Impact of grazing on fine fuels and potential wildfire behaviour in a non-native tropical grassland
Edward W. Evans A , Lisa M. Ellsworth A B and Creighton M. Litton A CA Department of Natural Resources and Environmental Management, University of Hawai‘i at Mānoa, 1910 East West Road, Honolulu, HI 96822, USA.
B Present address: Oregon State University, Corvallis, OR 97331, USA.
C Corresponding author. Email: litton@hawaii.edu
Pacific Conservation Biology 21(2) 126-132 https://doi.org/10.1071/PC14910
Submitted: 20 August 2014 Accepted: 1 March 2015 Published: 22 May 2015
Abstract
Non-native grass invasion has increased fuel loads and fire frequency in areas throughout the tropics, resulting in a non-native grass–wildfire cycle with negative impacts on native biodiversity and ecological processes. Megathyrsus maximus (guinea grass) invades dry and mesic ecosystems throughout the tropics, increasing fuel loads and wildfire intensity. Eradication of M. maximus is difficult, making effective wildfire management critical to the protection of adjacent developed areas and remnant native ecosystems. The use of domestic livestock grazing in non-native grass ecosystems may be effective at decreasing fine fuel loads and potential wildfire behaviour. Our objectives were to: (1) quantify live and dead fine fuel loads and moistures in a M. maximus–dominated ecosystem before and after cattle grazing, and (2) use these data to model potential wildfire behaviour in grazed and ungrazed M. maximus grasslands with the BehavePlus fire modelling system. Fine fuel loads and moistures, climate variables, and predicted wildfire behaviour were quantified at the same site (n = 1) over two 5-month periods (March–July 2009, ungrazed; March–July 2010, grazed) in the Wai‘anae Kai Forest Reserve on the Island of O‘ahu, Hawai‘i. Strong to conclusive evidence existed that cattle grazing in this system decreased dead and total fuel loads, but did not alter live fuel loads, or live and dead fuel moistures. Modelled wildfire behaviour under both low and average fuel moisture scenarios revealed that grazing decreased the potential rate of spread by 44–52% and flame length by 36–41%. These results demonstrate that cattle grazing may be an effective approach for reducing fuel loads and potential wildfire behaviour in non-native-dominated grasslands on tropical islands.
Additional keywords: BehavePlus fire model, guinea grass, invasive grass, Megathyrsus maximus, non-native grass–wildfire cycle, tropical dryland ecosystem.
References
Ammondt, S. A. E., and Litton, C. M. (2012). Competition between native Hawaiian plants and the invasive grass Megathyrsus maximus: Implications of functional diversity for ecological restoration. Restoration Ecology 20, 638–646.| Competition between native Hawaiian plants and the invasive grass Megathyrsus maximus: Implications of functional diversity for ecological restoration.Crossref | GoogleScholarGoogle Scholar |
Ammondt, S. A., Litton, C. M., Ellsworth, L. M., and Leary, J. K. (2013). Restoration of native plant communities in a Hawaiian dry lowland ecosystem dominated by the invasive grass Megathyrsus maximus. Applied Vegetation Science 16, 29–39.
| Restoration of native plant communities in a Hawaiian dry lowland ecosystem dominated by the invasive grass Megathyrsus maximus.Crossref | GoogleScholarGoogle Scholar |
Andrews, P. L., Bevins, C. D., and Seli, R. C. (2005). BehavePlus fire modeling system, version 4.0: User’s Guide. General Technical Report RMRS-GTR-106WWW Revised. Rocky Mountain Research Station, Department of Agriculture, Forest Service, Ogden, UT.
Ansari, S., Hirsh, H., and Thair, T. (2008). Removal of invasive fire-prone grasses to increase training lands in the Pacific. SWCA Environmental Consultants for Department of Defense Legacy Resource Management Program, Honolulu, HI.
Beavers, A. M. (2001). Creation and validation of a custom fuel model representing mature Panicum maximum (Guinea Grass) in Hawai‘i. Center for Environmental Management of Military Lands. Department of Forest Sciences, Colorado State University, CO.
