, Volume 31, Issue 3, pp 613–622 | Cite as

The Essential Role of the Lagg in Raised Bog Function and Restoration: A Review



The lagg of a raised bog is a transition zone where runoff collects from the ombrotrophic (rain-fed) bog and adjacent mineral soils. Distinct hydrological and hydrochemical gradients exist across the lagg zone, resulting in specific plant communities. Little research emphasis has been placed on the lagg zone in the past, with studies tending to focus on the more easily-defined bog instead. Recently, peatland researchers have begun to discuss the importance of the lagg to raised bog restoration. This paper reviews current knowledge on lagg zones, the function of this transition zone, some useful indicators to determine its location in the field, and argues that restoration of the lagg should be a key element in raised bog restoration.





We thank the members of the Burns Bog Scientific Advisory Panel, particularly Paul Whitfield, Richard Hebda, and John Jeglum for highlighting the importance of the lagg zone. Comments from two anonymous reviewers, particularly in reference to terminology, helped us to improve this manuscript.


  1. Aartolahti T (1965) Oberfl ächenformen von Hochmooren und ihre Entwicklung in Südwest-Häme und Nord-Satakunta. Fennia 93:1–268 + Beil. I–IVGoogle Scholar
  2. Andersen R, Rochefort L, Poulin M (2010) Peat, water and plant tissue chemistry monitoring: a seven-year case-study in a restored peatland. Wetlands 30:159–170CrossRefGoogle Scholar
  3. Baird AJ, Eades PA, Surridge BWJ (2008) The hydraulic structure of a raised bog and its implications for ecohydrological modelling of bog development. Ecohydrology 1:289–298CrossRefGoogle Scholar
  4. Balfour J, Banack L (2000) Burns Bog Ecosystem Review - Water Chemistry: Report prepared for Delta Fraser Properties Partnership and the Environmental Assessment Office in support of the Burns Bog Ecosystem Review, with additional data collected on publicly owned lands conducted for the Environmental Assessment Office in association with the Corporation of Delta. EBA Engineering Consultants Ltd., Vancouver, BCGoogle Scholar
  5. Banner A, Pojar J, Trowbridge R (1986) Representative wetland types of the northern part of the Pacific Oceanic Wetland Region. BC Ministry of Forests Research Report RR85008-PR.Google Scholar
  6. Blackwell I (1992) A hydrological study of the lagg zone of Clara Bog, County Offaly, Ireland. M.Sc.thesis, Imperial College, LondonGoogle Scholar
  7. Bourbonniere RA (2009) Review of water chemistry research in natural and disturbed peatlands. Can Water Resour J 34:393–414CrossRefGoogle Scholar
  8. Bragazza L, Gerdol R (1999) Hydrology, groundwater chemistry and peat chemistry in relation to habitat conditions in a mire on the South-eastern Alps of Italy. Plant Ecol 144:243–256CrossRefGoogle Scholar
  9. Bragazza L, Gerdol R (2002) Are nutrient availability and acidity-alkalinity gradients related in Sphagnum-dominated peatlands? J Veg Sci 13:473–482CrossRefGoogle Scholar
  10. Bragazza L, Rydin H, Gerdol R (2005) Multiple gradients in mire vegetation: a comparison of a Swedish and an Italian bog. Plant Ecol 177:223–236CrossRefGoogle Scholar
  11. Bragg OM (2002) Hydrology of peat-forming wetlands in Scotland. Sci Total Environ 294:111–129PubMedCrossRefGoogle Scholar
  12. Brooks S, Stoneman R (1997) Conserving Bogs: The Management Handbook. The Stationary Office Ltd, EdinbughGoogle Scholar
