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

Flammability of native understory species in pine flatwood and hardwood hammock ecosystems and implications for the wildland–urban interface

Anna L. Behm A , Mary L. Duryea B D , Alan J. Long A and Wayne C. Zipperer C
+ Author Affiliations
- Author Affiliations

A School of Forest Resources and Conservation, University of Florida, PO Box 110410, Gainesville, FL 32611, USA. Telephone: +1 352 846 0120; fax: +1 352 846 1277

B Institute of Food and Agricultural Sciences, University of Florida, PO Box 110200, Gainesville, FL 32611, USA.

C Southern Center for Wildland–Urban Interface Research and Information, USDA Forest Service, 408 W. University Ave (Suite 306), Gainesville, FL 32601, USA. Telephone: +1 352 376 4576; fax: +1 352 376 4536

D Corresponding author. Telephone: +1 352 392 1784; fax: +1 352 392 4965; email:

International Journal of Wildland Fire 13(3) 355-365
Submitted: 10 November 2003  Accepted: 1 July 2004   Published: 16 November 2004


Six understory species from five pine flatwood sites and six understory species from five hardwood hammock sites were harvested for biomass analyses to compare potential flammability between two ecosystems in the south-eastern coastal plain of the United States. Plant components were separated into live and dead foliage, accumulated litter on and under the plant, and small and large stems. Foliar biomass was further analysed for moisture content, volatile solid content, and energy content. Statistical analyses revealed differences among species and between ecosystems. Serenoa repens plants present a wildfire hazard because they contain greater biomass than other species studied. Ilex glabra and Lyonia ferruginea are also hazardous to wildland–urban interface (WUI) structures because they have greater foliar energy content than other species studied. Callicarpa americana plants present the least wildfire hazard to WUI structures. We conclude that differences in flammability among species exist, but the causes of flammability are different among species. In addition, species in the same genus do not always have the same flammability. Based on measured characteristics, understory plants in pine flatwoods have greater ignitability, sustainability and combustibility than understory plants in hardwood hammocks. However, the measurements for consumability were similar between ecosystems.

Additional keywords: Callicarpa americana; energy content; firewise landscaping; Gaylussacia dumosa; Ilex glabra; Ilex opaca; Lyonia ferruginea; Myrica cerifera; Quercus nigra; Serenoa repens; Vaccinium arboreum; Vaccinium myrsinites; wildland–urban interface.


Abrahamson WG ,  Hartnett DC (1990) Pine flatwoods and dry prairies. In ‘Ecosystems of Florida.’ (Eds  RL Myers ,  JJ Ewel )  pp. 103–149. (University of Central Florida Press: Orlando)

Anderson HE (1970) Forest fuel ignitibility. Fire Technology  6, 312–319.

Bond WJ , Midgley JJ (1995) Kill thy neighbor: an individualistic argument for the evolution of flammability. Oikos  73, 79–85.

Bond WJ,  Van Wilgen BW (1996) ‘Fire and plants.’ (Chapman & Hall: London)  

Brown JK (1970) Ratios of surface area to volume for common fine fuels. Forest Science  16, 101–105.

Burgan RE , Susott RA (1991) Influence of sample processing techniques and seasonal variation on quantities of volatile compounds of gallberry, saw-palmetto, and wax myrtle. International Journal of Wildland Fire  101, 57–62.

Dickinson KJM , Kirkpatrick JB (1985) The flammability and energy content of some important plant species and fuel components in the forests of southeastern Tasmania. Journal of Biogeography  12, 121–134.

Eriksson I, Teketay D , Granström A (2003) Response of plant communities to fire in an Acacia woodland and a dry Afromontane forest, southern Ethiopia. Forest Ecology and Management  177, 39–50.
CrossRef |

Etlinger MG (2000). Fire performance of landscape plants. MS Thesis, University of California, Berkeley.

FNAI (1990) ‘Guide to the natural communities of Florida.’ (Florida Natural Areas Inventory and Florida Department of Natural Resources: Tallahassee)  

Foote LE,  Jones SB, Jr (1989) ‘Native shrubs and woody vines of the southeast: Landscape uses and identification.’ (Timber Press: Portland, OR)  

Francis JK (2000) Comparison of hurricane damage to several species of urban trees in San Juan, Puerto Rico. Journal of Arboriculture  26, 189–197.

Gill AM, Trollope WSW , MacArthur DA (1978) Role of moisture in the flammability of natural fuels in the laboratory. Australian Forest Research  8, 199–208.

