Fire has positive effects on seed reproduction in <em>Andropogon gerardii</em> but negative impacts on <em>Ratibida pinnata</em> seed reproduction

  • J. R. Logan Grinnell College
  • I. H. Luby Grinnell College
  • I. A. McCallum-Cook Grinnell College


Fire plays an important role in tallgrass prairie ecology and as such, many prairie plants have evolved mechanisms to cope with or take advantage of its effects. We examined the effects that fire has on seed reproductive potential in Andropogon gerardii (Big Bluestem), Sorghastrum nutans (Indiangrass), and Ratibida pinnata (Grey-headed Coneflower) by measuring the number of seed heads, net seed production per plant, and germination success between seeds in annually spring burned plots and unburned plots of tallgrass Iowa prairie. We found significantly higher numbers of seed heads for A. gerardii in burned plots and a significantly greater number of seed heads and net seed weight in R. pinnata in unburned plots. We also found a trend towards higher germination of R. pinnata in unburned plots. Our study suggests that grasses invest more energy into reproduction via seeds after fires, perhaps because they are better able to colonize a greater area of exposed land, and that certain forbs produce fewer seeds after fire. We suggest that grass seeds used in restoring prairies come from burned prairies and R. pinnata seeds come from unburned areas.
How to Cite
LOGAN, J. R.; LUBY, I. H.; MCCALLUM-COOK, I. A.. Fire has positive effects on seed reproduction in Andropogon gerardii but negative impacts on Ratibida pinnata seed reproduction. Tillers, [S.l.], v. 6, p. 7-10, june 2012. Available at: <>. Date accessed: 22 sep. 2017.