Germination of Acacia harpophylla (Brigalow)seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem

Arnold, Sven, Kailichova, Yolana and Baumgartl, Thomas (2014) Germination of Acacia harpophylla (Brigalow)seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem. PeerJ, 2013 1: 1-15. doi:10.7717/peerj.268

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Author Arnold, Sven
Kailichova, Yolana
Baumgartl, Thomas
Title Germination of Acacia harpophylla (Brigalow)seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem
Formatted title
Germination of Acacia harpophylla (Brigalow)seeds in relation to soil water potential: implications for rehabilitation of a threatened ecosystem
Journal name PeerJ   Check publisher's open access policy
ISSN 2167-8359
Publication date 2014-02-25
Year available 2014
Sub-type Article (original research)
DOI 10.7717/peerj.268
Open Access Status DOI
Volume 2013
Issue 1
Start page 1
End page 15
Total pages 15
Place of publication London, United Kingdom
Publisher PeerJ
Language eng
Formatted abstract
Initial soil water conditions play a critical role when seeding is the primary approach to revegetate post-mining areas. In some semi-arid climates, such as the Brigalow Belt Bioregion in eastern Australia, extensive areas are affected by open-cut mining. Together with erratic rainfall patterns and clayey soils, the Brigalow Belt denotes a unique biome which is representative of other water-limited ecosystems worldwide. Apart from other environmental stressors, germination is governed by the water potential of the surrounding soil material.While previous studies have confirmed the high tolerance of Brigalow (Acacia harpophylla) seeds to a broad range of temperature and salinity, the question of how soil water potential triggers seed germination remains. In this study, we used three replicates of 50 seeds of Brigalow to investigate germination in relation to water potential as an environmental stressor. Solutions of Polyethylene Glycol (PEG 6000) were applied to expose seeds to nine osmotic water potentials ranging from soil water saturation (0 MPa) and field capacity (–.01 to –.03 MPa) to the permanent wilting point (–1.5 MPa).We measured germinability (number of germinated seeds relative to total number of seeds per lot) and mean germination time (mean time required for maximum germination of a seed lot) to quantify germination. Based on the empirical data of the germination we estimated the parameters of the hydrotime model which simulates timing and success of seed emergence. Our findings indicate that Brigalow seeds are remarkably tolerant to water stress, with germination being observed at a water potential as low as –1.5 MPa. Likewise, the average base water potential of a seed population (hydrotime model) was very low and ranged between –1.533 and –1.451 MPa. In general, Brigalow seeds germinate opportunistically over a broad range of abiotic conditions related to temperature, salinity, and water availability. Direct seeding and germination of native plants on post-mining land may be an effective and economically viable solution in order to re-establish plant communities. However, due to their capacity to reproduce asexually, alternative rehabilitation approaches such as transplantation of whole soil-root compartments may become attractive for restoration ecologists to achieve safe, stable, and non-polluting ecosystems.
Keyword Hydrotime model
Brigalow Belt bioregion
Ecosystem rehabilitation
Water potential
Acacia harpophylla
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Mined Land Rehabilitation Publications
Official 2015 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 1 times in Scopus Article | Citations
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Created: Wed, 26 Feb 2014, 20:51:14 EST by Dr Sven Arnold on behalf of Centre For Mined Land Rehabilitation