Cooper

1. Living in the Shade of
Social Injustice
Greg Cooper
The Nicholas School of the Environment
Partner’s in Community Forestry Conference 2016

2. My Story
Greg Cooper, Anne Liberti & Michael Asch
• Master of Forestry and
Master of Environmental
Management Student at
the Nicholas School of the
Environment at Duke
University
• Our Master’s Project Group
began working on the
project for the City of
Durham as part of an
Urban Forest Assessment

3. Are there distributional
differences in the Canopy
Cover in the City of
Durham?
The Question

4. The Data
• 4-Band, High-Resolution (1-
meter) National Agricultural
Imagery Program (NAIP)
photos (2014)
• Census Block Groups and
demographics from 2010-2014
American Community Survey

5. Canopy Cover and Demographics

6. Overall vs. Right-of-Way

7. Block Group Canopy Cover
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 0.2 0.4 0.6 0.8 1
CanopyCover(%)
Non-White Population (%)
Total ROW Linear (Total) Linear (ROW)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 50000 100000 150000 200000
CanopyCover(%)
Median Household Income ($)
Total ROW Linear (Total) Linear (ROW)

8. Is there a better explanation?

9. When were the street trees planted?
• In Durham, street trees began to be planted in the 1930’s under
direction of the City Tree Commission
• The chairman of the Commission, Clarence Korstian,
recommended widespread planting of Willow Oaks (Quercus
phellos)
Aerial photograph of Watts Hospital in the late 1920s (Kueber 2009) 2014 NAIP Imagery

10. Home Owner’s Loan Corporation (HOLC)
• A 1930’s Federal Program
designed to slow foreclosures
• Created color coded maps to
depict real estate risk levels
with grades from A to D
• Colors classified by racial
composition  “Redlining”
(Hillier 2003), (HOLC 1937), (Michaels & Stasio 2014)

11. The Assumptions
• In Durham, the trees were planted in the 1930’s
• Trees for the most part, don’t move; people do
• Trees making up the canopy are mostly 80+ years old
• Demographics in the 1930’s had an influence on tree planting
efforts
• Using the historic redline map, modern canopy cover will reveal
where trees were planted in the 1930’s

12. The Legacy Effects
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
A B C D
CanopyCover(%)
Private ROW

13. Implications in Durham
• Durham is a gentrifying city with rapid changes in the
socioeconomic composition of neighborhoods
• The tree canopy is senescing and most of the 1930’s trees will
be removed in the next 15 years
• The current replanting strategy is to replace upon removal
• Residents can request trees through a cost-share system that
may deter lower income people
• The result will likely be an upheld unequal distribution of
street trees.

14. Does this same trend happen anywhere
else?

15. Fresno, CA
0%
5%
10%
15%
20%
25%
30%
35%
A B C D
CanopyCover(%)
Private ROW

16. Pittsburgh, PA
0%
10%
20%
30%
40%
50%
60%
70%
80%
A B C D
CanopyCover(%)
Private ROW

17. Portland, OR
0%
10%
20%
30%
40%
50%
60%
70%
A B C D
CanopyCover(%)
Private ROW

18. Saint Louis, MO
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
A B C D
CanopyCover(%)
Private ROW

19. Richmond, VA
0%
10%
20%
30%
40%
50%
60%
70%
80%
A B C D
CanopyCover(%)
Private ROW

20. Baltimore, MD
0%
10%
20%
30%
40%
50%
60%
A B C D
CanopyCover(%)
Private ROW

21. Overall Trends
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Durham Fresno Pittsburgh Portland St. Louis Richmond Baltimore
CanopyCover(%)
A B C D

22. Compared to City Averages
-1
-0.5
0
0.5
1
1.5
A B C D
CanopyCover(Standardized)

23. HOLC Zones and Modern Demographics
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
A B C D
Non-WhitePopulation(%)2010
Portland
Durham
Pittsburgh
Richmond
Fresno
Saint Louis
Baltimore

24. HOLC Zones and Modern Demographics
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
A B C D
Non-WhitePopulation(%)2010
Portland
Durham
Pittsburgh
Richmond
Fresno
Saint Louis
Baltimore
Remember
this…
…and these

25. HOLC Zones and Modern Demographics
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
CanopyCover(Standardized)
Non-White Population (%)(2010)
A
B
C
D

26. HOLC Zones and Modern Demographics
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
CanopyCover(Standardized)
Non-White Population (%)(2010)
A
B
C
D
St. Louis
Baltimore

27. HOLC Zones and Modern Demographics
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
CanopyCover(Standardized)
Non-White Population (%)(2010)
A
B
C
D
This could be
gentrification…

28. What does this all mean?
• Historical investment of green
infrastructure leaves a long
legacy within Cities
• Canopy cover in the right-of-way
reflects a social inequity in the
historic distribution of public
goods
• Cities may be implementing a
replacement planting strategy
instead of expanding plantings

29. Consequences
• People living in these historic redlined districts are
receiving significantly fewer benefits
• More severe urban heat island effects
• Poorer air quality
• Decreased mental health benefits
• Effects on property value?
• Cities that use a remove then replace practice will
perpetuate this unequal distribution

30. What’s Next?
1. Managers need to raise awareness of tree benefits to all
communities in order to increase citywide canopy cover
2. Managers need to think critically about where to plant trees
3. Managers need to think about infrastructure improvements that will
allow for a more equal distribution of street trees
4. Tree planting distribution policies should accessible for all
communities

31. More HOLC Redlining Information
Website: https://dsl.richmond.edu/panorama/redlining

32. Questions?
Contact Info:
Greg Cooper
gregory.a.cooper@duke.edu