Applied Tree Biology

Many arborists learn tree work practices without fully understanding the biological and physiological principles behind them. However, outcomes for the health and longevity of trees are greatly improved when an arborist understands the science behind the care of tree root systems and crowns. In Applied Tree Biology, Drs. Hirons and Thomas draw upon their decades of experience in the laboratory, classroom, and the field - as well as the expertise of distinguished contributors to this volume - to provide those responsible for tree care with the scientific information that informs best practices for planting, pruning, soil decompaction, irrigation, and much more.

• Takes a multidisciplinary approach, integrating knowledge from plant biology, physiology, arboriculture, ecology, and more

• Provides a systematic presentation of fundamental tree biology and the scientific principles informing high quality tree care

• Presents accessible scientific information and best practices that help promote the health and longevity of trees

• Reflects the authors' decades of experience as tree biology researchers and educators, as well as their years of professional experience across the globe

Applied Tree Biology is an indispensable source of practical, succinct information on tree biology, physiology, and ecology for professionals and interested amateurs involved with the care of trees. Arborists, foresters, and horticulturists at all stages of their careers will find this text particularly useful.

Auteur

ANDREW D. HIRONS is a Senior Lecturer in Arboriculture at University Centre Myerscough, UK. He has international experience as a climbing arborist and a plant health care practitioner. As well as lecturing on a range of arboricultural courses he is also actively involved in research. His current research activity is motivated by the need to create resilience in our urban forests, and is focused on using plant traits to inform species selection for urban environments. PETER A. THOMAS is a Reader in Plant Ecology at Keele University, UK. He has more than 30 years of experience in ecological aspects of trees and forests in the UK, Europe, North & Central America, Africa, Russia, Asia and Australasia.

Contenu
List of Contributors xv

Foreword xvii

Preface xix

A Note on the Text xx

1 Introduction 1

Value of Trees Globally 1

Value of Urban Trees 2

Managing Trees 5

References 11

2 The Woody Skeleton: Trunk and Branches 15

What is a Tree? 15

How Does a Tree Grow? 15

Tree Design 18

How Shoots Grow 19

Building Blocks: Meristems and Buds 19

New Shoots From Buds 22

Apical Dominance and Apical Control 25

Epicormic Shoots and Sprouting 26

Epicormic Shoots (Sprouts) 27

Basal Sprouts 29

Branch and Trunk Sprouts 30

Opportunistic Sprouts 31

Sprouts Originating Underground 32

Practical Considerations of Sprouting 33

Sprouting in Response to Mechanical Injury 34

Sprouting in Response to Disturbance 34

Secondary Growth 34

The Vascular Cambium 35

Thickening of Woody Cell Walls 38

Programmed Cell Death 40

Bark and Secondary Phloem 40

How Bark Grows 41

Variation in Bark 43

Secondary Xylem Wood 44

Different Cell Types Found in Wood 46

Living Cells in the Wood Parenchyma 47

NonLiving Cells in the Wood Vessels, Tracheids and Fibres 49

Variation in Wood Structure 52

Gymnosperm Wood 52

Dicotyledonous Wood 53

Sapwood and Heartwood 56

Sapwood and Water Movement 57

Heartwood 59

Sapwood and Heartwood Considerations for Pruning Operations 62

Tradeoffs in Wood Design 62

Tradeoffs and the Movement of Water 63

FreezingInduced Cavitation 66

DroughtInduced Cavitation 67

Moving Water Around a Tree Vascular Sectorality 71

References 72

3 Leaves and Crowns 77

Angiosperm Leaves 78

Angiosperm Leaf Anatomy 82

Gymnosperm Leaves 83

Gymnosperm Leaf Anatomy 85

Juvenile Leaves 86

Sun and Shade Leaves 87

Leaf Arrangement 90

Compound Leaves 91

Evergreen and Deciduous Leaves 93

Value of Evergreen and Deciduous Leaves 94

Leaf Phenology 97

Tree Crowns 101

Shape of Tree Crowns 104

Role of Branches in Tree Crowns 107

Biomechanical Design of Tree Crowns 108

Reaction Wood 122

Branch Shedding as a Natural Process 124

Tree Pruning 126

Pruning Practices 129

Tree Crown Support 133

References 135

4 Tree Roots 141

Root Growth and Development 141

Root Systems 146

Secondary Root Growth 148

Root Architecture 150

Tree Anchorage 153

Extent of Root Systems 154

When Do Roots Grow? 157

Soil Compaction 161

Soil Resistance to Root Development 163

Management of Soil Compaction 165

Mulching 168

Decompaction 168

Estimating Appropriate Soil Volumes for Tree Roots 171

Improving Soil Volumes in Urban Environments 179

References 183

5 The Next Generation of Trees: From Seeds to Planting 187

Flowers, Seeds and Fruits 187

Variation in Flowers and Pollination 189

Not All Seeds Require Pollination 191

Cost of Reproduction 193

Numbers Involved 195

Flowering and Fruiting in Urban Landscapes 196

Tree Crops 198

Vegetative Reproduction 199

Growing Trees 203

Seeds and Their Origins 203

Storing Seeds 205

Seed Dormancy 205

Germination 207

Seedlings 208

Tree Establishment From Production to the Landscape 210 Momentum of Tree Establishment 211&...