HomeMy WebLinkAboutNB-2 - 26-149 - 1. Costa Mesa Canopy Assessment - 2/17/2026 1
CITY OF COSTA MESA
West Coast Arborists, Inc.
Anaheim, California
ATTACHMENT 1
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INTRODUCTION 3
1.1 Executive Summary 4
1.2 Costa Mesa Boundary 5
METHODOLOGY 6
2.1 Data Sources 7
2.2 Land Classification 7
2.3 Pervious vs Impervious 7
2.4 Suitable vs Unsuitable 8
KEY FINDINGS 9
3.1 City Wide 10
3.2 Council District 11
3.3 Census Group 13
3.4 Land Use 14
3.5 Parks 16
3.6 Prune District 17
TREE BENEFITS 18
4.1 Ecological Benefits 19
4.2 Tree Characteristics 20
4.3 Composition and Risk Assessment 21
RECOMMENDATIONS & CONCLUSIONS 22
5.1 Summary 23
APPENDIX 24
TABLE OF CONTENTS
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CITY OF COSTA MESA URBAN FOREST ASSESSMENT
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1: INTRODUCTION
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1.1 EXECUTIVE SUMMARY
Purpose of This Analysis
The City of Costa Mesa, located in Orange County,
California, spans approximately 15.7 square miles.
The city’s urban forest consists of trees along
streets, within parks, residential areas, and natural
spaces, forming an essential component of Costa
Mesa’s green infrastructure. These trees contribute
significantly to environmental quality, public
health, water management, economic stability, and
overall aesthetics. The primary goal of this
assessment is to provide a baseline evaluation of
Costa Mesa’s tree canopy, analyze its distribution,
and guide future strategies for urban forestry
development across various geographic areas.
Urban Tree Canopy in Costa
Mesa
The City of Costa Mesa currently has 13.88% Tree
Canopy Cover citywide. Additionally, 5.63% of the
city consists of areas suitable for future tree
planting, while 80.49% of land is unsuitable due to
existing land use constraints such as buildings,
roads, and water bodies.
The percentages for UTC and possible planting
areas are based on total land area.
•Non-canopy vegetation: 13.37%
•Soil/dry vegetation: 2.01%
•Impervious surfaces: 66.62%
•Water coverage: 0.79%
Further analysis of Costa Mesa’s urban tree
canopy reveals that 42.2% of the tree
population is deciduous, while 57.8%
consists of evergreen species. This
classification informs strategic planning
efforts for tree diversity, climate resilience,
and future planting initiatives.
Assessment Boundaries
This study evaluated Urban Tree Canopy (UTC) and
Possible Planting Areas (PPA) across multiple
geographic scales to provide relevant insights for
different stakeholders. By identifying the
distribution of tree canopy and planting
opportunities across these scales, the City can take
a more strategic and data-driven approach to
urban forestry management. The assessment
considered several geographic boundaries,
including the citywide boundary(1), six city council
districts (6), thirty-seven census tracts (37), twenty
land-use groups (20), and thirty-four designated
park areas(34). This multi-scale approach allows for
targeted decision-making to enhance Costa Mesa’s
urban forest.
1,408 Acres of Canopy Cover
13.88% Urban Canopy Cover
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5 Figure 1.1a. City of Costa Mesa’s boundary.
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Comparison
In 2024, Costa Mesa’s tree canopy cover was measured at 13.88%. While direct comparisons are limited due to differ-
ences in data collection years, figures from the CAL FIRE and USDA Forest Service’s California Urban Tree Canopy project
provide helpful regional context. Neighboring cities reported the following canopy coverage based on earlier assess-
ments: Newport Beach (12.6%), Irvine (12.7%), Santa Ana (11.6%), Huntington Beach (8.8%), and Tustin (10.1%). For
broader context, the City of Los Angeles reported an overall canopy cover of 21%, with district-level variation ranging
from 7% to 37%.
These figures indicate that many Southern California cities maintain canopy coverage around a regional average of ap-
proximately 15%. While this reflects typical conditions for the region, organizations such as American Forests recom-
mend a minimum urban canopy cover of 20% in arid and semi-arid climates to promote environmental resilience, miti-
gate urban heat, and enhance overall livability. Costa Mesa’s current canopy cover underscores ongoing progress and
helps identify opportunities for future urban forestry efforts.
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2: METHODOLOGY
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2.1 Data Sources
This assessment used high-resolution 4-band multispectral imagery from the U.S. Department of Agriculture’s
National Agriculture Imagery Program (NAIP), collected in Summer of 2024, to generate the land cover dataset.
The NAIP imagery facilitated the classification of all major land cover types, allowing for an accurate evaluation
of Costa Mesa’s urban tree canopy and potential planting areas. To improve spatial accuracy and ensure
consistency with local land use classifications, additional GIS layers provided by the City of Costa Mesa were also
integrated into the analysis.
