Advertisement

Fire Technology

, Volume 47, Issue 2, pp 421–436 | Cite as

Fuel Moisture Thresholds in the Flammability of Calluna vulgaris

Article

Abstract

Managed and wild fires play a significant role in the ecology of heathlands in the UK but we currently have little ability to forecast fire behaviour or the likelihood of accidental wildfires. Like many shrubland fuel types, heathlands display significant structural complexity and the role of different fuel components in governing flammability has not been clear. Using a series of small, field-based ignition tests, we demonstrate the critical importance of the moisture content of dead fine fuels in the lower canopy for determining when sustaining fires in the vegetation canopy can develop. At moisture contents above c. 70% both spot and line ignitions failed but where moisture contents were less than c. 60% fires developed rapidly. The initial rate of spread of successful ignitions was primarily controlled by the moisture content of the lower canopy and the moss/litter layer. Models that predict the moisture content of elevated dead fuels and the moss litter layer are urgently needed in order to protect heathlands from wildfire and to allow forecasts of the suitability of conditions for prescribed burning to be developed.

Keywords

Fire behaviour Fire sustainability Heathland Ignition Logistic regression Managed burning Rate of spread Wildfire 

Notes

Acknowledgements

We wish to express our thanks to the landowners and managers that allowed us access to their property for our research: the Ministry of Defence, the Scottish Agricultural College and Ralia Enterprises. The Game and Wildlife Conservation Trust kindly provided us with field logistical support. Teresa Valor-Ivars assisted with the fieldwork. This project forms part of the FireBeaters project (http://firebeaters.org.uk) and was funded by the Scottish Government through the Scottish Wildfire Forum and by Scottish Natural Heritage. We are grateful to Wendy Anderson for her advice and to Michael Bruce, the chairman, and the other members of the FireBeaters Scottish Wildfire Forum steering group.