Blackmore, M., and Vitousek, P. M. (2000). Cattle grazing, forest loss, and fuel loading in a dry forest ecosystem at Pu‘u Wa‘aWa‘a Ranch, Hawai‘i. Biotropica 32, 625–632.
| Cattle grazing, forest loss, and fuel loading in a dry forest ecosystem at Pu‘u Wa‘aWa‘a Ranch, Hawai‘i.Crossref | GoogleScholarGoogle Scholar |
Brooks, M. L., D’Antonio, C. M., Richardson, D. M., Grace, J. B., Keeley, J. E., DiTomaso, J. M., Hobbs, R. J., Pellant, M., and Pyke, D. (2004). Effects of invasive alien plants on fire regimes. Bioscience 54, 677–688.
| Effects of invasive alien plants on fire regimes.Crossref | GoogleScholarGoogle Scholar |
Bruegmann, M. M. (1996). Hawai‘i’s dry forests. Endangered Species Bulletin 11, 26–27.
Burgan, R. E., and Rothermal, R. C. (1984). BEHAVE: fire behavior prediction and fuel modeling system – FUEL subsystem. General Technical Report INT-167. Intermountain Forest and Range Experiment Station, U.S. Department of Agriculture, Forest Service, Ogden, UT.
Cabin, R. J., Weller, S. G., Lorence, D. H., Flynn, T. W., Sakai, A. K., Sandquist, D., and Hadway, L. J. (2000). Effects of long-term ungulate exclusion and recent alien species control on the preservation and restoration of a Hawaiian tropical dry forest. Conservation Biology 14, 439–453.
| Effects of long-term ungulate exclusion and recent alien species control on the preservation and restoration of a Hawaiian tropical dry forest.Crossref | GoogleScholarGoogle Scholar |
Castillo, J. M., Enriques, G., Nakahara, M., Weise, D., Ford, L., Moraga, R., and Vihnanek, R. (2007). Effects of cattle grazing, glyphosate, and prescribed burning on fountain grass fuel loading in Hawai‘i. In ‘Proceedings of the 23rd Tall Timbers Fire Ecology Conference: Fire in Grassland and Shrubland Ecosystems’. (Eds R. E. Masters and K. E. M. Galley.) pp. 230–239. (Tall Timbers Research Station: Tallahassee, FL.)
Cole, R. J., and Litton, C. M. (2014). Vegetation response to removal of non-native feral pigs from Hawaiian tropical montane wet forest. Biological Invasions 16, 125–140.
| Vegetation response to removal of non-native feral pigs from Hawaiian tropical montane wet forest.Crossref | GoogleScholarGoogle Scholar |
Cole, R. J., Litton, C. M., Koontz, M. J., and Loh, R. K. (2012). Vegetation recovery 16 years after feral pig removal from a wet Hawaiian forest. Biotropica 44, 463–471.
| Vegetation recovery 16 years after feral pig removal from a wet Hawaiian forest.Crossref | GoogleScholarGoogle Scholar |
D’Antonio, C. M., and Vitousek, P. M. (1992). Biological invasions by exotic grasses, the grass/fire cycle, and global change. Annual Review of Ecology and Systematics 23, 63–87.
D’Antonio, C. M., Tunison, T. J., and Loh, R. K. (2000). Variation in the impact of exotic grasses on native plant composition in relation to fire across an elevation gradient in Hawai‘i. Austral Ecology 25, 507–522.
| Variation in the impact of exotic grasses on native plant composition in relation to fire across an elevation gradient in Hawai‘i.Crossref | GoogleScholarGoogle Scholar |
Daehler, C. C. (2005). Upper-montane plant invasions in the Hawaiian islands: patterns and opportunities. Perspectives in Plant Ecology, Evolution and Systematics 7, 203–216.
| Upper-montane plant invasions in the Hawaiian islands: patterns and opportunities.Crossref | GoogleScholarGoogle Scholar |
Davison, J. (1996). Livestock grazing in wildland fuel management programs. Rangelands 18, 242–245.