2.2 Land Classification
Following the initial classification process, manual refinement and quality control measures were applied to
enhance the accuracy of the remote sensing products. To further refine the dataset and improve classification
precision, additional GIS layers provided by the city—including buildings, water bodies, and wetlands—were
incorporated. These supplemental data sources ensured greater spatial accuracy and alignment with local land
use characteristics.
Canopy Vegetation Soil Water
Building Road Other Shadow
2.3 Pervious vs Impervious
Land cover is classified as Pervious or Impervious based on water absorption and vegetation support.
Pervious Land allows water infiltration and includes Canopy, Vegetation, Soil, and Water, which contribute to
stormwater management and ecological health. Impervious Land prevents water absorption and includes
Buildings, Roads, and Other Impervious Surfaces, leading to increased runoff and heat retention.
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2.4 Suitable vs. Unsuitable
Planting Areas
In the context of urban forestry and strategic canopy
expansion, suitable planting areas refer to land
classifications where tree establishment is both
feasible and beneficial. These areas typically include
vegetated spaces and exposed soil that are not
obstructed by existing infrastructure. They present
optimal conditions for tree growth, allowing for
improved canopy expansion, enhanced stormwater
absorption, and increased environmental resilience.
Conversely, unsuitable planting areas are locations
where tree planting is impractical or conflicts with
existing land functions. These include impervious
surfaces such as roads, buildings, and other developed
infrastructure, as well as ecologically or functionally
restricted areas, such as water bodies, transportation
corridors, and utility easements. Additionally, certain
open spaces that might otherwise be considered plant
able—such as sports fields, school tracks, designated
recreational fields, and maintained open lawns in
parks—have been classified as unsuitable to preserve
their intended use. These areas are essential for
community recreation, athletics, and public events,
and as such, are excluded from tree planting
initiatives to maintain their functional integrity.
Of Costa Mesa’s approximately 441.9 million square
feet of total land area, 1.87% has been specifically
designated as unsuitable sports areas, while an
additional 12.31% falls under other types of
unsuitable planting area. This includes large
community spaces such as Fairview Park, the Costa
Mesa Golf Course, and Talbert Regional Park, as well
as open space associated with schools and maintained
park lawns.
By distinguishing between suitable and unsuitable
planting areas, this assessment ensures that urban
forest expansion efforts are strategically placed in
locations where they will provide the greatest
ecological, social, and economic value while
respecting existing land use priorities.
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3: KEY FINDINGS
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3.1 City Wide
This urban tree canopy assessment used a
detailed land cover classification to deter-
mine potential planting areas across Costa
Mesa. Additional data layers identifying un-
suitable planting areas, such as developed
infrastructure and designated open-use
spaces, were incorporated into the analysis.
It is important to note that this study evalu-
ates land area, to provide a more accurate
representation of possible planting opportu-
nities.
The results indicate that 61,314,990 SqFt
(13.88%) of Costa Mesa's total land area is
covered by tree canopy, while 24,897,493
SqFt (5.63%) consists of suitable planting
areas, including existing vegetation and soil
where trees could be planted. The remain-
ing 355,630,861 SqFt (80.49%) is classified
as unsuitable for planting, encompassing
impervious surfaces such as buildings, roads,
and developed infrastructure, as well as des-
ignated open-use spaces like athletic fields
and recreational areas. This analysis pro-
vides a foundation for targeted tree planting
efforts to enhance Costa Mesa’s urban for-
est while maintaining the functionality of
existing land uses.
Suitable vs Unsuitable
Classification Area SqFt %
Impervious Unsuitable - Building 144,651,840.44 32.74
Impervious Unsuitable - Other 1,534,901.56 0.35
Impervious Unsuitable - Road 148,154,875.53 33.53
Pervious Suitable - Canopy 55,825,374.74 12.63
Pervious Suitable - Soil 2,193,413.22 0.50
Pervious Suitable - Vegetation 22,704,080.40 5.14
Pervious Unsuitable - Canopy 5,489,616.23 1.24
Pervious Unsuitable - Soil 6,696,583.24 1.52
Pervious Unsuitable - Vegetation 36,365,538.24 8.23
Pervious Unsuitable - Water 3,473,248.37 0.79
Shadow 14,753,873.52 3.34
Grand Total 441,843,345.50 99.99
Land Classification
Figure 3.1a. Tree canopy (in green) distributed across the city's boundary.
Figure 3.1b. This chart illustrates the proportions of
total tree canopy, suitable planting areas, and un-
suitable planting areas within the city boundary.
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Summary
Costa Mesa currently has approximately 13.88% total tree
canopy coverage citywide, with an additional 5.63% of land
area identified as suitable for future tree planting. The
remaining 80.49% of land is considered unsuitable due to
existing uses like roads, buildings, or other hard surfaces.
While overall canopy coverage is modest, the presence of
plant-able areas indicates room for strategic expansion,
especially in zones where trees could support heat mitigation,
walkability, and neighborhood greening.
