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Ngwenya DK, Holmes PM, Geerts S, Esler KJ. Scaling up restoration efforts by simulating the effects of fire to circumvent prescribed burns when preparing restoration sites in South African fynbos ecosystems. AUSTRAL ECOL 2022. [DOI: 10.1111/aec.13258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Duduzile K. Ngwenya
- Department of Conservation Ecology and Entomology Stellenbosch University, Private Bag X1 Matieland South Africa
- Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Natural Sciences Building, Private Bag X1 Stellenbosch University Matieland South Africa
| | - Patricia M. Holmes
- Department of Conservation Ecology and Entomology Stellenbosch University, Private Bag X1 Matieland South Africa
- Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Natural Sciences Building, Private Bag X1 Stellenbosch University Matieland South Africa
| | - Sjirk Geerts
- Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Natural Sciences Building, Private Bag X1 Stellenbosch University Matieland South Africa
- Department of Conservation and Marine Sciences Cape Peninsula University of Technology Cape Town South Africa
| | - Karen J. Esler
- Department of Conservation Ecology and Entomology Stellenbosch University, Private Bag X1 Matieland South Africa
- Centre of Excellence for Invasion Biology, Department of Botany and Zoology, Natural Sciences Building, Private Bag X1 Stellenbosch University Matieland South Africa
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2
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Pausas JG, Lamont BB. Fire-released seed dormancy - a global synthesis. Biol Rev Camb Philos Soc 2022; 97:1612-1639. [PMID: 35384243 PMCID: PMC9540907 DOI: 10.1111/brv.12855] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 11/29/2022]
Abstract
Seed dormancy varies greatly between species, clades, communities, and regions. We propose that fireprone ecosystems create ideal conditions for the selection of seed dormancy as fire provides a mechanism for dormancy release and postfire conditions are optimal for germination. Thus, fire‐released seed dormancy should vary in type and abundance under different fire regimes. To test these predictions, we compiled data from a wide range of fire‐related germination experiments for species in different ecosystems across the globe. We identified four dormancy syndromes: heat‐released (physical) dormancy, smoke‐released (physiological) dormancy, non‐fire‐released dormancy, and non‐dormancy. In fireprone ecosystems, fire, in the form of heat and/or chemical by‐products (collectively termed ‘smoke’), are the predominant stimuli for dormancy release and subsequent germination, with climate (cold or warm stratification) and light sometimes playing important secondary roles. Fire (heat or smoke)‐released dormancy is best expressed where woody vegetation is dense and fires are intense, i.e. in crown‐fire ecosystems. In such environments, seed dormancy allows shade‐intolerant species to take advantage of vegetation gaps created by fire and synchronize germination with optimal recruitment conditions. In grassy fireprone ecosystems (e.g. savannas), where fires are less intense but more frequent, seed dormancy is less common and dormancy release is often not directly related to fire (non‐fire‐released dormancy). Rates of germination, whether controls or postfire, are twice as fast in savannas than in mediterranean ecosystems. Fire‐released dormancy is rare to absent in arid ecosystems and rainforests. The seeds of many species with fire‐released dormancy also possess elaiosomes that promote ant dispersal. Burial by ants increases insulation of seeds from fires and places them in a suitable location for fire‐released dormancy. The distribution of these dormancy syndromes across seed plants is not random – certain dormancy types are associated with particular lineages (phylogenetic conservatism). Heat‐released dormancy can be traced back to fireprone floras in the ‘fiery’ mid‐Cretaceous, followed by smoke‐released dormancy, with loss of fire‐related dormancy among recent events associated with the advent of open savannas and non‐fireprone habitats. Anthropogenic influences are now modifying dormancy‐release mechanisms, usually decreasing the role of fire as exaptive effects. We conclude that contrasting fire regimes are a key driver of the evolution and maintenance of diverse seed dormancy types in many of the world's natural ecosystems.
