Trees in the Urban Landscape: Principles and practice

Introduction. Aims of the manual. Lessons from the past. The value of trees. A history of trees in cities. The numbers of trees and their value. The contribution of trees to our environment. Problems for trees in cities. Survival of trees. Growth of trees. The cost of tree failure. Causes of tree failure. The major problems. The biology of trees. Growth. Water and nutrient uptake - roots: water - nutrients - roots. Photosynthesis - leaves: photosynthesis - leaves. Transport of materials - stems: transport - stems. Maintenance. Intrinsic site problems. Soil composition and properties: texture - organic matter - structure - pore space. Urban soils: water supply - compaction - drainage - nutrients - toxicity 5. Extrinsic site problems. Vandalism. Vehicle damage. Salt. Wind damage. Air pollution: dust - sulphur dioxide - nitrogen oxides and ozone. Site treatments. Surface drainage. Soil compaction. Under drainage. Drought. Nutrient deficiencies. Toxicity. Topsoil. Ameliorants and alternative materials. Ground surfaces. Assessment. Tree stock. Types of tree stock: standards - transplants and whips - extra heavy standards and semi mature trees - cuttings - seed. Root treatment. Quality of stock. Choice of species. General vigour. Deciduous or evergreen? Native or alien? Major types of native species. Alien species. Varieties and clones. Tolerance to special ecological conditions. Associations of species. Costs. No substitute for observation and experience. Planting techniques. Basic planting techniques: direct seeding - cuttings - notch planting - pit planting - tree spades. Backfill and soil amendments. Drainage. Planting pit design. Buildings and services. Time of planting. Post planting practices. The importance of water. Importance of water. Water requirements. Managing water supply: increasing the size of the root system - incorporation of ameliorants - irrigation. Controlling the water use by the tree: pruning - anti-transpirants. Soil volumes for established trees. The need for nutrients. Nutrient requirement and soil supply. The response of tres to nutrients. Methods of nutrient addition: use of good soil - fertilisers and manures - nitrogen-fixing species. Support and protection. Benefits and problems of support: stem and root growth - tie and stake damage - methods of support. Problems of protection: vandalism - mower and strimmer damage - animal damage - wind damage - road salt. Weed control. Effects on survival and growth: mechanisms of action. Methods of weed control: physical removal - cutting and mowing - herbicides - mulches. Area of treatment. Pruning. Principles of pruning. Nursery pruning. Pruning at planting. Pruning for shape. Controlling plant size. Pests, diseases, damage and decay. Diseases: beech bark disease - Dutch elm disease - fireblight - plane anthracnose - oak wilt - p