International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire

Ignition and fire spread thresholds in gorse (Ulex europaeus)

Stuart A. J. Anderson A C D and Wendy R. Anderson B
+ Author Affiliations
- Author Affiliations

A Scion, Rural Fire Research Group, PO Box 29237, Fendalton, Christchurch 8540, New Zealand.

B University of New South Wales at ADFA, Northcott Drive, ACT 2600, Australia.

C Present address: Ministry of Agriculture and Forestry, PO Box 1340, Rotorua 3040, New Zealand.

D Corresponding author. Email:

International Journal of Wildland Fire 19(5) 589-598
Submitted: 28 January 2009  Accepted: 20 November 2009   Published: 9 August 2010


Field experiments were carried out in stands of gorse (Ulex europaeus L.) in New Zealand to determine the conditions under which fires would both ignite and spread. Research and operational experience in shrub fuels suggest that there is a clear difference between conditions that support ignition only (fuel ignites but does not spread beyond a single bush or clump) and conditions that are conducive to fire spread (fuel ignites and develops into a spreading fire). It is important for fire management agencies to be equipped with knowledge of these thresholds, because the different conditions require different levels of preparedness and response. Results indicate that the major variable influencing both fire ignition and fire spread development in gorse is the moisture content of the elevated dead fine fuel layer. Fires were observed to spread successfully in this elevated fuel layer only, independently of the surface fuels and the near-surface fuels. Elevated dead fuels failed to ignite at a moisture content of greater than 36%, and ignition only resulted in a spreading fire at moisture contents below 19%. The results correlate well with field observations and fire practitioners’ experience in these fuels, and provide reliable guidelines for fire management planning.

Additional keywords: fire behaviour, fuel moisture content, shrubland.


Thanks are extended to the landowner of the Pines Beach study site, Ansell Moore, for allowing this research to be carried out on his property. We are indebted to the fire agencies that provided in-kind support for the field experiments, without which this research could not have taken place (Department of Conservation, Environment Canterbury, Pines Beach/Kairaki Volunteer Rural Fire Force, City Care Fire Team, Waimakariri District Council). Fraser Townsend and Kelsy Gibos provided valuable technical support during and after the field experiments. Comments on an earlier version of this manuscript by Grant Pearce (Scion) and Euan Mason (University of Canterbury) are appreciated. Feedback from two anonymous reviewers is gratefully acknowledged. This research was funded by the Rural Fire Program (Contract C04X0403) within the Resilient Infrastructure and Communities (Natural Physical Hazards) Portfolio provided by the Foundation for Research, Science and Technology in New Zealand.


Alexander ME, Lee BS, Lee CY (1984) Hourly calculation of the Fine Fuel Moisture Code, Initial Spread Index, and Fire Weather Index with the Texas Instruments model 59 hand-held calculator. Canadian Forestry Service, Northern Forestry Research Centre, File Report NOR-5–191. (Edmonton, AB)

Anderson SAJ (2004) Forest and rural fire danger rating. In ‘Forestry Handbook’. (Ed. M Colley) pp. 241–244. (New Zealand Institute of Forestry Inc.: Christchurch)

Anderson SAJ (2009) Future options for fire behaviour modelling and fire danger rating in New Zealand. Proceedings of the Royal Society of Queensland  115, 119–127.

Anderson SAJ , Anderson WR (2009) Predicting the elevated dead fine fuel moisture content in gorse (Ulex europaeus L.) shrub fuels. Canadian Journal of Forest Research  39(12), 2355–2368.
CrossRef |

Anderson SAJ, Doherty JJ , Pearce HG (2008) Wildfires in New Zealand from 1991 to 2007. New Zealand Journal of Forestry  53, 19–22.