Hermansen LA , Macie EA (2002) Introduction. ‘Human influences on forest ecosystems: The southern wildland–urban interface assessment.’ pp. 1–7. USDA Forest Service, General Technical Report GTR-SRS-55. (Asheville, NC)

Hough WA , Albini FA (1978) ‘Predicting fire behavior in palmetto–gallberry fuel complexes.’ USDA Forest Service Research Paper SE-184.

Lippi C, Kuypers M (1998) ‘Flagler horticulture: making your landscape more resistant to wildfires.’ Flagler County Extension, Florida Cooperative Extension Service. (Institute of Food and Agricultural Sciences, University of Florida: Gainesville, FL)

MacCubbin T,  Mudge D (2002) ‘Fire wise landscaping: making sensible choices.’ Orange County Extension, FL Cooperative Extension Service. (Institute of Food and Agricultural Sciences, University of Florida: Gainesville, FL)  

Martin RE, Gordon DA , Gutierrez MA (1994) Assessing the flammability of domestic and wildland vegetation. ‘Proceedings 12th conference on fire and forest meteorology, 26–28 October 1993, Jekyll Island, GA’. p. 796. (Society of American Foresters: Bethesda, MD)

Monroe MC, Long AJ (2001) ‘Landscaping in Florida with fire in mind.’ Florida Cooperative Extension Service. FOR 71. (Institute of Food and Agricultural Sciences, University of Florida: Gainesville, FL)

Monroe MC, Long AJ , Marynowski S (2003) Wildland fire in the Southeast: Negotiating guidelines for defensible space. Journal of Forestry  101, 14–19.

Montgomery KR , Cheo PC (1971) Effect of leaf thickness on ignitibility. Forest Science  17, 475–478.

Mutch RW (1970) Wildland fires and ecosystems—a hypothesis. Ecology  51, 1046–1051.

Mutch RW , Philpot CW (1970) Relation of silica content to flammability in grasses. Forest Science  16, 64–65.

Narog MG, Paysen TE, Koonce AL , Burke GM (1991) Burning irrigated and unirrigated chamise. ‘Proceedings 11th conference on fire and forest meteorology, 16–19 April 1991, Missoula, MT.’ pp. 352–356. (Society of American Foresters: Bethesda, MD)

Owens MK, Lin CD, Taylor CA , Whisenant SG (1998) Seasonal patterns of plant flammability and monoterpenoid content in Juniperus ashei. Journal of Chemical Ecology  24, 2115–2129.

CrossRef |

Papió C , Trabaud L (1990) Structural characteristics of fuel components of five Mediterranean shrubs. Forest Ecology and Management  35, 249–259.
CrossRef |

Philpot CW (1970) Influence of mineral content on the pyrolysis of plant materials. Forest Science  16, 461–471.

Platt WJ ,  Schwartz MW (1990) Temperate hardwood forests. In ‘Ecosystems of Florida.’ (Eds  RL Myers ,  JJ Ewel )  pp. 194–229. (University of Central Florida Press: Orlando)

Pyne SJ,  Andrews PL,  Laven RD (1996) ‘Introduction to wildland fire.’ 2nd edn. (John Wiley & Sons: New York)  

Rundel PW (1981) Structural and chemical components of flammability. In ‘Fire regimes and ecosystem properties.’ pp. 183–207. USDA Forest Service General Technical Report GTR-WO-26. (Washington, DC)

Schwilk DW (2003) Flammability is a niche construction trait: canopy architecture affects fire intensity. American Naturalist  162, 725–733.
CrossRef | PubMed |

Schwilk DW , Kerr B (2002) Genetic niche-hiking: an alternative explanation for the evolution of flammability. Oikos  99, 431–442.

CrossRef |

Shafizadeh F, Chin PPS , DeGroot WF (1977) Effective heat content of green forest fuels. Forest Science  23, 81–89.

Susott RA (1982) Characterization of the thermal properties of forest fuels by combustible gas analysis. Forest Science  28, 404–420.

Van Wilgen BW, Higgins KB , Bellstedt DU (1990) The role of vegetation structure and fuel chemistry in excluding fire from forest patches in the fire-prone fynbos shrublands of South Africa. Journal of Ecology  78, 210–222.

Wang S , Huffman JB (1982) Effect of extractives on heat content of melaleuca and eucalyptus. Wood Science  15, 33–38.

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