Dispersal potential of Scaevola crassifolia (Goodeniaceae) is influenced by intraspecific variation in fruit morphology along a latitudinal environmental gradient
Lydia K. Guja A B D , David J. Merritt B C , Kingsley W. Dixon B C and Grant Wardell-Johnson A
+ Author Affiliations
- Author Affiliations
A Curtin Institute for Biodiversity and Climate, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
B Kings Park and Botanic Garden, West Perth, WA 6005, Australia.
C School of Plant Biology, Faculty of Science, The University of Western Australia, Crawley, WA 6009, Australia.
D Corresponding author. Present address: Centre for Australian National Biodiversity Research, CSIRO Plant Industry, Acton, ACT 2601, Australia. Email: Lydia.Guja@environment.gov.au
Australian Journal of Botany 62(1) 56-64 https://doi.org/10.1071/BT13290
Submitted: 3 December 2013 Accepted: 24 March 2014 Published: 28 April 2014
Abstract
Dispersal of plant propagules by ocean currents can result in long-distance dispersal and is important for the persistence of coastal species. However, the ability of such species to disperse via the ocean is often unknown because there is relatively little evidence that demonstrates that seeds or fruits can float and survive for extended periods in seawater. Furthermore, the seed or fruit traits, and intraspecific variation in these traits, that facilitate buoyancy remain largely unidentified. The genus Scaevola (L.) contains several widespread coastal species that may be capable of oceanic dispersal, such as S. crassifolia (Labill). We collected fruits of S. crassifolia along 700 km of a latitudinal environmental gradient. These fruits were used to determine the influence of fruit morphology and anatomy on fruit buoyancy. Morphological and anatomical variation in S. crassifolia was associated with dispersal potential. Our empirical data demonstrated that fruits with larger aeriferous mesocarp layers have greater buoyancy and, therefore, enhanced capacity for long range oceanic dispersal. Of three characters hypothesised to affect buoyancy (aeriferous mesocarp, air pockets in empty locules, and number of vascular cavities), only the properties of the mesocarp were significant. Intraspecific variation can significantly affect dispersal potential, and should not be overlooked in dispersal ecology.
Additional keywords: coast, hydrochory, oceanic dispersal, seed buoyancy.
References
Andersen MC (1992) An analysis of variability in seed settling velocities of several wind-dispersed Asteraceae. American Journal of Botany 79, 1087–1091.| An analysis of variability in seed settling velocities of several wind-dispersed Asteraceae.Crossref | GoogleScholarGoogle Scholar |
Augspurger CK, Franson SE (1987) Wind dispersal of artificial fruits varying in mass, area, and morphology. Ecology 68, 27–42.
| Wind dispersal of artificial fruits varying in mass, area, and morphology.Crossref | GoogleScholarGoogle Scholar |
Bureau of Meteorology (2013) ‘Maps of average conditions.’ (Commonwealth of Australia: Canberra) Available at http://www.bom.gov.au/jsp/ncc/climate_averages. [Verified November 2013]
Carolin RC (1966) Seeds and fruit of the Goodeniaceae. Proceedings of the Linnean Society of New South Wales 91, 58–83.
Cousens R, Dytham C, Law R (2008) ‘Dispersal in plants: a population perspective.’ (Oxford University Press: New York)
CSIRO (2013) ‘The atlas of living Australia.’ Available at http://www.ala.org.au. [Verified November 2013]
Darling E, Samis KE, Eckert CG (2008) Increased seed dispersal potential towards geographic range limits in a Pacific coast dune plant. New Phytologist 178, 424–435.
| Increased seed dispersal potential towards geographic range limits in a Pacific coast dune plant.Crossref | GoogleScholarGoogle Scholar | 18194144PubMed |
Darwin C (1856) On the action of sea-water on the germination of seeds. Journal of the Proceedings of the Linnean Society of London Botany 1, 130–140.
