NH3 :: Scots pine

Latin name: 

Pinus sylvestris

Impact Type: Direct exposure to pollutant

Key Concerns:

The health of Scots pine in central and western Europe, and in forests such as Thetford, may be affected by increased atmospheric ammonia emissions from intensive livestock farming. Symptoms include needle yellowing, needle loss and large concentrations of N in the foliage. While this problem is largely associated with the Netherlands, there is evidence of damage to Scots pine in the vicinity of intensive animal farms in Scotland (Pitcairn et al. 1998).

Visible damage (including needle loss and yellowing) was observed on Scots pine at sites close to livestock buildings in Scotland, and increased foliar nitrogen and reduced potassium concentrations were measured (Pitcairn et al. 1998). Current year needle concentrations of N were large at 2.3 %, exceeding critical tissue concentrations for damage to Scots pine of 2.2 % reported in the Netherlands (van der Eerden et al. 1998). In the Peel area of the Netherlands where intensive animal husbandry occurs, foliar N content of Scots pine, increased from an average of 1.5 % in 1956 to 2.3 % in 1988, and increased susceptibility to drought stress and fungal disease was observed (de Vries et al. 1995). German studies also found a strong effect of NH4+/NH3 emissions from a poultry house on the vitality of Scots pine (Kaupenjohann et al. 1989).

In the very close vicinity up to 50m damage may be direct although initially on most sites there may be growth stimulation. Increasing deposition will enhance foliar N concentrations, paralleled by an increase in amino acids e.g.Arginine. This will increase the risk of herbivore, pest and pathogen damage, and suppress root uptake of NO3-. A reduced carbon allocation to the roots will increase the risk of drought which can be exacerbated by the negative impacts of NH3 on the stomatal opening. The diversity of associated mycorrhiza is expected to reduce.

Additional Comments:


Critical Load/level: 

Habitat/ Ecosystem Type Critical Load/ Level Status Indication of exceedance Reference
Higher plants

3 µg NH3 m-3 annual mean (uncertainty of 2-4 µg NH3 m-3)

UNECE, 2007

Direct visible injury; species composition changes. Ecosystems where sensitive lichens and bryophytes are an important part of the ecosystem integrity, the critical level is set at 1 µg NH3 m-3.



Fangmeir, A.; Hadwiger-Fangmeir, A.; Van der Eerden, L.J.M.; Jager, H.J. 1994 Effects of atmospheric ammonia on vegetation - a review Environmental Pollution 86 43-82
Kaupenjohann, M.; Dohler, H.; Bauer, M. 1989 Effects of N-emissions on nutrient status and vitality of Pinus sylvestris near a hen house. Plant and Soil 113 279-328
Pearson, J.; Stewart, G.R. 1993 The Deposition of Atmospheric Ammonia and Its Effects on Plants New Phytologist 125 283-305
Pitcairn, C.E.R.; Leith, I.D.; Sheppard, L.J.; Sutton, M.A.; Fowler, D.; Munro, R.C.; Tang, S.; Wilson, D. 1998 The relationship between nitrogen deposition, species composition and foliar nitrogen concentrations in woodland flora in the vicinity of livestock farms. Environmental Pollution 102 41-48
Van der Eerden, L.J.M.; Vries, W.; Dobben, H. 1998 Effects of ammonia deposition on forests in the Netherlands Atmospheric Environment 32 525-532
Van der Eerden, L.J.M.; Dueck, T.A.; Berdowski, J.J.M.; Greven, H.; Dobben, H.F. 1991 Influence of HN3 and (HN4)2 SO4 on heathland vegetation Atic Bot Neerl 40 281-296
Vriers, W.; Leeters, E.E.J.M.; Hendricks, C.M.A. 1995 Effects of acid deposition on Dutch forest ecosystems Water, Air and Soil Pollution 85 1063-1068

Species group: