Seed biology implications for the maintenance and establishment of Tetratheca juncea (Tremandraceae), a vulnerable Australian species
S. M. Bellairs A D , F. V. Bartier B , A. J. Gravina B and K. Baker B CA School of Science and Primary Industries, Charles Darwin University, Darwin, NT 0909, Australia.
B Centre for Mined Land Rehabilitation, The University of Queensland, St Lucia, Qld 4072, Australia.
C Current address: Alice Springs Desert Park, Alice Springs, NT 0871, Australia.
D Corresponding author. Email: sean.bellairs@cdu.edu.au
Australian Journal of Botany 54(1) 35-41 https://doi.org/10.1071/BT02004
Submitted: 18 January 2002 Accepted: 12 August 2005 Published: 22 February 2006
Abstract
Tetratheca juncea Smith is an endemic and vulnerable shrub species with apparently poor recruitment from New South Wales, Australia. Lack of understanding of seed biology limits management options for promoting survival of existing populations and recruitment of new populations. This study investigated the soil seed bank, seed viability, germination and seed dormancy. The plants release seeds in January but no seeds germinated from soil collected near the plants in September 1999, irrespective of the soil being treated by smoke, heat or fire. When sampled again in February 2001, seeds were present in the soil seed bank but were not viable. Viability testing of seeds collected from the plants determined that at least a third of the seeds being produced were viable, even after storage for 6 months. Seed germination and dormancy investigations found that the seeds germinated following exposure to smoke or scarification of the seed coat. Untreated seeds did not germinate during the preliminary study, although a proportion of untreated seeds germinated from a later seed lot. Fire management is important for promoting the survival of this species and the soil seed bank cannot be relied on for re-establishment of populations as the longevity of the soil seed bank seems to be short. Many other species of Tetratheca are also rare or threatened and this study suggests that hand-collected seeds treated with fire-related stimuli may be important for re-establishing those species and that the soil seed bank requires assessment before being relied on as a source of propagules or for maintaining a population.
Acknowledgments
We thank all people associated with ACARP project C8012, including industry monitors, steering committee members and other researchers, especially Dr David Mulligan and Dr Caroline Gross, for their advice and enthusiasm. Funding for this project was through ACARP, with additional sponsorship or inkind support provided by Oceanic Coal Limited, Powercoal Pty Ltd, Coal Operations Australia Limited, NSW National Parks & Wildlife, BHP Coal Pty Ltd, Lake Macquarie City Council and Wyong Shire Council. Gillian Kopittke, Melina Gillespie, Stuart Mutzig, Robert Payne, Laura Shield, Denise Smith and Terry Tame are thanked for their assistance with research and seed collection and Penny Wurm for advice on the manuscript. This project was carried out under a NSW Threatened Species Conservation Act (1995) Section 95 (2) Certificate (SYZ/99/037).
Adkins SW, Bellairs SM
(1997) Seed dormancy mechanisms in Australian native species. In ‘Proceedings of the second Australian workshop on native seed biology for revegetation’, Newcastle 11–12 October 1996. (Ed. SM Bellairs ,
JM Osborne )
pp. 81–91. (Australian Centre for Minesite Rehabilitation Research: Brisbane)
Bell DT,
Vlahos S, Watson LE
(1987) Stimulation of seed germination of understorey species of the northern jarrah forest of Western Australia. Australian Journal of Botany 35, 593–599.
| Crossref |
Bell DT,
Plummer JA, Taylor SK
(1993) Seed germination ecology in southwestern Western Australia. Botanical Review 59, 25–73.
Bellairs SM, Bell DT
(1993) Seed stores for restoration of species-rich shrubland vegetation following mining in Western Australia. Restoration Ecology 1, 231–240.
Benson D, McDougall L
(2001) Ecology of Sydney plant species Part 8: Dicotyledon families Rutaceaae to Zygophyllaceae. Cunninghamia 7, 241–462.
Boesewinkel FD
(1999) Ovules and seeds of Tremandraceae. Australian Journal of Botany 47, 769–781.
| Crossref |
Dixon KW,
Roche S, Pate JS
(1995) The promotive effect of smoke derived from burnt vegetation on seed germination of Western Australian plants. Oecologia 101, 185–192.
| Crossref | GoogleScholarGoogle Scholar |
Gregory’s Publishing Company (1999).
Gross CL,
Bartier FV, Mulligan DR
(2003) Floral structure, breeding system and fruit-set in the threatened sub-shrub Tetratheca juncea Smith (Tremandraceae). Annals of Botany 92, 771–777.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Harden, GD (Ed.) (1992).
Malone CR
(1967) A rapid method for enumeration of viable seeds in soil. Weeds 15, 381–382.
Murphy RG, Dalton GS
(1996)
Portlock CC,
Shea SR,
Majer JD, Bell DT
(1990) Stimulation of germination of Acacia pulchella: laboratory basis for forest management options. Journal of Applied Ecology 27, 319–324.
Read TR,
Bellairs SM,
Mulligan DR, Lamb D
(2000) Smoke and heat effects on soil seed bank germination for the re-establishment of a native forest community in New South Wales, Australia. Austral Ecology 25, 48–57.
| Crossref | GoogleScholarGoogle Scholar |
Ralph, M (1997).
Tierney DA
(2004) Towards an understanding of population change for the long-lived resprouting tree Angophora inopina (Myrtaceae). Australian Journal of Botany 52, 31–38.
| Crossref | GoogleScholarGoogle Scholar |
Universal Press Pty Ltd (2000).