Darwin C (1859) ‘The origin of species.’ (Oxford University Press: Oxford, UK)
Dawson MN, Hamner WM (2008) A biophysical perspective on dispersal and the geography of evolution in marine and terrestrial systems. Journal of the Royal Society, Interface 5, 135–150.
| A biophysical perspective on dispersal and the geography of evolution in marine and terrestrial systems.Crossref | GoogleScholarGoogle Scholar | 17626000PubMed |
de Queiroz A (2005) The resurrection of oceanic dispersal in historical biogeography. Trends in Ecology & Evolution 20, 68–73.
| The resurrection of oceanic dispersal in historical biogeography.Crossref | GoogleScholarGoogle Scholar |
Dixon KW (2011) ‘Coastal plants: a guide to the identification and restoration of plants of the Perth region.’ (CSIRO Publishing: Melbourne)
Donohue K (2009) Completing the cycle: maternal effects as the missing link in plant life histories. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 364, 1059–1074.
| Completing the cycle: maternal effects as the missing link in plant life histories.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXkslGgtrY%3D&md5=24b4f1465ae8634e1e42740818af4c52CAS | 19324611PubMed |
Greene DF, Johnson EA (1992) Can the variation in samara mass and terminal velocity on an individual plant affect the distribution of dispersal distances? American Naturalist 139, 825–838.
| Can the variation in samara mass and terminal velocity on an individual plant affect the distribution of dispersal distances?Crossref | GoogleScholarGoogle Scholar |
Guja LK, Merritt DJ, Dixon KW (2010) Buoyancy, salt tolerance and germination of coastal seeds: implications for oceanic hydrochorous dispersal. Functional Plant Biology 37, 1175–1186.
| Buoyancy, salt tolerance and germination of coastal seeds: implications for oceanic hydrochorous dispersal.Crossref | GoogleScholarGoogle Scholar |
Higgins SI, Nathan R, Cain ML (2003) Are long-distance dispersal events in plants usually caused by nonstandard means of dispersal? Ecology 84, 1945–1956.
| Are long-distance dispersal events in plants usually caused by nonstandard means of dispersal?Crossref | GoogleScholarGoogle Scholar |
Howarth DG, Gustafsson MHG, Baum DA, Motley TJ (2003) Phylogenetics of the genus Scaevola (Goodeniaceae): implication for dispersal patterns across the Pacific Basin and colonization of the Hawaiian Islands. American Journal of Botany 90, 915–923.
| Phylogenetics of the genus Scaevola (Goodeniaceae): implication for dispersal patterns across the Pacific Basin and colonization of the Hawaiian Islands.Crossref | GoogleScholarGoogle Scholar | 21659187PubMed |
Hroudova Z, Moravcova L, Zakravsky P (1997) Effect of anatomical structure on the buoyancy of achenes of two subspecies of Bolboschoenus maritimus. Folia Geobotanica et Phytotaxonomica 32, 377–390.
Hughes L (2000) Biological consequences of global warming: is the signal already apparent? Trends in Ecology & Evolution 15, 56–61.
| Biological consequences of global warming: is the signal already apparent?Crossref | GoogleScholarGoogle Scholar |
Hughes L, Westoby M (1992) Effect of diaspore characteristics on removal of seeds adapted for dispersal by ants. Ecology 73, 1300–1312.
| Effect of diaspore characteristics on removal of seeds adapted for dispersal by ants.Crossref | GoogleScholarGoogle Scholar |
Kokubugata G, Nakamura K, Forster PI, Hirayama Y, Yokota M (2012) Antitropical distribution of Lobelia species (Campanulaceae) between the Ryukyu Archipelago of Japan and Oceania as indicated by molecular data. Australian Journal of Botany 60, 417–428.
| Antitropical distribution of Lobelia species (Campanulaceae) between the Ryukyu Archipelago of Japan and Oceania as indicated by molecular data.Crossref | GoogleScholarGoogle Scholar |
Lesko GL, Walker RB (1969) Effect of sea water on seed germination in two Pacific atoll beach species. Ecology 50, 730–734.
| Effect of sea water on seed germination in two Pacific atoll beach species.Crossref | GoogleScholarGoogle Scholar |
Leyer I, Pross S (2009) Do seed and germination traits determine plant distribution patterns in riparian landscapes? Basic and Applied Ecology 10, 113–121.
| Do seed and germination traits determine plant distribution patterns in riparian landscapes?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.
| Seed flotation and postflooding germination in tropical terra firme and seasonally flooded forest species.Crossref | GoogleScholarGoogle Scholar | 24765572PubMed |
Marchant NG, Wheeler JR, Rye BL, Bennett EM, Lander NS, Macfarlane TD (1987) ‘Flora of the Perth region.’ (Western Australian Herbarium: Perth)
Matilla A, Gallardo M, Puga-Hermida MI (2005) Structural, physiological and molecular aspects of heterogeneity in seeds: a review. Seed Science Research 15, 63–76.
