Abstract
Understanding the flammability of species in fire-prone or fire-dependent ecosystems is necessary for modeling and predicting ecosystem dynamics. Wiregrass (Aristida stricta syn. A. beyrichiana), a keystone perennial bunchgrass, is a dominant groundcover species in southeastern United States pine savannas. Although wiregrass flammability as a driver of pine savanna fire regimes is a fundamental paradigm in pine savanna dynamics, no studies have quantified its fuel structure and flammability at the individual bunchgrass level. We studied wiregrass flammability at the Aiken Gopher Tortoise Heritage Preserve in Aiken County, South Carolina, USA. We linked tussock fuel structure characteristics (total biomass, live:dead biomass, mass of perched litter and pine needles, moisture content, and bulk density) to flammability (flaming duration, smoldering duration, and flame length). Flame length was strongly and positively related to wiregrass biomass. Pine needles and other litter fuels perched on wiregrass tussocks were not related to flame length, but increased the duration of flaming and smoldering. Within the ranges evaluated, neither fire weather (relative humidity, wind speed, and air temperature) nor fuel moisture significantly affected tussock flammability. Our results indicate that different fuel structural properties drive separate aspects of wiregrass flammability. Together with litter from pines and other groundcover shrubs and trees, wiregrass modifies fire behavior locally, potentially influencing ecosystem dynamics at larger scales. These results have strong implications for southeastern pine savannas and more broadly where grass-dominated vegetation influences fire regimes.
Similar content being viewed by others
References
Alexander ME (1982) Calculating and interpreting forest fire intensities. Can J Bot 60:349–357
Anderson HE (1970) Forest fuel ignitability. Fire Technol 6:312–319
Anderson DR, Burnham KP (2002) Avoiding pitfalls when using information-theoretic methods. J Wildl Manag 66:912–918
Beckage B, Platt WJ, Gross LJ (2009) Vegetation, fire, and feedbacks: a disturbance-mediated model of savannas. Am Nat 174:805–818
Beckage B, Gross LJ, Platt WJ (2011) Grass feedbacks on fire stabilize savannas. Ecol Model 222:2227–2233
Bond WJ, Midgley JJ (1995) Kill thy neighbour: an individualistic argument for the evolution of flammability. Oikos 73:79–85
Bond WJ, Midgley JJ (2005) The global distribution of ecosystems in a world without fire. New Phytol 165:525–538
Bond WJ, van Wilgen BW (1996) Fire and plants. Chapman & Hall, London
Burnham KP, Anderson DR (2002) Model selection and multimodel inference: a practical information-theoretic approach. Springer, New York
Burnham KP, Anderson DR, Huyvaert KP (2011) AIC model selection and multimodel inference in behavioral ecology: some background, observations, and comparisons. Behav Ecol Sociobiol 65:23–35
Byram GM (1959) Combustion of forest fuels. In: Davis P (ed) Forest fire: control and use. McGraw-Hill, New York, pp 61–89
Byram GM (1963) An analysis of the drying process in forest fuel material. USDA Forest Service, Fire Sciences Laboratory, Rocky Mountain Research Station Report, Missoula
Christensen NL (1977) Fire and soil–plant nutrient relations in a pine-wiregrass savanna on the coastal plain of North Carolina. Oecologia 31:27–44
Clewell AF (1989) Natural history of wiregrass (Aristida stricta Michx., Gramineae). Nat Areas J 9:223–233
de Magalhães RM, Schwilk DW (2012) Leaf traits and litter flammability: evidence for non-additive mixture effects in a temperate forest. J Ecol 100:1153–1163
Ellair DP, Platt WJ (2013) Fuel composition influences fire characteristics and understorey hardwoods in pine savanna. J Ecol 101:192–201
Engber EA, Varner JM, Arguello LA, Sugihara NG (2011) The effects of conifer encroachment and overstory structure on fuels and fire in an oak woodland landscape. Fire Ecol 7:32–50
Fill JM, Welch SM, Waldron JL, Mousseau TA (2012) The reproductive response of an endemic bunchgrass indicates historical timing of a keystone process. Ecosphere 3:art61
Fonda RW (2001) Burning characteristics of needles from eight pine species. For Sci 47:390–396
Frost CC (1998) Presettlement fire frequency regimes of the United States: a first approximation. In: Pruden TL, Brennan LA (eds) Fire in ecosystem management: shifting the paradigm from suppression to prescription. Tall Timbers Fire Ecology conference proceedings No. 20. Tall Timbers Research Station, Tallahassee, pp 70–81
Gagnon PR, Passmore HA, Slocum M, Myers JA, Harms KE, Platt WJ, Paine CET (2015) Fuels and fires influence vegetation via above- and belowground pathways in a high-diversity plant community. J Ecol 103:1009–1019
