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Biogeochemistry

, Volume 119, Issue 1–3, pp 125–138 | Cite as

Increased inorganic nitrogen leaching from a mountain grassland ecosystem following grazing removal: a hangover of past intensive land-use?

  • Stephanie T. McGovern
  • Chris D. EvansEmail author
  • Peter Dennis
  • Clive A. Walmsley
  • Alex Turner
  • Morag A. McDonald
Article

Abstract

Heathlands and grasslands occur in montane regions, naturally or due to anthropogenic land-use. These are typically nutrient-poor but exposure to elevated nitrogen deposition and intensive livestock grazing causes large-scale ecological change. We studied the long-term implications of grazing removal on soil and drainage water biogeochemistry and the implications for nitrogen cycling in 50-year replicated grazing exclosures on a montane grassland exposed to high rates of ambient nitrogen deposition. Evidence of ‘ecosystem recovery’ represented by successional change from graminoid to shrub-dominance after cessation of grazing was not reflected in the soil biogeochemistry. Cessation of grazing had a negative impact, with increased soil extractable and soil solution nitrate concentrations; an apparent shift towards a more nitrogen-rich, bacterially dominated microbial community; and the acidification of soils and leachate. The increase in nitrate leaching appears to have been counterbalanced by a decrease in dissolved organic nitrogen leaching, approximately maintaining the overall nitrogen balance of the system, whilst apparently altering ecosystem functioning. High rates of organic matter cycling and inorganic nitrogen uptake in grazed grassland may have sustained ecosystem N limitation under elevated nitrogen deposition. Grazing removal caused long-term over-supply of nitrogen from mineralisation of enriched organic matter, exacerbated by continued high nitrogen deposition, exceeding the uptake demand of heath vegetation and resulting in nitrification and nitrate leaching. This disequilibrium between vegetation and soil following grazing removal has implications for restoration after periods of intensive grazing. Grazing may not simply leave a legacy of nutrient enrichment but its cessation may trigger nitrogen saturation and soil and freshwater eutrophication and acidification which counteract the immediate benefits of natural vegetation recovery. Long term, nitrogen saturation of abandoned grasslands is likely to reduce ecosystem resilience to invasion by nitrophilous species, pathogen attack and vulnerability to environmental pressures such as climate change. We conclude that partial and/or phased reduction in grazing levels may permit the more synchronised recovery of soils and vegetation, thereby avoiding imbalances between nitrogen supply and nitrogen demand and detrimental ecological effects.

Keywords

Environmental pollution Ecosystem resilience Extensive sheep production Land use Nitrogen saturation Soil biogeochemistry 

Notes

Acknowledgments

SM was in receipt of a PhD studentship funded by the Countryside Council for Wales (CCW), now part of Natural Resources Wales (NRW) through the auspices of the Environmental Change University Partnership (a formal partnership between CCW, Centre for Ecology and Hydrology (CEH), Aberystwyth and Bangor Universities, designed to facilitate long-term, integrated environmental research on the pressures on and responses of ecosystems to environmental change). Thanks to Maggie Hatton-Ellis, Dylan Lloyd, Hywel Roberts (NRW) and Steven Hughes (CEH) for assistance in the field and lab. We are grateful to the reviewers of this paper for their positive and constructive comments.

