List of contributors, xiii
1 Intro: Urban trees ¢" Importance, benefits, problems, 1
Andreas Roloff
1.1 Introduction, 1
1.2 Aesthetics, sensory impressions, 1
1.3 Psychology, well]being, health, 3
1.4 Environmental education, ecology, 9
1.5 Orientation, spacious ordering, architecture, 9
1.6 Protection, quality of life, 9
1.7 Food/diet, healing powers, 11
1.8 Utilization of trees, 11
1.9 Economic and social advantages, 11
1.10 Issues, 12
1.11 Conclusion, 13
References, 13
2 Urban trees: Features and requirements, 15
Andreas Roloff
2.1 Urban tree site categories, 15
2.2 Special conditions for urban trees, 15
2.3 Requirements and selection criteria, 15
2.4 Conclusions, 19
References, 19
3 Fundamentals of tree biology for urban trees, 20
Doris Krabel
3.1 Morphological and anatomical features, 20
3.1.1 Trunk, 20
3.1.2 Roots, 22
3.1.3 Mycorrhizae, 24
3.1.4 Secondary growth, 25
3.1.5 Periderm and bark, 27
3.2 Tree growth and growth reactions, 28
3.2.1 Photosynthesis ¢" the fundamental growth process, 28
3.2.2 The role of water, 29
3.2.3 Seasonal dynamics, 30
3.2.4 Wound reactions, 31
3.3 Conclusions, 33
References, 34
4 Urban tree roots: Problems and peculiarities, 36
Sandra Korn
4.1 Damages to and influences on the root system of urban trees, 36
4.1.1 Site conditions, 36
4.1.2 Human activity, 37
4.1.3 Construction sites, 39
4.2 Damage caused by the root system of urban trees, 41
4.3 Precautions/preventing damage, 43
4.4 Conclusions, 44
References, 45
5 Drought stress: Adaptation strategies, 47
Sandra Korn
5.1 What is stress? ¢" Stress concepts, 47
5.2 Stress responses, 47
5.2.1 Adaptation to drought stress ¢" stress escape, 48
5.2.2 Adaptation to drought stress ¢" stress resistance by avoidance, 49
5.2.3 Adaptation to drought stress ¢" stress resistance by tolerance, 51
5.3 Identifying tree species adapted to stress, 53
5.3.1 Responses and adaptations to drought stress, 53
5.3.2 Identifying suitable tree species, 53
5.4 Conclusions, 56
References, 56
6 Aspects of urban tree pathology, 58
Rolf Kehr
6.1 Definitions, terms and concepts, 58
6.2 Abiotic damage and disorders, 59
6.3 Virus diseases, 61
6.4 Diseases caused by bacteria and other prokaryotes, 61
6.5 Diseases caused by oomycetes, 64
6.6 Fungal diseases, 65
6.6.1 Systemic fungal infections, 65
6.6.2 Leaf and needle diseases, 67
6.6.3 Shoot and stem diseases and cankers, 68
6.6.4 Rust diseases, 70
6.6.5 Root diseases, 70
6.6.6 Wood decay, 71
6.7 Parasitic plants, 72
6.8 Plant]parasitic nematodes and insect pests, 73
6.9 Damage by herbivorous mammals, 76
6.10 Impact of introduced pests and diseases, 76
6.11 Aspects of control methods for pests and diseases of urban trees, 76
6.12 Conclusions, 77
References, 77
7 Vitality assessment, tree architecture, 82
Andreas Roloff
7.1 Introduction, 82
7.2 Decline and stress symptoms of tree crowns: ¢leaf loss¢ vs. crown structure, 82
7.3 Tree architecture and reiterations, 83
7.3.1 Architectural models, 83
7.3.2 Reiterations, 85
7.4 Changes in the crown structure with decreasing vitality, 87
7.4.1 Shoot morphology: shoot base scars, short] and long]shoots, 87
7.4.2 Model of growth stages, 88
7.4.3 Vitality classes, 90
7.4.4 Vitality and tree life expectancy, 92
7.5 Conclusions, 94
References, 94
8 Body language of trees, tree diagnostics, 95
Andreas Roloff
8.1 Terms and definition, 95
8.2 Adaptation and optimization in trees, 95
8.3 Examples and explanation: branches, trunk/bark, roots, 96
8.3.1 Branch]shedding collar, 96
8.3.2 Hazard beams, 97
8.3.3 Bottle butts, 98
8.3.4 Forked trees, 98
8.3.5 Nose]like ribs on forked trees, 99
8.3.6 Sunburn, 99
8.3.7 Stem crack, 100
8.3.8 Longitudinal splitting, 100
8.3.9 Knobs and nodules, 100
8.3.10 Bark stripes on ribs, 102
8.3.11 Supply shadow, 103