  13. Bubier JL (1991) Patterns of Picea mariana (Black Spruce) growth and raised bog development in Victory Basin, Vermont. Bull Torrey Bot Club 118:399–411CrossRefGoogle Scholar
  14. Burlton B (1997) The Border Mires approach. In: Parkyn L, Stoneman RE, Ingram HAP (eds) Conserving Peatlands. CAB International, New York, pp 271–279Google Scholar
  15. Damman AWH (1977) Geographical changes in the vegetation pattern of raised bogs in the Bay of Fundy region of Maine and New Brunswick. Vegetatio 35:137–151CrossRefGoogle Scholar
  16. Damman AWH (1979) Geographical patterns in peatland development in eastern North America. In: Kivenin E, Heikurainen L, Pakarinen P (eds) Proceedings of the International Symposium on Classification of Peat and Peatlands. International Peat Society. pp 42–57Google Scholar
  17. Damman AWH (1986) Hydrology, development, and biogeochemistry of ombrogenous peat bogs with special reference to nutrient relocation in a western Newfoundland bog. Can J Bot 64:384–394CrossRefGoogle Scholar
  18. Damman AWH, Dowhan JJ (1981) Vegetation and habitat conditions in Western Head Bog, a southern Nova Scotian plateau bog. Can J Bot 59:1343–1359CrossRefGoogle Scholar
  19. Damman AWH, French TW (1987) The ecology of peat bogs of the glaciated northeastern United States: a community profile. US Fish and Wildlife Service Biological Report 85Google Scholar
  20. De Mars H, Wassen MJ (1999) Redox potentials in relation to water levels in different mire types in the Netherlands and Poland. Plant Ecol 140:41–51CrossRefGoogle Scholar
  21. Eurola S (1962) Über die regionale Einteilung der südfinnischen Moore. Annales Botanici Societatis Zoologicae Botanicae Fennicae ´Vanamo´ 33:1–243Google Scholar
  22. Freléchoux F, Buttler A, Schweingruber FH, Gobat J (2000) Stand structure, invasion, and growth dynamics of bog pine (Pinus uncinata var rotundata) in relation to peat cutting and drainage in the Jura Mountains, Switzerland. Can J For Res 30:1114–1126Google Scholar
  23. Freléchoux F, Buttler A, Schweingruber FH, Gobat J (2004) Spatio-temporal pattern of bog pine (Pinus uncinata var. rotundata) at the interface with the Norway spruce (Picea abies) belt on the edge of a raised bog in the Jura Mountains, Switzerland. Ann For Sci 61:309–318CrossRefGoogle Scholar
  24. Ginzler C (1997) A hydrological approach to bog management. In: Parkyn L, Stoneman RE, Ingram HAP (eds) Conserving Peatlands. CAB International, New York, pp 280–286Google Scholar
  25. Glaser PH (1992) Vegetation and water chemistry. In: Wright HE Jr, Coffin BA, Asseng NEP (eds) The patterned peatlands of Minnesota. University of Minnesota Press, St. Paul, pp 15–26Google Scholar
  26. Glaser PH, Janssens JA, Siegel DI (1990) The response of vegetation to chemical and hydrological gradients in the Lost River peatland, northern Minnesota. J Ecol 78:1021–1048CrossRefGoogle Scholar
  27. Glaser PH, Siegel DI, Romanowicz EA, Shen YP (1997) Regional linkages between raised bogs and the climate, groundwater, and landscape of north-western Minnesota. J Ecol 85:3–16CrossRefGoogle Scholar
  28. Godwin H, Conway VM (1939) The ecology of a raised bog near Tregaron, Cardiganshire. J Ecol 27:313–359CrossRefGoogle Scholar
  29. Gorham E (1950) Variation in some chemical conditions along the borders of a Carex lasiocarpa fen community. Oikos 2:217–240CrossRefGoogle Scholar
  30. Gosz JR (1992) Gradient analysis of ecological change in time and space: implications for forest management. Ecol Appl 2:248–261CrossRefGoogle Scholar
  31. Gosz JR, Sharpe PJH (1989) Broad-scale concepts for interactions of climate, topography, and biota at biome transitions. Landscape Ecol 2:229–243CrossRefGoogle Scholar
