University of Wollongong
Browse

The effect of seasonal ambient temperatures on fire-stimulated germination of species with physiological dormancy: a case study using Boronia (Rutaceae)

Download (1.26 MB)
journal contribution
posted on 2024-11-16, 07:19 authored by Berin D E Mackenzie, Tony AuldTony Auld, David Keith, Francis K C Hui, Mark Ooi
Dormancy and germination requirements determine the timing and magnitude of seedling emergence, with important consequences for seedling survival and growth. Physiological dormancy is the most widespread form of dormancy in flowering plants, yet the seed ecology of species with this dormancy type is poorly understood in fire-prone vegetation. The role of seasonal temperatures as germination cues in these habitats is often overlooked due to a focus on direct fire cues such as heat shock and smoke, and little is known about the combined effects of multiple fire-related cues and environmental cues as these are seldom assessed in combination. We aimed to improve understanding of the germination requirements of species with physiological dormancy in fire-prone floras by investigating germination responses across members of the Rutaceae from south eastern Australia. We used a fully factorial experimental design to quantify the individual and combined effects of heat shock, smoke and seasonal ambient temperatures on germination of freshly dispersed seeds of seven species of Boronia, a large and difficult-to-germinate genus. Germination syndromes were highly variable but correlated with broad patterns in seed morphology and phylogenetic relationships between species. Seasonal temperatures influenced the rate and/or magnitude of germination responses in six species, and interacted with fire cues in complex ways. The combined effects of heat shock and smoke ranged from neutral to additive, synergistic, unitive or negative and varied with species, seasonal temperatures and duration of incubation. These responses could not be reliably predicted from the effect of the application of single cues. Based on these findings, fire season and fire intensity are predicted to affect both the magnitude and timing of seedling emergence in wild populations of species with physiological dormancy, with important implications for current fire management practices and for population persistence under climate change.

Funding

Predicting climate change impacts on biodiversity: testing and applying new approaches

Australian Research Council

Find out more...

History

Citation

Mackenzie, B. D. E., Auld, T. D., Keith, D. A., Hui, F. K. C. & Ooi, M. K. J. (2016). The effect of seasonal ambient temperatures on fire-stimulated germination of species with physiological dormancy: a case study using Boronia (Rutaceae). PLoS One, 11 (5), e0156142-1 - e0156142-.

Journal title

PLoS ONE

Volume

11

Issue

5

Language

English

RIS ID

108190

Usage metrics

    Categories

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC