Construction Construction ManagementManagement

City Ordinance Landscaping & Tree Preservation

Chad HerwaldChad HerwaldCity ArboristCity ArboristColumbia, MOColumbia, MOcmherwal@gocolumbiamo.comcmherwal@gocolumbiamo.com

City OrdinanceCity Ordinance

Sec. 29-25Sec. 29-25 Chapter 12-AChapter 12-A

29-2529-25Screening & Landscaping Screening & Landscaping

RequirementsRequirements Purpose is to establish healthy Purpose is to establish healthy

environmental conditions environmental conditions Provide visual buffering from streetsProvide visual buffering from streets Encourage PreservationEncourage Preservation

Sec 29-25 (c-d)Sec 29-25 (c-d)

Private & Public land located w/in City Private & Public land located w/in City LimitsLimits

Must have a Landscape PlanMust have a Landscape Plan Minimum of 15% of total land area of the Minimum of 15% of total land area of the

tract, parcel, or lot shall be landscapedtract, parcel, or lot shall be landscaped Follow Chapter 12-AFollow Chapter 12-A

29-25 (e)(1-8)29-25 (e)(1-8)Parking lots & ScreeningParking lots & Screening 50’ Paved area w/in 20’ of St. ROW shall 50’ Paved area w/in 20’ of St. ROW shall

have 6’ St. yard landscaping striphave 6’ St. yard landscaping strip Shall contain at least 4 categories from Shall contain at least 4 categories from

(F)(F) Shall contain at least 1 tree per 50’ of Shall contain at least 1 tree per 50’ of

street frontagestreet frontage At least 30% of trees shall be M/L varietyAt least 30% of trees shall be M/L variety

Parking lotParking lot

No parking areas containing more than No parking areas containing more than 150 spaces w/o 10’ landscaped divider150 spaces w/o 10’ landscaped divider

Landscape strip shall contain 4 Landscape strip shall contain 4 categories from (F)categories from (F)

1 tree/ 50 linear ft1 tree/ 50 linear ft No less than 50% of St. frontage forming No less than 50% of St. frontage forming

the perimeter shall have screening the perimeter shall have screening material material

Parking lotParking lot

Paved areas greater than 4,500 sq.ft. Paved areas greater than 4,500 sq.ft. shall contain 1 tree per 4,500 sq.ft.shall contain 1 tree per 4,500 sq.ft.

Trees are to be in a configuration that Trees are to be in a configuration that shades the lotshades the lot

Screening MaterialScreening Material

LandscapingLandscaping WallsWalls BermsBerms FencesFences Screening must be 3’ above the grade of Screening must be 3’ above the grade of

the parking lotthe parking lot Other City Ordinances have specific Other City Ordinances have specific

details that must be followeddetails that must be followed

Screening Parking LotScreening Parking Lot

Paved area of 1,500 Sq.ft. w/in 50’ of Paved area of 1,500 Sq.ft. w/in 50’ of residential zoningresidential zoning

And not separated by a streetAnd not separated by a street Shall have screening and at least 80% Shall have screening and at least 80%

opacity, viewed horizontally, between 1-5 opacity, viewed horizontally, between 1-5 above gradeabove grade

4 growing seasons if using plant material4 growing seasons if using plant material

Installation, Installation, Maintenance, and Maintenance, and

EnforcementEnforcement Deviations from approved plan shall be Deviations from approved plan shall be

corrected or new plan submittedcorrected or new plan submitted Comply with 12-AComply with 12-A Replacement of dead, insect or disease Replacement of dead, insect or disease

damaged trees by next planting seasondamaged trees by next planting season 170 sq.ft for trees170 sq.ft for trees 75 sq.ft. for shrubs75 sq.ft. for shrubs Existing trees maybe used if properly Existing trees maybe used if properly

protected!protected!

12-A12-ATree PreservationTree Preservation

No mechanized tree clearing on tracts large No mechanized tree clearing on tracts large than 1 ac w/o land dist. Permitthan 1 ac w/o land dist. Permit

Minimum of 25% of Climax Forest is perservedMinimum of 25% of Climax Forest is perserved A landscape plan demonstrating complianceA landscape plan demonstrating compliance 18 month survival on trees to remain18 month survival on trees to remain 6 months to replant dead ones on a 1:1 basis6 months to replant dead ones on a 1:1 basis

Existing TreesExisting Trees

4” DBH4” DBH Wooded lots bring value to lotsWooded lots bring value to lots Certified Arborist should be involved at Certified Arborist should be involved at

the planning and design stagethe planning and design stage Construction damage causes decline and Construction damage causes decline and

death to urban treesdeath to urban trees Damaged trees may not show symptoms Damaged trees may not show symptoms

until 3-6 yrs lateruntil 3-6 yrs later

Construction Construction Management Management

How Trees are DamagedHow Trees are Damaged Function & Location of tree rootsFunction & Location of tree roots Construction ImpactsConstruction Impacts Tree Protection Zone & TechniquesTree Protection Zone & Techniques