  32. Groenveld DP, Or D (1994) Water table induced shrub-herbaceous ecotone: hydrologic management implications. Water Resources Bulletin (Paper No. 94040), American Water Resources Association 30:911–920Google Scholar
  33. Hájková P, Hájek M (2004) Bryophyte and vascular plant responses to base-richness and water level gradients in western Carpathian Sphagnum-rich mires. Folia Geobot 39:335–351CrossRefGoogle Scholar
  34. Hebda RJ, Biggs WG (1981) The vegetation of Burns Bog, Delta, British Columbia. Syesis 14:1–20Google Scholar
  35. Hebda RJ, Gustavson K, Golinski K, Calder AM (2000) Burns Bog Ecosystem Review Synthesis Report for Burns Bog, Fraser River Delta, South-western British Columbia, Canada. Victoria, Environmental Assessment OfficeGoogle Scholar
  36. Hobbs NB (1986) Mire morphology and the properties and behaviour of some British and foreign peats. Q J Eng Geol 19:7–80CrossRefGoogle Scholar
  37. Holden J (2005) Peatland hydrology and carbon release: why small-scale process matters. Philos trans R Soc A 363:2891–2913CrossRefGoogle Scholar
  38. Howie SA, Whitfield PH, Hebda RJ, Jeglum JK, Dakin RA (2009a) Can analysis of historic lagg forms be of use in the restoration of highly altered raised bogs? Examples from Burns Bog, British Columbia. Can Water Resour J 34:427–440CrossRefGoogle Scholar
  39. Howie SA, Whitfield PH, Hebda RJ, Munson TG, Dakin RA, Jeglum JK (2009b) Water table and vegetation response to ditch blocking: restoration of a raised bog in southwestern British Columbia. Can Water Resour J 34:381–392CrossRefGoogle Scholar
  40. Hughes PDM, Barber KE (2003) Mire development across the fen-bog transition on the Teifi floodplain at Tregaron Bog, Ceredigan, Wales, and a comparison with 13 other raised bogs. J Ecol 91:253–264CrossRefGoogle Scholar
  41. Ingram HAP (1982) Size and shape in raised mire ecosystems: a geophysical model. Nature 297:300–303CrossRefGoogle Scholar
  42. Ingram HAP (1983) Hydrology. In: Gore AJP (ed) Ecosystems of the world. 4A. Mires: Swamp, Bog, Fen and Moor, General studies. Elsevier, Oxford, pp 67–158Google Scholar
  43. Ivanov KE (1981) Water movement in Mirelands. Academic, LondonGoogle Scholar
  44. Jeglum JK (1971) Plant indicators of pH and water level in peatlands at Candle Lake, Saskatchewan. Can J Bot 49:1661–1676CrossRefGoogle Scholar
  45. Kent M, Gill WJ, Weaver RE, Armitage RP (1997) Landscape and plant community boundaries in biogeography. Prog Phys Geogr 21:315–353CrossRefGoogle Scholar
  46. Keough JP, Pippen RW (1984) The movement of water from peatland into surrounding groundwater. Can J Bot 62:835–839CrossRefGoogle Scholar
  47. Laitinen J, Rehell S, Huttunen A, Tahvanainen T, Heikkilä R, Lindholm T (2007) Mire systems in Finland – special view to aapa mires and their water-flow pattern. Suo 58:1–26Google Scholar
  48. Lapen DR, Price JS, Gilbert R (2005) Modelling two-dimensional steady-state groundwater flow and flow sensitivity to boundary conditions in blanket peat complexes. Hydrological Processes 19:371–386CrossRefGoogle Scholar
  49. Levrel G, Rousseau AN, Lafrance P, Jutras S, Clerc C (2009) Characterization of water retention and hydraulic conductivity in boreal soils of the James Bay region: presentation of an experimental protocol and preliminary results. Can Water Resour J 34:329–348CrossRefGoogle Scholar
  50. Lindholm T, Heikkilä R (eds) (2006) Finland – land of mires. Finnish Environment Institute, HelsinkiGoogle Scholar
