Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T16:07:49.607Z Has data issue: false hasContentIssue false
  • English
  • Français

Susceptibility of Exotic Annual Grass Seeds to Fire

Published online by Cambridge University Press:  20 January 2017

Sara B. Sweet ,
Guy B. Kyser  and
Joseph M. DiTomaso
Sara B. Sweet
Affiliation:
Department of Plant Sciences, Mail Stop 4, University of California at Davis, Davis, CA 95616
Guy B. Kyser
Affiliation:
Department of Plant Sciences, Mail Stop 4, University of California at Davis, Davis, CA 95616
Joseph M. DiTomaso*
Affiliation:
Department of Plant Sciences, Mail Stop 4, University of California at Davis, Davis, CA 95616
*
Corresponding author's E-mail: jmditomaso@ucdavis.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

Prescribed burning can control invasive annual grasses that threaten the biological and economic value of California grasslands. Susceptibility of grass seed to burning can depend on burn timing, exposure time, and type of exposure (direct flame heat or convective heat); thus, these factors can influence the success of a prescribed burning program. To further investigate these factors, laboratory simulations were conducted on barb goatgrass, medusahead, and ripgut brome at several stages of seed maturity, as determined by percent moisture of the inflorescences. Seeds were exposed either to direct flame using a Bunsen burner or to heated air in a muffle furnace. Flame treatments were conducted at one temperature (∼400 C) and several exposure times (0 to 14 s), depending on the species. Furnace treatments included four temperatures (150, 200, 250, and 300 C) and seven exposure times (0, 10, 20, 30, 40, 60, or 80 s). Seed germination was analyzed for each temperature series to determine the LD50 and LD90 in seconds of exposure time. Susceptibility to furnace treatments, which simulated heat exposure of seeds on the soil surface, was not statistically different within a range of seed moisture levels for all three species. The LD50 values at 250 C (typical soil temperature with grassland fire) ranged from 28 to 49 s, which far exceeds the time of exposure during a typical grassland fire. Susceptibility to flame showed a similar lack of change over maturation of medusahead and barb goatgrass seeds, with LD90 values ranging between 4.8 and 7.4 s for all seed moisture levels. In contrast, ripgut brome seeds exposed to flame showed increasing susceptibility with reduced seed moisture content. The LD90 values for exposure were less than one second for seed moisture levels at or below 10%, compared to 3.7 s for seeds at 55 to 60%. Although flame susceptibility increased for ripgut brome, seeds at all maturation stages were more sensitive than medusahead and barb goatgrass. Additionally, the LD90 values for all three species are attainable under field conditions. Thus, burn prescriptions for these three species are not constrained by maturation stage, but should occur prior to seed drop and when fuel loading is high. This will maximize exposure time of seeds to direct flame.

