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Investigation of 18 physiologically dormant Australian native species: germination response, environmental correlations and the implications for conservation

Published online by Cambridge University Press:  15 December 2020

Justin C. Collette*
Affiliation:
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, UNSW, Sydney, NSW2052, Australia The Australian PlantBank, Australian Institute of Botanical Science, Australian Botanic Garden, Mount Annan, NSW2567, Australia
Mark K.J. Ooi
Affiliation:
Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, UNSW, Sydney, NSW2052, Australia
*
Author of Correspondence: Justin C. Collette, E-mail: justin.collette@unsw.edu.au

Abstract

For physiologically dormant (PD) species in fire-prone environments, dormancy can be both complex due to the interaction between fire and seasonal cues, and extremely deep due to long intervals between recruitment events. Due to this complexity, there are knowledge gaps particularly surrounding the dormancy depth and cues of long-lived perennial PD species. This can be problematic for both in situ and ex situ species management. We used germination experiments that tested seasonal temperature, smoke, dark and heat for 18 PD shrub species distributed across temperate fire-prone Australia and assessed how germination was correlated with environmental factors associated with their home environments. We found extremely high levels of dormancy, with only eight species germinating above 10% and three species producing no germination at all. Seven of these eight species had quite specific seasonal temperature requirements and/or very strong responses to smoke cues. The maximum germination for each species was positively correlated with the mean temperature of the source population but negatively correlated with rainfall seasonality and driest months. The strong dependence on a smoke cue for some of the study species, along with examples from other studies, provides evidence that an obligate smoke response could be a fire-adapted germination cue. Germination response correlated with rainfall season of the source populations is a pattern which has often been assumed but little comparative data across sites with different rainfall seasonality exists. Further investigation of a broader range of species from different rainfall season environments would help to elucidate this knowledge gap.

Type
Research Paper
Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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References

