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”.
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
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
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
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.
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