1.
Does Urban Tree Planting
Cause Gentrification?
Abigail Kaminski
Social Science Information Specialist
Pacific Northwest Research Station, USDA Forest Service
Partners in Community Forestry Conference
11/17/2022
Donovan, G. H., Prestemon, J. P., Butry, D. T., Kaminski, A. R., Monleon, V. J. (2021).
The politics of urban trees: Tree planting is associated with gentrification in Portland,
Oregon. Forest Policy and Economics. 124.

2.
Overview
• Urban trees
• Gentrification
• Value of trees
• Neighborhood desirability
• Results
• Discussion
Research objective:
Assess whether tree planting is
associated with gentrification
in Portland, Oregon.
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3.
Forest Park, Portland OR. Image credit: David Dayan
Pier Park, Portland OR. Image credit: Abigail Kaminski
Milwaukee Street lined with Mature Ash Trees by usfs_Eastern_Region is
marked with Public Domain Mark 1.0.
Young street tree in Portland, OR. Image credit:
Abigail Kaminski
Flowering street tree, Portland OR. Image credit:
Abigail Kaminski
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4.
Urban Trees
Costs include:
• Planting and pruning
• Street debris clean-up
• Infrastructure repair
• Liability
Benefits include:
• Air quality (Nowak 2006)
• Stormwater management
(Berland et al. 2017)
• Reduce heat island effect
(Rahman et al. 2020)
• Crime rate reduction (Kuo
and Sullivan 2001)
• Improved health (Donovan
et al. 2011; Wolf et al.
2020)
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5.
An influx of more affluent
residents causing a change in the
demographic composition and
character of a neighborhood
Gentrification
Many ways to define. • New types of businesses
• Influxes of investment
• Increased property values &
rents
• Displacement of established
communities
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6.
Green Gentrification
• Green space is often
distributed unequally across a
city
• Greening efforts make
neighborhoods more
desirable
• Housing and other costs may
increase
• Major changes to natural
amenities
• Does this apply to tree
planting, too?
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7.
Measuring gentrification
• No one definition and no
one measurement
• Housing sales as an
indicator
Image credit: Suburban: house 6 by Tracey Saxby, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0 )
F O R
S A L E
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8.
Hedonic method
Image credits: Suburban: house 6 by Tracey Saxby, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
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What is the value of a tree?
• Portland, Oregon
• Homeowners
• (Donovan and Butry 2010)
• Street trees
• Street trees increase sales price
• Spillover effects to neighbors
• Cost of trees is homeowner
responsibility
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Image credit: Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0

10.
What is the value of a tree?
• Portland, Oregon
• Renters
• (Donovan and Butry 2011)
• Street and yard trees
• Houses with trees have higher
rents
• Street trees have higher
premium than yard trees
Image credit: Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
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Neighborhood-level process
+$$$
Image credits: Suburban: house 6 by Tracey Saxby, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
"035364: Carliol Street Newcastle upon Tyne Dept of Environmental Health c.1935" by Newcastle Libraries is marked with Public Domain Mark 1.0.
"panorama architecture Gantoise" by angelobrathot is marked with Public Domain Mark 1.0.
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Tree planting in Portland, OR
Non-profit planting trees in
Portland for 30 years
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• 1990 – 2019
• Street trees & yard trees
• Year planted
• Census tracts
Image credit: Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
Restoration: Planting trees by Tracey Saxby, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0

13.
What makes a neighborhood desirable?
NEIGHBORHOOD
DESIRABILITY
Green Space
Historic
Landmarks
Light Rail
Characteristics of
Houses in Area
Tree planting
Tree cover
National Register
of Historic Places
Mean size of houses
Mean age of houses
Light rail stops
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14.
Historic landmarks (+)
Light rail stop (+)
Significant about 2 years before
opening
Results
Mean age of houses (+)
Mean size of houses (+)
Tree cover (+)
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15.
Tree planting is
associated with a
modest increase in
neighborhood-level
house prices but
not until at least 6
years after planting.
<1 year
since planting
6 years
since planting
12 years
since planting
Image credit: Geoffrey Donovan
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16.
6 years
8 years
9 years
11 years
12 years
↑ $119
↑ $150
↑ $180
↑ $170
↑ $265
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Image credit: Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0
Neighborhood price premium