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3.2 Council District
The assessment of Urban Tree Canopy (UTC)
and Possible Planting Area (PPA) across Costa
Mesa’s six council districts highlights key differ-
ences in canopy coverage and planting poten-
tial. District 1 has the highest tree canopy at
16.34%, while District 5 has the lowest at
12.73%, with the other districts falling within a
4% range. In terms of planting opportunities,
District 1, while having a lower percentage of
PPA, possesses the most square foot of land
with 146.9 acres of plant-able space. Converse-
ly, District 4, with just 19.78 acres available, pre-
sents fewer opportunities for tree expansion.
These findings provide valuable insights for pri-
oritizing future tree planting efforts and enhanc-
ing Costa Mesa’s urban forest.
Figure 3.2a. Tree canopy distributed across Council Districts.
Suitable vs Unsuitable Percentage
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Figure 3.2b. This chart illustrates the proportions of total tree canopy, suitable planting areas, and unsuitable planting areas
within each council district .
District Canopy (Sqft) Suitable (Sqft) Unsuitable (Sqft) Total Area (Sqft)
1 18,789,743.95 6,400,041.64 51,731,990.22 115,026,391.30
2 12,009,395.78 5,790,041.72 33,642,265.02 93,479,583.35
3 9,802,908.63 5,237,125.25 27,502,277.33 75,596,229.03
4 3,464,911.76 861,709.18 10,990,825.62 25,574,421.83
5 9,770,084.24 2,475,327.11 41,432,486.49 76,767,708.46
6 7,475,158.18 4,132,294.40 27,411,033.16 55,405,142.28
Figure 3.2c. This table shows
canopy cover, suitable
planting area, and Unsuitable
planting area in relation to
each council district in square
feet.
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3.2 Council District (cont’d)
Summary
Canopy coverage varies between Costa Mesa’s six council districts, ranging between 12.73% to 16.34%. The
highest canopy coverage was found in District 1, while District 5 had the lowest. Potential planting space also
differs across districts, with the highest amount of suitable planting area in District 1, suggesting strong
opportunities for future expansion. Conversely, District 4 and 5 have the least amount of suitable space,
reinforcing the need to prioritize protection and maintenance of its existing canopy.
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3.3 Census Tracts
Tree canopy and potential planting areas were
analyzed across Costa Mesa’s 37 Census Tracts.
Canopy cover ranged notably between tracts,
with the highest concentration found in Tract
636.01 at 24.26%, and the lowest in Tract
525.01 at 3.6%. Similarly, suitable planting
areas (vegetation and soil combined) varied,
with Tract 525.01 offering the greatest
opportunity at 23.71%, while Tract 636.05 had
the least at only 1.38%. Most Census Tracts fell
within a middle range of canopy coverage,
between 10% and 15%, showing a relatively
even distribution of established trees across
neighborhoods. However, disparities in
available planting areas highlight key
opportunities for expanding canopy in under-
resourced tracts, especially where space exists
in grassy or soil-rich zones. Shadow and water
classifications were minimal across tracts and
do not significantly impact overall trends.
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Suitable vs Unsuitable Square Footage
Figure 3.3a. Shows Canopy in Costa Mesa by Census Tracts
Figure 3.3b. Graph displays the distribution of suitable planting areas, existing canopy, and unsuitable planting areas across census
tracts, sorted from highest to lowest suitable planting area. See Appendix A, Table A.1 for full dataset
Summary
Canopy cover across Costa Mesa’s Census Tracts ranged from 3.6% to 24.26%, while suitable planting
opportunities varied from 1.38% to 23.7%. The most promising tracts for expansion include Tract 525.01, due
to its high percentage of suitable space. Tracts with lower canopy and available area, such as 636.04 and
636.05, may require alternative strategies for greening efforts.
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3.4 Land Use
Tree canopy, suitable planting areas, and
land constraints were analyzed across Costa
Mesa’s land uses. Low-Density Residential
areas, covering nearly 99 million square
feet, contribute the most to the city’s cano-
py at 23.82%, while Agriculture (0.47%) and
Mobile Homes (1.34%) have minimal impact
due to their small total areas.
Medical and Right-of-Way also offer signifi-
cant planting potential, with 26.19% and
11.91% of their land suitable for canopy
growth. In contrast, Mobile Homes (98.13%
unsuitable) and Agriculture (93.72% Unsuit-
able) have limited space for new plantings.
Tree Canopy Potential
Figure 3.4a. This map shows all pervious features across Costa Mesa.
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Land Use Acres Canopy % Suitable % Unsuitable %
Low Density Res 2281.01 23.82 9.13 67.05
Golf 379.72 17.85 0.16 81.99
Medium Density Res 264.03 17.52 7.55 74.93
Medical 114.39 17.32 26.19 56.49
High Density Res 1115.17 15.78 4.47 79.75
Open Space 746.66 14.66 8.02 77.33
Senior Housing 21.92 12.38 5.58 82.04
Private School 34.51 12.12 6.59 81.29
Church 63.64 9.31 5.49 85.2
Hotel / Motel 60.46 9.24 1.3 89.46
College/University 209.80 8.59 5.19 86.22
Mixed Use 5.99 8.58 5.11 86.3
City Facilities 193.84 7.98 4.33 87.69
Vacant 20.35 7.98 3.91 88.11
Right-of-Way 83.22 6.92 11.91 81.17
Commercial 1925.91 6.8 1.9 91.29
School (non private) 288.85 6.74 0.98 92.28
Railroad 0.74 4.08 8.44 87.48
Mobile Homes 33.70 1.34 0.53 98.13
Agriculture 66.62 0.47 2.81 96.72
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Figure 3.4b. This chart illustrates the proportions of total tree canopy, suitable planting areas, and unsuitable planting areas within
the city boundary. See Appendix A, Table A.2 for the full dataset .
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Summary
Costa Mesa’s tree canopy is highest in Low-Density Residential areas (23.82%) while the Agriculture
(0.47%) and Mobile Homes (1.34%) contribute the smallest Canopy and have the highest unsuitable
planting area. Planting efforts should be focused in Medical, Right-of-Way, and Low Density Residentials
due to their high percentage of suitable planting area. Planting in Right-of-Way areas, which currently
have the lowest canopy cover, would have a strong impact on increasing Costa Mesa’s overall canopy due
to the potential for significant gains.
3.4 Land Use (cont’d)
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3.5 Parks
Urban Tree Canopy (UTC) and Possible
Planting Areas (PPA) were assessed across 34
parks in Costa Mesa, showing considerable
variation in coverage.
Canyon Park had the highest UTC at 78.1%,
while Fairview Park had the lowest at 4.48%.
Suitable planting areas also varied widely,
with Shalimar Park having the least at 0.74%,
while Costa Mesa Bark Park had the highest
at 75.36%. This doesn't prioritize Costa Mesa
Golf Course, Fairview Park, and Talbert Re-
gional Park due to unsuitable planting parks.
Parks that offer significant opportunities for
canopy expansion, based on the size of their
suitable planting areas, include TeWinkle
Park with approximately 270,000 sq ft of PPA,
and Wakeham Park with 177,000 sq ft of PPA.
These results help identify key locations for
targeted tree planting efforts to enhance
Costa Mesa’s urban forest.
Suitable vs Unsuitable
Canopy(%)
Suitable Plant-
ing Area(%)
Unsuitable
Planting Area(%)
Balearic Park 21.7 18.8 59.4
Brentwood Park 60.1 31.0 8.9
Canyon Park 78.1 17.0 4.7
Costa Mesa Bark Park 21.9 75.4 2.7
Costa Mesa Golf Course 13.6 0.0 86.4
Costa Mesa Skate Park 36.2 25.1 38.7
Costa Mesa Tennis Center 42.3 13.4 44.3
Del Mesa Park 49.2 29.5 21.3
Estancia Park 54.9 23.1 21.9
Fairview Park 4.5 0.0 95.5
Gisler Park 37.5 54.6 7.8
Harper Park 14.3 22.9 62.8
Heller Park 39.0 31.8 29.2
Jordan Park 29.4 29.2 41.4
Ketchum-Libolt Park 53.8 13.5 32.7
Lindbergh Park 11.3 23.9 64.8
Lions Park 8.8 22.6 68.7
Marina View Park 70.1 8.5 21.4
Mesa Verde Park 65.4 21.1 13.4
Moon Park 54.0 22.6 23.5
Neath Park 31.0 62.8 6.2
Paularino Park 39.8 53.3 6.9
Pinkley Park 38.8 28.5 32.7
Shalimar Park 23.0 0.7 76.3
Shiffer Park 48.6 17.8 33.6
Smallwood Park 21.8 47.2 30.9
Suburbia Park 60.8 18.4 20.8
Talbert Regional Park 6.9 0.0 93.0
Tanager Park 47.9 30.3 21.8
TeWinkle Park 29.5 23.7 46.8
Vista Park 31.6 46.2 22.3
Wakeham Park 32.3 40.7 26.9
Wilson Park 32.4 43.9 23.7
Wimbledon Park 46.5 21.5 32.0
Figure 3.5a. This map shows the canopy percentage per park.
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Summary
Urban tree canopy coverage in Costa Mesa’s parks varies significantly, ranging from just 4.5% at Fairview Park
to 78.1% at Canyon Park. While parks like Talbert Regional Park, Fairview Park, and the Costa Mesa Golf Course
are not currently prioritized for new canopy planting due to limited suitable planting areas or specialized land
use, several other parks present strong opportunities for expansion. For example, Costa Mesa Bark Park has
over 75% of its area classified as suitable for planting, and Neth Park, Paularino Park, and Gisler Park each have
more than 50% of their land available for potential tree canopy growth. These parks—many with low to moder-
ate existing canopy—offer ideal conditions for targeted planting efforts that can enhance shade, environmental
benefits, and overall park experience for the surrounding communities.