Baeza MJ, De Luis M, Raventos J , Escarre A (2002) Factors influencing fire behaviour in shrublands of different stand ages and the implications for using prescribed burning to reduce wildfire risk. Journal of Environmental Management  65, 199–208.
CrossRef | CAS | PubMed |

Beverly JL , Wotton BM (2007) Modelling the probability of sustained flaming: predictive value of fire weather index components compared with observations of site weather and fuel moisture conditions. International Journal of Wildland Fire  16, 161–173.
CrossRef |

Blackmarr WH (1972) Moisture content influences ignitability of slash pine litter. USDA Forest Service, Southeastern Forest Experiment Station, Research Note SE-173. (Asheville, NC)

Blaschke PM, Hunter GG, Eyles GO , Van Berkel PR (1981) Analysis of New Zealand’s vegetation cover using land resource inventory data. New Zealand Journal of Ecology  4, 1–19.

Bruner AD, Klebenow DA (1979) Predicting success of prescribed fires in pinyon–juniper woodland in Nevada. USDA Forest Service, Intermountain Forest and Range Experiment Station, Research Paper INT-219. (Ogden, UT)

Cheney NP (1981) Fire behaviour. In ‘Fire and the Australian Biota’. (Eds AM Gill, RH Groves, IR Noble) pp. 151–175. (Australian Academy of Science: Canberra, ACT)

Cruz MG, Gould JS (2008) Fuel discontinuities and associated non-linear fire dynamics in Australian mallee-heath vegetation. In ‘Fire Environment and Society: from Research into Practice. The International Bushfire Research Conference, incorporating the 15th AFAC Conference’, 1–3 September 2008, Adelaide, SA. pp. 98–99. (Bushfire CRC and AFAC: Melbourne)

Davies GM, Legg CJ (2008) Developing a live fuel moisture model for moorland fire danger rating. In ‘Forest Fires: Modelling, Monitoring and Management of Forest Fires’. (Eds J de Las Heras, CA Brebbia, D Viegas, V Leone) pp. 225–236. (WIT Press: Southampton, UK)

Davies GM, Legg CJ, Smith A, MacDonald A (2006) Developing shrub fire behaviour models in an oceanic climate: burning in the British Uplands. In ‘5th International Conference on Forest Fire Research’, 27–30 November 2006, Figueira da Foz, Portugal. (Ed. DX Viegas) (Elsevier: Amsterdam)

de Groot WJ, Wardati B , Wang J (2005) Calibrating the Fine Fuel Moisture Code for grass ignition potential in Sumatra, Indonesia. International Journal of Wildland Fire  14, 161–168.
CrossRef |

De Luis M, Baeza MJ, Raventos J, Gonzalez Hidalgo JC , de Luis M (2004) Fuel characteristics and fire behaviour in mature Mediterranean gorse shrublands. International Journal of Wildland Fire  13, 79–87.
CrossRef |

Di Castri F (1981) Mediterranean-type shrublands of the world. In ‘Mediterranean-type Shrublands’. (Eds F Di Castri, DW Goodall, RL Specht) pp. 1–52. (Elsevier Scientific Publishing Company: Amsterdam)

Fernandes PAM (2001) Fire spread prediction in shrub fuels in Portugal. Forest Ecology and Management  144, 67–74.
CrossRef |

Fernandes PM (1998) Fire spread modelling in Portuguese shrubland. In ‘Third International Conference on Forest Fire Research and 14th Fire and Forest Meteorology Conference’, 16–20 November 1998, Luso, Coimbra, Portugal. (Ed. DX Viegas) pp. 611–628.

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. Canadian Journal of Forest Research  38, 190–201.
CrossRef |

Fletcher T, Pickett BM, Smith SG, Spittle G, Woodhouse MM, Haake E , Weise DR (2007) Effects of moisture on ignition behavior of moist California chaparral and Utah leaves. Combustion Science and Technology  179, 1183–1203.
CrossRef | CAS |

Fogarty LG (1996) Two rural/urban interface fires in the Wellington suburb of Karori: assessment of associated burning conditions and fire control strategies. New Zealand Forest Research Institute, Rotorua, in association with the National Rural Fire Authority, Wellington. Forest Research Bulletin No. 197, Forest and Rural Fire Scientific and Technical Series Report No.1. (Rotorua)

Fogarty LG, Pearce HG, Catchpole WR, Alexander ME (1998) Adoption vs. adaptation: lessons from applying the Canadian Forest Fire Danger Rating System in New Zealand. In ‘3rd International Conference on Forest Fire Research and 14th Fire and Forest Meteorology Conference’, 16–20 November 1998, Luso, Coimbra, Portugal. (Ed. DX Viegas) pp. 1011–1028.