References

  1. 1.
    de Smidt JT (1995) The imminent destruction of northwest European heaths due to atmospheric nitrogen deposition. In: Thompson DBA, Hester AJ, Usher MB (eds) Heaths and moorland: cultural landscapes. HMSO, Edinburgh, pp 206-217Google Scholar
  2. 2.
    Thompson DBA, MacDonald AJ, Marsden JH, Galbraith CA (1995) Upland heather moorland in Great Britain: a review of international importance, vegetation change and some objectives for nature conservation. Bio Cons 71:163–78CrossRefGoogle Scholar
  3. 3.
    Davies GM, Gray A, Hamilton A, Legg CJ (2008) The future of fire management in the British uplands. Int J Biodiversity Science and Management 4:127–147Google Scholar
  4. 4.
    Ascoli D, Beghin R, Ceccato R, Gorlier A, Lombardi G, Lonati M, Marzano R, Bovio G, Cavallero A (2009) Developing an Adaptive Management approach to prescribed burning: a long-term heathland conservation experiment in north-west Italy. Int J Wildland Fire 17:727–735CrossRefGoogle Scholar
  5. 5.
    Simmons IG (2003) The moorlands of England and Wales: an environmental history 8000 BC to AD 2000. Edinburgh University Press, EdinburghGoogle Scholar
  6. 6.
    Maltby E, Legg CJ, Proctor MCF (1990) The ecology of severe moorland fire on the North York Moors: effects of the 1976 fires, and subsequent surface and vegetation development. J Ecol 78:490–518Google Scholar
  7. 7.
    Farage P, Ball A, McGenity TJ, Whitby C, Pretty J (2009) Burning management and carbon sequestration of upland heather moorland in the UK. Aust J Soil Res 47:351-361CrossRefGoogle Scholar
  8. 8.
    Legg CJ, Davies GM, Gray A (2010) Comment on “Burning management and carbon sequestration of upland heather moorland in the UK”. Aust J Soil Res 48:100–103CrossRefGoogle Scholar
  9. 9.
    McMorrow J, Aylen J, Albertson K, Cavan G, Lindley S, Handley J, Karooni R (2006) Climate change and the visitor economy. Technical report 3: Moorland wild fires in the Peak District National Park. Centre for Urban & Regional Ecology, ManchesterGoogle Scholar
  10. 10.
    Pyne SJ, Andrews PL, Laven RD (1996) Introduction to wildland fire. John Wiley and Sons Inc, ChichesterGoogle Scholar
  11. 11.
    Kitchen K, Marno P, Legg C, Bruce M, Davies GM (2006) Developing a fire danger rating system for the United Kingdom. For Ecol and Management 234S:S21CrossRefGoogle Scholar
  12. 12.
    Countryside Council for Wales. Countryside access map. http://www.ccw.gov.uk/interactive-maps/countryside-access-map.aspx?lang=en. Accessed 17 January 2010
  13. 13.
    Natural England (2005) Fire Severity. http://www.naturalengland.org.uk/ourwork/enjoying/places/openaccess/fireseverity.aspx. Accessed 17 January 2010
  14. 14.
    Legg CJ, Davies GM, Marno P, Kitchen K (2007) Developing a Fire Danger Rating System for the UK: FireBeaters final report. Report to the Scottish Wildfire Forum. http://www.era.lib.ed.ac.uk/handle/1842/3011. Accessed 17 January 2010
  15. 15.
    Legg CJ, Davies GM (2009) FireBeaters phase II report. Report to Scottish Natural Heritage. http://firebeaters.geos.ed.ac.uk/UserFiles/File/Exec%20summary.doc. Accessed 17 January 2010
  16. 16.
    Anderson HE (1970) Forest fuel ignitibility. Fire Technology 6:312-319CrossRefGoogle Scholar
  17. 17.
    Davies GM, Legg CJ, Smith AA, MacDonald AJ (2006) Developing shrub fire behaviour models in an oceanic climate: burning in the British Uplands. For Ecol Manage 234S:S107. http://www.era.lib.ed.ac.uk/handle/1842/2700. Accessed 17 January 2010
  18. 18.
    Davies GM, Legg CJ, Smith AA, MacDonald AJ (2009) Rate of spread of fires in Calluna vulgaris-dominated moorlands. J App Ecol 46:1054-1063CrossRefGoogle Scholar
  19. 19.
    Jackson GE, Irvine J, Grace J (1999) Xylem acoustic emissions and water relations of Calluna vulgaris L. at two climatological regions of Britain. Plant Ecology 140:3-14CrossRefGoogle Scholar
  20. 20.
    Davies GM (2005) Fire behaviour and impact on heather moorland. PhD dissertation, The University of Edinburgh. http://www.era.lib.ed.ac.uk/handle/1842/2609. Accessed 17 January 2010
  21. 21.
    Curtis R (2009) Development of an appropriate live fuel moisture model for heather (Calluna vulgaris) for wildfire risk. BSc dissertation, The University of Edinburgh School of GeoSciencesGoogle Scholar
  22. 22.
    Weise DR, Zhou X, Sun L, Mahalingam S (2005) Fire spread in chaparral—‘go or no-go?’ Int J Wildland Fire 14:99-106CrossRefGoogle Scholar
  23. 23.
    Bunting SC, Wright HA, Wallace WH (1983) Seasonal variation in the ignition time of Redberry Juniper in West Texas. J Range Management 36:169-171CrossRefGoogle Scholar
  24. 24.
    Marsden-Smedley JB, Catchpole WR, Pyrke A (2001) Fire modelling in Tasmanian buttongrass moorlands. IV Sustaining versus non-sustaining fires. Int J Wildland Fire 10:255-262CrossRefGoogle Scholar
  25. 25.
    Tanskanen H, Venäläinen A, Puttonen P, Granström A (2005). Impact of stand structure on surface fire ignition potential in Picea Abies and Pinus sylvestris forests in southern Finland. Can J For Res 35:410-420CrossRefGoogle Scholar
  26. 26.
    Fernandes PM, Botelho H, Rego F, Loureiro C (2008). Using fuel and weather variables to predict the sustainability of surface fire spread in maritime pine stands. Can J For Res 38:190-201CrossRefGoogle Scholar
  27. 27.
    Anderson SAJ (2009) Fuel moisture and development of ignition and fire spread thresholds in gorse (Ulex europaeus). M For Sci dissertation, University of CanterburyGoogle Scholar
  28. 28.
    Leonard S (2009) Predicting sustained fire spread in Tasmanian native grasslands. Environmental Management 44: 430-440CrossRefGoogle Scholar
  29. 29.
    Dimitrakopoulos AP, Papaioannou KK (2001) Flammability assessment of Mediterranean forest fuels. Fire Technology 37:1572-8099CrossRefGoogle Scholar
  30. 30.
    Guijarro M, Hernando C, Díez C, Martínez E, Madrigal J, Cabaret CL, Blanc L, Colin PY, Pérez-Gorostiaga P, Vega JA, Fonturbel MT (2002) Flammability of some fuel beds common in the South-European ecosystems. In: Viegas DX (ed) Forest fire research and wildland fire safety: proceedings of IV international conference on forest fire research 2002 wildland fire safety summit, Luso, Coimbra, Portugal, 18–23 November 2002. Millpress, AmsterdamGoogle Scholar
  31. 31.
    Ganteaume A, Lampin-Maillet C, Guijarro M, Hernando C, Jappiot M, Fonturbel T, Pérez-Gorostiaga P, Vega JA (2009) Spot fires: fuel bed flammability and capability of firebrands to ignite fuel beds. Int J Wildland Fire 18:951–969CrossRefGoogle Scholar
  32. 32.
    SEERAD (2008) The muirburn code. The Scottish Government, Edinburgh. http://www.scotland.gov.uk/Resource/Doc/219276/0058846.pdf. Accessed 15 December 2009
  33. 33.
    Davies GM & Legg CJ (2008) Developing a live fuel moisture model for moorland fire danger rating. In: de Las Heras J, Brebbia CA, Viegas DX, Leone V (eds.), Forest fires: modelling, monitoring and management of forest fires. WIT Transactions on the Environment, Vol 119. WIT Press, Southampton, pp 225-236CrossRefGoogle Scholar
  34. 34.
    O’Hara R (2006) Spatial and temporal variability in moorland fuels and implications for fire behaviour and management. BSc dissertation, The University of Edinburgh School of GeoSciencesGoogle Scholar
  35. 35.
    Davies GM, Hamilton A, Smith A and Legg CJ (2008) Using visual obstruction to estimate heathland fuel load and structure. Int J of Wildland Fire 17:380–389CrossRefGoogle Scholar
  36. 36.
    Zhou X, Mahalingam S, Weise D (2005) Modeling of marginal burning state of fire spread in live chaparral shrub fuel bed. Combustion and Flame 143: 183-198CrossRefGoogle Scholar
  37. 37.
    Anderson SAJ, Anderson WR (in press) Ignition and fire spread thresholds in gorse (Ulex europaeus). Int J Wildland Fire, WF09008Google Scholar
  38. 38.
    Anderson SAJ, Anderson WR (2009) Predicting the elevated dead fine fuel moisture content in gorse (Ulex europaeus L.) shrub fuels. Can J For Res 39:2355-2368CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.Centre for the Study of Environmental Change and Sustainability, School of GeoSciencesThe University of EdinburghEdinburghUK
  2. 2.School of Forest ResourcesUniversity of WashingtonSeattleUSA

Personalised recommendations