Appraising widespread resprouting but variable levels of postfire seeding in Australian ecosystems: The effect of phylogeny, fire regime and productivity

Lawes, M.J., Crisp, M.D., Clarke, P.J., Murphy, B.P., Midgley, J.J., Russell-Smith, J., Nano, C.E.M., Bradstock, R.A., Enright, N.J.ORCID: 0000-0003-2979-4505, Fontaine, J.B.ORCID: 0000-0002-6515-7864, Gosper, C.R. and Woolley, L-A (2022) Appraising widespread resprouting but variable levels of postfire seeding in Australian ecosystems: The effect of phylogeny, fire regime and productivity. Australian Journal of Botany, 70 (2). pp. 114-130.

Abstract

Postfire resprouting (R+) and recruitment from seed (S+) are common resilience traits in Australian ecosystems. We classified 2696 woody Australian taxa as R+ or not (R−) and as S+ or not (S−). The proportions of these traits in Australian ecosystems were examined in relation to fire regimes and other ecological correlates, and by trait mapping on a phylogeny scaled to time. Resprouting mapped as an ancestral trait. Postfire reseeding recruitment, while ancient, is more taxonomically restricted and has evolved independently several times. Nevertheless, both R+ and S+ are common in most clades, but negatively correlated at the ecosystem level indicating an evolutionary trade-off related to differences in the severity of fire regimes, determined in part by ecosystem productivity. Thus, R+ was associated with persistence in ecosystems characterised by higher productivity and relatively frequent surface fires of moderate to low severity (fire-productivity hypothesis). S+, the fire-stimulated recruitment by seed, occurred in ecosystems characterised by infrequent but intense crown-fire and topkill, reducing competition between postfire survivors and recruits (fire-resource-competition hypothesis). Consistently large proportions of R+ or S+ imply fire has been a pervasive evolutionary selection pressure resulting in highly fire-adapted and fire-resilient flora in most Australian ecosystems.

Item Type:	Journal Article
Murdoch Affiliation(s):	Environmental and Conservation Sciences
Publisher:	CSIRO Publishing
Copyright:	© 2022 The Author(s) (or their employer(s)).
URI:	http://researchrepository.murdoch.edu.au/id/eprint/64105

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