Diamond, J. M., Call, C. A., and Devoe, N. (2009). Effects of targeted cattle grazing on fire behavior of cheatgrass-dominated rangeland in the northern Great Basin, USA. International Journal of Wildland Fire 18, 944–950.
| Effects of targeted cattle grazing on fire behavior of cheatgrass-dominated rangeland in the northern Great Basin, USA.Crossref | GoogleScholarGoogle Scholar |
Ellsworth, L. M., Litton, C. M., Taylor, A. D., and Kauffman, J. B. (2013). Spatial and temporal variability of guinea grass (Megathyrsus maximus) fuel loads and moisture on O‘ahu, Hawai‘i. International Journal of Wildland Fire 22, 1083–1092.
| Spatial and temporal variability of guinea grass (Megathyrsus maximus) fuel loads and moisture on O‘ahu, Hawai‘i.Crossref | GoogleScholarGoogle Scholar |
Ellsworth, L. M., Litton, C. M., Dale, A. P., and Miura, T. (2014). Invasive grasses change landscape structure and fire behavior in Hawaii. Applied Vegetation Science 17, 680–689.
| Invasive grasses change landscape structure and fire behavior in Hawaii.Crossref | GoogleScholarGoogle Scholar |
Flory, S. L., and Clay, K. (2010). Non-native grass invasion alters native plant composition in experimental communities. Biological Invasions 12, 1285–1294.
| Non-native grass invasion alters native plant composition in experimental communities.Crossref | GoogleScholarGoogle Scholar |
Giambelluca, T. W., Chen, Q., Frazier, A. G., Price, J. P., Chen, Y.-L., Chu, P.-S., Eischeid, J. K., and Delparte, D. M. (2013). Online rainfall atlas of Hawai‘i. Bulletin of the American Meteorological Society 94, 313–316.
| Online rainfall atlas of Hawai‘i.Crossref | GoogleScholarGoogle Scholar |
Giambelluca, T. W., Shuai, X., Barnes, M. L., Alliss, R. J., Longman, R. J., Miura, T., Chen, Q., Frazier, A. G., Mudd, R. G., Cuo, L., and Businger, A. D. (2014). Evapotranspiration of Hawai‘i. Final report submitted to the U.S. Army Corps of Engineers – Honolulu District, and the Commission on Water Resource Management, State of Hawai‘i.
Hatheway, W. H. (1952). Composition of certain native dry forests: Mokuleia, Oahu. Ecological Monographs 22, 153–168.
| Composition of certain native dry forests: Mokuleia, Oahu.Crossref | GoogleScholarGoogle Scholar |
Holechek, J. L., Pieper, R. F., and Herbel, C. H. (2010). ‘Range Management: Principles and Practices.’ 6th edn. (Prentice Hall: Upper Saddle River, NJ.)
Hughes, F., Vitousek, P. M., and Tunison, T. J. (1991). Alien grass invasions and fire in the seasonal submontane zone of Hawai‘i. Ecology 72, 743–746.
| Alien grass invasions and fire in the seasonal submontane zone of Hawai‘i.Crossref | GoogleScholarGoogle Scholar |
Kauffman, J. B., and Krueger, W. C. (1984). Livestock impacts on riparian ecosystems and streamside management implications: a review. Journal of Range Management 37, 430–437.
| Livestock impacts on riparian ecosystems and streamside management implications: a review.Crossref | GoogleScholarGoogle Scholar |
Kintisch, E. (2013). Computing a better fire forecast. Science 341, 609–611.
| Computing a better fire forecast.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXht1Grtr7P&md5=542046ca12bca8a149783f06a0aa8c3aCAS | 23929964PubMed |
LaRosa, A. M., Tunison, J. T., Ainsworth, A., Kauffman, J. B., and Hughes, R. F. (2008). Fire and nonnative invasive plants in the Hawaiian Islands bioregion. In ‘Wildland Fire in Ecosystems: Fire and Nonnative Invasive Plants’. (Eds K. Zouhar, J. K. Smith, S. Sutherland, and M. L. Brooks.) pp. 225–242. USDA Forest Service General Technical Report RMRS-GTR-42 Vol. 6. Rocky Mountain Research Station, Ogden, UT.
Leonard, S., Kirkpatrick, J., and Marsden-Smedley, J. (2010). Variation in the effects of vertebrate grazing on fire potential between grassland structural types. Journal of Applied Ecology 47, 876–883.
| Variation in the effects of vertebrate grazing on fire potential between grassland structural types.Crossref | GoogleScholarGoogle Scholar |
Lipponcott, C. L. (2000). Effects of Imperata cylindrical (cogon grass) invasion on fire regime in Florida sandhill. Natural Areas Journal 20, 140–149.