Garson D (2008) Logistic regression. In ‘Statnotes: Topics in Multivariate Analysis’. Available at [Verified 23 December 2008]

Gimingham CH, Chapman SB (1979) European heathlands. In ‘Heathlands and Related Shrublands. Descriptive Studies’. (Ed. RL Specht) pp. 365–413. (Elsevier Scientific Publishing Company: Amsterdam)

Gould JS, McCaw WL, Cheney NP, Ellis PF, Knight IK, Sullivan AL (2007a) ‘Project Vesta – Fire in Dry Eucalypt Forest: Fuel Structure, Dynamics and Fire Behaviour.’ (Ensis–CSIRO and Department of Environment and Conservation: Canberra, ACT, and Perth, WA)

Gould JS, McCaw WL, Cheney NP, Ellis PF, Matthews S (2007b) ‘Field Guide – Fuel Assessment and Fire Behaviour Prediction in Dry Eucalypt Forest.’ (Ensis–CSIRO and Department of Environment and Conservation: Canberra, ACT, and Perth, WA)

Guijarro M, Hernando C, Díez C, Martínez E, Madrigal J, Lampin Cabaret C, Blanc L, Colin PY, Pérez-Gorostiaga P, Vega JA, Fonturbel MT (2002) Flammability of some fuel beds common in the south European ecosystems. In ‘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’. (Ed. DX Viegas) pp. 152–161. (Millpress Science Publishers: Rotterdam)

Hoshovsky M (1989) ‘Element Stewardship Abstract for Ulex europaeus Gorse.’ (The Nature Conservancy, TNC-ESA: Arlington, VA)

Hosmer DW, Lemeshow S (2000) ‘Applied Logistic Regression. 2nd edn.’ (Wiley: New York)

Lawson BD, Armitage OB, Dalrymple GN (1994) Ignition probabilities for simulated people-caused fires in British Columbia’s lodgepole pine and white spruce-subalpine fir forests. In ‘Proceedings of the 12th International Conference on Fire and Forest Meteorology, 26–29 October 1993’, Jekyll Island, GA. pp. 493–505. (Society of American Foresters: Bethesda, MA)

Lin CC (1999) Modeling probability of ignition in Taiwan red pine forests. Taiwan Journal of Forest Science  14, 339–344.

Luke RH, McArthur AG (1978) ‘Bushfires in Australia.’ (Australian Government Publishing Service: Canberra, ACT)

Manzello SL, Cleary TG, Shields JR , Yang JC (2006) Ignition of mulch and grasses by firebrands in wildland–urban interface fires. International Journal of Wildland Fire  15, 427–431.
CrossRef |

Marsden-Smedley JB, Catchpole WR , Pyrke A (2001) Fire modelling in Tasmanian buttongrass moorlands. IV Sustaining versus non-sustaining fires. International Journal of Wildland Fire  10, 255–262.
CrossRef |

McCaw WL, Burrows ND, Friend GR, Gill AM (1995) Predicting fire spread in Western Australian mallee-heath. In ‘Landscape Fires ’93: Proceedings of Conference’, 27–29 September 1993, Perth, WA. CALMScience (Suppl. 4), pp. 35–42. (Department of Conservation and Land Management: Como, WA)

New Zealand Soil Bureau (1968) ‘Soils of New Zealand. Part 1.’ New Zealand Department of Scientific and Industrial Research, Soil Bureau Bulletin 26(1). (Wellington)