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3.6 Prune Districts
Tree canopy and planting opportunities were assessed across Costa Mesa’s 30 prune districts. Canopy
cover ranged widely, with the highest levels in District 11 (30.25%) and in starred districts 10* and 21*—areas
dominated by golf courses and parks and therefore not considered priorities for canopy expansion. The lowest
canopy appeared in Districts 17, 23, 24, and 1, all below 9%. Most districts fell within a middle range of 12% to
18% canopy.
Suitable planting areas showed similar varia-
tion. Districts 18, 15 and 5 offered the greatest gen-
uine opportunity for new trees, while highly built-
out districts such as 20, 23, and 24 had very limited
space. The starred districts (10*, 16*, 21*) are large
recreational open spaces that the City considers un-
suitable for planting, though their data is included
for reference.
Canopy & Suitable
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Summary
In an effort to increase canopy cover, it is recommended
to focus planting efforts in areas with a high to moderate
percentage of suitable planting area and low existing can-
opy. This will create the greatest impact on overall canopy
cover. For example, District 17 has a moderate amount of
suitable area and the lowest canopy cover. Trees planted
here would influence the citywide canopy more than trees
planted in District 18, which already has strong canopy
cover and the highest suitable area (excluding districts pri-
marily covered by golf courses and parks). Focusing on ar-
eas with lower canopy in relation to their suitable planting
area will lead to maximizing canopy growth impact per
tree planted.
Prune District Canopy Suitable Unsuitable
1 8.62 4.30 86.99
2 14.50 13.57 69.37
3 11.59 11.20 71.79
4 13.40 12.48 74.12
5 17.81 17.05 65.14
6 17.99 9.32 72.69
7 18.21 10.11 71.68
8 19.00 9.13 71.88
9 17.43 5.94 76.63
10* 23.43 48.73 27.84
11 30.25 15.61 54.14
12 22.75 9.79 67.46
13 15.03 5.74 79.23
14 13.95 8.04 78.01
15 13.24 16.55 70.21
16* 14.49 50.17 35.34
17 6.70 11.50 81.80
18 16.82 25.16 57.38
19 16.70 4.93 78.37
20 8.97 2.40 88.63
21* 25.90 26.51 46.74
22 12.52 5.49 81.99
23 6.97 2.72 88.92
24 7.66 3.10 88.94
25 11.91 6.47 80.01
26 10.79 8.24 80.84
27 12.62 12.69 73.82
28 12.61 8.79 74.27
29 17.48 4.68 77.11
30 8.88 4.24 86.14
Figure 3.6a. This map shows the canopy percentage per prune district.
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4: TREE BENEFITS
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Ton: short ton (U.S.) (2,000 lbs)
Monetary values $ are reported in US Dollars throughout the report except where noted. Ecosystem service estimates are
reported for trees. With Complete Inventory Projects, oxygen production is estimated from gross carbon sequestration and does
not account for decomposition. Oxygen production in Plot Inventory Projects is estimated from net carbon sequestration.
Avoided Runoff
2.327 million gallon/year ($20.8 thousand/year)
Avoided runoff quantifies the volume of stormwater that is intercepted or absorbed
by trees, preventing it from flowing directly into storm drains or local waterways.
Trees reduce surface runoff by capturing rainfall on their leaves and branches and by
increasing soil infiltration through their root systems.
Oxygen Production
1.485 thousand tons/year
Oxygen production measures the amount of oxygen generated by trees during pho-
tosynthesis. As trees convert carbon dioxide and water into glucose, they release oxy-
gen as a byproduct. This natural process is essential for maintaining breathable air
and supporting life on Earth.
4.1 Ecological Benefits
Understanding an urban forest's structure, function and value can promote management decisions that
will improve human health and environmental quality. An assessment of the vegetation structure, func-
tion, and value of the City of Costa Mesa urban forest was conducted during 2025. Data from 23221 trees
located throughout City of Costa Mesa were analyzed using the i-Tree Eco model developed by the U.S.
Forest Service, Northern Research Station.
Carbon Storage
12.85 thousand tons ($5.56 million)
Carbon storage refers to the total amount of carbon currently held within a tree's bi-
omass—its trunk, branches, leaves, and roots. As trees grow, they absorb carbon di-
oxide (CO2) from the atmosphere and store it as carbon in their tissue, helping to off-
set greenhouse gas emissions.
Carbon Sequestration
556.9 tons ($241 thousand/year)
This is the rate at which trees absorb and store carbon from the atmosphere each
year. Unlike carbon storage, which is a cumulative total, carbon sequestration is an
annual measurement that reflects the ongoing environmental service of reducing at-
mospheric CO2 levels.
Pollution Removal
12.61 tons/year ($173 thousand/year)
This value represents the amount of air pollutants that trees remove from the atmos-
phere through leaf surfaces. Common pollutants include ozone (O3), nitrogen dioxide
(NO2), sulfur dioxide (SO2), carbon monoxide (CO), and particulate matter (PM10). By
intercepting these pollutants, trees help improve air quality and support public health.
