United States

Department of 

Agriculture

Forest Service

Northern 

Research Station

Resource Bulletin 

NRS-84

Urban Trees and Forests of 

the Chicago Region

David J. Nowak

Robert E. Hoehn III

Allison R. Bodine

Daniel E. Crane

John F. Dwyer

Veta Bonnewell

Gary Watson
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August 2013 Email: nrspubs@fs.fed.us

Abstract

An analysis of trees in the Chicago region of Illinois reveals that this area has about 

157,142,000 trees with tree and shrub canopy that covers 21.0 percent of the region. 

The most common tree species are European buckthorn, green ash, boxelder, black 

cherry, and American elm. Trees in the Chicago region currently store about 16.9 

million tons of carbon (61.9 million tons CO2) valued at $349 million. In addition, 

these trees remove about 677,000 tons of carbon per year (2.5 million tons CO2/year) 

($14.0 million/year) and about 18,080 tons of air pollution per year ($137 million/year). 

Chicago’s regional forest is estimated to reduce annual residential energy costs by 

$44.0 million/year. The compensatory value of the trees is estimated at $51.2 billion. 

Various invasive species, insects and diseases, and lack of adequate regeneration 

of certain species currently threaten to change the extent and composition of this 

forest. Information on the structure and functions of the regional forest can be used 

to inform forest management programs and to integrate forests into plans to improve 

environmental quality in the Chicago region. These findings can be used to improve 

and augment support for urban forest management programs and to integrate urban 

forests within plans to improve environmental quality in the Chicago region.

Cover Photo

Photo by Antonio Perez, Chicago Tribune, used with permission.

Manuscript received for publication 10 August 2012

Acknowledgments

Thanks go to Gerard T. Donnelly, Ph.D., President and CEO of The Morton 

Arboretum for commissioning and supporting this project; Beth Corrigan, Angela 

Hewitt, and Edith Makra for project coordination; Al Zelaya for outstanding support 

of i-Tree software; Jeanette McBride for map support; Cherie LeBlanc Fisher for 

training and procedure consultation; Northeastern Area State and Private Forestry for 

substantial funding; and to our data collection team: Amy Aghababian, Sarah Akinde,

Greg Deresinski, Alec Edwards, Guy Fischer, Eric Injerd, Lisa Maenpaa, Carrie 

Tauscher, James Van Someren, Philip Watson, and Evelyn Wisniewski.
Urban Trees and Forests of the Chicago Region

David J. Nowak

Robert E. Hoehn III

Allison R. Bodine

Daniel E. Crane

John F. Dwyer

Veta Bonnewell

Gary Watson

The Authors

DAVID J. NOWAK is a research forester and project leader with the U.S. Forest 

Service’s Northern Research Station at Syracuse, New York.

ROBERT E. HOEHN III is a forester with the U.S. Forest Service’s Northern 

Research Station at Syracuse, New York.

ALLISON R. BODINE is a research urban forester with the Davey Institute at 

Syracuse, New York.

DANIEL E. CRANE is an information technology specialist with the U.S. Forest 

Service’s Northern Research Station at Syracuse, New York.

JOHN F. DWYER is a research associate with The Morton Arboretum in Lisle, Illinois.

VETA BONNEWELL is a data specialist with The Morton Arboretum in Lisle, Illinois.

GARY WATSON is head of research with The Morton Arboretum in Lisle, Illinois.
 Morton Arboretum, used with permission.
CONTENTS

 Executive Summary 1

 i-Tree Eco Model and Field Measurements 2

 Tree Characteristics of the Regional Forest 5

 Urban Forest Cover and Leaf Area 12

 Air Pollution Removal by Urban Trees 14

 Carbon Storage and Sequestration 15

 Trees Affect Energy Use in Buildings 18

 Structural and Functional Values 19

 Street Tree Populations 20

 Variation in Urban Forest Structure by County 22

 Changing Species Composition and Size Structure 26

Potential Insect and Disease Impacts 28

Potential Loss of Ash Species 31

European Buckthorn Prominence 32

 Conclusion 36

 Appendices 37

 References 98
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1

EXECUTIVE SUMMARY

Trees in the Chicago regional forest can contribute signifi cantly to human health and 

environmental quality. Th e urban forest resource comprises all trees, both within and 

outside forested stands. Th is can include boulevard trees, trees planted in parks, and 

trees that naturally occur in public rights-of-way, as well as trees planted on private 

or commercial properties. Relatively little is known about this forest resource, what it 

contributes to society and the economy, and the value of its contributions.