Have A Plan orHave A Plan or

PlanPlan

Site EvaluationSite Evaluation GIS & GPSGIS & GPS Add it to a layerAdd it to a layer

Construction ImpactConstruction Impact

SunlightSunlight OxygenOxygen Carbon DioxideCarbon Dioxide Soil texture (sand, Soil texture (sand,

silt or clay)silt or clay) TemperatureTemperature

Available WaterAvailable Water Available NutrientsAvailable Nutrients Soil structure Soil structure Available spaceAvailable space

How Construction How Construction Damages Trees Damages Trees

Physical InjuriesPhysical Injuries Root DamageRoot Damage New ExposuresNew Exposures Compaction Compaction Grade ChangeGrade Change

Physical InjuryPhysical Injury

Physical InjuryPhysical Injury

Damage to vascular tissuesDamage to vascular tissues But trees heal…don’t they?But trees heal…don’t they? Mortality spiral…againMortality spiral…again

Root DamageRoot Damage

Of all damages this is the most seriousOf all damages this is the most serious Damaging roots can spread a distance Damaging roots can spread a distance

greater than one tree.greater than one tree.

Root DamageRoot Damage

Severing 1 root can remove 15 to Severing 1 root can remove 15 to 25% of root system25% of root system

Root loss may increase potential for Root loss may increase potential for tree failuretree failure

The Root of itThe Root of it

90-95% of trees root system is in the top 90-95% of trees root system is in the top 3’ of soil.3’ of soil.

Over half is in the top 1’Over half is in the top 1’ They can extend up 3x the drip lineThey can extend up 3x the drip line They grow best with oxygen, water, and They grow best with oxygen, water, and

nutrients.nutrients. Most absorption is done by fine rootsMost absorption is done by fine roots

Root DamageRoot Damage

Root injury may show decline in a Root injury may show decline in a few months or several yearsfew months or several years

The mortality spiral?The mortality spiral? Common symptoms: yellowing or Common symptoms: yellowing or

early fall color, watersprouts, early fall color, watersprouts, dieback of small twigs and dieback of small twigs and eventually major brancheseventually major branches

How Roots are DamagedHow Roots are Damaged

CuttingCutting Smothering Smothering ExposingExposing CompactionCompaction

SmotheringSmothering

Adding as little as 2” of soil can restrict Adding as little as 2” of soil can restrict proper amount of water and oxygen to proper amount of water and oxygen to tree roots.tree roots.

Removing as little as 2” can remove Removing as little as 2” can remove many important roots.many important roots.

Smothering RootsSmothering Roots

Cutting & ExposingCutting & Exposing

Cutting & Exposing Cutting & Exposing

Cutting & ExposingCutting & Exposing

CuttingCutting

CompactionCompaction

The compressing of soil particles to limit The compressing of soil particles to limit the movement of oxygen, water, and the movement of oxygen, water, and nutrientsnutrients

Prevention & ProtectionPrevention & Protection

To prevent construction damage one To prevent construction damage one needs to know tree physiology.needs to know tree physiology.

One should know the components One should know the components needed for tree health.needed for tree health.

Know your Tree Species & Know your Tree Species & CharacteristicsCharacteristics

PreventionPrevention

Tree IslandTree Island [soil or landscape [soil or landscape surrounding a tree, such as within a surrounding a tree, such as within a paved area]paved area]

Similar to terracingSimilar to terracing Excellent for retaining small grovesExcellent for retaining small groves

PreventionPrevention

ProtectionProtection

Create a Travel RouteCreate a Travel Route

Treatments for Stressed Trees After Construction:

Water Aerate Fertilize (careful!) Mulch Prune Dead Limbs Thin Crown Remove Cambistat

AerationAeration

Radial TrenchesRadial Trenches

[means of aerating the soil in the root [means of aerating the soil in the root zone of a tree by removing and zone of a tree by removing and replacing soil in a spoke-like pattern]replacing soil in a spoke-like pattern]

Mechanical trenchers should not Mechanical trenchers should not operate within 4-8’ of trunkoperate within 4-8’ of trunk

Trench at least to dripline; 1’ depthTrench at least to dripline; 1’ depth

Air excavator Air excavator [device that blows [device that blows air at high force; air at high force; used to remove used to remove soil from the root soil from the root zone of trees]zone of trees]

Fertilizer & ChemicalsFertilizer & Chemicals

When to Prune or When to Prune or RemoveRemove

Chad HerwaldChad HerwaldCity ArboristCity ArboristColumbia, MOColumbia, MOcmherwal@gocolumbiamo.comcmherwal@gocolumbiamo.com