. However, there is no published research on the effect of air pollution on this group, so it is uncertain how filmy ferns compare in sensitivity to bryophytes. As a first approximation, a similar sensitivity might be assumed to the more sensitive bryophyte species.

Additional Comments:

N deposition :: Dotterel

Impact Type: Deposition of pollutant

Key Concerns:

Current work suggests that N deposition leads to habitat change, with a loss of Racomitrium heath (Milne & Hartley 2001). This impacts on the birds through loss of nesting sites and reduction in insect prey (sawfly larvae) for the chicks (van de Wal pers comm.).

Additional Comments:

The move from moss dominated heath to grasses also increases trampling by sheep, so increasing the risk of destruction of nests and eggs. 

N deposition :: Devil's bolete

Impact Type: Deposition of pollutant

Key Concerns:

Devil's Bolete (Boletus satanus) grows in strict association with mature beech trees, so any factors affecting tree health may reduce its vitality. Nitrogen deposition has been shown to alter the competitive balance of soil fungi, with mycorrhizal fungi (of which Devil's Bolete is one) suffering at the expense of saprotrophic and parasitic fungi (van der Eerden et al. 1998).

Additional Comments:

Pages

Subscribe to RSS - Nitrogen Deposition

This page was accessed on Wednesday, September 19, 2018 17:44