Hazard Trees and Urban ForestsKen RussellForest and Tree Health ServicesSafety and LegalObligationsHazard Tree PublicationsWhat is a Hazard Tree?A Hazard Tree Has Two Attributes:•Defect•TargetDefectsA hazard tree has defects that can cause the tree or its parts to fall on a target.Defects Are Discussed laterTargetA target is people or property that could be injured or damaged by tree failure.Hazard Tree InspectionsTargets to Inspect•State Roads•Viewpoints•School Yards•Public Buildings•Trails•Picnic Sites•Campsites*•Urban Streets•Playgrounds•Parking Lots•Parks•Waysides•Interpretive Sites•Homes*How Do I Evaluate a Hazard Tree?Hazard Rating SystemAssign a Two PartNumerical Rating:1. Tree2. TargetRate The Tree1- Low Failure Probability2- Moderate Failure Probability3- High Failure Probability4- Extreme Failure Probability (Take care of it now.)Rate The Target1- Low Damage2- Moderate Damage3- High DamageAssign highest values where people are present.Total Tree and Target RatingsUse the total rating to make a correction decision.Total RatingDegree of HazardCorrection DecisionLowModerateHigh2-34-56-7Monitor TreeMonitor/ Remove Tree/TargetRemove Tree or TargetKeep RecordsLocate Hazard TreesRecord DefectsDocument Action TakenDevelop Inspections ScheduleDefectsRoot DiseasesStage 0Tree HealthyStage 1Tree loses vigor:No obvious symptomsPhaeolus SchweinitziiStage 2P schweinitziiArmillariaPerenniporiaBark BeetlesTree Health PoorWindthrown!Construction Damage• Soil Compaction• Changing the Grade• Trenching Near Roots• Vegetation Removal • Changing Water Table • Wounding Trees• Surfacing Near TreesGrading and FillingFlood SedimentationExcessive Vegetation RemovalCorrecting Hazardous TreesTreatment Options• Remove Target• Remove Tree• Pruning• Wound Treatment• Crown Thinning• Topping Not RecommendedProper Pruning CutsWoundsCODITHumans HealTrees SealMore Treatment Options• Pushover Tree Removal• Plant Alternate Species• Convert RR Centers• Mark RR Centers/Saw Cuts• Talk to Media First• Making safe snagsStorm PlanDevelop a storm warning evacuation plan for unusual sites.Long Range
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