Abstract
Northern hemispheric background concentrations of ozone are increasing, but few studies have assessed the ecological significance of these changes for grasslands of high conservation value under field conditions. We carried out a 3-year field experiment in which ozone was released at a controlled rate over three experimental transects to produce concentration gradients over the field site, an upland mesotrophic grassland located in the UK. We measured individual species biomass in an annual hay cut in plots receiving ambient ozone, and ambient ozone elevated by mean concentrations of approximately 4 ppb and 10 ppb in the growing seasons of 2008 and 2009. There was a significant negative effect of ozone exposure on herb biomass, but not total grass or legume biomass, in 2008 and 2009. Within the herb fraction, ozone exposure significantly decreased the biomass of Ranunculus species and that of the hemi-parasitic species Rhinanthus minor. Multivariate analysis of species composition, taking into account spatial variation in soil conditions and ozone exposure, showed no significant ozone effect on the grass component. In contrast, by 2009, ozone had become the dominant factor influencing species composition within the combined herb and legume component. Our results suggest that elevated ozone concentrations may be a significant barrier to achieving increased species diversity in managed grasslands.
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References
Ashmore M, Ainsworth N (1995) The effects of ozone and cutting on the species composition of artificial grassland communities. Funct Ecol 9:708–712
Ashmore MR (2005) Assessing the future global impacts of ozone on vegetation. Plant Cell Environ 28:949–964
Bassin S, Volk M, Suter M, Buchmann N, Fuhrer J (2007) Nitrogen deposition but not ozone affects productivity and community composition of subalpine grassland after 3 yr of treatment. New Phytol 175:523–534
Fuhrer J, Shariat-Madari H, Perler R, Grub WT (1994) Effects of ozone on managed pasture: II. Yield, species composition, canopy structure, and forage quality. Environ Pollut 86:307–314
Jarvis RA (1984) Description of soil associations. In: Green RD (ed) Soils and their use in northern England. Soil Survey of England and Wales Bulletin 10, Harpenden
Jäggi M, Ammann C, Neftel A, Fuhrer J (2006) Environmental control of profiles of ozone concentration in a grassland canopy. Atmos Environ 40:5496–5507
Jongman RHG, ter Braak CJF, van Tongeren OFR (1987) Data analysis in community and landscape ecology. Pudoc, Wageningen
Joshi J, Matthies D, Schmid B (2000) Root hemiparasites and plant diversity in experimental grassland communities. J Ecol 88:634–644
Lepš J, Šmilauer P (2003) Multivariate analysis of ecological data using Canoco. Cambridge University Press, Cambridge
Mills G, Hayes F, Jones MLM, Cinderby S (2007) Identifying ozone-sensitive communities of (semi-)natural vegetation suitable for mapping exceedance of critical levels. Environ Pollut 146:736–743
Mills G, Hayes F, Simpson D, Emberson L, Norris D, Harmens H, Buker P (2011) Evidence of widespread effects of ozone on crops and (semi-)natural vegetation in Europe (1990–2006) in relation to AOT40- and flux-based risk maps. Glob Change Biol 17:592–613
Mortensen L (1993) Effects of ozone on growth of several subalpine plant species. Norw J Agric Sci 7:129–138
Nussbaum S, Bungener P, Geissmann M, Fuhrer J (2000) Plant–plant interactions and soil moisture might be important in determining ozone impacts on grasslands. New Phytol 147:327–335
Rämö K, Kanerva T, Nikula S, Ojanpera K, Manninen S (2006) Influences of elevated ozone and carbon dioxide in growth responses of lowland hay meadow mesocosms. Environ Pollut 144:101–111
Rodwell JS (1998) British plant communities; grassland and montane communities. Cambridge University Press, Cambridge
Royal Society (2008) Ground-level ozone in the 21st century: future trends, impacts and policy implications. Science Policy Report 15/08. Royal Society, London
Stampfli A, Fuhrer J (2010) Spatial heterogeneity confounded ozone-exposure experiment in semi-natural grassland. Oecologia 162:515–522
Thwaites RH (1996) The effects of tropospheric ozone on calcaerous grassland communities, PhD thesis, Imperial College, London
Thwaites RH, Ashmore MR, Morton AJ, Pakeman RJ (2006) The effects of tropospheric ozone on the species dynamics of calcaerous grassland. Environ Pollut 144:500–509
Vingarzan R (2004) A review of surface ozone background levels and trends. Atmos Environ 38:3431–3442
Volk M, Bungener P, Contat F, Montani M, Fuhrer J (2006) Grassland yield declined by a quarter in 5 years of free-air ozone fumigation. Glob Change Biol 12:74–83
Wedlich KV (2009) Impacts of troposheric ozone on semi-natural ecosystems. PhD dissertation, University of York
Westbury DB, Dunnett NP (2008) The promotion of grassland forb abundance: a chemical or biological solution? Basic Appl Ecol 9:653–662
Wilbourn S, Davison AW, Ollerenshaw JH (1995) The use of an unenclosed field fumigation system to determine the effects of elevated ozone on a grass-clover mixture. New Phytol 129:23–32
Wilkins RJ (2005) Grassland. In: Soffe R (ed) The countryside notebook. Blackwell, Oxford
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This work was supported by the UK Department for Environment, Food and Rural Affairs as part of contract AQ0811.
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Communicated by Pascal Niklaus.
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Wedlich, K.V., Rintoul, N., Peacock, S. et al. Effects of ozone on species composition in an upland grassland. Oecologia 168, 1137–1146 (2012). https://doi.org/10.1007/s00442-011-2154-2
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DOI: https://doi.org/10.1007/s00442-011-2154-2