Th e trees and forests of the Chicago region in Illinois are important natural resources 

that contribute substantially to the environment, human health, and quality of life of 

the region. Th e value of these contributions are posed to increase in the future, but at 

the same time mounting threats from insects, disease, invasive species, climate change, 

development, and changing infrastructure could limit the contributions. Addressing 

these future challenges is complicated by the diversity of the region’s trees and 

forests, their dynamic character, the fragmented ownership pattern, and the lack of 

comprehensive information about the resources. To address these critical information 

needs, Th e Morton Arboretum undertook an assessment of the Chicago region’s 

urban forests in collaboration with the U.S. Forest Service. Th is assessment seeks to 

inform approaches for urban forest management that will inspire the citizens of the 

region to plant and protect trees and improve the vigor of the urban forest. Th e data 

reported illustrates important trends and strives to convey the importance of trees to 

constituencies that may not principally value trees but value the services they provide. 

Targeting information on the value of the urban forest fosters regional collaboration 

among the many stakeholders.

To better understand the urban forest resource and its value, the U.S. Forest Service, 

Northern Research Station, developed the Urban Forest Eff ects (UFORE) model, 

which is now known and distributed as i-Tree Eco (www.itreetools.org). Information 

derived from this advances the understanding of the forest resource; improves forest 

policies, planning and management; provides data to support the potential inclusion 

of trees within environmental regulations; and determines how trees aff ect the 

environment and consequently enhance human health and environmental quality in 

urban and rural areas.

Th e i-Tree Eco model quantifi es forest structure, function, and values. Forest structure 

is a measure of various physical attributes of the vegetation, including tree species 

composition, number of trees, tree density, tree health, leaf area, biomass, and species 

diversity. Forest functions, which are determined by forest structure, include a wide 

range of environmental and ecosystem services such as air pollution removal and cooler 

air temperatures. Forest values are an estimate of the economic worth of the various 

forest functions.

The trees and forests 

of the Chicago region 

in Illinois are important 

natural resources that 

contribute substantially 

to the environment, 

human health, and 

quality of 

life of the 

region.

Photo by ©Mark Donnelly
2

Table 1.—Summary of urban forest features, Chicago region, 2010

Feature Measure

Number of trees 157,142,000

Tree and shrub canopy cover 21.0%

Tree cover 15.5%

Most dominant species by:

 Number of trees European buckthorn, green ash, boxelder, black cherry, 

American elm

 Leaf surface area silver maple, boxelder, green ash, European buckthorn, 

black walnut

Trees < 6 inches diameter (%) 73.3%

Pollution removal

Trees 18,080 tons/year ($137 million/year)

Trees and shrubsa 24,170 tons/year ($183 million/year)

VOC emissions 11,976 tons/year

Carbon storage 16.9 million tons ($349 million)

Carbon sequestration 677,000 tons/year ($14.0 million/year)

Building energy reduction $44.0 million/year

Reduced carbon emissions $1.3 million/year

Compensatory value $51.2 billion

a Shrub removal estimate is approximate as shrub leaf area parameters were not measured.

To determine the vegetation structure, functions, and values of trees in the Chicago 

region, a vegetation assessment was conducted during the summer of 2010. For this 

assessment, 2,076 one-tenth-acre fi eld plots were sampled and analyzed using the 

i-Tree Eco model. Th is report summarizes results of this assessment (see Table 1).
3

I-TREE ECO MODEL AND FIELD MEASUREMENTS

To help assess the regional forest, data from 2,076 fi eld plots located throughout the 

Chicago region were analyzed using the Forest Service’s i-Tree Eco (formerly UFORE) 

model.1

 Th is region was defi ned as the city of Chicago and the seven counties 

surrounding it: Cook, DuPage, Kane, Kendall, Lake, McHenry, and Will (Figure 1). 

In the analysis, data is presented for the region as a whole as well as the city of Chicago 

and each of the counties. Cook County is referred to as suburban Cook because it 

excludes the Chicago city area to avoid redundancy.

Th ough forests have many functions and values, only a few of these attributes can be 

assessed due to current limited ability to quantify all of these values through standard 

data analyses. i-Tree Eco uses standardized fi eld data from randomly located plots and 

local hourly air pollution and meteorological data to quantify forest structure (e.g., 

species composition, tree density, tree health, leaf area, leaf and tree biomass, species 

diversity, etc.) and its numerous eff ects, including: 

• Amount of pollution removed hourly by the forest, and its associated percent 

air quality improvement throughout a year. Pollution removal is calculated 

for ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide, and particulate 

matter (<10 microns)

• Total carbon stored and net carbon annually sequestered by the forest

• Eff ects of trees on building energy use and consequent eff ects on carbon 

dioxide emissions from power sources

• Compensatory value of the forest as well as the value of air pollution removal 

and carbon storage and sequestration

• Potential impact of infestations by insects/diseases such as Asian longhorned 

beetle, gypsy moth, emerald ash borer, oak wilt, or Dutch elm disease

For more information go to www.itreetools.org

Figure 1.—Chicago region, 2010. 

