Philip K. Groom, Byron B. Lamont Plant Life of Southwestern Australia. Adaptations for Survival Unauthenticated Download Date | 6/13/15 12:13 PM Unauthenticated Download Date | 6/13/15 12:13 PM Philip K. Groom, Byron B. Lamont Plant Life of Southwestern Australia Adaptations for Survival Managing Editor: Katarzyna Michalczyk Unauthenticated Download Date | 6/13/15 12:13 PM Published by De Gruyter Open Ltd, Warsaw/Berlin Part of Walter de Gruyter GmbH, Berlin/Munich/Boston This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 license, which means that the text may be used for non-commercial purposes, provided credit is given to the author. For details go to http://creativecommons.org/licenses/by-nc-nd/3.0/. Copyright © 2015 Philip K. Groom, Byron B. Lamont ISBN: 978-3-11-037016-4 e-ISBN: 978-3-11-037019-5 Bibliographic information published by the Deutsche Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available in the Internet at http://dnb.dnb.de. Managing Editor: Katarzyna Michalczyk www.degruyteropen.com Cover illustration: © Peter Mioduszewski Unauthenticated Download Date | 6/13/15 12:13 PM “Owing to its arresting beauty, the vegetation of Western Australia arouses both interest and affection” Ludwig Diels (1906) Unauthenticated Download Date | 6/13/15 12:13 PM Acknowledgments Much is known about the southwestern Australian flora. The impetus for preparing this book was the need to compile this vast knowledge base into one publication. We would like to thank members of the Department of Environment and Agriculture (and its predecessor the Department of Environmental Biology), Curtin University, Western Australia, for their support and encouragement during the writing phase, especially Professors Jonathan Majer and Jacob John. Special mention goes to the thousands of students we have taught in the undergraduate unit ‘Flowering Plants/Australian Flora’ (and their predecessors) for inspiring us to make this book a reality. Most photographs and drawings were sourced from the authors’ personal collection. Allen Lowrie graciously provided photographs of the wasp-pollinated orchids, in addition to images of other orchids and Drosera species. Mark Brundrett kindly provided additional orchid photos including the monotypic genera and the underground orchid. Special thanks to Jiri Lochman of Lochman Transparencies for providing several photos from his vast photographic collection. William Archer allowed us the use of photographs from his online collection Esperance Wildflowers. We also thank Haylee D’Agui, Geoff Burrows, Melissa Darling, Katherine Downes, Aaron Gove, Geoffrey Groom, Peter Mioduszewski, William Parkinson, Allan Tinker and Stephen van Leeuwen for providing additional photographs. Katherine Downes is thanked for providing information on fire ephemerals and soil-stored seeds. Hervé Sauquet provided the Proteaceae chronogram that was then reanalysed for fire-proneness and fire-related traits and redrawn by Tianhua He. Maps and tables were compiled from published journal articles or books, the sources of which are acknowledged in their associated captions. Wesley Lamont is thanked for redesigning the maps and all line drawings. Christine Cooper and Tim Lardner assisted with access to relevant references. Alex George, Neville Marchant, Laco Mucina and Ross Young graciously commented on earlier drafts. Brian Heterick assisted with ant identifications. Special thanks to Fran, Byron and Zoe from Dome Maylands for all their encouragement and support during the later drafts of the book. We dedicate this book to Peter Mioduszewski, a colleague and friend who had a passion for the southwestern Australian flora and natural history in general. He was well respected by his peers, and the students he assisted as a botanical technical officer at Curtin University. Peter passed away suddenly in late 2012. In his memory we selected one of his photographs for the cover page. We began writing this book in 2010, the