i-Tree Eco Analyses in the GTA
Evaluating the Ecosystem Services Provided by
Our Urban Forests
Outline
• Introduction to i-Tree Eco
• Collaboration on GTA studies
• Toronto study results
• GTA study results
• Next steps
www.itreetools.org
Rationale for i-Tree Eco Studies
• USDA Forest Service i-Tree suite provides
science-based analysis and benefits
assessment tools
• Eco uses field plots, air pollution and
meteorological data to quantify urban forest
structure, environmental effects and value
• Generates baseline data that can inform
management decisions, policy and strategic
planning
GTA i-Tree
Collaboration
• 2008 TRCA joint planning session
– i-Tree experts, researchers, users from GTA and other
Ontario municipalities
• Harmonized study design & methodologies
• Potential for consolidating data in future
• Opportunity to raise profile of urban forests
• Connected UF professionals across the GTA
Toronto Study Elements
• In Toronto: i-Tree Eco “plus…”
1999
basics
Field data collection (407 plots)
i-Tree Eco data analysis (USDA)
plus
2005
extras
Measuring
land cover
change
using
orthophotos
i-Tree Hydro, Grow Out modeling
Forest & land cover change analysis
Digital land cover map
Street tree data
Automated land cover
classification using 0.6m
Quickbird satellite imagery
*Tree canopy is approximately 20%
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Goal: Achieve & maintain between 30-40%
Toronto’s
tree cover is
average
compared
to cities of
similar size.
Toronto’s urban forest is a vital city asset with a
replacement value of $7 billion.
Distribution of Tree Cover
Goal: More even/equitable distribution of tree cover
Average tree cover by ward
Average tree
cover by
neighbourhood
• Distribution of tree cover is uneven
• Data can be used to prioritize planting areas
Private
60%
City
40%
Ownership
60% located on
private property
6% located in City road
allowances
34% located in City
parks and natural
areas
Private property owners control a majority of the City’s
existing and possible tree canopy.
Land Use Affects Tree Canopy
Goal: Improve distribution & quality of tree cover
Generalized Land
Use
% Tree
Cover
% of City’s
land area
Parks
44%
11%
Open Space
27%
6%
Residential Single
24%
41%
Residential Multi
16%
6%
Institutional
15%
7%
Other (vacant)
14%
7%
Utility & Trans
12%
4%
Commercial
5%
7%
Industrial
4%
11%
Land use affects
• Distribution of forest cover
• Species composition & diversity
• Average tree size
Land/Forest Cover Change (*preliminary)
Land & Forest Cover Change: 1999-2005
50
45
46.2
47.7
Biggest change in
neighbourhoods
(-1.3%)
40
percent
35
31.4 30.6
30
25
20
20.6
19.9
15
Tree Cover
-0.7%
10
5
0
Hard surface
Soft (pervious)
surface
Forest cover
Forest Composition & Condition
Goal: High diversity, appropriate species, healthy trees
Top tree species by leaf area (m2)
16
Average tree condition (% of population)
12
10
50%
8
45%
6
40%
4
0
rw
No
ay
All Trees
Street Trees
35%
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species
percent of population
percent cover
14
30%
25%
20%
15%
10%
5%
0%
Excellent
•
•
•
Good
Fair
Poor
Good species diversity overall - 144 species & cultivars
Exception - maple & ash (41%)