References

  1. Aber J, McDowell W, Nadelhoffer K, Alison M, Berntson G, Kamakea M, McNulty S, Currie W, Rustad L, Fernandez I (1998) Nitrogen saturation in temperate forest ecosystems. Bioscience 48:921–934CrossRefGoogle Scholar
  2. Aerts R, Chapin FS (1999) The mineral nutrition of wild plants revisited: a re-evaluation of processes and patterns. In: Raffaelli DG, Fitter AH (eds) Advances in ecological research. Academic Press, London, pp 1–67CrossRefGoogle Scholar
  3. Allott TEH, Curtis CJ, Hall J, Harriman R, Battarbee RW (1995) The impact of nitrogen deposition on upland surface waters in Great Britain: a regional assessment of nitrate leaching. Water Air Soil Pollut 85:297–302CrossRefGoogle Scholar
  4. Bardgett RD, Leemans DK, Cook R, Hobbs PJ (1997) Seasonality of the soil biota of grazed and ungrazed hill grasslands. Soil Biol Biochem 29:1285–1294CrossRefGoogle Scholar
  5. Britton AJ, Fisher JM (2007) Interactive effects of nitrogen deposition, fire and grazing on diversity and composition of low-alpine prostrate Calluna vulgaris heathland. J Appl Ecol 44:125–135CrossRefGoogle Scholar
  6. Britton AJ, Pearce ISK, Jones B (2005) Impacts of grazing on montane heath vegetation in Wales and implications for the restoration of montane areas. Biol Conserv 125:515–524Google Scholar
  7. Brookes PC, Landman A, Pruden G, Jenkinson D (1985) Chloroform fumigation and the release of soil nitrogen: a rapid direct extraction method to measure microbial biomass nitrogen in soil. Soil Biol Biochem 17:837–842Google Scholar
  8. Curtis CJ, Emmett BA, Reynolds B, Shilland J (2004) Nitrate leaching from moorland soils: can soil C: N ratios indicate N saturation? Water Air Soil Pollut Focus 4:359–369CrossRefGoogle Scholar
  9. Curtis CJ, Evans CD, Helliwell RC, Monteith DT (2005) Nitrate leaching as a confounding factor in chemical recovery from acidification in UK upland waters. Environ Pollut 137:73–82CrossRefGoogle Scholar
  10. Curtis CJ, Evans CD, Goodale CL, Heaton T (2011) What have stable isotope studies revealed about the nature and mechanisms of N saturation and nitrate leaching from semi-natural catchments? Ecosystems 14:1021–1037CrossRefGoogle Scholar
  11. de Vries F, Bloem J, Quirk H, Stevens C, Bol R, Bardgett RD (2012) Extensive management promotes plant and microbial nitrogen retention in temperate grassland. PLoS One 7:1932–6203Google Scholar
  12. de Vries W, Solberg S, Dobbertin MD, Sterba H, Laubhann D, van Oijen M, Evans C, Gundersen P, Kros H, Wamelink GWW, Reinds GJ, Sutton MA (2009) The impact of nitrogen deposition on carbon sequestration by terrestrial ecosystems. For Ecol Manag 258:1814–1823Google Scholar
  13. Downes MT (1978) An improved hydrazine reduction method for the automated determination of low nitrate levels in freshwater. Water Res 12:673–675Google Scholar
  14. Elser JE, Andersen T, Baron JS, Bergström A-K, Jansson M, Kyle M, Nydick KR, Steger L, Hessen DO (2009) Shifts in lake N: P stoichiometry and nutrient limitation driven by atmospheric nitrogen deposition. Science 326:835–837CrossRefGoogle Scholar
  15. Evans CD, Caporn SJM, Carroll JA, Pilkington MG, Wilson DB, Ray N, Cresswell N (2006a) Modelling nitrogen saturation and carbon accumulation in heathland soils under elevated nitrogen deposition. Environ Pollut 143:468–478CrossRefGoogle Scholar
  16. Evans CD, Reynolds B, Jenkins A et al (2006b) Evidence that soil carbon cool determines susceptibility of semi-natural ecosystems to elevated nitrogen leaching. Ecosystems 9:453–462CrossRefGoogle Scholar