Gill AM, Trollope WSW, MacArthur DA (1978) Role of moisture in the flammability of natural fuels in the laboratory. Aust For Res 8:199–208
Glitzenstein JS, Platt WJ, Streng DR (1995) Effects of fire regime and habitat on tree dynamics in north Florida longleaf pine savannas. Ecol Monogr 65:441–476
Grace SL, Platt WJ (1995) Effects of adult tree density and fire on the demography of pregrass stage juvenile longleaf pine (Pinus palustris Mill.). J Ecol 83:75–86
Hammond DH, Varner JM, Kush JS, Fan Z (2015) Contrasting sapling bark allocation of five southeastern USA hardwood tree species in a fire-prone ecosystem. Ecosphere 6: art112
Hardin ED, White DL (1989) Rare vascular plant taxa associated with wiregrass (Aristida stricta) in the southeastern United States. Nat Areas J 9:234–245
Hendricks JJ, Wilson CA, Boring LR (2002) Foliar litter position and decomposition in a fire-maintained longleaf pine-wiregrass ecosystem. Can J For Res 32:928–941
Hoffmann WA, Adasme R, Haridsasan M, de Carvalho MT, Giger EL, Pereira MAB, Gotsch SG, Franco AC (2009) Tree topkill, not mortality, governs the dynamics of savanna- forest boundaries under frequent fire in central Brazil. Ecol 90:1326–1337
Hoffmann WA, Geiger EL, Gotsch SG, Rossatto DR, Silva LCR, Lau OL, Haridasan M, Franco AC (2012a) Ecological thresholds at the savanna-forest boundary: how plant traits, resources and fire govern the distribution of tropical biomes. Ecol Lett 15:759–768
Hoffmann WA, Jaconis SY, Mckinley KL, Geiger EL, Gotsch SG, Franco AC (2012b) Fuels or microclimate? Understanding the drivers of ire feedbacks at savanna-forest boundaries. Austral Ecol 37:634–643
Kane JM, Varner JM, Hiers JK (2008) The burning characteristics of southeastern oaks: discriminating fire facilitators from fire impeders. For Ecol Manag 256:2039–2045
Kreye JK, Varner JM, Knapp EE (2011) Effects of particle fracturing and moisture content on fire behavior in masticated fuelbeds burned in a laboratory. Int J Wildland Fire 20:308–317
Kreye JK, Varner JM, Hiers JK, Mola J (2013) Toward a mechanism for eastern North American forest mesophication: differential litter drying across 17 species. Ecol Appl 23:1976–1986
Kreye JK, Brewer NW, Morgan P, Varner JM, Smith AMS, Hoffman CM, Ottmar RD (2014) Fire behavior in masticated fuels: a review. For Ecol Manag 314:193–207
Lawes MJ, Adie H, Russell-Smith J, Murphy B, Midgley JJ (2011) How do small savanna trees avoid stem mortality by fire? The roles of stem diameter, height and bark thickness. Ecosphere 2:art42
Loudermilk EL (2010) Linking plant demography, forest fuels, and fire in longleaf pine (Pinus palustris) savannas using lidar remote sensing and simulation modeling. PhD dissertation, University of Florida, Gainesville, FL, USA
Loudermilk EL, Hiers JK, O’Brien JJ, Mitchell RJ, Singhania A, Fernandez JC, Cropper WP, Slatton KC (2009) Ground-based LiDAR: a novel approach to quantify finescale fuelbed characteristics. Int J Wildland Fire 18:676–685
Martin RE, Gorden DA, Gutierrez ME, Lee DS, Molina DM, Schroeder RA, Sapsis DA, Stephens SL, Chambers M (1993) Assessing the flammability of domestic and wildland vegetation. In: Proceedings of the 12th conference on fire and forest Meteorology. Society of American Foresters Publication 94-02, Bethesda, pp 130-137
Mayer AL, Khalyani AH (2011) Grass trumps trees with fire. Science 334:188–189
Mola JM, Varner JM, Jules ES, Spector T (2014) Altered community flammability in Florida’s Apalachicola ravines and implications for the persistence of the endangered conifer Torreya taxifolia. PLoS ONE 9(e103933):85
Noss RF (1989) Longleaf pine and wiregrass: keystone components of an endangered ecosystem. Nat Areas J 9:211–213
Parrott RT (1967) A study of wiregrass (Aristida stricta Michx.) with particular reference to fire. MS Thesis, Duke University, Durham, NC, USA
Pausas JG, Keeley JE (2009) A burning story: the role of fire in the history of life. Bioscience 59:593–601
Peet RK (2006) Ecological classification of longleaf pine woodlands. In: Jose S, Jokela EJ, Miller DL (eds) The longleaf pine ecosystem: ecology, silviculture, and restoration. Springer, New York, pp 51–93
Platt WJ (1999) Southeastern pine savannas. In: Anderson RC, Fralish JS, Baskin J (eds) The savannas, barrens, and rock outcrop communities of North America. Cambridge University Press, Cambridge, pp 23–51
Platt WJ, Glitzenstein JS, Streng DR (1991) Evaluating pyrogenicity and its effects on vegetation in longleaf pine savannas. Proc Tall Timbers Fire Ecol Conf 17:143–161
Platt WJ, Orzell SL, Slocum MG (2015) Seasonality of fire weather strongly influences fire regimes in south Florida savanna-grassland landscapes. PLoS ONE 10:e0116952