Majority of trees are in good condition (exception: street trees)
Forest Size Class Structure
Goal: Maintain regeneration, reduce mortality,
increase % mid- to large-size trees
Size class distribution compared to ideal
70
60
All trees
percent of population
Suggested ideal
50
increase
40
30
20
10
0
0-15.2
15.3-30.5
30.6-45.7
45.8-61
61+
tree size class
•
•
•
Number of large trees relative to small is low
Have good regeneration, but
Large trees provide maximum benefits
Value of Ecological Services Provided
by Toronto’s Urban Forest
Annual equivalent value = $60 million+
•
•
•
•
•
Carbon storage = 1.1 million tonnes
Carbon sequestration = 46,700 tonnes
Building energy reduction = 41,200 MWH
Avoided carbon emissions = 17,000 tonnes
Air pollution removed = 1,680 metric tonnes
Hydrology
• i-Tree Hydro shows
reduction in stream flow
rates with increased forest
cover
• % impervious cover has
more significant effects
0
Bridle Path-Sunnybrooke-York Mills
Rosedale-Moore Park
High Park-Swansea
Princess-Rosethorn
The Beaches
Forest Hill South)/Forest Hill North
Lansing-Westgate
Humewood-Cedarvale
Lambton Baby Point
Cabbagetown-South St.Jamestown
Cliffcrest
Edenbridge-Humber Valley
Thistletown-Beaumond Heights
Leaside-Bennington
Runnymede-Bloor West Village
Lawrence Park North/Lawrence Park South
Scarborough Village
Humber Heights-Westmount
Blake-Jones
Kingsway South
Bedford Park-Nortown
Newtonbrook East
Bayview Village
O'Connor-Parkview
West Hill
Banbury-Don Mills
Willowdale West
South Parkdale
Casa Loma
Guildwood
Broadview North
East End-Danforth
Woodbine Corridor
Parkwoods-Donalda
StAndrew-Windfields
Crescent Town
Beechborough-Greenbrook
Oakridge
Bendale
Newtonbrook West
Thorncliffe Park
Don Valley Village
Bathurst Manor
Weston
Willowdale East
Markland Woods
Old East York
Mount Dennis
Woburn
Flemington Park
Highland Creek
Rexdale-Kipling
Victoria Village
Dufferin Grove
Agincourt North
L'Amoureaux
Kennedy Park
Tam O'Shanter-Sullivan
Henry Farm
Playter Estates-Danforth
Birchcliffe-Cliffside
Long Branch
Palmerston-Little Italy
Oakwood-Vaughan
Malvern
Pleasant View
Junction Area
Alderwood
Woodbine-Lumsden
Clairlea-Birchmount
North Riverdale
Hillcrest Village
Islington-City Centre West
Annex
Dorset Park
Wexford/Maryvale
New Toronto
Kensington-Chinatown
Church-Yonge Corridor
Downsview-Roding-CFB
Roncesvalles
Danforth Village - East York
Weston-Pellam Park
Dovercourt-Wallace Emerson-Junction
Trinity-Bellwoods
Corsa Italia-Davenport
Bay Street Corridor
Moss Park
Mimico
Keelesdale-Eglinton West
Humber Summit
Yorkdale-Glen Park
Milliken
average home sale value ($10Ks)
Average home sale value compared to tree cover in Toronto
neighbourhoods
450
400
350
Tree cover
300
Home sale value
250
Linear (Home sale value)
200
150
100
50
Other values?
Benefits of i-Tree Eco Study
for Toronto Urban Forestry

Provides baseline information and a
monitoring framework to inform
management of the urban forest.

Results support current program direction &
priorities.

Confirms that 60% of the urban forest is on
private property - supports rationale for new
policy/programs.

Provides an important information platform
to continue engaging other operating
divisions, Council and the public.