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How Costa Mesa’s City Trees Benefit the Community
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4.2 Tree Characteristics
The urban forest of City of Costa Mesa has 23,221 trees with the most common being Liquidambar. The three
most common species are Liquidambar styraciflua (8.8 percent), Pyrus calleryana (7.5 percent), and Pinus canar-
iensis (7.5 percent).
Figure 4.2a. Tree species composition in City of Costa Mesa
Figure 4.2b. Percent of tree population by diameter class (DBH—stem diameter at 4.5 feet)
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4.3 Urban Forest Composition and Risk Assessment
In City of Costa Mesa, the most dominant species in terms of leaf area are Pinus canariensis, Liquidambar
styraciflua, and Platanus racemosa. The 10 species with the greatest importance values are listed in Table 1.
Importance values (IV) are calculated as the sum of percent population and percent leaf area. High
importance values do not mean that these trees should necessarily be encouraged in the future; rather these
species currently dominate the urban forest structure.
Scientific Name Common Name
Percent
Population
Percent Leaf
Area IV
Pinus canariensis Canary island pine 7.5 14.8 22.3
Liquidambar styraciflua Sweetgum 8.8 8.7 17.5
Pyrus calleryana Callery pear 7.5 5.2 12.7
Lophostemon confertus Vinegartree 5.8 4.7 10.5
Platanus racemosa California sycamore 3.5 6.1 9.6
Fraxinus uhdei Shamel ash 2.4 4.7 7.1
Washingtonia robusta Mexican fan palm 3.5 3.4 6.9
Lagerstroemia indica Common crapemyrtle 5.5 0.9 6.4
Cupaniopsis anacardioides Carrotwood 3.1 2.7 5.7
Corymbia citriodora Lemonscented gum 1.2 4.5 5.6
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Code Scientific Name Common Name Trees at
Risk (#)
Value ($ mil-
lions)
PSHB Euwallacea nov. sp. Polyphagous Shot Hole Borer 11936 49.54
PSB Tomicus piniperda Pine Shoot Beetle 2445 20.46
SPB Dendroctonus frontalis Southern Pine Beetle 2445 20.46
SW Sirex noctilio Sirex Wood Wasp 2445 20.46
SOD Phytophthora ramorum Sudden Oak Death 2202 9.13
ALB Anoplophora glabripennis Asian Longhorned Beetle 940 4.1
SLF Lycorma delicatula Spotted Lanternfly 836 3.16
EAB Agrilus planipennis Emerald Ash Borer 620 5.8
BM Euproctis chrysorrhoea Browntail Moth 619 2.49
WM Operophtera brumata Winter Moth 444 1.52
OW Ceratocystis fagacearum Oak Wilt 443 1.56
LWD Raffaelea lauricola Laurel Wilt 399 1.61
GSOB Agrilus auroguttatus Goldspotted Oak Borer 343 1.17
LAT Choristoneura conflictana Large Aspen Tortrix 93 0.32
RPS Matsucoccus resinosae Red Pine Scale 34 0.1
DED Ophiostoma novo-ulmi Dutch Elm Disease 16 0.09
FTC Malacosoma disstria Forest Tent Caterpillar 15 0.13
ARD Armillaria spp. Armillaria Root Disease 4 0.03
TCD Geosmithia morbida Thousand Canker Disease 3 0.02
AL Phyllocnistis populiella Aspen Leafminer 1 0.01
Potential Risk of Pests
Fifty-three insects and diseases were analyzed to quantify their potential impact on the urban forest. As each
insect/ disease is likely to attack different host tree species, the implications for will vary. The number of trees at
risk reflects only the known host species that are likely to experience mortality.
For more information, see Table A.3 and Table A.4 in Appendix A
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5: RECOMMENDATIONS & CONCLUSIONS
23
5.1 Summary
Where Canopy is Lacking
Tree canopy is significantly lacking in Districts 2, 5, and 6, where canopy coverage falls
between 12.73% and 13.49%, notably below the citywide average of 13.88%. This pattern is
reflected in census tracts such as Tract 637.01 and 626.01, which show the lowest canopy
percentages citywide, ranging from 9.8% to 11.7%. High-density residential zones and
commercial corridors — such as those surrounding Harbor Boulevard, Bristol Street, and the
South Coast Plaza area — are particularly short on possible planting area. These areas contain
extensive impervious surfaces, minimal public green space, and limited planting within private
parcels, all contributing to their reduced canopy footprint limitation. Prioritize prevention
maintenance in these areas to ensure minimal loss in canopy cover.
Where the Most Opportunity Lies
The most suitable areas for new tree planting are found in Districts 3 and 6, which contain the
highest possible planting area percentages, at 6.93% and 7.46% respectively. Land use
categories with the most available planting space include Right-of-Way (11.91% suitable area),
Medical (26.2%), and Low-Density Residential (9.13%). Individual locations like TeWinkle Park
(270,000 Sqft plant-able area) and Wakeham Park (177,000 Sqft plant-able area) have the
largest amount of plant-able area within their boundaries. These spaces feature existing soil
or vegetated ground and manageable impervious barriers, making them ideal for canopy
expansion that supports cooling, aesthetics, and stormwater control.
