title: Consistent ozone-induced decreases in pasture forage quality across several grassland types and consequences for UK lamb production.
abstract: In this study we have demonstrated that rising background ozone has the potential to reduce grassland forage quality and explored the implications for livestock production. We analysed pasture samples from seven ozone exposure experiments comprising mesotrophic, calcareous, haymeadow and sanddune unimproved grasslands conducted in open-top chambers, solardomes and a field release system. Across all grassland types, there were significant increases in acid detergent fibre, crude fibre and lignin content with increasing ozone concentration, resulting in decreased pasture quality in terms of the metabolisable energy content of the vegetation. We derived a dose-response function for metabolisable energy of the grassland with ozone concentration, applicable to a range of grassland types, and used this to predict effects on pasture quality of UK vegetation at 1 km resolution using modelled ozone data for 2007 and for predicted higher average ozone concentrations in 2020. This showed a potential total reduction in lamb production in the UK of approximately 4% in 2020 compared to 2007. The largest impacts were in geographical areas of modest ozone increases between the two years, but where large numbers of lambs were present. For an individual farmer working to a very small cost margin this could represent a large reduction in profit, both in regions where the impacts per lamb and those where the impacts per km(2) of grazing land are largest. In the short term farmers could adapt their lamb management in response to changed forage quality by additional supplementary feed of high metabolisable energy content. Nationally this increase in annual additional feed in 2020 compared to 2007 would be 2,166 tonnes (an increase of 0.7%). Of added concern are the longer-term consequences of continual deterioration of pasture quality and the implications for changes in farming practices to compensate for potential reductions in livestock production capacity.
authors.affiliation: Centre for Ecology and Hydrology, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.. Electronic address: fhay@ceh.ac.uk.
authors.forename: Felicity
authors.initials: F
authors.lastname: Hayes
authors.affiliation: Centre for Ecology and Hydrology, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
authors.forename: Gina
authors.initials: G
authors.lastname: Mills
authors.affiliation: Centre for Ecology and Hydrology, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
authors.forename: Laurence
authors.initials: L
authors.lastname: Jones
authors.affiliation: Ricardo-AEA, The Gemini Building, Fermi Avenue, Harwell, Didcot, OX11 0QR, UK.
authors.forename: John
authors.initials: J
authors.lastname: Abbott
authors.affiliation: Environment Department, University of York, Heslington, York YO10 5DD, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Ashmore
authors.affiliation: School of Biology, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Barnes
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: J
authors.initials: J
authors.lastname: Neil Cape
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: Mhairi
authors.initials: M
authors.lastname: Coyle
authors.affiliation: School of Biology, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Peacock
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: Naomi
authors.initials: N
authors.lastname: Rintoul
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Toet
authors.affiliation: Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB, UK.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wedlich
authors.affiliation: Centre for Ecology and Hydrology, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.; School of Biology, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Wyness
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000821:Animal Feed; D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D017753:Ecosystem; D004784:Environmental Monitoring; D065948:Grassland; D058751:Livestock; D008460:Meat; D010126:Ozone / Q000032:analysis*; D012756:Sheep; D006113:United Kingdom
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Air pollution; Grazing; Lambs; Livestock production; Metabolisable energy; Ozone; Pasture quality; Sheep