The ignition index based on flammability of vegetation improves planning in the wildland-urban interface: A case study in Southern Spain

Abstract Forest fires in the wildland urban interface (WUI) are a widespread and growing problem due to changes in land use and climate. The impacts of WUI fire depend on the exposure of homes to dense vegetation (both natural and ornamental), as well as fire intensity, which is determined by meteorological, topographical, and vegetation conditions. In this study, our goal was to identify the ignition index in one risky Mediterranean WUI based on the potential flammability of the main intermix species at the particle level. The flammability of 18 species (natural and ornamental) commonly found in southern Spain was analyzed at the particle level. Flammability experiments ranked the flammability of the different species from moderately flammable to extremely flammable. Flaming duration (a variable related to fire suppression difficulty) and the ignition coefficient of the surrounding vegetation helped to complete the ignition risk for each vegetation aggregation. Thuja orientalis and Ligustrum vulgare showed the greatest individual potential to mitigate fire spread, and are recommended for planting and use as landscaping hedges in the Mediterranean WUI. We concluded that this methodological procedure is a useful tool for prioritization and budget allocation of fire risk reduction treatments. Furthermore, the development of technical guidelines for public urban landscaping as well as landscaping on private residences is required to adequately address and mitigate fire impacts both on homes and the surrounding landscapes.

[1]  A. C. Batista,et al.  Avaliação da inflamabilidade de Ligustrum lucidum Aiton (Oleaceae) para uso potencial em cortinas de segurança na região sul do Brasil - DOI:10.5039/agraria.v4i4a11 , 2009 .

[2]  M. Cruz,et al.  Plant flammability experiments offer limited insight into vegetation-fire dynamics interactions. , 2012, The New phytologist.

[3]  D. Evan Mercer,et al.  Fire in the Wildland–Urban Interface , 2012 .

[4]  Susan L. LeVan,et al.  Kinetic properties of the components of Douglas-fir and the heat of combustion of their volatile pyrolysis products , 2007 .

[5]  Alexandros Dimitrakopoulos,et al.  Flammability Assessment of Mediterranean Forest Fuels , 2001 .

[6]  L. Kobziar,et al.  Extreme temperature days and their potential impacts on southern Europe , 2014 .

[7]  C. Canham,et al.  NEIGHBORHOOD MODELS OF THE EFFECTS OF INVASIVE TREE SPECIES ON ECOSYSTEM PROCESSES , 2008 .

[8]  Robert H. White,et al.  Testing and classification of individual plants for fire behaviour: plant selection for the wildland-urban interface , 2010 .

[9]  Juan Ramón Molina-Martínez,et al.  Modeling Mediterranean forest fuels by integrating field data and mapping tools , 2011, European Journal of Forest Research.

[10]  Jesus Solana,et al.  A Wildland–Urban Interface Typology for Forest Fire Risk Management in Mediterranean Areas , 2011 .

[11]  Susan I. Stewart,et al.  Using structure locations as a basis for mapping the wildland urban interface. , 2013, Journal of environmental management.

[12]  F. A. Rutigliano,et al.  Preliminary studies on litter flammability in Mediterranean region , 2006 .

[13]  Matthew P. Thompson,et al.  A national approach for integrating wildfire simulation modeling into Wildland Urban Interface risk assessments within the United States , 2013 .

[14]  E. Chuvieco,et al.  Prediction of fire occurrence from live fuel moisture content measurements in a Mediterranean ecosystem , 2009 .

[15]  J. Moya,et al.  Possible land management uses of common cypress to reduce wildfire initiation risk: a laboratory study. , 2015, Journal of environmental management.

[16]  J.-C. Valette.  Inflammabilités des espèces forestières méditerranéennes. Conséquences sur la combustibilité des formations forestières , 1990 .

[17]  M. Westoby,et al.  Leaf litter flammability in some semi-arid Australian woodlands , 2006 .

[18]  R. Bradstock,et al.  A semi-mechanistic model for predicting the moisture content of fine litter , 2015 .

[19]  J. Madrigal,et al.  Characterization of wildland-urban interfaces for fire prevention in the province of Valencia (Spain) , 2013 .

