EH Urb For. Fall 2011 - UC Davis Plants€¦ · fair or better; only 79% strip) • More...

EH Urb For.Fall 2011

Designing for Designing for Longevity

ENH 100Davis, California

Paula Peper, EcologistUrban Ecosystems & Social DynamicsPacific Southwest Research Station Pacific Southwest Research Station,

USDA Forest Service

…early tree planting …early tree planting in the west

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Imposing Imposing ourselves

on the land

1910 - on G looking north from Fifth Street, Davis, CA

41913 - 6th and E Streets, Davis, CA

Cheyenne WyomingCheyenne, Wyoming

Vegas Vegas Beginningsg g

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Las Vegas Today

Center for Urban Forest Research

7Eric Condra Photography, Paoli, IN http://www.flickr.com/photos/32838849@N08/4177942149/

Case Study: SacramentoCase Study: Sacramento

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Center for Urban Forest Research 9

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Center for Urban Forest Research 11Photo credit: Alan Grinberg

Gold RushGold Rush

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h d h lWhy Did They Plant?H lth • Health – swamp reduction

• Flood protectionFlood protection• Shade• Winter windbreaks• Food• Aesthetics

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Sacramento’s “Park Neighborhoods”: Neighborhoods :

What Worked, What Did Not?• Planting space• Spatial relations

• Sacramento’s “streetcar suburbs” p

between houses, infrastructure,

• Trees became drawing point

trees• What happened to

t ti ?

• Major planting 1860s through 90s

trees over time?• Was anything

learned?learned?14

Center for Urban Forest Research 15

Center for Urban Forest Research 16

Center for Urban Forest Research 17

Center for Urban Forest Research 18

h dWhat and How

• Plane trees and elms

• Planted 20’ apart• Planting strips –

– P. orientalis, occidentalisU glabra procera

g pcame in late 1800s

– U. glabra, procera, americana, thomasii, alata

– 2.5’ to 15’

• lawns/lots

• Palms• Redwoods

• 1938 – trees are 70 years old

• Eucalypts19

Center for Urban Forest Research 20

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CausesCauses• Improper planting• Improper planting• Improper pruning• Roots cut with street and

sidewalk development• Began systematic removals

35-50 ft spacing (until $$ p g (ran out)

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Trees in Planting Strips(<15 feet)

• Smaller the space, more treesS ll th • Smaller the space, higher mortalityS ll • Smaller space, poorer condition (94% lawn trees in (94% lawn trees in fair or better; only 79% strip)p)

• More replacement23

Sidewalk DamageSidewalk DamageSidewalk Damage - Large Trees

85.7

70

80

90

g 61.1

53.3

40

50

60

ees

Dam

agin

g

33.3

20

30

40

% o

f Tre

0

10

2-4 4-6 6-8 8-10 10-12 18-20Setback Between Tree Center and Sidewalk (ft)

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( )

Our research: Larger space = larger tree + longer life

Center for Urban Forest Research 2525Larger tree = greater benefits for longer period

Factors Affecting Tree Factors Affecting Tree Growth and Longevityg y

Still making some of the same Still making some of the same old mistakes

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Today

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Today

Coast Redwoods

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Coast Redwoods

Drainage

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l f lCycle of Failure

• Plant trees• They grow upy g p• Bad things happen• We don’t like those trees anymorey• Time passes• Same “bad” trees planted in same places Same bad trees planted in same places

again

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When things go wrong…When things go wrong…

t t th bl32

…trees get the blame

SustainabilitySustainability• Maximize and Maximize and

maintain benefits through time

• Trees may not “belong” but are top mitigators of the harsh environments we environments we create

Arborists and Landscape hArchitects --Site Assessment:

3-Step Approach3 Step Approach• Assess the site above groundg• Assess the site below ground• Select the best tree for that • Select the best tree for that

site (what does the tree need?)need?)

+

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h h lThe Right Place

Aboveground

The RightPlace

g

Belowgrounde o g ou d

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Space for successful trees

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Space for Successful Trees

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S i Species Match Site Match Site

Conditions & R i Requirements at Local Levelat Local Level

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Develop Develop Area

SpecificSpecies Species Profiles

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Local Tree Matrix• Climate adapted• Disease/pest /p

susceptibility• Soil Toleranee• Pruning needs• Branch Strengthg• Root damage• Longevityg y• Availability• BVOC emissionsBVOC emissions• Aesthetic Value 40

Tree Growth in U.S.Tree Growth in U.S.

