Significance of post-germination buoyancy in Helmholtzia glaberrima and Philydrum lanuginosum (Philydraceae)
Peter J. Prentis A B , Noel M. Meyers A and Peter B. Mather AA School of Natural Resource Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Qld 4001, Australia.
B Corresponding author. Email: p.prentis@student.qut.edu.au
Australian Journal of Botany 54(1) 11-16 https://doi.org/10.1071/BT04208
Submitted: 14 December 2004 Accepted: 1 August 2005 Published: 22 February 2006
Abstract
Post-germination buoyancy has been proposed to reduce seedling establishment in amphibious plants if seeds germinate under flooded conditions. We tested this hypothesis in two amphibious species, Helmholtzia glaberrima (Hook.) and Philydrum lanuginosum (Banks & Sol.). We tested whether seed germination was affected by different levels of inundation, whether seedlings germinating underwater floated and whether seedlings established after prolonged floatation at rates comparable to seedling establishment in waterlogged soil. Germination underwater and in waterlogged soil was similar for both species. Seeds germinating underwater exhibited post-germination buoyancy and established at similar rates to seedlings in waterlogged soil. The results demonstrated that if seeds germinated underwater, post-germination buoyancy conferred the potential to avoid inundation and promote establishment, when waters recede and/or in areas of high soil moisture that are not submerged. More generally, this finding showed that post-germination buoyancy can promote seedling dispersal and the deposition of seedlings in conditions more favourable for establishment if seeds germinate under flooded conditions or in permanent wetlands.
Acknowledgments
The authors are greatly indebted to Ana Pavasovic and Dr Tony Clarke for commenting on earlier drafts of this manuscript. Financial support for this project was provided by a QUT doctoral fellowship awarded to Peter Prentis.
Adams, LG (1989). Philydraceae. In ‘Flora of Australia. Vol. 45. Hydatellaceae to Liliaceae’. pp. 40–46. (AGPS: Canberra)
Boedeltje G,
Bakker JP,
Bekker RM,
Van Groenendael JM, Soesbergen M
(2003) Plant dispersal in a lowland stream in relation to occurrence and three specific life-history traits of the species in the species pool. Journal of Ecology 91, 855–866.
| Crossref | GoogleScholarGoogle Scholar |
Boedeltje G,
Bakker JP,
Ten Brinke A,
Van Groenendael JM, Soesbergen M
(2004) Dispersal phenology of hydrochorous plants in relation to discharge, seed release time and buoyancy of seeds: the flood pulse concept supported. Journal of Ecology 92, 786–796.
| Crossref | GoogleScholarGoogle Scholar |
Clifford, TA (1983). Philydraceae. In ‘Flowering plants in Australia’. pp. 345–347. (Rigby Publishers: Adelaide)
Evans DE
(2004) Aerenchyma formation. New Phytologist 161, 35–49.
| Crossref | GoogleScholarGoogle Scholar |
Fukao T, Bailey-Serres J
(2004) Plant responses to hypoxia—is survival a balancing act? Trends in Plant Science 9, 449–456.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Gunawardena AHLAN,
Greenwood JS, Dengler NG
(2004) Programmed cell death remodels lace plant leaf shape during development. The Plant Cell 16, 60–73.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Hamann, U (1998). Philydraceae. In ‘The families and genera of vascular plants. IV. Flowering plants–monocotyledons–alismatanae and commelinanae’. pp. 389–394. (Springer-Verlag: Berlin)
Leck MA, Brock MA
(2000) Ecological and evolutionary trends in wetlands: evidence from seeds and seed banks in New South Wales, Australia and New Jersey, USA. Plant Species Biology 15, 97–112.
| Crossref | GoogleScholarGoogle Scholar |
Lopez OR
(2001) Seed flotation and postflooding germination in tropical terra firme and seasonally flooded forest species. Functional Ecology 15, 763–771.
| Crossref | GoogleScholarGoogle Scholar |
Lopez OR, Kursar TA
(2003) Does flood tolerance explain tree species distribution in tropical seasonally flooded habitats? Oecologia 136, 193–204.
| Crossref | GoogleScholarGoogle Scholar |
Nathan R, Muller-Landau HC
(2000) Spatial patterns of seed dispersal, their determinants and consequences for recruitment. Trends in Ecology & Evolution 15, 278–285.
| Crossref | GoogleScholarGoogle Scholar |
Nicol JM, Ganf GG
(2000) Water regimes, seedling recruitment and establishment in three wetland plant species. Marine and Freshwater Research 51, 305–309.
| Crossref | GoogleScholarGoogle Scholar |
Nicol JM,
Ganf GG, Pelton GA
(2003) Seed banks of a southern Australian wetland: the influence of water regime on final species composition. Plant Ecology 168, 191–205.
| Crossref | GoogleScholarGoogle Scholar |
Pons TL
(1982) Factors affecting weed seed germination and seedling growth in lowland rice in Indonesia. Weed Research 22, 155–161.
Prentis PJ,
Vesey A,
Meyers NM, Mather PB
(2004) Genetic structuring of the stream lily Helmholtzia glaberrima (Philydraceae) within Toolona Creek, south-eastern Queensland. Australian Journal of Botany 52, 201–207.
| Crossref | GoogleScholarGoogle Scholar |
Rand TA
(2000) Seed dispersal, habitat suitability and the distribution of halophytes across a salt marsh tidal gradient. Journal of Ecology 88, 608–621.
| Crossref | GoogleScholarGoogle Scholar |
Ridley, HN (1930).
Sculthorpe, CD (1967).
Sifton HB
(1959) The germination of light sensitive seeds of Typha latifolia L. Canadian Journal of Botany 37, 719–739.
ter Steege H
(1994) Flooding and drought tolerance in seeds and seedlings of 2 Mora species segregated along a soil hydrological gradient in the tropical rain-forest of Guyana. Oecologia 100, 356–367.
| Crossref | GoogleScholarGoogle Scholar |
Van der Valk AG
(1981) Succession in wetlands: a gleasonian approach. Ecology 62, 688–696.
Weller MW
(1975) Studies of cattail in relation to management for marsh wildlife. Iowa State Journal of Science 49, 383–412.