  17. FAO (2006) World reference base for soil resources. A framework for international classification, correlation and communication. World Soil Resources Reports 103, Food and Agriculture Organisation of the United Nations, Rome, p 145Google Scholar
  18. Foster D, Swanson F, Aber J, Burke I, Brokaw N, Tilman D, Knapp A (2003) The importance of land-use legacies to ecology and conservation. BioScience 53:77–88Google Scholar
  19. Fowler D, Smith RI, Muller JBA, Hayman G, Vincent KJ (2005) Changes in the atmospheric deposition of acidifying compounds in the UK between 1986 and 2001. Environ Pollut 137:15–25CrossRefGoogle Scholar
  20. Galloway JN, Townsend AR, Erisman JW, Bekunda M, Cai Z, Freney JR, Martinelli LA, Seitzinger SP, Sutton MA (2008) Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science 320:889–892CrossRefGoogle Scholar
  21. Goodale C, Aber JD (2001) The long-term effects of land-use history on nitrogen cycling in northern hardwood forests. Ecol Appl 11:253–267CrossRefGoogle Scholar
  22. Goodale C, Aber JD, McDowell WH (2000) The long-term effects of disturbance on organic and inorganic nitrogen export in the White Mountains, New Hampshire. Ecosystems 3:433–450CrossRefGoogle Scholar
  23. Gordon IJ, Hester AJ, Festa-Bianche M (2004) Review. The management of wild large herbivores to meet economic, conservation and environmental objectives. J Appl Ecol 41:1021–1031CrossRefGoogle Scholar
  24. Gundersen P, Callesen I, de Vries W (1998) Nitrate leaching in forest ecosystems is related to forest floor C/N ratios. Environ Pollut 102:403–407Google Scholar
  25. Hagedorn F, Mulder J, Jandl R (2010) Mountain soils under a changing climate and land-use. Biogeochemistry 97:1–5CrossRefGoogle Scholar
  26. Hannah L, Midgley GF, Lovejoy T, Bond WJ, Bush M, Lovett JC, Scott D, Woodward FI (2002) Conservation of biodiversity in a changing climate. Cons Biol 16:264–268CrossRefGoogle Scholar
  27. Härdtle W, Niemeyer M, Niemeyer T, Assmann T, Fottner S (2006) Can management compensate for atmospheric nutrient deposition in heathland ecosystems? J Appl Ecol 43:759–769CrossRefGoogle Scholar
  28. Hedin LO, Armesto JJ, Johnson AH (1995) Patterns of nutrient loss from unpolluted, old-growth temperate forests: evaluation of biogeochemical theory. Ecology 76:493–509Google Scholar
  29. Heil GW, Bobbink R (1993) “Calluna”, a simulation model for evaluation of impacts of atmospheric nitrogen deposition on dry heathlands. Ecol Model 68:161–182CrossRefGoogle Scholar
  30. Helliwell R, Britton A, Gibbs S, Fisher J, Potts J (2010) Interactive effects of N deposition, land management and weather patterns on soil solution chemistry in a Scottish alpine heath. Ecosystems 13:696–711CrossRefGoogle Scholar
  31. Hester A, Miles J, Gillingham C (1991) Succession from heather moorland to birch woodland.1. Experimental alteration of specific environmental-conditions in the field. J Ecol 79:303–315CrossRefGoogle Scholar
  32. Hill M, Evans D, Bell S (1992) Long-term effects of excluding sheep from hill pastures in North Wales. J Ecol 80:1–13CrossRefGoogle Scholar
  33. Högberg MN, Chen Y, Högberg P (2007) Gross nitrogen mineralisation and fungi-to-bacteria ratios are negatively correlated in boreal forests. Biol Fert Soils 44:363–366CrossRefGoogle Scholar
  34. Hughes RE (1973) Studies in sheep population and environment in the mountains of North-West Wales. J Appl Ecol 10:107–112CrossRefGoogle Scholar
