The Guiding Principles of Arboriculture - College of Natural ...

What is arboriculture?The art, science, and technology of selecting, establishing,and maintaining woody plants in and around humansettlements Woody Plants – trees, shrubs, and vines Selection•intended function•site evaluation•species selection•nursery stock evaluation Establishment – site preparation, planting, after-care Maintenance – cultural practices, pest management, pruning

Why arboriculture?The urban environment is an inhospitable environment•Disturbed soils•Extreme microclimate•Toxins, pollutants•Pests•Abuse, injury, vandalism

Why arboriculture?There are consequences for “bad trees”•Property damage•Personal injury•Inconvenience•Liability

Why arboriculture?Managed trees are better trees•Functionality•Cost-effectiveness•Longevity•Health•Appearance•Safety

The Guiding Principles of ArboricultureThe most comprehensive, up-todatearboriculture textbookavailableNow in fourth editionRichard Harris, Professor EmeritusEnvironmental HorticultureU. California-DavisISBN: 0130888826

The Guiding Principles of Arboriculture1. Arboriculture and forestry are related but not equivalentfieldsArborists…•See trees as individuals•Manage for different benefits•Have limited concern for management time frame•Work with trees in a different environment

The Guiding Principles of Arboriculture2. Arboricultural treatments can have either positive benefitsor negative consequencesPruningIrrigationFertilizationMulchingDose, Timing, Limits of the System ~ AlexShigo

The Guiding Principles of Arboriculture3. Tree care is founded on the principles of plant health carePlant Health Care – a comprehensive program to managethe appearance, structure, and vitality of ornamentallandscapes within client expectations•A holistic approach to landscape management•Woody plants are part of a greater landscape system•Plant types should not be viewed in isolation•Monitoring and Maintaining vitality

The Guiding Principles of Arboriculture4. An ounce of prevention is worth a pound of cure becausewe have limited ability to cureWhat we can’t undo…•Improper species selection•Incorrect planting technique•Bad pruning•Severed/damaged roots•Advanced declineWhat we can do…•Choose appropriate species•Use proper arboricultural techniques•Provide a favorable growing environment•Protect trees from injury

The Guiding Principles of Arboriculture5. Tree selection is founded on “right plant, right place”•Intended plant function•Environmental conditions•Site conditions•Management conditionsFighting the site and/or the tree’s genetic proclivity is usually a losingproposition

The Guiding Principles of Arboriculture6. Good trees and tree care start with quality plantsNursery Stock TypeConfiguration and Defects•Crown•Trunk•RootsTree Health•Vitality•Injuries and pests

The Guiding Principles of Arboriculture7. Tree care applies general concepts to specific genotypesGenotype - the genetic makeup of an individual organismFundamentally, woody plants have similar biology andrequirements•Anatomy•PhysiologySpecies can differ greatly in their tolerancesStewartia vs. Red mapleVigor vs. Vitality ~ Alex Shigo

The Guiding Principles of Arboriculture8. Tree care is a long-term, low-intensity processTrees generally thrive under conditions of stabilityChange, in almost any form, represents stress for treesManagement should strive for stabilityDose, Timing, Limits of the System ~ Alex Shigo

The Guiding Principles of Arboriculture9. As tree development changes with time, so must treecareYoung trees•Promote growth and establishmentImmature trees•Promote good crown structureMature trees•Maintain environmental stability•Minimize stressDynamic Mass vs. Static Mass ~ Alex Shigo

The Guiding Principles of Arboriculture10.Tree health and integrity are related but not equivalent

Summary• Proper arboriculture is essential for woody plant health,structural integrity, longevity, and aesthetics• Arboriculture is best practiced using guiding principles