8.3.12 Elephant¢s foot, 103
8.3.13 Hollow trunks, 104
8.3.14 Crown/root relationship, 104
8.3.15 Root symphysis, 105
8.3.16 Tension roots on slopes, 105
8.3.17 Covered root collars, 106
8.3.18 Root collar strangling, 107
8.3.19 Sealing of the root area, 107
8.3.20 Inner roots, 108
8.3.21 Adventitious roots, 108
8.4 Conclusions, 109
References, 110
9 Tree inventory, risk assessment and management, 111
Steffen Rust
9.1 Introduction, 111
9.2 Tree inventory, 112
9.2.1 Inventory parameters, 112
9.2.2 Technology, 112
9.3 Tree risk assessment, 113
9.3.1 Terms and concepts, 113
9.3.2 Visual assessment, 115
9.3.3 Advanced assessment, 122
9.3.4 Risk categorization and reporting, 130
9.4 Conclusions, 132
References, 132
10 Tree preservation, maintenance and repair, 135
Steffen Rust
10.1 Introduction, 135
10.2 Preserving existing trees during development, 135
10.2.1 Tree constraints plan, 136
10.2.2 Tree survey, 136
10.2.3 Root protection area, 138
10.2.4 Tree Protection Plan, 138
10.2.5 Arboricultural method statement, 138
10.2.6 Pre]development treatments, 139
10.3 Maintenance of planted and established trees, 139
10.3.1 Physical support, 139
10.3.2 Protection against collisions, 143
10.3.3 Solar radiation, 144
10.3.4 Wound treatment, 144
10.3.5 Water management, 144
10.3.6 Mulching, 146
10.3.7 Mycorrhizae, 148
10.3.8 Soil compaction, 148
10.3.9 De]icing salt, 150
10.3.10 Pruning to mitigate risk, 150
10.3.11 Ancient and veteran trees, 151
10.3.12 Precautionary measures, 151
10.4 Conclusions, 152
References, 153
11 Tree pruning: Methods and parameters, 154
Ulrich Pietzarka
11.1 Introduction, 154
11.2 Consequences of pruning, 154
11.3 Important parameters, 157
11.4 The pruning system, 160
11.4.1 Palms, 162
11.5 Intensity of pruning, 164
11.6 Date of pruning, 165
11.6.1 Reduction of assimilates and reserves, 166
11.6.2 Species and nature conservation, 167
11.6.3 Hazard of fungal infestation, 167
11.6.4 Risk of sunburn, 167
11.6.5 Severe frost, 167
11.6.6 Visibility, 167
11.7 Conclusion, 168
References, 168
12 Transplanting large trees, 169
Ulrich Pietzarka
12.1 Introduction, 169
12.2 Definitions, tasks, decisions, 169
12.3 Preparation, 172
12.4 Transplantation practices, 173
12.5 Post]planting care, 175
12.6 Conclusion, 175
References, 175
13 Dust and noise reduction, 177
Britt Kniesel
13.1 Dust, 177
13.1.1 Dust definition and origins, 177
13.1.2 Interaction between dust particles and vegetation, 177
13.1.3 Planting design, 180
13.2 Noise, 180
13.2.1 Noise control, 180
13.2.2 Noise attenuation by vegetation, 180
13.2.3 Planting design, 182
13.3 Conclusions, 183
References, 183
14 Invasive species, indigenous vs. alien dendroflora, 185
Matthias Meyer
14.1 Introduction, 185
14.2 Floristic statuses ¢" important definitions for urban dendroflora, 185
14.2.1 ¢Indigenous¢ vs. ¢alien¢, 186
14.2.2 ¢Casual¢ and ¢naturalized¢ vs. ¢invasive¢, 187
14.3 Invasibility of habitats and invasiveness of dendroflora
in urban landscapes, 188
14.4 Arguments pro or contra ¢alien¢ woody species and risk assessment, 189
14.5 The example of the tree of heaven (Ailanthus altissima), 190
14.6 Prevention and control measures against invasive woody
species or tree weeds, 191
14.7 Conclusions, 193
References, 193
15 Criteria for species selection: Development of a database for urban trees, 196
Sten Gillner, Mathias Hofmann, Andreas Tharang and Juliane Vogt
15.1 Introduction, 196
15.2 Species description, growth conditions, and risks related
to species use, 198
15.2.1 Data pool and nomenclature, 198
15.2.2 Literature review and evaluation, 198
15.2.3 Structure of the database, 199
15.3 Urban Tree Location Categorization, 199
15.3.1 Urban tree location types, 202
15.3.2 Specific demographic groups, 204