The striped area is the city of Chicago.

Field Survey Data

Plot Information

• Land use

• Percent tree cover

• Percent shrub 

cover

• Percent plantable

• Percent ground 

cover types

• Shrub species/

dimensions

Tree parameters

• Species

• Stem diameter

• Total height

• Height to crown base

• Crown width

• Percent foliage 

missing

• Percent dieback

• Crown light 

exposure

• Distance and 

direction to 

buildings from trees
4

Since the city of Chicago was analyzed in 20072

, the most recent study focused on 

analyzing the seven counties outside of Chicago with 0.1-acre plots established as a 

randomized grid within each county. Th e plots were divided among the following 

counties: suburban Cook (Cook County exclusive of Chicago) (203 plots, 17.9 percent 

of area), DuPage (192 plots, 8.2 percent of area), Kane (184 plots, 12.9 percent of area), 

Kendall (187 plots, 7.9 percent of area), Lake (188 plots, 11.5 percent of area), McHenry 

(188 plots, 15.0 percent of area), and Will (189 plots, 20.9 percent of area). Results from 

the 2007 Chicago city plots were added to the most recent study plots based on land use 

classifi cations3

 for the Chicago region (city of Chicago = 745 plots, 5.7 percent of area).

All plots were distributed among the following land uses (Figure 2):

• Residential (751 plots, 30.1 percent of area) includes areas with single and 

multiple family dwellings.

• Agriculture (450 plots, 32.9 percent) includes row crops, pasture, and nurseries.

• Open space (419 plots, 23.0 percent) includes open land primarily for 

conservation such as forest preserves, private hunting clubs and campgrounds, 

vacant forest and grassland, wetlands and open water such as lakes and rivers. 

Open water is 20 percent of the area of open space land use and 4.6 percent of 

the total area.

• Commercial/transportation/institutional (CTI) (456 plots, 14.0 percent) is a 

group of less prevalent land uses. Commercial land use (57 percent of the group 

by area) includes manufacturing, mining, and industrial parks. Transportation 

land use (19 percent of the group by area) includes major highways and 

associated facilities, aircraft transportation, communications and utility, and 

waste facilities. Institutional land use (24 percent of the group by area) includes 

medical, educational, religious, and government facilities.

Field data were collected by the Morton Arboretum personnel through a project known 

as the “Tree Census.” Data collection took place during the leaf-on season to properly 

assess tree canopies. Within each plot, data collected included ground and tree cover, 

shrub characteristics, and individual tree attributes of: species, stem-diameter at breast 

height (d.b.h.; measured at 4.5 ft.), tree height, height to base of live crown, crown 

width, percentage crown canopy missing and dieback, and distance and direction to 

Morton Arboretum, used with permission

Photo by ©Mark Donnelly

Photo by ©Mark Donnelly

Morton Arboretum, used with permission

Figure 2.—Land use distribution, 

Chicago region, 2010, for 

inventoried plots.

Agriculture 

32.9% 

Residential 

30.1% 

Open Space 

23.0%

CTI 

14.0%

Morton Arboretum, used with permission
5

residential buildings.4

 Trees were defi ned as woody plants with a diameter greater 

than or equal to 1 inch at breast height (d.b.h.). Some species that would commonly 

be considered shrubs were classifi ed as trees for this analysis if they met the 1-inch 

minimum diameter requirement. Measurements of crown dimensions and percentage 

crown canopy missing and dieback were used to assess leaf surface area of trees.

During data collection, trees sampled in the inventoried plots were identifi ed to the 

most specifi c taxonomic classifi cation possible. In this analysis, there are trees that have 

been identifi ed to the species or genus level. In the event that a tree was identifi ed to 

the species level (e.g., Siberian elm) and other trees of the same genus were sampled, the 

genera classifi cation (e.g., elm) includes all sampled trees of the genus that could not 

be classifi ed to a specifi c species level. Trees designated as “hardwood” or “softwood” 

include the sampled trees that could not be identifi ed as a more specifi c species or genera 

classifi cation. Since hardwood and softwood are species groups that comprise multiple 

species and genera, they are not included in the analysis of the most common species. In 

this report, tree species, genera, or species groups are hereafter referred to as tree species.