Alahakoon, AACB, Perera, GAD, Merritt, DJ, Turner, SR and Gama-Arachchige, NS (2020) Species-specific smoke effects on seed germination of plants from different habitats from Sri Lanka. Flora: Morphology, Distribution, Functional Ecology of Plants 263, 151530.CrossRefGoogle Scholar
Aronne, GI and Mazzoleni, ST (1989) The effects of heat exposure on seeds of Cistus incanus L. and Cistus monspeliensis L. Giornale Botanico Italiano 123, 123283.Google Scholar
Auld, TD (2001) The ecology of the Rutaceae in the Sydney region of south-eastern Australia: poorly known ecology of a neglected family. Cunninghamia 7, 213239.Google Scholar
Auld, TD and O'Connel, MA (1991) Predicting patterns of post-fire germination in 35 eastern Australian Fabaceae. Austral Ecology 16, 5370.CrossRefGoogle Scholar
Auld, TD and Ooi, MKJ (2009) Heat increases germination of water-permeable seeds of obligate-seeding Darwinia species (Myrtaceae). Plant Ecology 200, 117127.CrossRefGoogle Scholar
Auld, TD, Keith, DA and Bradstock, RA (2000) Patterns in longevity of soil seedbanks in fire-prone communities of south-eastern Australia. Australian Journal of Botany 48, 539548.CrossRefGoogle Scholar
Barton, K (2020) MuMIn: Multi-Model inference. R package version 1.43.17. Available at: https://CRAN.R-project.org/package=MuMIn.Google Scholar
Baskin, CC and Baskin, JM (2014) Seeds: ecology, biogeography, and evolution of dormancy and germination (2nd edn). San Diego, CA, Academic Press.Google Scholar
Baskin, CC, Baskin, JM, Yoshinaga, A and Thompson, K (2005) Germination of drupelets in multi-seeded drupes of the shrub Leptecophylla tameiameiae (Ericaceae) from Hawaii: a case for deep physiological dormancy broken by high temperatures. Seed Science Research 15, 349356.CrossRefGoogle Scholar
Bell, DT (1999) The process of germination in Australian species. Australian Journal of Botany 47, 475517.CrossRefGoogle Scholar
Çatav, ŞS, Küçükakyüz, K, Akbaş, K and Tavşanoǧlu, Ç (2014) Smoke-enhanced seed germination in Mediterranean Lamiaceae. Seed Science Research 24, 257264.CrossRefGoogle Scholar
Chamorro, D, Luna, B and Moreno, JM (2018) Local climate controls among-population variation in germination patterns in two Erica species across western Iberia. Seed Science Research 28, 112122.CrossRefGoogle Scholar
Cochrane, JA, Crawford, AD and Monks, LT (2007) The significance of ex situ seed conservation to reintroduction of threatened plants. Australian Journal of Botany 55, 356361.CrossRefGoogle Scholar
Collette, JC and Ooi, MKJ (2017) Germination ecology of the endangered species Asterolasia buxifolia (Rutaceae): smoke response depends on season and light. Australian Journal of Botany 65, 283291.CrossRefGoogle Scholar
Collette, JC and Ooi, MKJ (2020) Evidence for physiological seed dormancy cycling in the woody shrub Asterolasia buxifolia and its ecological significance in fire-prone systems. Plant Biology 22, 745749.CrossRefGoogle ScholarPubMed
Daws, MI, Downes, KS, Koch, JM and Willyams, D (2014) Is broad-scale smoke-water application always a useful tool for improving seedling emergence in post-mining restoration? Evidence from Jarrah forest restoration in Western Australia. South African Journal of Botany 90, 109113.CrossRefGoogle Scholar
Debieu, M, Tang, C, Stich, B, Sikosek, T, Effgen, S, Josephs, E, Schmitt, J, Nordborg, M, Koornneef, M and de Meaux, J (2013) Co-variation between seed dormancy, growth rate and flowering time changes with latitude in Arabidopsis thaliana. PLoS ONE 8, e61075.CrossRefGoogle ScholarPubMed
Dixon, KW, Roche, S and Pate, JS (1995) The promotive effect of smoke derived from burnt native vegetation on seed germination of Western Australian plants. Oecologia 101, 185192.CrossRefGoogle ScholarPubMed
Downes, KS, Light, ME, Pošta, M, Kohout, L and van Staden, J (2014) Do fire-related cues, including smoke-water, karrikinolide, glyceronitrile and nitrate, stimulate the germination of 17 Anigozanthos taxa and Blancoa canescens (Haemodoraceae)? Australian Journal of Botany 62, 347.CrossRefGoogle Scholar
Enright, NJ and Thomas, I (2008) Pre-European fire regimes in Australian ecosystems. Geography Compass 2, 9791011.CrossRefGoogle Scholar
Erickson, TE and Merritt, DJ (2016) Seed collection, cleaning and storage procedures, pp. 716 in Erickson, TE; Barrett, RL; Merritt, DJ and Kingsley, DW (Eds) Pilbara seed atlas and field guide: plant restoration in Australia's arid Northwest. Melbourne, CSIRO Publishing.CrossRefGoogle Scholar
Fenner, M and Thompson, K (2005) The ecology of seeds. Cambridge, Cambridge University Press.CrossRefGoogle Scholar
Finch-Savage, WE and Leubner-Metzger, G (2006) Seed dormancy and the control of germination. New Phytologist 171, 501523.CrossRefGoogle ScholarPubMed
Gama-Arachchige, NS, Baskin, JM, Geneve, RL and Baskin, CC (2013) Identification and characterization of ten new water gaps in seeds and fruits with physical dormancy and classification of water-gap complexes. Annals of Botany 112, 6984.CrossRefGoogle ScholarPubMed
Gilmour, CA, Crowden, RK and Koutoulis, A (2000) Heat shock, smoke and darkness: partner cues in promoting seed germination in Epacris tasmanica (Epacridaceae). Australian Journal of Botany 48, 603609.CrossRefGoogle Scholar