Pellizzaro G, Duce P, Ventura A , Zara A (2007) Seasonal variations of live moisture content and ignitability in shrubs of the Mediterranean Basin. International Journal of Wildland Fire  16, 633–641.
CrossRef |

Plucinski MP , Anderson WR (2008) Laboratory determination of factors influencing successful point ignition in the litter layer of shrubland vegetation. International Journal of Wildland Fire  17, 628–637.
CrossRef |

SAS Institute (2004) ‘SAS/STAT 9.1 User’s guide.’ (SAS Publishing: Cary, NC)

Schwarz G (1978) Estimating the dimension of a model. Annals of Statistics  6, 461–464.
CrossRef |

Stocks BJ, Lawson BD, Alexander ME, Van Wagner CE, McAlpine RS, Lynham TJ , Dube DE (1989) Canadian Forest Fire Danger Rating System: an overview. Forestry Chronicle  65, 258–265.

Stockstad DS (1975) Spontaneous and piloted ignition of pine needles. USDA Forest Service, Intermountain Forest and Range Experiment Station, Research Note INT-194. (Ogden, UT)

Stockstad DS (1976) Spontaneous and piloted ignition of cheatgrass. USDA Forest Service, Intermountain Forest and Range Experiment Station, Research Note INT-204. (Ogden, UT)

Tachajapong W, Lozano J, Mahalingam S, Zhou X , Weise DR (2008) An investigation of crown fuel bulk density effects on the dynamics of crown fire initiation in shrublands. Combustion Science and Technology  180, 593–615.
CrossRef | CAS |

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. Canadian Journal of Forest Research  35, 410–420.
CrossRef |

Tarayre M, Bowman G, Schermann-Legionnet A, Barat M , Atlan A (2007) Flowering phenology of Ulex europaeus: ecological consequences of variation within and among populations. Evolutionary Ecology  21, 395–409.
CrossRef |

Tolhurst KG, Cheney NP (1999) ‘Synopsis of the Knowledge Used in Prescribed Burning in Victoria.’ (Department of Natural Resources and Environment: Melbourne)

Turner MG, Lawson BD (1978) Weather in the Canadian Forest Fire Danger Rating System. A user guide to national standards and practices. Environment Canada, Forestry Service, Information Report BC-X-177. (Victoria, BC)

Vega JA, Fernandez C , Fonturbel T (2005) Throughfall, runoff and soil erosion after prescribed burning in gorse shrubland in Galicia (NW Spain). Land Degradation & Development  16, 37–51.
CrossRef |

Weise DR, Zhou X, Sun L , Mahalingam S (2005) Fire spread in chaparral – ‘go or no-go?’ International Journal of Wildland Fire  14, 99–106.
CrossRef |

Woodman M, Rawson R (1982) Fuel reduction burning in radiata pine plantations. Fire Management Branch, Department of Conservation and Environment, Research report No 14. (Melbourne)

Zabkiewicz JA (1975) The ecology of gorse and its relevance to New Zealand forestry. In ‘Use of Herbicides in Forestry in New Zealand. FRI Symposium No.18’, Rotorua. (Ed. CGR Chavasse) pp. 63–70. (NZ Forest Service, Forest Research Institute: Rotorua)

Zhou X, Mahalingam S , Weise D (2005a) Modeling of marginal burning state of fire spread in live chaparral shrub fuel bed. Combustion and Flame  143, 183–198.
CrossRef | CAS |

Zhou X, Weise D , Mahalingam S (2005b) Experimental measurements and numerical modelling of marginal burning in live chaparral fuel beds. Proceedings of the Combustion Institute  30, 2287–2294.
CrossRef |

Zhou X, Mahalingam S , Weise D (2007) Experimental study and large eddy simulation of effect of terrain slope on marginal burning in shrub fuel beds. Proceedings of the Combustion Institute  31, 2547–2555.
CrossRef |

Export Citation Cited By (22)