  51. Malmer N (1986) Vegetational gradients in relation to environmental conditions in northwestern European mires. Can J Bot 64:375–383CrossRefGoogle Scholar
  52. Mawby FJ, Brock A (2007) The rehabilitation of lagg fen to lowland raised mires in Cumbria, north west England. http://www.pole-tourbieres.org/docs/Lamoura_Mawby.pdf. Accessed 11 Oct 2009
  53. McNamara JP, Siegel DI, Glaser PH, Beck RM (1992) Hydrogeologic controls on peatland development in the Malloryville Wetland, New York (USA). J Hydrol 140:279–296CrossRefGoogle Scholar
  54. Millington RJ (1954) Sphagnum bogs of the New England Plateau, New South Wales. J Ecol 42:328–344CrossRefGoogle Scholar
  55. Mitchell CPJ, Branfireun BA, Kolka RK (2008) Spatial characteristics of net methylmercury production hot spots in peatlands. Environ Sci Technol 42:1010–1016PubMedCrossRefGoogle Scholar
  56. Morgan-Jones W, Poole JS, Goodall R (2005) Characterization of hydrological protection zones at the margins of designated lowland raised peat bog sites. Joint Nature Conservation Committee, Peterborough. JNCC Report No. 365Google Scholar
  57. Muller J, Wust RAJ, Weiss D, Hu Y (2006) Geochemical and stratigraphic evidence of environmental change at Lynch’s Crater, Queensland, Australia. Glob Planet Change 53:269–277CrossRefGoogle Scholar
  58. Naucke W, Heathwaite AL, Egglesmann R, Schuch M (1993) Mire chemistry. In: Heathwaite AL, Göttlich Kh (eds) Mires: process, exploitation and conservation. John Wiley & Sons Ltd., Chichester, pp 263–310Google Scholar
  59. Økland RH, Økland T, Rydgren K (2001) A Scandinavian perspective on ecological gradients in north-west European mires: reply to Wheeler and Proctor. J Ecol 89:481–486CrossRefGoogle Scholar
  60. Osvald H (1933) Vegetation of the Pacific Coast bogs of North America. Acta Phytogeogr Suec 5:1–32Google Scholar
  61. Peart B (2006) A Lagg is not a Ditch. Notes from the Burns Bog Ecological Conservancy Area Technical Workshop on Restoring a Functioning Lagg. University of British Columbia, Vancouver, BC, February 16–17, 2006Google Scholar
  62. Peregon A, Uchida M, Yamagata Y (2009) Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia. Environmental Research Letters 4:1–7Google Scholar
  63. Price JS, Heathwaite AL, Baird AJ (2003) Hydrological processes in abandoned and restored peatlands: an overview of management approaches. Wetlands Ecol Manage 11:65–83CrossRefGoogle Scholar
  64. Proctor MCF (2003) Malham Tarn Moss: the surface-water chemistry of an ombrotrophic bog. Field Stud 10:553–578Google Scholar
  65. Richardson MC, Mitchell CPJ, Branfireun BA, Kolka RK (2010) Analysis of airborne LiDAR surveys to quantify the characteristic morphologies of northern forested wetlands. J Geophys Res. doi: 10.1029/2009JG000972 Google Scholar
  66. Rigg GB (1925) Some Sphagnum bogs of the north Pacific coast of North America. Ecology 6:260–279CrossRefGoogle Scholar
  67. Rigg GB, Richardson CT (1938) Profiles of some Sphagnum bogs on the Pacific coast of North America. Ecology 19:408–434CrossRefGoogle Scholar
  68. Risser PG (1995) The status of the science examining ecotones. Bioscience 45:318–325CrossRefGoogle Scholar
  69. Rydin H, Jeglum JK (2006) The biology of peatlands. Oxford University Press, UKCrossRefGoogle Scholar
  70. Rydin H, Sjörs H, Lofroth M (1999) Mires. In: Rydin H, Snoejis P, Diekmann M (eds) Swedish Plant Geography. Acta Phytogeographica Suecica 84:91–112Google Scholar
  71. Schouten MGC (ed.) (2002) Conservation and restoration of raised bogs: geological, hydrological, and ecological studies. Department of Environment and Local Government, DublinGoogle Scholar