To calculate current carbon storage, biomass for each tree was estimated using forestderived equations5

 from the literature and fi eld measured tree data. Since open-grown, 

maintained urban trees tend to have less biomass than predicted by those forestderived biomass equations, we adjusted for this diff erence by multiplying by 0.8.5

 No 

adjustment was made for trees found in natural stand conditions. Tree dry-weight 

biomass was converted to stored carbon by multiplying by 0.5.5

To estimate the gross amount of carbon sequestered annually, average annual diameter 

growth from appropriate genera, diameter class, and tree condition was added to the 

existing tree diameter (year x) to estimate tree diameter and carbon storage in year x+1.

Air pollution removal estimates are derived from calculated hourly tree-canopy resistances 

for ozone, and sulfur and nitrogen dioxides based on a hybrid of big-leaf and multi-layer 

canopy deposition models.6, 7 As the removal of carbon monoxide and particulate matter 

by vegetation is not directly related to transpiration, removal rates (deposition velocities) 

for these pollutants were based on average measured values from the literature8, 9 that were 

adjusted depending on leaf phenology and leaf area. Particulate removal incorporated a 50 

percent resuspension rate of particles back to the atmosphere.10

Eff ect of trees on residential building energy use was calculated based on procedures11

using distance and direction of trees from residential structures, tree height, and tree 

condition data.

Compensatory values were based on valuation procedures of the Council of Tree 

and Landscape Appraisers, which uses tree species, diameter, condition, and location 

information.12

To learn more about i-Tree Eco methods1,13 visit: http://nrs.fs.fed.us/tools/ufore/, or 

www.itreetools.org.

Morton Arboretum, used with permission
6

TREE CHARACTERISTICS OF THE REGIONAL FOREST

Th e Chicago region has an estimated 157,142,000 trees (standard error [SE] of 

10,244,000). Tree and shrub cover in the Chicago region is estimated to be 21.0 

percent.14 Based on the fi eld data in conjunction with photo-interpretation, tree cover 

in the Chicago region is estimated to be 15.5 percent.14

Th e fi ve most common species in the regional forest were European buckthorn (28.2 

percent), green ash (5.5 percent), boxelder (5.5 percent), black cherry (4.9 percent), 

and American elm (3.4 percent) (Figure 3). Th e 10 most common species account for 

59.0 percent of all trees; their relative abundance is illustrated in Figure 3. In total, 

161 tree species were sampled in the Chicago region; these species and their relative 

abundance are presented in Appendix I. See Appendix II for more information on 

species distribution by land use and area.

Th e overall urban tree density in the Chicago regional forest is 60.4 trees/acre. Th e 

highest density of trees occurs in open space (134.2 trees/ac), followed by residential 

(69.3 trees/ac) and CTI land (42.5 trees/ac) (Figure 4). Land uses that contain the 

most trees are open space (51.1 percent of tree population), followed by residential 

areas (34.6 percent) (Figure 4). More information on the tree species in each land use 

is given in Appendix II and III.

Total leaf area is greatest in residential (46.6 percent of total tree leaf area) and open 

space (40.3 percent) land use (Figure 5). Leaf area is a measure of leaf surface area (one 

side). Leaf area index (LAI) is a measure of the total leaf surface area (one side) divided 

by land area. As each land use has a diff erent land area, LAI standardizes the canopy 

depth on an equal area basis. Higher LAIs indicate a greater leaf surface area per acre 

of land. Land uses that have the highest LAI are open space (1.9) and residential (1.7) 

(Figure 5).

Figure 3.—Urban tree species composition, Chicago region, 2010.

European buckthorn 

28.2% 

Green ash 

5.5% 

Boxelder 

5.5% 

Black cherry 

4.9% 

American elm 

3.4% 

Sugar maple 

2.8% 

White ash 

2.6% 

Amur honeysuckle 

2.1% 

Silver maple 

2.0% 

Northern red oak 

2.0% 

other species 

41.0% 

The five most common 

species in the Chicago 

regional forest were 

European buckthorn, 

green ash, boxelder, 

black cherry, and 

American elm.
7

The overall urban 

tree density in the 

Chicago regional 

forest is 60.4 trees 

per acre.

Figure 4.—Number of trees and tree density by land use, Chicago region, 2010.

0

20

40

60

80

100

120

140

0

10

20

30

40

50

60

70

80

90

Open Space Residential CTI Agriculture

Density (trees per acre) 

Number of Trees (millions) 

Land Use 

Number of trees

Density

Figure 5.—Total leaf area and leaf area index by land use, Chicago region, 2010.