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Affiliation(s)
- Juli G Pausas
- CIDE-CSIC, Consejo Superior de Investigaciones Científicas, Montcada, Valencia, 46113, Spain
| | - Byron B Lamont
- Ecology Section, School of Life and Molecular Sciences, Curtin University, Perth, WA, 6845, Australia
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Lamont BB. Seed biologists beware: Estimates of initial viability based on ungerminated seeds at the end of an experiment may be error-prone. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:399-403. [PMID: 35238136 PMCID: PMC9314915 DOI: 10.1111/plb.13407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Seed viability is routinely measured on seeds that fail to germinate at the end of an experiment. Together with the number of germinants, this is used to estimate viability of the seeds at start of the experiment (i.e., initial viability) and provides the comparative basis on which germination success is determined. The literature and recent data on the germination requirements of Leucadendron species were examined to determine if there was any evidence for a treatment effect on viability of ungerminated seeds at the end of the experiment. The survey showed that sometimes (perhaps often, as the problem has yet to be recognized or reported) prolonged duration in the treatment, especially the control where little germination occurs, lead to loss of viability during the experiment. This resulted in underestimation of initial viability if that treatment was used. I caution against the routine use of end-of-trial germination and viability of ungerminated seeds as an estimate of initial viability in determining germination success of various treatments. I explore ways to deal with the problem but the preference is for estimates of initial viability to be undertaken on a separate sample of seeds concurrently with the experiment as this avoids the risk of seed death during the trial.
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Affiliation(s)
- B. B. Lamont
- Department of Molecular and Life Sciences (Ecology Section)Curtin UniversityPerthWAAustralia
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Shi C, Wang S, Cai HH, Zhang HR, Long XX, Tihelka E, Song WC, Feng Q, Jiang RX, Cai CY, Lombard N, Li X, Yuan J, Zhu JP, Yang HY, Liu XF, Xiang QP, Zhao ZT, Long CL, Schneider H, Zhang XC, Peng H, Li DZ, Fan Y, Engel MS, Wang YD, Spicer RA. Fire-prone Rhamnaceae with South African affinities in Cretaceous Myanmar amber. NATURE PLANTS 2022; 8:125-135. [PMID: 35102275 DOI: 10.1038/s41477-021-01091-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The rapid Cretaceous diversification of flowering plants remains Darwin's 'abominable mystery' despite numerous fossil flowers discovered in recent years. Wildfires were frequent in the Cretaceous and many such early flower fossils are represented by charcoalified fragments, lacking complete delicate structures and surface textures, making their similarity to living forms difficult to discern. Furthermore, scarcity of information about the ecology of early angiosperms makes it difficult to test hypotheses about the drivers of their diversification, including the role of fire in shaping flowering plant evolution. We report the discovery of two exquisitely preserved fossil flower species, one identical to the inflorescences of the extant crown-eudicot genus Phylica and the other recovered as a sister group to Phylica, both preserved as inclusions together with burned plant remains in Cretaceous amber from northern Myanmar (~99 million years ago). These specialized flower species, named Phylica piloburmensis sp. nov. and Eophylica priscastellata gen. et sp. nov., exhibit traits identical to those of modern taxa in fire-prone ecosystems such as the fynbos of South Africa, and provide evidence of fire adaptation in angiosperms.
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Affiliation(s)
- Chao Shi
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Shuo Wang
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China.
- Fushun Amber Institute, Fushun, China.