Litt, A. R., and Steidl, R. J. (2010). Insect assemblages change along a gradient of invasion by a nonnative grass. Biological Invasions 12, 3449–3463.
| Insect assemblages change along a gradient of invasion by a nonnative grass.Crossref | GoogleScholarGoogle Scholar |
Marris, E. (2011). Australian grazing trial ignites debate. Nature 471, 422.
| Australian grazing trial ignites debate.Crossref | GoogleScholarGoogle Scholar | 21430746PubMed |
Matthews, S. (2010). Effect of drying temperature on fuel moisture content measurements. International Journal of Wildland Fire 19, 800–802.
| Effect of drying temperature on fuel moisture content measurements.Crossref | GoogleScholarGoogle Scholar |
McCosker, T. H., and Teitzel, J. K. (1976). A review of guinea grass (Panicum maximum) for the wet tropics of Australia. Tropical Grasslands 9, 177–190.
Motooka, P., Castro, L., and Duane, N. (2003). ‘Weeds of Hawai‘i Pastures and Natural Areas: an Identification and Management Guide.’ (University of Hawai‘i at Mānoa College of Tropical Agriculture and Human Resources: Honolulu, HI.)
Motta, M. S. (1953). Panicum maximum. Empire Journal of Experimental Agriculture 21, 33–41.
Mueller-Dombois, D. (2001). Biological invasion and fire in tropical biomes. In ‘Proceedings of the Invasive Species Workshop: the Role of Fire in the Control and Spread of Invasive Species. Fire Conference 2000: The First National Congress on Fire Ecology, Prevention, and Management’. Miscellaneous Publication No. 11. (Eds K. E. M. Galley and T. P. Wilson.) pp. 112–121. (Tall Timbers Research Station: Tallahassee, FL.)
Nader, G., Henkin, Z., Smith, E., Ingram, R., and Narvaez, N. (2007). Planned herbivory in the management of wildfire fuels. Rangelands 29, 18–24.
| Planned herbivory in the management of wildfire fuels.Crossref | GoogleScholarGoogle Scholar |
Pyne, S. J., Andrews, P. L., and Laven, R. D. (1996). ‘Introduction to Wildland Fire.’ 2nd edn. (Wiley: Hoboken, NJ.)
Ramsey, F., and Schafer, D. (2013). ‘The Statistical Sleuth: a Course in Methods of Data Analysis.’ 3rd edn. (Cengage Learning: Boston, MA.)
Savadogo, P., Sawadogo, L., and Tiveau, D. (2007). Effects of grazing intensity and prescribed fire on soil physical and hydrological properties and pasture yield in the savanna woodlands of Burkina Faso. Agriculture, Ecosystems & Environment 118, 80–92.
| Effects of grazing intensity and prescribed fire on soil physical and hydrological properties and pasture yield in the savanna woodlands of Burkina Faso.Crossref | GoogleScholarGoogle Scholar |
Scott, J. H., and Burgan, R. E. (2005). Standard fire behavior fuel models: A comprehensive set for use with Rothermel’s surface fire spread model. USDA Forest Service General Technical Report RMRS-GTR-153. Fort Collins, CO.
Scowcroft, P. G. (1983). Tree cover changes in mamane (Sophora chrysophylla) forests grazed by sheep and cattle. Pacific Science 37, 109–119.
Scowcroft, P. G., and Giffin, J. G. (1983). Feral herbivores suppress mamame and other browse species on Mauna Kea, Hawai’i. Journal of Range Management 36, 638–645.
| Feral herbivores suppress mamame and other browse species on Mauna Kea, Hawai’i.Crossref | GoogleScholarGoogle Scholar |
Sherley, G., and Meyer, J. Y. (2000). Invasive species in the Pacific: a technical review and draft regional strategy: preliminary review of the invasive plants in the Pacific Islands. South Pacific Regional Environmental Programme, Apia, Samoa.
Williams, D. G., and Baruch, Z. (2000). African grass invasion in the Americas: ecosystem consequences and the role of ecophysiology. Biological Invasions 2, 123–140.
| African grass invasion in the Americas: ecosystem consequences and the role of ecophysiology.Crossref | GoogleScholarGoogle Scholar |