17.
Street trees vs. Yard trees
• Street trees:
• Similar results as combined
model
• Yard trees:
• Larger effect than combined
model
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Image credit: Quercus coccinea (Scarlet Oak) by Dylan Taillie, Integration and Application Network (ian.umces.edu/media-library) is licensed under CC BY-SA 4.0

18.
Comparing to other neighborhood
characteristics
• ↑ Increase in neighborhood price premium
associated with:
• ↑ Increase in median household income
• ↑ Increase in percent non-Hispanic white population
• ↑ Increase in percent of owner-occupied housing
• ↓Decrease in percent of residents without a high school
diploma
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19.
Discussion
• Limitations of our study
• Not causal link between tree planting and
gentrification
• We used one metric of gentrification
• Tree planting data isn’t exhaustive
• Tree health over study period not considered
• Results specific to study area
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20.
Summary
• Tree planting is associated with
measures of gentrification, but the
overall effect is modest.
• The effect of tree planting gets larger
as trees age.
• Yard trees may have a larger impact
than street trees (maybe because
they are larger species)
• Our results are specific to Portland,
Oregon.
Tree planting is a cost-effective
way of improving the
environment of underserved
neighborhoods.
However, it would be
counterproductive if such efforts
displaced the residents that tree-
planting programs were
designed to benefit.
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21.
References
Berland, A., Shiflett, S. A., Shuster, W. D., Garmestani, A. S., Goddard, H. C., Herrmann, D. L., Hopton, M. E. (2017). The role of trees in
urban stormwater management. Landscape and Urban Planning. 162. 167 – 177.
Donovan, G. H., Michael, Y. L., Burty, D. T., Sullivan, A. D., Chase, J. M. Urban trees and risk of poor birth outcomes. (2010). Health &
Place. 17(1). 390 – 393.
Donovan, G.H., Butry, D.T. (2010). Trees in the city: valuing street trees in Portland, Oregon. Landscape and Urban Planning. 94. 77–83.
Donovan, G.H., Butry, D.T., (2011). The effect of urban trees on the rental price of single family homes in Portland, Oregon. Urban Forestry
& Urban Greening 10. 163–168.
Kuo, F. E., Sullivan, W. C. (2001). Environment and crime in the inner city: Does vegetation reduce crime? Environmental Behavior. 33.
343 – 367.
Nowak, D. J., Crane, D. E., & Stevens, J. C. (2006). Air pollution removal by urban trees and shrubs in the United States. Urban forestry
& urban greening, 4(3-4), 115-123.
Rahman, M. A., Stratopoulos, L. M. F., Moser-Reischl, A., Zölch, T., Karl-Heinz, Häberle, Rötzer, T., Pretzsch, H., Pauleit, S. (2020). Traits
of trees for cooling urban heat islands: A meta-analysis. Building and Environment. 170.
Schroeder, H., Flannigan, J., Coles, R. (2006). Residents’ Attitudes Toward Street Trees in the UK and U.S. Communities. Arboriculture
& Urban Forestry. (2006). 32(5): 236 – 246.
Wolf, K. L., Lam, S. T., McKeen, J. K., Richardson, G. R. A., van den Bosch, M., Bardekjian, A. C. (2020). Urban Trees and Human Health:
A Scoping Review. International Journal of Environmental Research and Public Health. 17.
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22.
Data used in analysis
based on time since
planting
• Not full 1990 – 2019
dataset
• 6 years since planting:
• House sales from 1996 –
2019
• Houses sold in 1996 paired
with trees planted in 1990
• 12 years since planting:
• House sales from 2002 –
2019
• Houses sold in 2002 paired
with trees planted in 1990
<1 year
since planting
6 years
since planting
12 years
since planting
Image credit: Geoffrey Donovan
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23.
lnPi,j = β0 + β1Ln(House area)i,j + β2Ln(Lot area)i,j
+ β3House agei,j + β4Bathroomsi,j + β5-7Season of
salei,j + β8-14Heating systemi,j + uj + ei
Neighborhood Desirabilityi,j = β0 + β1Trees
Plantedi,j + βX + uj + ei,j
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Thank you!
Abigail Kaminski:
Abigail.Kaminski@usda.gov
Geoffrey Donovan:
Geoffrey.Donovan@usda.gov
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