15.4 Psychological aspects of the database, 205
15.4.1 User]based urban green space categorization, 205
15.4.2 Tree perception and tree preferences, 206
15.5 Application possibilities and limitation of use, 207
15.6 Conclusions, 208
References, 209
16 Genetic aspects, 211
Doris Krabel
16.1 The problem of trees from a genetic point of view, 211
16.2 Diversity, monoculture, variety and clones ¢" some general comments, 214
16.3 The risk of missing diversity, 215
16.4 Genetic diversity as an element of design and planning in urban spaces, 217
16.5 Conclusions, 219
References, 219
17 Governance in urban forestry, 221
J¼rgen Pretzsch
17.1 Introduction: challenges and need for action, 221
17.2 Objectives and definitions, 221
17.2.1 Objectives, 221
17.2.2 Definitions, 222
17.3 Diagnosis and conceptual framework, 222
17.3.1 Socio]ecological co]evolution model for urban forestry, 222
17.3.2 Historical development of urban forestry governance, 223
17.3.3 Increasing complexity and paradigm change, 224
17.3.4 Stakeholder analysis and differentiation in participant groups, 225
17.3.5 Assessment by the livelihood framework, 226
17.4 Governance models for urban forestry, 227
17.4.1 Introduction to urban forestry governance models, 227
17.4.2 Public administration: changing functions and diversification, 227
17.4.3 Public]private partnerships, 228
17.4.4 Governance based on private urban forestry, 228
17.4.5 Donations, 228
17.4.6 Allotment gardens, 228
17.4.7 Neighborhood groups and collective gardening, 230
17.5 Lessons learned for the future development of urban forestry, 230
17.5.1 Paradigm change, 230
17.5.2 Chances and limits of collective action in urban forestry, 231
17.5.3 Exclusion and conflict management, 231
17.5.4 Adaptive management, 231
17.5.5 Forthcoming steps in practice and research, 232
17.6 Conclusions, 232
References, 234
18 Allotment gardens and privately managed green
space in urban environment, 236
Eckhard Auch
18.1 Introduction, 236
18.2 Some definitions, 236
18.2.1 Green space as urban soft infrastructure, 236
18.2.2 Urban gardening vs. urban horticulture, agriculture
and agroforestry, 237
18.3 Urban gardens, 237
18.3.1 Generic types of urban gardens, 237
18.3.2 Urban gardens in history, 238
18.3.3 Urban gardens for the disadvantaged in the 20th Century, 239
18.4 Function and benefits/services of trees and gardens in urban contexts, 241
18.5 Recent forms of urban gardening in the global North and global South, 242
18.5.1 Factors facilitating the emergence, 242
18.5.2 Newer urban garden forms (selection), 243
18.6 Conclusions, 245
References, 245
19 Urban woods for relaxation and inspiration, 247
Eckhard Auch, Hubertus Pohris and Markus Biernath
19.1 Introduction, 247
19.2 Some definitions, 247
19.3 Forest ecosystem functions and services, 248
19.4 Changing demands on urban and peri]urban forests ¢" the case of Dresden, 251
19.4.1 Change in forest functions, 251
19.4.2 Functional transformation of the Dresdner Heide forest, with focus on
recreation, 251
19.5 Urban forestry and silviculture, 254
19.5.1 Urban forests as recreational resource, 254
19.5.2 Silvicultural operations for recreational resources, 254
19.6 Silvicultural specifics of urban and peri]urban forest management, 256
19.7 Conclusions, 259
References, 259
20 Acceptance for urban trees: Environmental education programs, 262
Ulrich Pietzarka
20.1 Introduction, 262
20.2 Education for sustainable development, 262
20.3 Features of successful education programs, 264
20.3.1 Specific to target groups, 264
20.3.2 Inviting, 266
20.3.3 Focused, 266
20.3.4 Relevant, 267
20.3.5 Active, 267
20.3.6 Entertaining, 268
20.4 The search for professional partners, 268
20.5 Conclusions, 269
References, 270
Index, 271