International Year of Biodiversity. Unauthenticated Download Date | 6/13/15 12:13 PM Contents Acknowledgments VI Prologue 1 P.1 Southwestern Australia and its Functional Biodiversity 1 P.2 Environmental and Biotic Constraints 2 P.3 Our Book 4 1 Evolution and Diversity of the Flora 6 1.1 A Radiating and Hyperdiverse Flora 6 1.2 Evolutionary Constraints and Responses 11 1.3 The SouthWest Flora 45 Million Years Ago and Now 13 1.4 A Relict Podocarp 17 1.5 Fire and Evolution of the Proteaceae 18 1.6 Floristics and Phytogeography 22 1.7 The SouthWest as a Biodiversity Hotspot 27 2 Fire Adaptations 30 2.1 Fire-enhancement 40 2.2 Fire-dependence 40 2.3 Fire-resistance 42 2.4 Fire-avoidance 44 2.4.1 Post-fire Persistence via Resprouting 45 2.4.2 Lignotubers 46 2.4.3 Epicormic Growth 48 2.4.4 Rhizomes 48 2.5 Fire-sensitivity 49 2.6 Flammability 50 2.7 Evolution of Fire-adapted Traits 52 3 Drought Responses 58 3.1 Herbaceous Drought Avoiders and Resisters 59 3.2 Drought Response of Woody Plants 60 3.2.1 Diallagy 62 3.3 Classifying Species into Functional Groups 62 3.3.1 Functional Significance of Rooting Depth Patterns for Groundwater- Dependent Vegetation 66 3.3.2 Woody Perennial Rooting Patterns 67 3.4 Stomatal Location—a Drought Response? 68 3.5 Case Study: Ecophysiology of Dimorphic Leaves in Hakea trifurcata 70 Unauthenticated Download Date | 6/13/15 12:13 PM 4 Carnivorous Plants 72 4.1 Drosera 72 4.2 Byblis 75 4.3 Cephalotus 76 4.4 Utricularia 77 5 Parasitic Plants 79 5.1 Stem Hemiparasites - Mistletoes 79 5.1.1 Host Mimicry 80 5.1.2 Seed Dispersal 82 5.2 Root Hemiparasites 84 5.2.1 Nuytsia floribunda (Loranthaceae) 84 5.2.2 Olax phyllanthi (Olacaceae) 86 5.2.3 Santalum (Santalaceae) 86 5.3 Stem Holoparasites 87 5.3.1 Pilostyles (Apodanthaceae) 87 5.3.2 Cuscuta (Convolvulaceae) 89 5.4 Stem Hemi or Holoparasite? Cassytha (Lauraceae) 89 6 Specialised Nutrient Uptake Mechanisms 91 6.1 Nitrogen 91 6.1.1 Cyanobacterial Symbionts 91 6.1.2 Rhizobial Symbionts 93 6.1.3 Actinorhizal Symbionts 93 6.2 Phosphorus 95 6.2.1 Mycorrhizal Associations 95 6.2.2 Arbuscular Mycorrhizas 96 6.2.3 Ectomycorrhizas 97 6.2.4 Orchid and Ericoid Mycorrhizas 98 6.3 Case Study: Dispersal of Ectomycorrhizal Fungi by Marsupials 103 6.4 Root Clusters 104 6.4.1 Proteoid Roots 104 6.4.2 Dauciform Roots 106 6.4.3 Capillaroid Roots 106 6.5 The Bizarre Root System of Kingia australis 106 6.6 Nutrient-impoverished Soils Promote Species Richness 108 7 Pollination Strategies 109 7.1 Outbreeding Strategies 110 7.1.1 Protandry 111 7.1.1.1 Eucalyptus (Myrtaceae) 111 7.1.1.2 Pimelea (Thymelaeaceae) 112 Unauthenticated Download Date | 6/13/15 12:13 PM 7.1.1.3 Goodeniaceae 112 7.1.1.4 Banksia (Proteaceae) 113 7.1.1.5 Petrophile and Isopogon (Proteaceae) 113 7.1.1.6 Grevillea and Hakea (Proteaceae) 115 7.1.1.7 Persoonia (Proteaceae) 116 7.1.1.8 Stylidium (Stylidiaceae) 116 7.1.1.9 Eremophila (Scrophulariaceae) 117 7.1.2 Protogyny 118 7.2 Autogamy 118 7.3 Attracting Pollinators 119 7.4 Flower Colour Change 120 7.5 What Role Do Extrafloral Nectaries Play? 122 8 Pollination Syndromes 126 8.1 Insect-pollinated Species 127 8.1.1 Case study: Grevillea leucopteris 127 8.1.2 Bee Pollination 130 8.1.3 Orchid Pollination 135 8.1.3.1 Food Rewards 137 8.1.3.2 Pollinator Deception 138 8.1.3.3 Gnat Pollination 140 8.1.3.4 Sexual Deception 142 8.2 Honeyeater-pollinated Species 145 8.2.1 Case Study: Gastrolobium 148 8.2.2 Pollen Dispersal 149 8.3 Mini-possum Pollination 150 9 Leaf Properties 153 9.1 Leaf Size 153 9.2 Leaf Design 156 9.2.1 Reducing Summer Leaf Heat Loads 156 9.2.2 Heterophylly 157 9.3 Sclerophylly 158 9.3.1 Case Study: Two Banksias With Long-lived Leaves 161 9.4 Leaf-like Structures 162 9.5 Alternatives to Sclerophylly for Protecting Leaves 164 9.6 Leaves as Defensive Mechanisms Against Herbivores, Florivores and Granivores 166 9.6.1 Cryptic Mimicry 169 9.6.2 Fruits Hidden by Leaves 169 9.6.3 Herbivore Defence Among Restios 171 Unauthenticated Download Date | 6/13/15 12:13 PM