  35. Hughes RE, Dale J (1970) Trends in montane grasslands in Snowdonia, expressed in terms of “relative entropy”. Nature 225:756–758CrossRefGoogle Scholar
  36. Janssens IA, Luyssaert S (2009) Carbon cycle: nitrogen’s carbon bonus. Nat Geosci 2:318–319 Google Scholar
  37. Joergensen RG (1996) The fumigation–extraction method to estimate soil microbial biomass: calibration of the kEC value. Soil Biol Biochem 28:25–31CrossRefGoogle Scholar
  38. Kalbitz K, Solinger S, Park J-H, Michalzik B, Matzner E (2000) Controls on the dynamics of dissolved organic matter in soils: a review. Soil Sci 165:277–304CrossRefGoogle Scholar
  39. Kopáček J, Cosby BJ, Evans CD, Moldan F, Oulehle F, Šantrůčková H, Tahovská K, Wright RF (2013) Nitrogen, organic carbon and sulphur cycling in terrestrial ecosystems: linking nitrogen saturation to carbon limitation of soil microbial processes. Biogeochemistry 115:33–51CrossRefGoogle Scholar
  40. Lloyd D, Turner A, Skates J, Easter J, Bowmaker V (2011) 15 years of monitoring on Yr Wyddfa/Snowdon. Countryside Council for Wales, Bangor. (http://www.ecn.ac.uk/publications/snowdon-15-years)
  41. MacDonald D, Crabtree JR, Wiesinger G, Dax T, Stamou N, Fleury P, Lazpita JG, Gibon A (2000) Agricultural abandonment in mountain areas of Europe: environmental consequences and policy response. J Environ Manag 59:47–69CrossRefGoogle Scholar
  42. Malcolm IA, Bacon PJ, Middlemas RJ, Fryer EM, Shilland EM, Collen P (2014) Relationships between hydrochemistry and the presence of juvenile brown trout (Salmo trutta) in headwater streams recovering from acidification. Ecol Indic 37:352–364Google Scholar
  43. Marrs RH, Rizand A, Harrison AF (1989) The effects of removing sheep grazing on soil chemistry, above-ground nutrient distribution, and selected aspects of soil fertility in long-term experiments at Moor House National Nature Reserve. J Appl Ecol 26:647–661CrossRefGoogle Scholar
  44. McGovern ST, Evans CD, Dennis PD, Walmsley CA, Turner A, McDonald MA (2013) Resilience of upland soils to long term environmental changes. Geoderma 197–198:36–42CrossRefGoogle Scholar
  45. McLean CJ, van den Berg LJL, Ashmore MR, Preston CD (2011) Atmospheric nitrogen deposition explains patterns of species loss. Glob Change Biol 17:2882–2892CrossRefGoogle Scholar
  46. Medina-Roldán E, Paz-Ferreiro J, Bardgett RD (2012) Grazing exclusion affects soil and plant communities, but has no impact on soil carbon storage in an upland grassland. Agr Ecosys Environ 149:118–123CrossRefGoogle Scholar
  47. Miles J (1988) Vegetation and soil changes in the uplands. In: Usher MB, Thompson DBA (eds) Ecological change in the uplands. Blackwell Scientific Publications, Oxford, pp 57–70Google Scholar
  48. Milne JA, Hartley SE (2001) Upland plant communities—sensitivity to change. Catena 42:333–343CrossRefGoogle Scholar
  49. Mitchell RJ, Auld MHD, Hughes JM, Marrs RH (2000) Estimates of nutrient removal during heathland restoration on successional sites in Dorset, Southern England. Biol Cons 95:233–246CrossRefGoogle Scholar
  50. Monteith DT, Evans CD, Henrys PA, Simspon GL, Malcolm IA (2014) Trends in the hydrochemistry of acid-sensitive surface waters in the UK 1988–2008. Ecol Indic 37:287–303Google Scholar
  51. Mulvaney RL (1996) Nitrogen—inorganic forms. In: Sparks DL (ed) Methods of soil analysis. Part 3. Chemical Methods. SSSA, Madison, WI, USA, pp 1123–1184Google Scholar