Keywords

Medusahead, Taeniatherum caput-medusae (L.) Nevski ELYCAbarb goatgrass, Aegilops triuncialis L. AEGTRripgut brome, Bromus diandrus Roth BRODIGrasslandprescribed burningrangelandseed moisturetiming
Type
Research Articles
Information
Invasive Plant Science and Management , Volume 1 , Issue 2 , April 2008 , pp. 158 - 167
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Bovey, R. W., LeTourneau, D., and Erickson, L. C. 1960. The chemical composition of medusahead and downy brome. Weeds 9:307–311.Google Scholar
Dahl, B. E. and Tisdale, E. W. 1975. Environmental factors related to medusahead distribution. J. Range Manage 28:463–468.CrossRefGoogle Scholar
DiTomaso, J. M. 2000. Invasive weeds in rangelands: species, impacts and management. Weed Sci 48:255–265.CrossRefGoogle Scholar
DiTomaso, J. M., Heise, K. L., Kyser, G. B., Merenlender, A. M., and Keiffer, R. J. 2001. Carefully timed burning can control barb goatgrass. Calif. Agric 55/6:47–53.CrossRefGoogle Scholar
DiTomaso, J. M., Kyser, G. B., and Hastings, M. S. 1999. Prescribed burning for control of yellow starthistle (Centaurea solstitialis) and enhanced native plant diversity. Weed Sci 47:233–242.Google Scholar
DiTomaso, J. M., Kyser, G. B., McDougald, N. K., Vargas, R. N., Doran, M. P., Wilson, R., and Orloff, S. 2005. Medusahead control. Proc. Calif. Weed Sci. Soc 57:145–148.Google Scholar
DiTomaso, J. M., Kyser, G. B., Miller, J. R., Garcia, S., Smith, R. F., Nader, G., Connor, J. M., and Orloff, S. B. 2006. Integrating prescribed burning and clopyralid for the management of yellow starthistle (Centaurea solstitialis). Weed Sci 54:757–782.Google Scholar
Dyer, A. R. 2004. Maternal and sibling factors induce dormancy in dimorphic seed pairs of Aegilops triuncialis . Plant Ecol 172:211–218.Google Scholar
Furbush, P. 1953. Control of medusa-head on California ranges. J. Forestry 51:118–121.Google Scholar
George, M. L. 1992. Ecology and management of medusahead. Davis, CA University of California, Davis Agricultural Experiment Station Range Science Report #32. 3.Google Scholar
Gill, G. S. and Blacklow, W. M. 1985. Variations in seed dormancy and rates of development of great brome, Bromus diandrus Roth, as adaptations to the climates of southern Australia and implications for weed control. Aust. J. Agr. Res 36:295–304.Google Scholar
Jacobsen, W. C. 1929. Goatgrass—a weed pest of the range. Calif. Dept. Agr. Mon. Bull 18/1:37–41.Google Scholar
Keeley, J. E. and McGinnis, T. W. 2007. Impact of prescribed fire and other factors on cheatgrass persistence in a Sierra Nevada ponderosa pine forest. Int. J. Wildland Fire 16:96–106.CrossRefGoogle Scholar
Kennedy, P. B. 1928. Goatgrass or wild wheat (Aegilops triuncialis). J. Am. Soc. Agron 20:1292–1296.Google Scholar
Kyser, G. B. and DiTomaso, J. M. 2002. Instability in a grassland community after the control of yellow starthistle (Centaurea solstitialis) with prescribed burning. Weed Sci 50:648–657.CrossRefGoogle Scholar
McKell, C. M., Wilson, A. M., and Kay, B. L. 1962. Effective burning of rangelands infested with medusahead. Weeds 10:125–131.Google Scholar
Murphy, A. H. and Lusk, W. C. 1961. Timing medusahead burns. Calif. Agr 15/11:6–7.Google Scholar
Nelson, J. R. and Wilson, A. M. 1969. Influence of age and awn removal on dormancy of medusahead seeds. J. Range Manage 22:289–290.CrossRefGoogle Scholar
Pollak, O. and Kan, T. 1996. The use of prescribed fire to control invasive exotic weeds at Jepson Prairie Preserve. Pages 241–249. in Witham, C. W., editor. Proceedings, Ecology, Conservation, and Management of Vernal Pool Ecosystems. Sacramento, CA California Native Plant Society.Google Scholar
Sawyer, J. O. and Keeler-Wolf, T. 1995. A Manual of California Vegetation. Sacramento, CA California Native Plant Society Press. 412.Google Scholar
Shinn, S. L. and Thill, D. C. 2004. Tolerance of several perennial grasses to imazapic. Weed Technol 18:60–65.Google Scholar
Sweet, S. B. 2005. Effect of seed maturity on the resistance of weed seeds to simulated fire: implications for prescribed burns. M.S. thesis. Davis, CA University of California at Davis. 56.Google Scholar
Tibor, D. P. 2001. California Native Plant Society's Inventory of Rare and Endangered Plants of California. 6th ed. Sacramento, CA California Native Plant Society Press. 386. convening editor.Google Scholar
Willis, B. D., Evans, J. O., and Dewey, S. A. 1988. Effects of temperature and flaming on germinability of jointed goatgrass (Aegilops cylindrica Host) seed. Proc. West Soc. Weed Sci 41:49–55.Google Scholar
Young, J. A. 1992. Ecology and management of medusahead (Taeniatherum caput-medusae ssp. asperum [Simk.] Melderis). Great Basin Nat 52:245–252.Google Scholar
Young, J. A., Evans, R. A., and Eckert, R. E. 1968. Germination of medusahead in response to temperature and afterripening. Weed Sci 16:92–95.CrossRefGoogle Scholar
Young, J. A., Evans, R. A., and Kay, B. L. 1970. Phenology of reproduction of medusahead. Weed Sci 18:451–454.Google Scholar
Young, J. A., Evans, R. A., and Robison, J. 1972. Influence of repeated annual burning on a medusahead community. J. Range Manage 25:372–375.Google Scholar