Fire regime, soil fertility and growth form interact to shape fire and growth traits in two co-occurring Banksia species

• Published in: Evolutionary ecology Vol. 30; no. 1; pp. 35 - 45
• Main Authors: Clarke, Peter J., Lawes, Michael J., Midgley, Jeremy J., Atri, M.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-02-2016; Springer; Springer Nature B.V
• Subjects: Animal Ecology; Banksia; Bark; Biomedical and Life Sciences; Ecology; Evolutionary Biology; Forest & brush fires; Life history; Life Sciences; Original Paper; Plant ecology; Plant growth; Plant populations; Plant Sciences; Soil fertility; Soil nutrients; Soils; Woodlands; Australia; Sclerophyll forests; Bark thickness; Fire ecology; Bradychory; Fire adaptations
• ISSN: 0269-7653; 1573-8477
• DOI: 10.1007/s10682-015-9799-y

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Inter- and intra-specific comparisons were made between several co-occurring populations of two
Banksia
species growing in Eastern Australian dry sclerophyll open woodland that experiences a grass-fueled surface-fire regime. The two species differ in life-history from a short basal resprouter (
B. Neoanglica
) to a tall fire-survivor (
B. integrifolia
). Growth (LMA = leaf mass per unit mass area), persistence (bark thickness) and recruitment (serotiny) traits were determined across independent gradients in soil fertility and fire frequency. Trait correlations for the two species showed distinct patterns, from each other and across environments, with the resprouter having higher LMA and infructescence retention but lower bark thickness. However, there were no consistent intra-specific patterns with variation in fire and soil nutrients. LMA only varied in
B. integrifolia
with soil fertility, and fire frequency had no effect on either species. Relative bark thickness varied with plant size but not among sites. There was a trend of increasing pyriscence with fire in
B. neoanglica
and with lower nutrients soils but not in
B. integrifolia
. Clearly the two species respond differently to variability in nutrients and fire. Nevertheless, growth form appears to be the strongest determinant of both growth (LMA) and fire traits (thicker bark; pyriscence) in these co-existing
Banksia
species.