  52. Neff JC, Townsend AR, Gleixner G, Lehman SJ, Turnbull J, Bowman WD (2002) Variable effects of nitrogen additions on the stability and turnover of soil carbon. Nature 419:915–917CrossRefGoogle Scholar
  53. Ormerod S, Durance I (2009) Restoration and recovery from acidification in upland Welsh streams over 25 years. J Appl Ecol 46:164–174CrossRefGoogle Scholar
  54. Page AL (1982) Methods of soil analysis. Part 2. Chemical and microbiological properties. American Society of Agronomy, Inc., Soil Science Society of America, Inc., Madison, WisconsinGoogle Scholar
  55. Payne RJ, Stevens CJ, Dise NB, Gowing DJ, Pilkington MG, Phoenix GK, Emmett BA, Ashmore MR (2011) Impacts of atmospheric pollution on the plant communities of British acid grasslands. Environ Pollut 159:2602–2608CrossRefGoogle Scholar
  56. Payne R, Dise NB, Stevens C, Gowing DJG, BEGIN Partners (2013) Impact of nitrogen deposition at the species level. P Natl Acad Sci USA 110:984–998CrossRefGoogle Scholar
  57. Perkins DF (1978) Snowdonia grassland: Introduction, vegetation and climate. In: Heal OW, Perkins DF (eds) Production ecology of British Moors and Montane Grasslands. Springer, BerlinGoogle Scholar
  58. Phoenix GK, Emmett BA, Britton AJ, Caporn SJM, Dise NB, Helliwell R, Jones MLM, Leake JR, Leith ID, Sheppard LJ, Sowerby A, Pilkington MG, Rowe EC, Ashmore MR, Power SA (2012) Impacts of atmospheric nitrogen deposition: responses of multiple plant and soil parameters across contrasting ecosystems in long-term field experiments. Glob Change Biol 18:1197–1215CrossRefGoogle Scholar
  59. Pilkington MG, Caporn SJM, Carroll JA, Cresswell N, Lee JA, Ashenden TW, Brittain SA, Reynolds B, Emmett BA (2005) Effects of increased deposition of atmospheric nitrogen on an upland moor: leaching of N species and soil solution. Environ Pollut 135:29–40Google Scholar
  60. Power SA, Green ER, Barker CG, Nigel J, Bell B, Ashmore MR (2006) Ecosystem recovery: heathland response to a reduction in nitrogen deposition. Glob Change Biol 12:1241–1252CrossRefGoogle Scholar
  61. R Development Core Team (2010) R: A language and environment for statistical computing. In. Vienna, Austria: R Foundation for Statistical ComputingGoogle Scholar
  62. RoTAP (2012) Acidification, eutrophication, ground level ozone and heavy metals in the UK. Defra, LondonGoogle Scholar
  63. Rowe E, Evans C, Emmett B, Reynolds B, Helliwell R, Coull M, Curtis C (2006) Vegetation type affects the relationship between soil carbon to nitrogen ratio and nitrogen leaching. Water Air Soil Pollut 177:335–347CrossRefGoogle Scholar
  64. Smart SM, Robertson JC, Shield EJ, Van de Poll HM (2003) Locating eutrophication effects across British vegetation between 1990 and 1998. Glob Change Biol 9:1763–1774CrossRefGoogle Scholar
  65. StatsWales n.d. Statistics and research—survey of agriculture and horticulture. Source URL: http://wales.gov.uk/statistics-and-research/survey-agricultural-horticulture/?lang=en. Accessed June 11 2013
  66. Stevens CJ, Dise N, Mountford J, Gowing D (2004) Impact of nitrogen deposition on the species richness of grasslands. Science 303:1876–1879CrossRefGoogle Scholar
  67. Stevens CJ, Thompson K, Grime JP, Long CJ, Gowing DJG (2010) Contribution of acidification and eutrophication to declines in species richness of calcifuge grasslands along a gradient of atmospheric nitrogen deposition. Funct Ecol 24:478–484CrossRefGoogle Scholar
  68. Stevens CJ, Duprè C, Dorland E, Gaudnik C, Gowing DJG, Bkleeker A, Diekmann M, Alard D, Bobbink R, Fowler D, Corcket E, Owen Mountford J, Vandvik V, Arild Aarrestad P, Muller S, Dise NB (2011) The impact of nitrogen deposition on acid grasslands in the Atlantic region of Europe. Environ Pollut 159:2243–2250CrossRefGoogle Scholar