Areas Most in Need of Protection vs. Expansion
Neighborhoods such as Eastside Costa Mesa and parts of District 1 contain large residential
lots with existing mature tree canopy — up to 16.34% in some districts — and should be
prioritized for canopy protection through proactive maintenance and enforcement of
preservation policies. In contrast, commercial zones (with only 6.8% canopy) and school
properties (averaging under 8% UTC) require focused expansion efforts. Specific targets
include public schools like Estancia High and Fairview Developmental Center, both of which
have large pervious surfaces and poor canopy coverage. These land uses offer meaningful
expansion potential with long-term environmental returns.
General Citywide Trends or Disparities
Canopy coverage in Costa Mesa is unevenly distributed, favoring low-density residential areas
(23.83% canopy) while under-serving high-density residential (15.77%) and commercial
(6.73%) zones. Large parcels such as Talbert Regional Park, Fairview Park, and the Costa Mesa
Golf Course contain extensive canopy and open space but offer limited benefit to street-level
urban canopy goals, as they do not align with equity-driven or pedestrian-oriented planting
strategies. In contrast, census tracts in central and west Costa Mesa — including Tracts 638.02
and 639.02 — show a combination of low existing canopy and high planting suitability,
identifying them as key focus areas for bridging environmental disparities. 5:
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APPENDIX A
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Table A.1
Census Canopy Suitable Planting Area Unsuitable Planting Area Total Area
639.07 6,558,877.70 2,944,861.21 47,133,271.84 56,637,010.75
638.03 3,582,526.14 1,057,422.73 24,267,416.53 28,907,365.40
638.07 4,841,509.68 2,125,886.71 21,235,993.59 28,203,389.98
639.04 3,214,109.84 1,896,370.27 21,348,668.02 26,459,148.13
639.02 3,216,234.52 1,374,398.43 21,385,044.52 25,975,677.47
626.10 2,202,204.02 1,114,325.69 21,317,953.44 24,634,483.14
638.06 5,186,084.87 1,401,095.76 17,006,288.75 23,593,469.39
639.08 3,192,094.19 1,656,214.22 15,185,185.33 20,033,493.74
636.01 4,682,432.14 920,066.26 12,244,200.31 17,846,698.72
639.03 2,059,494.52 1,070,864.18 11,562,239.57 14,692,598.28
639.05 2,789,845.78 901,784.08 10,840,905.03 14,532,534.90
633.02 1,815,464.02 1,207,381.43 11,060,096.83 14,082,942.28
631.02 2,434,339.18 624,256.77 10,812,813.82 13,871,409.76
638.02 2,663,168.33 845,398.68 9,814,274.21 13,322,841.22
636.04 892,906.14 188,918.70 11,407,312.83 12,489,137.67
637.02 980,936.03 404,354.15 10,686,574.26 12,071,864.45
639.06 1,161,444.30 330,131.23 9,834,636.35 11,326,211.88
636.05 895,803.38 156,770.51 10,267,787.69 11,320,361.59
632.01 1,364,701.41 844,214.37 8,597,788.40 10,806,704.18
637.01 1,418,207.11 349,564.65 8,968,258.79 10,736,030.55
632.02 1,458,695.31 1,015,942.40 8,125,089.04 10,599,726.75
638.05 1,400,789.14 745,663.05 8,404,155.86 10,550,608.05
633.01 927,970.64 442,359.04 8,573,519.32 9,943,849.00
638.08 1,377,498.60 368,761.71 6,267,097.67 8,013,357.98
631.03 672,123.55 465,701.63 4,621,776.06 5,759,601.24
631.01 222,715.36 117,226.43 2,314,231.92 2,654,173.71
525.01 42,919.56 282,092.43 864,056.37 1,189,068.36
636.03 47,435.76 35,208.57 865,346.60 947,990.93
741.06 10,400.72 3,377.65 243,418.50 257,196.87
634.00 275.50 6,319.95 163,683.91 170,279.36
740.04 19.37 35.39 68,545.13 68,599.89
992.40 1,001.54 - 57,962.19 58,963.74
740.06 14.28 3.88 48,022.98 48,041.14
741.07 719.93 91.05 24,509.96 25,320.94
630.10 - 154.99 18,404.52 18,559.51
740.03 5.58 259.92 5,723.51 5,989.01
630.09 - 15.51 1,086.05 1,101.56
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Row Labels Canopy Vegetation Soil Building Road Water Other Shadow Grand Total
Grand Total
51,125,340.5
7
53,820,537.9
3 7,460,119.37
140,934,220.
59
75,253,326.3
4 2,772,136.29 1,464,997.52
11,751,233.0
2
344,581,911.
