Does pyrogenicity protect burning plants?

Citation

Gagnon PR, Passmore HA, Platt WJ, Myers JA, Paine CET & Harms KE (2010) Does pyrogenicity protect burning plants?. Ecology, 91 (12), pp. 3481-3486. https://doi.org/10.1890/10-0291.1

Abstract
Pyrogenic plants dominate many fire-prone ecosystems. Their prevalence suggests some advantage to their enhanced flammability, but researchers have had difficulty tying pyrogenicity to individual-level advantages. Based on our review, we propose that enhanced flammability in fire-prone ecosystems should protect the belowground organs and nearby propagules of certain individual plants during fires. We base this hypothesis on five points: (1) organs and propagules by which many fire-adapted plants survive fires are vulnerable to elevated soil temperatures during fires; (2) the degree to which burning plant fuels heat the soil depends mainly on residence times of fires and on fuel location relative to the soil; (3) fires and fire effects are locally heterogeneous, meaning that individual plants can affect local soil heating via their fuels; (4) how a plant burns can thus affect its fitness; and (5) in many cases, natural selection in fire-prone habitats should therefore favor plants that burn rapidly and retain fuels off the ground. We predict an advantage of enhanced flammability for plants whose fuels influence local fire characteristics and whose regenerative tissues or propagules are affected by local variation in fires. Our "pyrogenicity as protection" hypothesis has the potential to apply to a range of life histories. We discuss implications for ecological and evolutionary theory and suggest considerations for testing the hypothesis.

Keywords
adaptations; ecosystem engineering; evolution; fire ecology; heat; Mutch hypothesis; niche construction; plant flammability; pyrogenicity as protection; resprouting; serotiny

Journal
Ecology: Volume 91, Issue 12