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
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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
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involves many players
Bottom Line: Trees are like puppiespuppies