@article {2040, title = {Mapping Critical Levels for Vegetation: Chapter 3}, year = {2017}, month = {10/2017}, abstract = {

This fully revised version of Chapter 3 of the ICP Vegetaition report includes updates to the critical levels for ozone agreed at the 30th ICP Vegetation Task Force Meeting, 14-17 February, 2017, Poznan, Poland. The critical levels for SO2, NOX and NH3 and associated text have not been changed since the previous version. This version was published in April 2017 (minor edits October 2017).

}, url = {https://icpvegetation.ceh.ac.uk/publications/documents/FinalnewChapter3v4Oct2017_000.pdf}, author = {Defra} } @article {1271, title = {RoTAP: Review of Transboundary Air Pollution: Acidification, Eutrophication, Ground Level Ozone and Heavy Metals in the UK}, year = {2012}, institution = {Centre for Ecology \& Hydrology}, url = {http://www.rotap.ceh.ac.uk/documents}, author = {Defra} } @article {317, title = {The Air Quality Strategy for England, Scotland, Wales and Northern Ireland (Volume 1)}, year = {2007}, publisher = {Department for Environment, Food \& Rural Affairs}, url = {http://www.official-documents.gov.uk/document/cm71/7169/7169_i.pdf}, author = {Defra} } @article {1551, title = {An introductory guide to valuing ecosystem services. }, year = {2007}, institution = {Defra}, address = {London}, url = {http://www.defra.gov.uk/wildlife-countryside/natres/eco-value.htm}, author = {Defra} }