  72. Schouwenaars JM (1995) The selection of internal and external water management options for bog restoration. In: Wheeler BD, Shaw SC, Fojt WJ, Robertson RA (eds) Restoration of Temperate Wetlands. John Wiley & Sons Ltd., New YorkGoogle Scholar
  73. Shotyk W (1996) Peat bog archives of atmospheric metal deposition: geochemical evaluation of peat profiles, natural variations in metal concentrations, and metal enrichment factors. Environ Rev 4:149–183CrossRefGoogle Scholar
  74. Sjörs H (1950) On the relation between vegetation and electrolytes in north Swedish mire waters. Oikos 2:241–258CrossRefGoogle Scholar
  75. Sjörs H, Gunnarsson U (2002) Calcium and pH in north and central Swedish mire waters. J Ecol 90:650–57CrossRefGoogle Scholar
  76. Smit R, Bragg OM, Ingram HAP (1999) Area separation of streamflow in an upland catchment with partial peat cover. Journal of Hydrology 219:46–55CrossRefGoogle Scholar
  77. Sottocornola M, Laine A, Kiely G, Byrne KA, Tuittila ES (2009) Vegetation and environmental variation in an Atlantic blanket bog in South-western Ireland. Plant Ecol 203:69–81CrossRefGoogle Scholar
  78. Svensson G (1988) Bog development and environmental conditions as shown by the stratigraphy of Store Mosse mire in southern Sweden. Boreas 17:89–111CrossRefGoogle Scholar
  79. Tahvanainen T (2004) Water chemistry of mires in relation to the poor-rich vegetation gradient and contrasting geochemical zones of the north-eastern Fennoscandian shield. Folia Geobot 39:353–369CrossRefGoogle Scholar
  80. Tahvanainen T, Sallantaus T, Heikkila R, Tolonen K (2002) Spatial variation of mire surface water chemistry and vegetation in northeastern Finland. Ann Bot Fenn 39:235–251Google Scholar
  81. Vitt DH, Bayley SE, Jin T (1995) Seasonal variation in water chemistry over a bog-rich fen gradient in Continental Western Canada. Can J Fish Aquat Sci 52:587–606CrossRefGoogle Scholar
  82. Von Post L (1924) Das genetische System der organogenen Bildungen Schwedens. Comité International de Pédologie IV, Commission No. 22, 287–304.Google Scholar
  83. Waughman GJ (1980) Chemical aspects of the ecology of some south German peatlands. J Ecol 68:1025–1046CrossRefGoogle Scholar
  84. Weiss D, Shotyk W, Cheburkin AK, Gloor M, Reese S (1997) Atmospheric lead deposition from 12,400 to Ca. 2000 yrs BP in a peat bog profile, Jura mountains, Switzerland. Water Air Soil Pollut 100:311–324CrossRefGoogle Scholar
  85. Wells ED (1996) Classification of peatland vegetation in Atlantic Canada. J Veg Sci 7:847–878CrossRefGoogle Scholar
  86. Wheeler BD, Proctor MCF (2000) Ecological gradients, subdivisions and terminology of north-west European mires. J Ecol 88:187–203CrossRefGoogle Scholar
  87. Wheeler BD, Shaw SC (1995) Restoration of damaged peatlands with particular reference to lowland raised bogs affected by peat extraction. HMSO, LondonGoogle Scholar
  88. Wheeler BD, Shaw SC, Fojt WJ, Robertson RA (1995) Restoration of Temperate Wetlands. John Wiley & Sons Ltd., New YorkGoogle Scholar
  89. Whitfield PH, van der Kamp G, St-Hilaire A (2009) Introduction to peatlands special issue: improving hydrological prediction in Canadian peatlands. Can Water Resour J 34:303–310CrossRefGoogle Scholar

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© Society of Wetland Scientists 2011

Authors and Affiliations

  1. 1.Department of GeographySimon Fraser UniversityBurnabyCanada

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