[20]  Frank C. Beall,et al.  Development of a laboratory protocol for fire performance of landscape plants , 2004 .

[21]  W. Anderson,et al.  Laboratory determination of factors influencing successful point ignition in the litter layer of shrubland vegetation , 2008 .

[22]  M. Monroe,et al.  Negotiating guidelines for defensible space , 2003 .

[23]  Pierpaolo Duce,et al.  Seasonal variations of live moisture content and ignitability in shrubs of the Mediterranean Basin , 2007 .

[24]  Francisco Rodríguez y Silva,et al.  A methodology for determining operational priorities for prevention and suppression of wildland fires , 2014 .

[25]  E. Lois,et al.  TG and autoignition studies on forest fuels , 2002 .

[26]  Julia Touza,et al.  Forest fires in the wildland–urban interface: A spatial analysis of forest fragmentation and human impacts , 2013 .

[27]  A. Ganteaume,et al.  Assessing the flammability of surface fuels beneath ornamental vegetation in wildland-urban interfaces in Provence (South-Eastern France). , 2013 .

[28]  Ross A. Bradstock,et al.  Countervailing effects of urbanization and vegetation extent on fire frequency on the Wildland urban interface: disentangling fuel and ignition effects , 2014 .

[29]  Corinne Lampin-Maillet,et al.  Mapping wildland-urban interfaces at large scales integrating housing density and vegetation aggregation for fire prevention in the South of France. , 2010, Journal of environmental management.

[30]  Marielle Jappiot,et al.  Application of a geographical assessment method for the characterization of wildland–urban interfaces in the context of wildfire prevention: A case study in western Madrid , 2012 .

[31]  R. Lathrop,et al.  Structure-level fuel load assessment in the wildland–urban interface: a fusion of airborne laser scanning and spectral remote-sensing methodologies , 2016 .

[32]  Nicole M. Vaillant,et al.  A comparison of landscape fuel treatment strategies to mitigate wildland fire risk in the urban interface and preserve old forest structure , 2010 .

[33]  Can private land conservation reduce wildfire risk to homes? A case study in San Diego County, California, USA , 2017 .

[34]  Matthias M. Boer,et al.  Predicting dead fine fuel moisture at regional scales using vapour pressure deficit from MODIS and gridded weather data. , 2016 .

[35]  S. L. Manzello,et al.  The wildland-urban interface fire problem - current approaches and research needs , 2010 .

[36]  Jack D. Cohen,et al.  The wildland-urban interface fire problem: A consequence of the fire exclusion paradigm , 2008 .

[37]  K. McGarigal,et al.  FRAGSTATS: spatial pattern analysis program for quantifying landscape structure. , 1995 .

[38]  W. Matt Jolly,et al.  Sensitivity of a surface fire spread model and associated fire behaviour fuel models to changes in live fuel moisture , 2007 .

[39]  J. Touza,et al.  Wildfire risk associated with different vegetation types within and outside wildland-urban interfaces , 2016 .

[40]  Alan J. Long,et al.  Flammability of native understory species in pine flatwood and hardwood hammock ecosystems and implications for the wildland–urban interface , 2004 .

[41]  Martha C. Monroe,et al.  Wildland Fire in the Southeast: Negotiating Guidelines for Defensible Space , 2003 .

[42]  J. Peñuelas,et al.  Short-chained oxygenated VOC emissions in Pinus halepensis in response to changes in water availability , 2009, Acta Physiologiae Plantarum.

[43]  M. Finney.  Design of Regular Landscape Fuel Treatment Patterns for Modifying Fire Growth and Behavior , 2001, Forest Science.

[44]  Gavriil Xanthopoulos,et al.  Fire hazard and flammability of European forest types , 2012 .

[45]  Gary L. Achtemeier,et al.  Fuels and fire behavior in chipped and unchipped plots: Implications for land management near the wildland/urban interface , 2006 .

[46]  F. Halter,et al.  Pinus pinea emissions and combustion characteristics of limonene potentially involved in accelerating forest fires , 2012 .

[47]  C. Canham,et al.  Neighbourhood analyses of the allelopathic effects of the invasive tree Ailanthus altissima in temperate forests , 2008 .