  69. Stoddard JL (1994) Long-term changes in watershed retention of nitrogen: its causes and aquatic consequences. In: Baker LA (ed) Environmental chemistry of lakes and reservoirs. ACS advances in chemistry series No. 237. American Chemical Society, Washington, DC, pp 223–284Google Scholar
  70. Sutton MA, Oenema O, Erisman JW, Leip A, van Grinsven H, Winiwarter W (2011) Too much of a good thing. Nature 472:159–161CrossRefGoogle Scholar
  71. Turner AJ, Bowmaker V, Lloyd DS (2010) Environmental Change Network Yr Wyddfa/Snowdon ECN Site. Progress report to the Welsh Assembly Government for financial year 2009/2010. CCW Staff Science Report Number 10/2/1, 80 ppGoogle Scholar
  72. Turunen J, Roulet N, Moore TR, Richard PJH (2004) Nitrogen deposition and increased carbon accumulation in ombrotrophic peatlands in eastern Canada. Glob Biogeochem Cycl 18:GB3002. doi: 10.1029/2003GB002154
  73. van den Berg LJL, Vergeer P, Rich TCG, Smart AM, Guest D, Ashmore MR (2011) Direct and indirect effects of nitrogen deposition on species composition change in calcareous grasslands. Glob Change Biol 17:1871–1883CrossRefGoogle Scholar
  74. van der Wal R, Pearce I, Brooker R, Scott D, Welch D, Woodin S (2003) Interplay between nitrogen deposition and grazing causes habitat degradation. Ecol Lett 6:141–146Google Scholar
  75. van Vuuren M, van der Eerden L (1992) Effects of three rates of atmospheric nitrogen deposition enriched with 15N on litter decomposition in a heathland. Soil Biol Biochem 24:527–532CrossRefGoogle Scholar
  76. Vance E, Brookes PC, Jenkinson DS (1987) An extraction method for assessing microbial biomass-C. Soil Biol Biochem 19:703–707CrossRefGoogle Scholar
  77. Venables WN, Smith DM, the R Core Team (2013) An introduction to R. notes on R: a programming environment for data analysis and graphics, Version 3.0.2 (2013-09-25). The R Foundation for Statistical ComputingGoogle Scholar
  78. Vinton MA, Burke IC (1995) Interactions between individual plant species and soil nutrient status in shortgrass steppe. Ecology 76:1116–1133CrossRefGoogle Scholar
  79. Williams DL, Emmett BA, Brittain SA, Pugh B, Hughes S, Norris DA, Meadows K, Richardson C, Bell S (2000) Influence of forest type, structure and management on nitrate leaching. Centre for Ecology and Hydrology, Bangor, 56 ppGoogle Scholar
  80. Wright RF, Alewell C, Cullen JM, Evans CD, Marchetto A, Moldan F, Prechtel A, Rogora M (2001) Trends in nitrogen deposition and leaching in acid-sensitive streams in Europe. Hydrol Earth Syst Sci 5:299–310CrossRefGoogle Scholar
  81. Wu J, Joergensen RG, Pommerening B, Chaussod R, Brookes PC (1990) Measurement of soil microbial biomass C by fumigation–extraction—an automated procedure. Soil Biol Biochem 22:1167–1169CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Stephanie T. McGovern
    • 1
  • Chris D. Evans
    • 2
    Email author
  • Peter Dennis
    • 3
  • Clive A. Walmsley
    • 4
  • Alex Turner
    • 4
  • Morag A. McDonald
    • 1
  1. 1.School of Environment, Natural Resources and GeographyBangor UniversityBangorUK
  2. 2.Centre for Ecology and HydrologyEnvironment Centre WalesBangorUK
  3. 3.Institute of Biological, Environmental and Rural SciencesAberystwyth UniversityCeredigionUK
  4. 4.Natural Resources WalesBangorUK

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