• Started in 1998• Completed 2010• Goal

– 16 Climate zonesid i h – Provide users with

ability to import a tree inventory and yreceive info on benefits and costs

T th d t • Tree growth data 41

Tree Growth• Over 17,000• 171 species• 171 species• Overlap

– Sweetgum 10– Honeylocust 10– Silver maple 9– Callery pear 9– Green ash 8

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Comparisons and trendsComparisons and trendsSilver Maple

80

90

BIS

• Overlap– Sweetgum 10

40

50

60

70

eigh

t (ft)

BOI

CLT

CYS

FNL

– Honeylocust 10– Silver maple 9

Callery pear 9

10

20

30

40

He FNL

IND

JFK

MOD

– Callery pear 9– Green ash 8

0

10

Years After Planting

MOD

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Boise

Fort Collins

30-year old green ash

Cheyenne

Green Ash

70

80

Green Ash

67 ft

50

6062 ft

100%

57%52 ft

30

40

Gro

wth

(ft)

45 ft

55%44 ft

10

20

G 45 ft29 ft

00 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Years

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Cheyenne Boise Ft. Collins

Benefits ($) from 100 Green Benefits ($) from 100 Green Ash over 40 Years

City Energy CO2Air    

QualityStorm‐ water

Total Services

Ft C lli 86 18 14 83 201Ft. Collins 86 18 14 83 201Boise 63 12 8 56 139Cheyenne 30 6 3 28 67Cheyenne 30 6 3 28 67

units in $1,000s

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Cheyenne Climate– 4th windiest city– Highest incidence of

h il thailstorms– 14.4 in precipitation– Low humidity and higher – Low humidity and higher

altitude (6138 ft)– Alkaline soils– Low water-holding capacity

Wyoming: Not for lightweights

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LiquidambarLiquidambarSweetgum in three California cities at age 40

Pruning Effects on $$

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Sweetgum

50

60 60 ft$25$100k

30

40

50

th (f

t)

72%

$25

20

30

Gro

wt

$18 $72k

0

10

0 5 10 15 20 25 30 35 40 45 50 55 60 65

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65Years

MOD CLM

Pruning Effect on Benefits ( T )(100 Trees over 40 Years)

90Siberian Elm

70

80

90

40

50

60

wth

(ft)

74 ft

51 ft

f

52 ft

36 ft

$177k

$139k

10

20

30

Gro

w

40 ft

43 ft

21 ft31 ft

36 ft

24 ft$97k

00 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Years

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Cheyenne Boise San Fran

Tree FoliageTree Foliage• Intercept air pollution and

particulates• Intercept rainfallp• Process carbon

dioxidedioxide• Shade –heat

island and energygy

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Poor pruning• Increases maintenance cost• Turns large trees into small• Turns large trees into small• Decrease life expectancy

Largeg$213/tree

Small53

Small$44/tree

Don’t Generalize --Localize Know local conditions and how

trees respond to those trees respond to those conditions

Put the right tree in the right Put the right tree in the right city….

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Communicate

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In most In most communities

the links are not 56connected

In most In most communities

We seldom 57

We seldom communicate

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C i tCommunicateto Build Longevity into Life to Build Longevity into Life

Cycle

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NurseriesNurseries

• Planting practicesg p– Containers– Root issues– Species offerings– Cultivars

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Retailers• Stop holding stock• Expand selectionp• Reduce invasives• Promote the

benefits at less cost

Center for Urban Forest Research

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Plan Space CorrectlyR t l f 2 id ti l t tRecent plans for 2-way residential street

Actual Two-way Streets

Center for Urban Forest Research 63

Enough Space for Healthy Growth

12 ft

Red mapleSh d d t • Shaded out one side

• Imbalance• Imbalance• Top damaged by

falling ash branchfalling ash branch

Think about the Tree’s Needs

Overplanted—soil and water issues

Oak & ZelkovaBeneath Ash

Improper placement

lPlant More Trees

…with forethought

Plant Larger Growing Trees

Photo courtesy of David Roberts

Smaller Space? p

Plant smaller tree for fewer costs 70+ more benefits

Maintain Existing Trees

Photo courtesy of David Roberts

Plan Ahead & Educate

To Optimize Tree Benefits and Plan for Sustainability

• Trees become integral component of infrastructureco po e t o ast uctu e

• Masterplanning and design i t processes incorporate

appropriate space for trees from outset

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SustainabilitySustainability• Frequent interdepartmental

communication understand and communication – understand and educate each otherU d d l l • Understand local tree performance/needs/limitations

• Plant for quality not quantity• Prune to ANSI standards – with

benefits in mind• Educate educate educateEducate, educate, educate

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U b f t Urban forest sustainabilityy

i l l75

involves many players

Bottom Line: Trees are like puppiespuppies