Harel, D, Holzapfel, C and Sternberg, M (2011) Seed mass and dormancy of annual plant populations and communities decreases with aridity and rainfall predictability. Basic and Applied Ecology 12, 674684.CrossRefGoogle Scholar
Hay, FR, Merritt, DJ, Soanes, JA and Dixon, KW (2010) Comparative longevity of Australian orchid (Orchidaceae) seeds under experimental and low temperature storage conditions. Botanical Journal of the Linnean Society 164, 2641.CrossRefGoogle Scholar
Holdsworth, MJ, Bentsink, L and Soppe, WJJ (2008) Molecular networks regulating Arabidopsis seed maturation, after-ripening, dormancy and germination. New Phytologist 179, 3354.CrossRefGoogle ScholarPubMed
Kassambara, A (2019) ggcorrplot. Visualization of a correlation matrix using ‘ggplot2’. R package version 0.1.3. Available at: https://CRAN.R-project.org/package=ggcorrplot.Google Scholar
Keeley, JE, Pausas, JG, Rundel, PW, Bond, WJ and Bradstock, RA (2011) Fire as an evolutionary pressure shaping plant traits. Trends in Plant Science 16, 406411.CrossRefGoogle ScholarPubMed
Li, DZ and Pritchard, HW (2009) The science and economics of ex situ plant conservation. Trends in Plant Science 14, 614621.CrossRefGoogle ScholarPubMed
Mackenzie, BDE, Auld, TD, Keith, DA, Hui, FKC and Ooi, MKJ (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, e0156142.CrossRefGoogle Scholar
Marcante, S, Sierra-Almeida, A, Spindelböck, JP, Erschbamer, B and Neuner, G (2012) Frost as a limiting factor for recruitment and establishment of early development stages in an alpine glacier foreland? Journal of Vegetation Science 23, 858868.CrossRefGoogle Scholar
Merritt, DJ, Kristiansen, M, Flematti, GR, Turner, SR, Ghisalberti, EL, Trengove, RD and Dixon, KW (2006) Effects of a butenolide present in smoke on light-mediated germination of Australian Asteraceae. Seed Science Research 16, 2935.CrossRefGoogle Scholar
Merritt, DJ, Turner, SR, Clarke, S and Dixon, KW (2007) Seed dormancy and germination stimulation syndromes for Australian temperate species. Australian Journal of Botany 55, 336344.CrossRefGoogle Scholar
Miller, BP and Murphy, BP (2017) Fire and Australian vegetation, pp. 113134 in Keith, D (Ed.) Australian vegetation. Cambridge, Cambridge University Press.Google Scholar
Moreira, B and Pausas, JG (2012) Tanned or burned: the role of fire in shaping physical seed dormancy. PLoS ONE 7, e51523.CrossRefGoogle ScholarPubMed
Moreira, B and Pausas, JG (2018) Shedding light through the smoke on the germination of Mediterranean Basin flora. South African Journal of Botany 115, 244250.CrossRefGoogle Scholar
Ooi, MKJ (2007) Dormancy classification and potential dormancy-breaking cues for shrub species from fire-prone south-eastern Australia, pp. 205216 in Seeds: biology, development and ecology. (Eds Adkins SW, Ashmore SE, Navie SC). Wallingford, UK, CAB International.Google Scholar
Ooi, MKJ, Auld, TD and Whelan, RJ (2006) Dormancy and the fire-centric focus: germination of three Leucopogon species (Ericaceae) from south-eastern Australia. Annals of Botany 98, 421430.CrossRefGoogle ScholarPubMed
Ooi, MKJ, Denham, AJ, Santana, VM and Auld, TD (2014) Temperature thresholds of physically dormant seeds and plant functional response to fire: variation among species and relative impact of climate change. Ecology and Evolution 4, 656671.CrossRefGoogle ScholarPubMed
Purdie, RW (1977) Early stages of regeneration after burning in dry sclerophyll vegetation. II. Regeneration by seed germination. Australian Journal of Botany 25, 3546.CrossRefGoogle Scholar
R Core Team (2018) R A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria. Available at. http://www.R-project.org/.Google Scholar
Ramos, DM, Diniz, P, Ooi, MKJ, Borghetti, F and Valls, JFM (2017) Avoiding the dry season: dispersal time and syndrome mediate seed dormancy in grasses in Neotropical savanna and wet grasslands. Journal of Vegetation Science 28, 798807.CrossRefGoogle Scholar
Roche, S, Dixon, KW and Pate, JS (1998) For everything a season: smoke-induced seed germination and seedling recruitment in a Western Australian Banksia woodland. Austral Ecology 23, 111120.CrossRefGoogle Scholar
Spindelböck, JP, Cook, Z, Daws, MI, Heegaard, E, Måren, IE and Vandvik, V (2013) Conditional cold avoidance drives between-population variation in germination behaviour in Calluna vulgaris. Annals of Botany 112, 801810.CrossRefGoogle ScholarPubMed
Thomas, PB, Morris, EC and Auld, TD (2003) Interactive effects of heat shock and smoke on germination of nine species forming soil seed banks within the Sydney region. Austral Ecology 28, 674683.CrossRefGoogle Scholar
Thompson, K and Ooi, MKJ (2010) To germinate or not to germinate: more than a question of dormancy. Seed Science Research 20, 209211.CrossRefGoogle Scholar
Thompson, K and Ooi, MKJ (2013) Germination and dormancy breaking: two different things. Seed Science Research 23, 1.CrossRefGoogle Scholar
Wagmann, K, Hautekèete, NC, Piquot, Y, Meunier, C, Schmitt, SE and Van Dijk, H (2012) Seed dormancy distribution: explanatory ecological factors. Annals of Botany 110, 12051219.CrossRefGoogle ScholarPubMed
Walters, C, Wheeler, L and Stanwood, PC (2004) Longevity of cryogenically stored seeds. Cryobiology 48, 229244.CrossRefGoogle ScholarPubMed
Whelan, RJ (1995) The ecology of fire. Cambridge, Cambridge University Press.Google Scholar
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