Study Elements
• Peel and York Regions
–
–
–
–
–
i-Tree Eco
Digital Land Cover Map
Priority Planting Index
Grow-out Scenarios
i-Tree Hydro
• Ajax and Pickering
– i-Tree Eco
– Aerial photo
interpretation
85
215
217
199
207
214
224
200
Canopy Cover and Leaf Area
Table 1: Canopy cover and leaf area metrics for study areas
Study Area
Canopy Cover
Leaf Area (km2)
Leaf Area Density
Mississauga
15 %
223.8
0.78
Brampton
11 %
145.2
0.54
Caledon East
29 %
13.1
2.74
Bolton
17 %
13.5
0.80
Toronto
20 %
1015
1.60
Ajax
18 %
85.6
1.27
New York City
21 %
740.6
0.93
Urban Forest Distribution
• Text
• Etc
Figure 1: Existing and possible tree canopy in Peel study areas summarized by service delivery
areas (SDA)
Priority Planting Index
• Summarized by
small geographic
unit (SGU)
• Prioritize areas of
high population
density and low
canopy cover
• Equitable distribution
of ecosystem
services
Figure 2: Priority planting index in Mississauga
summarized by small geographic unit
Distribution by Land Use
Agriculture
Existing TC
Possible TC Vegetation
Commercial
Possible TC Impervious
Industrial
Not Suitable
Institutional
Natural Cover
Open Space
Other
Residential Low
Residential Medium / High
Utilities & Transportation
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000
20,000
Hectares
Figure 3: Existing and possible tree canopy in Peel study areas summarized by land use
Species Composition - Mississauga
14
Leaf Area
12
Stems
Percent of Population
10
8
6
4
2
0
sugar maple Norway
maple
green ash
Manitoba
maple
white ash blue spruce red pine
Austrian
pine
willow spp.
white
spruce
Tree Species
Figure 4: Dominant tree species in Mississauga by percent of total leaf area and total
number of stems
• 10 most common species account for 57% percent of all trees
• 56 % of species are native to Ontario
• 58 % of all trees are planted
Species Composition - Brampton
35
Leaf Area
Percent of Total Species
30
Stems
25
20
15
10
5
0
white
spruce
European white ash
buckthorn
Norway
maple
Manitoba silver maple hawthorn
eastern blue spruce sugar maple
maple
spp.
cottonwood
Tree Species
Figure 5: Dominant tree species in Brampton by percent of total leaf area and total
number of stems
• 10 most common species account for 72% percent of all trees
• 43 % of species are native to Ontario
• 20 % of all trees are planted
Tree Size
90
Mississauga
80
Brampton
Percent of Total Stems
70
Caledon East
Bolton
60
Recommended
50
40
30
20
10
0
< 15.3 cm
15.3 - 30.5 cm
30.6 - 61 cm
> 61 cm
Diameter Class
Figure 6: Diameter class distribution of trees in Peel study areas
In Brampton a tree that is 65 cm in diameter stores 10 times more carbon and 75
times more pollution than a tree that is 11 cm in diameter
Air Pollution Removal
250
Annual Removal Value:
Mississauga: $4.8 million
Brampton: $ 3.2 million
Bolton: $110,000
Brampton
200
Volume Removed (tonnes)
Annual sulfur dioxide
removal in Mississauga =
Annual sulfur dioxide
emissions from 19,100
automobiles
Mississauga
Bolton
150
100
50
Annual PM10 removal in
Brampton = Annual PM10
emissions from 170,700
automobiles
0
CO
NO2
O3
PM10
SO2
Pollutant
Figure 7: Annual air pollution removal by trees in Peel study areas
Climate Change Mitigation
• Carbon storage = 405,000
tonnes or $11.5 million
• Annual carbon sequestration
= 19,050 tonnes or $ 544,000
• Annual residential energy
savings = $2.4 million
• Annual carbon emissions
avoided = 4,300 tonnes or
$128,000
Carbon stored in Mississauga =
annual carbon emissions from
167,400 single family homes
Carbon stored in Brampton =
annual carbon emissions from
116,000 automobiles
Next Steps
• Urban Forest Strategies and
Management Plans
–
–
–
–
Educate and engage
Protect
Maintain
Plant
• Monitoring and Research
–
–
–
–
Repeat at 10 year intervals
Evaluate trends
Anticipate future challenges
Pursue partnerships
• Regional Study
– Municipal comparisons
– Encourage provincial support
Acknowledgments
Andy Kenney
Rike Burkhardt
City of Toronto
Urban Forestry
Meaghan Eastwood
Toronto and Region Conservation Authority
Ecology Division