| Structural, physiological and molecular aspects of heterogeneity in seeds: a review.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXmtleltb8%3D&md5=b71c244883ef034961d49594984222b0CAS |
Nathan R (2006) Long-distance dispersal of plants. Science 313, 786–788.
| Long-distance dispersal of plants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XnvVyntr4%3D&md5=d288ca8c37c82270bcf1bfe0def7db06CAS | 16902126PubMed |
Nathan R, Schurr FM, Spiegel O, Steinitz O, Trakhtenbrot A, Tsoar A (2008) Mechanisms of long-distance seed dispersal. Trends in Ecology & Evolution 23, 638–647.
| Mechanisms of long-distance seed dispersal.Crossref | GoogleScholarGoogle Scholar |
Nilsson C, Brown RL, Jansson R, Merritt DM (2010) The role of hydrochory in structuring riparian and wetland vegetation. Biological Reviews of the Cambridge Philosophical Society 85, 837–858.
Rippey E, Rowland B (2004) ‘Coastal plants: Perth and the south-west region.’ 2nd edn. (University of Western Australia Press: Perth)
Römermann C, Tackenberg O, Poschlod P (2005) How to predict attachment potential of seeds to sheep and cattle coat from simple morphological seed traits. Oikos 110, 219–230.
| How to predict attachment potential of seeds to sheep and cattle coat from simple morphological seed traits.Crossref | GoogleScholarGoogle Scholar |
Telenius A, Torstensson P (1989) The seed dimorphism of Spergularia marina in relation to dispersal by wind and water. Oecologia 80, 206–210.
Thomson FJ, Moles AT, Auld TD, Ramp D, Ren S, Kingsford RT (2010) Chasing the unknown: predicting seed dispersal mechanisms from plant traits. Journal of Ecology 98, 1310–1318.
| Chasing the unknown: predicting seed dispersal mechanisms from plant traits.Crossref | GoogleScholarGoogle Scholar |
Travis JMJ, Delgado M, Bocedi G, Baguette M, Bartoń K, Bonte D, Boulangeat I, Hodgson JA, Kubisch A, Penteriani V, Saastamoinen M, Stevens VM, Bullock JM (2013) Dispersal and species’ responses to climate change. Oikos 122, 1532–1540.
| Dispersal and species’ responses to climate change.Crossref | GoogleScholarGoogle Scholar |
Turner SR, Commander LE, Baskin JM, Baskin CC, Dixon KW (2009) Germination behaviour of Astroloma xerophyllum (Ericaceae), a species with woody indehiscent endocarps. Botanical Journal of the Linnean Society 160, 299–311.
| Germination behaviour of Astroloma xerophyllum (Ericaceae), a species with woody indehiscent endocarps.Crossref | GoogleScholarGoogle Scholar |
Vargas P, Nogales M, Jaramillo P, Olesen JM, Traveset A, Heleno R (2014) Plant colonization across the Galápagos Islands: success of the sea dispersal syndrome. Botanical Journal of the Linnean Society 174, 349–358.
| Plant colonization across the Galápagos Islands: success of the sea dispersal syndrome.Crossref | GoogleScholarGoogle Scholar |
Western Australian Herbarium (1998) ‘FloraBase – the Western Australian flora.’ (Department of Parks and Wildlife). Available at http://florabase.dpaw.wa.gov.au/. [Verified April 2014]
Will H, Maussner S, Tackenberg O (2007) Experimental studies of diaspore attachment to animal coats: predicting epizoochorous dispersal potential. Oecologia 153, 331–339.
| Experimental studies of diaspore attachment to animal coats: predicting epizoochorous dispersal potential.Crossref | GoogleScholarGoogle Scholar | 17516091PubMed |
Williamson GB, Costa F, Vera CVM (1999) Dispersal of Amazonian trees: hydrochory in Swartzia polyphylla. Biotropica 31, 460–465.
| Dispersal of Amazonian trees: hydrochory in Swartzia polyphylla.Crossref | GoogleScholarGoogle Scholar |
Yang H, Lu Q, Wu B, Zhang J (2012) Seed dispersal of east Asian coastal dune plants via seawater – short and long distance dispersal. Flora 207, 701–706.
| Seed dispersal of east Asian coastal dune plants via seawater – short and long distance dispersal.Crossref | GoogleScholarGoogle Scholar |