Raudenbush SW, Yang ML, Yosef M (2000) Maximum likelihood for generalized linear models with nested random effects via high-order, multivariate Laplace approximation. J Comput Graph Stat 9:141–157
Reid AM, Robertson KM (2012) Energy content of common fuels in upland pine savannas of the south-eastern US and their application to fire behavior modelling. Int J Wildland Fire 21:591–595
Reid AM, Robertson KM, Hmielowski T (2012) Predicting litter and live herb fuel consumption during prescribed fires in native and old-field upland pine communities of the southeastern United States. Can J For Res 42:1611–1622
Robertson KM, Ostertag TE (2007) Effects of land use on fuel characteristics and fire behavior in pinelands of Southwest Georgia. In: Masters RE, Galley KEM (eds) Proceedings of the 23rd Tall Timbers Fire Ecology Conference: fire in grassland and shrubland ecosystems. Tall Timbers Research Station, Florida, pp 181–191
Robertson KM, Hmielowski T (2014) Effects of fire frequency and season on resprouting of woody plants in southeastern US pine-grassland communities. Oecologia 174:765–776
Rossiter NA, Setterfield SA, Douglas MM, Hutley LB (2003) Testing the grass-fire cycle: alien grass invasion in the tropical savannas of northern Australia. Divers Distrib 9:169–176
Rothermel RC (1983) How to predict the spread and intensity of forest and range fires. USDA Forest Service General Technical Report INT-143
Scholes RJ, Archer SR (1997) Tree–grass interactions in savannas. Annu Rev Ecol Syst 28:517–544
Setterfield SA, Rossiter-Rachor NA, Hutley LB, Douglas MM, Williams RJ (2010) Turning up the heat: the impacts of Andropogon gayanus (gamba grass) invasion on fire behaviour in northern Australian savannas. Biodivers Res 16:854–861
Solbrig OT, Medina E, Silva JF (1996) Determinants of tropical savannas. In: Solbrig OT, Medina E, Silva JF (eds) Biodiversity and ecosystem processes. Springer, Berlin, pp 31–41
Southeast Regional Climate Center (2011) Aiken 4 NE, South Carolina (380074): Period of Record Monthly Climate Summary [on-line]. Online at http://www.sercc.com/cgi-bin/sercc/cliMAIN.pl?sc0074 [accessed May 10, 2011]
Stambaugh MC, Guyette RP, Marschall JM (2011) Longleaf pine (Pinus palustris Mill.) fire scars reveal new details of a frequent fire regime. J Veg Sci 22:1094–1104
Staver AC, Archibald S, Levin SA (2011) The global extent and determinants of savanna and forest as alternative biome states. Science 324:230–232
Streng DR, Harcombe PA (1982) Why don’t east Texas savannas grow up to be forest? Am Mid Nat 108:278–294
Thaxton JM, Platt WJ (2006) Small-scale fuel variation alters fire intensity and shrub abundance in a pine savanna. Ecology 87:1331–1337
Trauernict C, Murphy BP, Portner TE, Bowman DMS (2012) Tree cover–fire interactions promote the persistence of a fire-sensitive conifer in a highly flammable savanna. J Ecol 100:958–968
United States Department of Agriculture (1985) Soil survey of Aiken County Area: South Carolina. USDA Soil Conservation Service
Varner JM, Kane JM, Kreye JK, Enger E (2015) The flammability of forest and woodland litter: a synthesis. Curr For Rep 1:91–99
Veldman JW, Mattingly WB, Brudvig LA (2013) Understory plant communities and the functional distinction between savanna trees, forest trees, and pines. Ecology 94:424–434
Wenk ES, Wang GG, Walker JL (2011) Within-stand variation in understorey vegetation affects fire behaviour in longleaf pine xeric sandhills. Int J Wildland Fire 20:866–875
Wenk ES, GG Wang, JL Walker (2013) Understory fuel variation at the Carolina Sandhills National Wildlife Refuge: a description of chemical and physical properties. In: Guldin JM (ed) Proceedings of the 15th biennial southern silvicultural research conference. USDA Forest Service, Southern Research Station General Technical Report SRS-GTR-175, pp 351–356
Whelan RJ (1995) The ecology of fire. Cambridge University Press, Cambridge
Wiggers MS, Kirkman LK, Boyd RS, Hiers JK (2013) Fine-scale variation in surface fire environment and legume germination in the longleaf pine ecosystem. For Ecol Manag 310:54–63
Williamson GB, Black EM (1981) High temperature of forest fires under pines as a selective advantage over oaks. Nature 293:643–644
Acknowledgments
Michael Small and Barry Kesler (South Carolina Department of Natural Resources) and Andy Johnson (South Carolina Forestry Commission) provided generous field assistance. Funding was provided by our respective institutions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Communicated by Devan Allen McGranahan.
Rights and permissions
About this article
Cite this article
Fill, J.M., Moule, B.M., Varner, J.M. et al. Flammability of the keystone savanna bunchgrass Aristida stricta . Plant Ecol 217, 331–342 (2016). https://doi.org/10.1007/s11258-016-0574-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11258-016-0574-0