| | - Hao-Hong Cai
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Hong-Rui Zhang
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xiao-Xuan Long
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Erik Tihelka
- School of Earth Sciences, University of Bristol, Life Sciences Building, Bristol, UK
| | - Wei-Cai Song
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Qi Feng
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Ri-Xin Jiang
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Chen-Yang Cai
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing, China
| | - Natasha Lombard
- Biosystematics and Biodiversity Collections Division, National Herbarium, South African National Biodiversity Institute, Pretoria, South Africa
| | - Xiong Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Ji Yuan
- Shanghai World Expo Museum, Shanghai, China
| | - Jian-Ping Zhu
- College of Life Science, Shandong Normal University, Jinan, China
| | - Hui-Yu Yang
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Xiao-Fan Liu
- College of Marine Science and Biological Engineering, Qingdao University of Science and Technology, Qingdao, China
| | - Qiao-Ping Xiang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Zun-Tian Zhao
- College of Life Science, Shandong Normal University, Jinan, China
| | - Chun-Lin Long
- College of Life and Environmental Sciences, Minzu University of China, Beijing, China
| | - Harald Schneider
- Department of Life Sciences, Natural History Museum, London, UK
- School of Life Sciences, Sun Yatsen University, Guangzhou, Guangdong, China
| | - Xian-Chun Zhang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Hua Peng
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - De-Zhu Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Yong Fan
- Fushun Amber Institute, Fushun, China
| | - Michael S Engel
- Natural History Museum, and Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
| | - Yong-Dong Wang
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing, China
| | - Robert A Spicer
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, China
- School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
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Newton RJ, Mackenzie BDE, Lamont BB, Gomez-Barreiro P, Cowling RM, He T. Fire-mediated germination syndromes in Leucadendron (Proteaceae) and their functional correlates. Oecologia 2021; 196:589-604. [PMID: 34159425 PMCID: PMC8241639 DOI: 10.1007/s00442-021-04947-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 05/15/2021] [Indexed: 11/29/2022]
Abstract
A mechanistic understanding of fire-driven seedling recruitment is essential for effective conservation management of fire-prone vegetation, such as South African fynbos, especially with rare and threatened taxa. The genus Leucadendron (Proteaceae) is an ideal candidate for comparative germination studies, comprising 85 species with a mixture of contrasting life-history traits (killed by fire vs able to resprout; serotinous vs geosporous) and seed morphologies (nutlets vs winged achenes). Individual and combined effects of heat and smoke on seed germination of 40 species were quantified in the laboratory, and Bayesian inference applied to distinguish biologically meaningful treatment effects from non-zero, but biologically trivial, effects. Three germination syndromes were identified based on whether germination was dependent on, enhanced by, or independent of direct fire cues (heat and smoke). Seed storage location was the most reliable predictor of germination syndromes, with soil-stored seeds c. 80% more likely to respond to direct fire cues (primarily smoke) than canopy-stored seeds. Notable exceptions were L. linifolium, with an absolute requirement for smoke to germinate (the third serotinous species so reported), and two other serotinous species with smoke-enhanced germination. Nutlet-bearing species, whether serotinous or geosporous, were c. 70% more likely to respond to fire cues than winged seeds, but there was no evidence for an effect of phylogeny or persistence strategy on germination. This comprehensive account of seed germination characteristics and identification of germination syndromes and their predictors, supports propagation, conservation and restoration initiatives in this iconic fynbos genus and other fire-prone shrubs with canopy or soil-stored seeds.
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Affiliation(s)
- Rosemary J Newton
- Conservation Science, Royal Botanic Gardens Kew, Wakehurst, Ardingly, West Sussex, RH17 6TN, UK.
| | - Berin D E Mackenzie
- Science Division, NSW Department of Planning, Industry and Environment, Locked Bag 5022, Parramatta, NSW, 2124, Australia.,Centre for Ecosystem Science, University of New South Wales, Kensington, NSW, 2052, Australia
| | - Byron B Lamont
- Ecology Section, School of Molecular and Life Sciences, Curtin University, PO Box U1987, Perth, WA, 6845, Australia
| | - Pablo Gomez-Barreiro
- Conservation Science, Royal Botanic Gardens Kew, Wakehurst, Ardingly, West Sussex, RH17 6TN, UK
| | - Richard M Cowling
- Department of Botany, Nelson Mandela Metropolitan University, PO Box 7700, Port Elizabeth, 6000, South Africa
