tree sites: good, bad and ugly · design and installation by peter trowbridge and nina bassuk •...

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Tree Sites: Good, Bad and Ugly …or why is the tree you recommended tearing up my driveway? Paula Peper, Ecologist Center for Urban Forest Research Pacific Southwest Research Station,USDA Forest Service

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Page 1: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Tree Sites: Good, Bad and Ugly…or why is the tree you recommended tearing up my driveway?

Paula Peper, EcologistCenter for Urban Forest Research

Pacific Southwest Research Station,USDA Forest Service

Page 2: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Why site assessment?

Page 3: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 3

When they’re small, it is hard to imagine….

Page 4: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 4

…tall

Page 5: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 5

…crammed into

Page 6: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 6

…small spaces

Page 7: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 7

and weird places

Page 8: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 8

Our Job: Simple as This?

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Page 9: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 9

Species Profiles

Benefits vs. Costs

Page 10: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Why is Knowing Mature Tree Size Important?

• Placement for tree health and longevity

• Maintenance requirements

• Planning for low maintenance costs

Page 11: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Don’t We Already Know All About Tree Size?

• Different resources classify trees as small, medium, large– Same tree classified as medium or

large depending upon resource• Example:

– Utah – large tree >40 feet– California – large tree > 50-60 feet

Page 12: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Define Size: Which direction?

Tree Height Crown Diameter

Page 13: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

What Determines Size?

• Tree Height– Important under

utility lines– Vistas and view

clearance• Crown Diameter

– Site constraints• Leaf area

– Benefits

Page 14: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 14

Growth rate – how fast trees grow – what influences,

growth?

• Climate• Site• Management• Culture

Page 15: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Climate

• Climate– Precipitation– Temperature– Elevation– Wind

Page 16: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Northern Mountain & Prairie Growth Comparisons

Silver Maple

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

0 15 30 45 60 75

Years After Planting

Hei

ght (

ft)

Bismarck

Cheyenne

Ft Collins

65%

46%58%

85%

Page 17: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Silver Maple at 70

Bismarck

Cheyenne

Ft. Collins

Page 18: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Throughout the West

Page 19: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Cheyenne Climate and Environmental Factors

• Weather:– 4th windiest city– Highest incidence of hailstorms– Average 14.4 inches precipitation annually– Low humidity and higher altitude (6138 ft)

• Soils:– Alkaline– Low water-holding capacity

Page 20: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 20

What Influences Growth?

• Culture– Local mindset

• Management

Page 21: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Sweetgum

Sweetgum

02468

101214161820

0 5 10 15 20 25 30 35 40 45 50Years

Bol

e &

Tot

al H

eigh

t (m

)

Santa Monica

Modesto

Claremont

70%40% 26%

Page 22: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

LiquidambarSweetgum in three cities at age 40

Claremont Santa Monica Modesto

Page 23: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 23

Consider the tree’s needs• Big trees need more

space• As many or more

roots below ground as there are branches above

Page 24: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 24

Water access and soil

Page 25: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 25

Pruning Requirements

Page 26: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 26

Pollen and Litter

Page 27: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 27

Species Needs

Match Site Conditions

Page 28: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 28

Resources:

• Sacramento Tree Foundation– Tree Advisory Committee Tree Matrix

• Selectree (caution on sizes)– http://selectree.calpoly.edu/

• Dirr’s Manual of Woody Landscape Plants

• Sunset Western Garden• Ed Gilman’s website

– http://hort.ifas.ufl.edu/woody/selection.html

Page 29: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 29

The Right Place

Page 30: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 30

Space to grow & space for other trees

Page 31: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 31

Learning from the past – size and conflicts

Page 32: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Development and RetrofitRecent plans for 2-way residential street

Page 33: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 33

Actual Two-way Streets

Page 34: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 34

Sacramento’s Park Neighborhoods

Page 35: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 35

Close Tree Spacing (20-30 feet)

• Advantages:1. quick shade2. cathedral-like canopy3. less pruning of

drooping branches required due to the upright canopy

4. more natural, upright form develops

5. trees are less susceptible to wind damage

• Disadvantages:1. outer trees bend away

from others and are one-sided

2. if one or several die, adjacent trees may be susceptible to wind damage

3. more costly than farther spacing

Page 36: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 36

Wider tree spacing (40-60 ft)

Advantages:

1. Less costly than close spacing

2. Larger trees

3. More stable as adjacent trees die and are removed

Disadvantages:1. except for trees with an

upright habit, drooping branches need regular removal

2. large lower branches often develop, requiring removal and creating a large wound that can initiate decay

3. longer time needed to form a closed canopy

Page 37: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 37

Larger space = longer life, larger tree

Page 38: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 38

Space for Successful Trees

Page 39: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 39

The Unseen: below ground

Page 40: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Soil Volume

Center for Urban Forest Research 40

Page 41: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Soil Compaction

*Critical bulk density = maximum compaction allowed for healthy root growth

109.210195.590.585.5Very poorly graded sand

87.4103989387.4Heavy clay

87.410910498.693Lean silty clay

87.410610195.590.5Loessial silt

93.611510910497.4Lean sandy silty clay

106.1120114109102Med. Graded sandy loam

106.1128122115109Well-graded sandy loam

109.2136129122115Well-graded loamy sand

Critical Bulk Density*100%95%90%85%Soil Type

Dry bulk density of several soils (lb/ft3) at 85-100% relative compaction

Page 42: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 42

Site: Soil Compaction

• Remediation:– Replace– Cover it up (Gold

River example)– Amend it

Page 43: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Soil Texture and Structure

Soil texture refers to the distribution (%) of the different soil mineral particles - sand, silt and clay

High % clay - soils may compact and hold more waterHigh % sand - no soil compaction and limited water retention

Soil structure refers to the arrangement or aggregation of the soil particles

Page 44: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Soil pHMeasure of soil acidity or alkalinity.

Influences absorption of essential elements absorption from soil ( but not of essential elements carbon, oxygen and hydrogen from air and water).

The pH scale runs from 0 - 14 with 7 representing neutral. Below 7 is acid and above 7 is alkaline. Generally the recommended range for trees is slightly acid - 5.5 to 6.5.

Page 45: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Soil Maps

Center for Urban Forest Research 45

Page 46: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Drainage

Center for Urban Forest Research 46

Page 47: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 47

Sacramento Region’s Past

Page 48: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Site History: Natomas

In Transition…Center for Urban Forest Research 48

Page 49: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Site History: Gold RiverBefore

After

Center for Urban Forest Research 49

Page 50: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 50

Space for successful trees

Page 51: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 51

Light and Slope

Page 52: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 52

Salt

Page 53: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 53

Wind

Page 54: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 54

Conflicts

Page 55: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Vandalism “Reward Offered In Roseville High Tree Vandalism

Vandals Cut Down 21 Trees At Roseville High School”

Center for Urban Forest Research 55

Page 56: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 56

Regulations• Regulations for

PLACEMENT OF OBSTRUCTIONS ON SIDEWALKS OR STREETS

Chapter 20.40 Street Tree and Other Public Tree Regulations

• E. At street intersections, trees shall not be located within 70 feet of the intersection of curb lines (or pavement edge where curbs do not exist) when planted along arterial streets, within 50 feet when planted along collector streets, nor within 30 feet of the intersection of local streets. (City Engineer is to calculate distances.)

Page 57: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

What Citizens Value

• Santa Monica– Semi-tropical

influence– Sunshine– Ocean views

• Claremont & Modesto– Heat relief– Suburban life

Page 58: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 58

Tree + Site + Management + Education = Tree Longevity

Page 59: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Center for Urban Forest Research 59

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Page 60: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Additional Resources• Cornell:

http://www.hort.cornell.edu/uhi/outreach/recurbtree/index.html

• Trees in the Urban Landscape Site Assessment, Designand Installation by Peter Trowbridge and Nina Bassuk

• Tree Roots in the Built Environment – Centre for Ecology and Hydrology

• Reducing Infrastructure Damage by Tree Roots: A Compendium of Strategies

• Integrated Management of Landscape Trees, Shrubs, and Vines

Page 61: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Homework Photos

Page 62: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing

Homework

• Choose a photo and describe what items you would consider in choosing the right tree for the right place.

• My email: [email protected]• Snail mail: 1731 Research Park Dr.

Davis, CA 95618

Page 63: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing
Page 64: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing
Page 65: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing
Page 66: Tree Sites: Good, Bad and Ugly · Design and Installation by Peter Trowbridge and Nina Bassuk • Tree Roots in the Built Environment – Centre for Ecology and Hydrology • Reducing