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Low Density
Res
23,668,186.1
2 8,853,592.76 305,261.91
57,299,833.3
4 6,918,203.78 315,855.39 12,711.90 1,987,282.96
99,360,928.1
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Commercial 5,708,246.06 1,710,605.75 236,734.23
37,266,296.2
3
33,036,149.7
5 83,587.05 1,175,995.04 4,674,906.80
83,892,520.9
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High Density
Res 7,664,144.85 2,269,444.06 116,365.43
28,158,685.6
6 8,486,576.94 121,306.10 46,920.98 1,713,548.81
48,576,992.8
3
Open Space 4,766,557.83
16,521,426.2
6 2,939,518.00 809,980.18 6,501,300.79 356,424.38 1,436.08 627,757.29
32,524,400.8
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Golf 2,953,260.65
11,447,926.8
0 314,078.18 125,839.91 664,622.85 365,415.38 3,906.69 665,414.25
16,540,464.7
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School (non
private) 847,438.67 5,318,823.61 381,456.06 2,138,654.94 3,617,652.88 27,839.32 7,889.23 242,356.45
12,582,111.1
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Medium Den-
sity Res 2,015,468.10 954,138.10 21,187.33 6,426,462.73 1,748,679.09 21,397.93 3,133.82 310,555.60
11,501,022.7
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College/
University 784,920.99 1,428,468.05 181,949.36 2,360,618.10 4,019,946.56 24,084.35 62,169.60 276,675.29 9,138,832.31
City Facilities 673,804.41 2,369,808.69 420,798.14 806,054.30 2,685,130.91 1,158,434.47 6,218.73 323,256.39 8,443,506.04
Medical 862,948.89 1,077,231.00 484,706.90 956,069.52 1,377,716.83 950.11 4,362.32 218,811.32 4,982,796.89
Right-of-Way 251,031.33 332,057.69 283,362.82 187,472.82 2,155,425.26 256,267.94 1,418.74 158,152.55 3,625,189.14
Agriculture 13,598.66 848,056.28 1,726,226.16 13,803.51 268,484.73 16,248.49 15,544.15 2,901,961.98
Church 258,096.56 344,546.91 11,645.76 958,696.80 1,102,103.35 570.46 711.49 95,669.58 2,772,040.90
Hotel / Motel 243,244.20 73,053.30 821.01 1,255,149.97 790,196.69 17,349.80 2,229.42 251,646.62 2,633,691.01
Private
School 182,192.10 182,088.38 5,443.78 437,112.19 619,042.32 818.70 1,307.73 75,117.23 1,503,122.44
Mobile
Homes 19,622.62 7,568.36 215.30 764,550.04 520,303.02 1,718.68 121,966.98 32,202.64 1,468,147.64
Senior Hous-
ing 118,150.26 36,144.71 17,110.70 507,072.30 219,934.99 2,153.97 1,152.19 52,917.15 954,636.26
Vacant 70,714.08 30,672.42 12,056.61 344,804.88 391,838.12 365.09 10,835.30 25,103.98 886,390.48
Mixed Use 22,400.50 12,166.08 1,181.69 108,180.60 110,829.79 1,338.75 631.27 4,229.64 260,958.31
Railroad 1,313.67 2,718.73 8,882.57 19,187.69 9.96 84.31 32,196.93
Table A.2
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Table A.3
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In the following graph, the pests are color coded according to the county's proximity to the pest occurrence in the
United States. Red indicates that the pest is within the county; orange indicates that the pest is within 250 miles of
the county; yellow indicates that the pest is within 750 miles of the county; and green indicates that the pest is
outside of these ranges.
Note: points - Number of trees, bars - Replacement value
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Table A.4
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Based on the host tree species for each pest and the current range of the pest (Forest Health Technology
Enterprise Team 2014), it is possible to determine what the risk is that each tree species in the urban forest could
be attacked by an insect or disease.
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Table A.4
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Table A.4
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Table A.4
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Table A.4
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Table A.4
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Table A.4
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Note:
Species that are not listed in the matrix are not known to be hosts to any of the pests analyzed.
Species Risk:
•Red indicates that tree species is at risk to at least one pest within county
•Orange indicates that tree species has no risk to pests in county, but has a risk to at least one pest
within 250 miles from the county
•Yellow indicates that tree species has no risk to pests within 250 miles of county, but has a risk to at
least one pest that is 250 and 750 miles from the county
•Green indicates that tree species has no risk to pests within 750 miles of county, but has a risk to at
least one pest that is greater than 750 miles from the county
Risk Weight:
Numerical scoring system based on sum of points assigned to pest risks for species. Each pest that could
attack tree species is scored as 4 points if red, 3 points if orange, 2 points if yellow and 1 point if green.
Pest Color Codes:
•Red indicates pest is within Orange county
•Red indicates pest is within 250 miles county
•Yellow indicates pest is within 750 miles of Orange county
•Green indicates pest is outside of these ranges