| | - Tianhua He
- Ecology Section, School of Molecular and Life Sciences, Curtin University, PO Box U1987, Perth, WA, 6845, Australia
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Hall SA, Bastos R, Vicente J, Vaz AS, Honrado JP, Holmes PM, Gaertner M, Esler KJ, Cabral JA. A dynamic modeling tool to anticipate the effectiveness of invasive plant control and restoration recovery trajectories in South African fynbos. Restor Ecol 2021. [DOI: 10.1111/rec.13324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Stuart A. Hall
- Department of Conservation Ecology and Entomology and Centre for Invasion Biology Stellenbosch University Private Bag X1, Matieland 7602 South Africa
- Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Matieland South Africa
| | - Rita Bastos
- Laboratory of Applied Ecology, CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Sciences University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
| | - Joana Vicente
- Laboratory of Applied Ecology, CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Sciences University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
- Research Network in Biodiversity and Evolutionary Biology, Research Centre in Biodiversity and Genetic Resources (InBIO‐CIBIO), Faculty of Sciences University of Porto Campus Agrário de Vairão, Vairão Portugal
| | - Ana Sofia Vaz
- Research Network in Biodiversity and Evolutionary Biology, Research Centre in Biodiversity and Genetic Resources (InBIO‐CIBIO), Faculty of Sciences University of Porto Campus Agrário de Vairão, Vairão Portugal
- Botany Department and Interuniversity Institute for Earth System Research (IISTA‐CEAMA, iEcolab) University of Granada, Faculty of Sciences, Campus Fuentenueva s/n Granada 18071 Spain
| | - João P. Honrado
- Research Network in Biodiversity and Evolutionary Biology, Research Centre in Biodiversity and Genetic Resources (InBIO‐CIBIO), Faculty of Sciences University of Porto Campus Agrário de Vairão, Vairão Portugal
| | - Patricia M. Holmes
- Department of Conservation Ecology and Entomology and Centre for Invasion Biology Stellenbosch University Private Bag X1, Matieland 7602 South Africa
| | - Mirijam Gaertner
- Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Matieland South Africa
- Nürtingen‐Geislingen University of Applied Sciences (HFWU) Nürtingen Germany
| | - Karen J. Esler
- Department of Conservation Ecology and Entomology and Centre for Invasion Biology Stellenbosch University Private Bag X1, Matieland 7602 South Africa
- Centre for Invasion Biology, Department of Botany and Zoology Stellenbosch University Matieland South Africa
| | - João Alexandre Cabral
- Laboratory of Applied Ecology, CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Sciences University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
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Holmes PM, Esler KJ, van Wilgen BW, Richardson DM. Ecological restoration of ecosystems degraded by invasive alien plants in South African Fynbos: Is spontaneous succession a viable strategy? ACTA ACUST UNITED AC 2020. [DOI: 10.1080/0035919x.2020.1781291] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Patricia M. Holmes
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosh University, Private Bag X1, Matieland, 7602, South Africa
| | - Karen J. Esler
- Centre for Invasion Biology, Department of Conservation Ecology and Entomology, Stellenbosh University, Private Bag X1, Matieland, 7602, South Africa
| | - Brian W. van Wilgen
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - David M. Richardson
- Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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Kildisheva OA, Dixon KW, Silveira FAO, Chapman T, Di Sacco A, Mondoni A, Turner SR, Cross AT. Dormancy and germination: making every seed count in restoration. Restor Ecol 2020. [DOI: 10.1111/rec.13140] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
| | - Kingsley W. Dixon
- Centre for Mine Site Restoration, School of Molecular and Life SciencesCurtin University Bentley WA 6102 Australia
| | - Fernando A. O. Silveira
- Department of Genetics, Ecology and EvolutionFederal University of Minas Gerais Belo Horizonte Brazil
| | - Ted Chapman
- Conservation Science, Royal Botanic Gardens KewMillennium Seed Bank Wakehurst, Ardingly West Sussex RH17 6TN UK
| | - Alice Di Sacco
- Conservation Science, Royal Botanic Gardens KewMillennium Seed Bank Wakehurst, Ardingly West Sussex RH17 6TN UK
| | - Andrea Mondoni
- Department of Earth and Environmental ScienceUniversity of Pavia Pavia Italy
| | - Shane R. Turner
- Centre for Mine Site Restoration, School of Molecular and Life SciencesCurtin University Bentley WA 6102 Australia
- Kings Park Science, Department of BiodiversityConservation and Attractions Kings Park WA 6005 Australia
- School of Biological SciencesUniversity of Western Australia Crawley WA 6009 Australia
| | - Adam T. Cross
- Centre for Mine Site Restoration, School of Molecular and Life SciencesCurtin University Bentley WA 6102 Australia
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