Report 449
Interpretation of evidence of nitrogen impacts on vegetation in relation to UK
(2011)
Emmett, B.A., Rowe, E.C., Stevens, C.J., Gowing, D.J., Henrys, P.A., Maskell, L.C. & Smart, S.M.
In this second part of the project, the results of the new analysis, together with other sources of independent evidence, are interpreted in respect of implications for “conservation commitments”.

Summary

 

 

 

There is evidence of widespread impacts on nitrogen deposition on semi-natural habitats.  This project considered the implications of new evidence of nitrogen impacts for both conservation commitments and biodiversity targets, and ecosystem service provision.

 

Large areas of the country exceed the critical load and level for reactive nitrogen (N) pollutants, and are predicted to continue to do so in 2020 despite reductions in emissions of reactive N gases.  This project addressed the need to test if this risk is translating to visible change in the wider countryside resulting in broad scale ecological damage which impacts on both conservation commitments and biodiversity targets, and ecosystem service provision.

 

The study was second part of a project to analyse national vegetation data sets in relation to N deposition.  The project statistically analysed eight independent national vegetation surveillance datasets using a consistent approach, to identify evidence of N deposition impacts in four habitat types; acidic and calcareous grassland, heathland and bogs.  The first part of the project, covering the analysis and the results, is published in JNCC Report 447.

 

In this second part of the project, the results of the new analysis, together with other sources of independent evidence, are interpreted in respect of implications for “conservation commitments”. 

 

The results demonstrate effects of nitrogen deposition on habitats through reduced occurrence of a range of plant and lichen species and changes in ecosystem function.  These effects have been shown to occur below current critical loads, but effects also continue after critical loads are exceeded. The report highlights that nitrogen deposition is a serious challenge for the conservation of natural habitats and species in the UK, and this has implications for meeting “conservation commitments”.

 

Recommendations are given for improving both site based and broad scale vegetation surveillance schemes.

 

A project summary, presenting the key messages and summarising the impacts, is also provided.

 
 
ISSN 0963 8091
 
Please cite as: Emmett, B.A., Rowe, E.C., Stevens, C.J., Gowing, D.J., Henrys, P.A., Maskell, L.C. & Smart, S.M., (2011), Interpretation of evidence of nitrogen impacts on vegetation in relation to UK, JNCC Report 449, ISSN 0963 8091