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Rajapakshe RPVGSW, Tomlinson S, Tudor EP, Turner SR, Elliott CP, Lewandrowski W. Same, same, but different: dissimilarities in the hydrothermal germination performance of range-restricted endemics emerge despite microclimatic similarities. CONSERVATION PHYSIOLOGY 2024; 12:coae009. [PMID: 38487732 PMCID: PMC10939308 DOI: 10.1093/conphys/coae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 01/17/2024] [Accepted: 01/24/2024] [Indexed: 03/17/2024]
Abstract
Seed germination responses for most narrow-range endemic species are poorly understood, imperilling their conservation management in the face of warming and drying terrestrial ecosystems. We quantified the realized microclimatic niches and the hydrothermal germination thresholds in four threatened taxa (Tetratheca erubescens, Tetratheca harperi, Tetratheca paynterae subsp. paynterae and Tetratheca aphylla subsp. aphylla) that are restricted to individual Banded Ironstone Formations in Western Australia. While T. aphylla subsp. aphylla largely failed to germinate in our trials, all other species demonstrated extended hydrothermal time accumulation (186-500°C MPa days), cool minimum temperatures (7.8-8.5°C), but broad base water potential thresholds (-2.46 to -5.41 MPa) under which germination occurred. These slow germination dynamics are suggestive of cool and wet winter months, where soil moisture is retained to a greater capacity in local microsites where these species occur, rather than the warmer and drier conditions in the surrounding arid environment. Hydrothermal time-to-event modelling showed that each species occupied unique hydrothermal germination niches, which correspond with the microclimatic differences the species are exposed to. Our results provide a baseline understanding for environmental and germination thresholds that govern the recruitment, and ultimately the population structure and persistence, of these short-range endemic plants. In addition, our results can aid future conservation, as well as restoration actions such as translocation to bolster population numbers and to mitigate against losses due to anthropogenic disturbance and global environmental change.
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Affiliation(s)
- Rajapakshe P V G S W Rajapakshe
- ARC Centre for Mine Site Restoration, Curtin University, Bentley, 6102, Australia
- School of Molecular and Life Sciences, Curtin University, Bentley, 6102, Australia
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, 6005, Australia
| | - Sean Tomlinson
- School of Molecular and Life Sciences, Curtin University, Bentley, 6102, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, 5000, Australia
| | - Emily P Tudor
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, 6005, Australia
- School of Biological Sciences, University of Western Australia, Crawley, 6009, Australia
| | - Shane R Turner
- ARC Centre for Mine Site Restoration, Curtin University, Bentley, 6102, Australia
- School of Molecular and Life Sciences, Curtin University, Bentley, 6102, Australia
| | - Carole P Elliott
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, 6005, Australia
- School of Biological Sciences, University of Western Australia, Crawley, 6009, Australia
| | - Wolfgang Lewandrowski
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, 6005, Australia
- School of Biological Sciences, University of Western Australia, Crawley, 6009, Australia
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Rajapakshe RPVGSW, Cross AT, Turner SR, Tomlinson S. Understanding the interplay of temperature and moisture on the germination niche to improve management of threatened species impacted by mining. Restor Ecol 2022. [DOI: 10.1111/rec.13708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Rajapakshe P. V. G. S. W. Rajapakshe
- ARC Centre for Mine Site Restoration, School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
- School of Molecular and Life Sciences Curtin University Bentley Western Australia 6102 Australia
- Kings Park Science, Department of Biodiversity Conservation and Attractions Kings Park Western Australia 6005 Australia
| | - Adam T. Cross
- ARC Centre for Mine Site Restoration, School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
- School of Molecular and Life Sciences Curtin University Bentley Western Australia 6102 Australia
- EcoHealth Network, 1330 Beacon St, Suite 355a Brookline MA 02446 United States
| | - Shane R. Turner
- ARC Centre for Mine Site Restoration, School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
- Kings Park Science, Department of Biodiversity Conservation and Attractions Kings Park Western Australia 6005 Australia
- School of Biological Sciences University of Western Australia Crawley Western Australia 6009 Australia
| | - Sean Tomlinson
- School of Molecular and Life Sciences Curtin University Bentley Western Australia 6102 Australia
- Kings Park Science, Department of Biodiversity Conservation and Attractions Kings Park Western Australia 6005 Australia
- School of Biological Sciences, University of Adelaide, North Terrace Adelaide South Australia 5000 Australia
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Cochrane JA. Thermal Requirements Underpinning Germination Allude to Risk of Species Decline from Climate Warming. PLANTS 2020; 9:plants9060796. [PMID: 32630588 PMCID: PMC7355932 DOI: 10.3390/plants9060796] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/18/2020] [Accepted: 06/19/2020] [Indexed: 11/16/2022]
Abstract
The storage of seeds is a commonly used means of preserving plant genetic diversity in the face of rising threats such as climate change. Here, the findings of research from the past decade into thermal requirements for germination are synthesised for more than 100 plant species from southern Western Australia. This global biodiversity hotspot is predicted to suffer major plant collapse under forecast climate change. A temperature gradient plate was used to assess the thermal requirements underpinning seed germination in both commonly occurring and geographically restricted species. The results suggest that the local climate of the seed source sites does not drive seed responses, neither is it indicative of temperatures for optimal germination. The low diurnal phase of the temperature regime provided the most significant impact on germination timing. Several species germinated optimally at mean temperatures below or close to current wet quarter temperatures, and more than 40% of species were likely to be impacted in the future, with germination occurring under supra-optimal temperature conditions. This research highlights both species vulnerability and resilience to a warming climate during the regeneration phase of the life cycle and provides vital information for those aiming to manage, conserve and restore this regional flora.
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Affiliation(s)
- Jennifer Anne Cochrane
- Department of Biodiversity, Conservation and Attractions, Locked Bag 104, Bentley Delivery Centre, Western Australia 6983, Australia; ; Tel.: +61-429-698-644
- Division of Ecology and Evolution, College of Science, Australian National University, Canberra ACT 0200, Australia
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Tausz-Posch S, De Kok LJ. Plant functioning in a changing global atmosphere. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22 Suppl 1:3-4. [PMID: 31808222 DOI: 10.1111/plb.13051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- S Tausz-Posch
- Department of Agriculture, Science and the Environment, CQ University Australia, Kawana, QLD, Australia
| | - L J De Kok
- Laboratory of Plant Physiology, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
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