0

0.5

1

1.5

2

2.5

0

200

400

600

800

1,000

1,200

1,400

1,600

Residential Open Space CTI Agriculture

Leaf Area Index (LAI) 

Leaf Area (thousand acres) 

Land Use 

Leaf area

Leaf area index

Trees with diameters less than 6 inches account for 73.3 percent of the population 

(Figure 6). Trees in this diameter class also contain 21.6 percent of the total leaf area. 

Most of the common trees are relatively small, with the exception of silver maple and 

northern red oak (Figure 7). Trees that have diameters greater than 18 inches account 

for 4.8 percent of the tree population, but comprise 32.7 percent of the total leaf 

area. Th ough these large-diameter trees are a small percentage of the tree population, 

they are an important part of the regional forest in the Chicago region. Leaf area 

has a strong correlation with benefi ts that the trees produce for the ecosystem, such as 

pollution removal.
8

Figure 6.—Percent of total population and leaf area by diameter class, Chicago 

region, 2010. 05

10

15

20

25

30

35

40

45

50

1-3 3-6 6-9 9-12 12-15 15-18 18-21 21-24 24-27 27-30 30+

Proportion of Total Population (percent) 

Diameter Class (d.b.h. in inches) 

Leaf area

Abundance

Figure 7.—Percent of species population by diameter class for 10 most 

common tree species, Chicago region, 2010.

(uropean buckthorn

Green ash

Boxelder

Black cherry

American elm

Sugar maple

White ash

Amur honeysuckle

Silver maple

Northern red oak

0

10

20

30

40

50

60

70

80

1-3

3-6

6-9

9-12

12-15

15-18

18-21

21-24

24-27

27-30

30+

Species 

Species Population (percent)

Diameter Class 

(d.b.h. in inches) 
9

Tree populations vary between the small diameter (less than 3 inches diameter) and 

large diameter trees (greater than 18 inches diameter). Th e 10 most common species of 

small diameter trees are European buckthorn (43.4 percent of trees in diameter class), 

green ash (4.6 percent), boxelder (4.0 percent), amur honeysuckle (3.6 percent), sugar 

maple (3.6 percent), black cherry (3.3 percent), American elm (2.6 percent), white ash 

(2.4 percent), mulberry species (1.5 percent), and honeysuckle species (1.5 percent). 

Th e 10 most common species of large diameter trees are silver maple (12.7 percent of 

trees in class), bur oak (11.9 percent), white oak (11.4 percent), eastern cottonwood (8.2 

percent), boxelder (6.8 percent), northern red oak (6.2 percent), green ash (4.9 percent), 

honeylocust (3.4 percent), Norway maple (3.2 percent), and Siberian elm (2.9 percent). 

Green ash and boxelder are are among the 10 most common small diameter trees and the 

10 most common large diameter trees (Figures 8-9).

Two of the 10 most common small diameter trees are classifi ed as invasive: European 

buckthorn and amur honeysuckle. Siberian elm is one of the 10 most common large 

diameter trees and is also classifi ed as invasive. Several of the most common large diameter 

tree species had very few small diameter trees, which is an indication that there is likely 

not enough regeneration of these species to sustain the current species population through 

time. Bur and white oak stand out as having a greater proportion of large trees than small 

diameter trees. Mean and median stem diameter by species are presented in Appendix I.

Th e region’s forests are a mix of native tree species that existed prior to the development 

of the region and exotic species that were introduced by residents or other means. 

Th us, these forests often have a tree diversity that is higher than the surrounding native 

landscapes. Increased tree diversity can minimize the overall impact or destruction by a 

species-specifi c insect or disease, but the increase in the number of exotic plants can also 

pose a risk to native plants if exotic species are invasive and out-compete and displace 

native species. In the Chicago region, about 46.6 percent of the trees are native to Illinois. 

Trees with a native origin outside of North America are mostly from Eurasia (32.2 

percent of the trees) (Figure 10).

Morton Arboretum, used with permission

Figure 8.—Percent of diameter 

class (<3 or >18 inches) 

population made up by the most 

common tree species in those 

classes, Chicago region, 2010. 0

5

10

15

20

25

30

35

40

45

Diameter Class Population (percent) 

Species 

< 3 inches

> 18 inches

Diameter Class (d.b.h.) 
10

Figure 9.—Number of trees 

in diameter class (<3 or >18 

inches) made up by the most 

common tree species in those 

classes, Chicago region, 2010 0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

Number of Trees (thousands) 

Species 

< 3 inches

> 18 inches

Diameter Class (d.b.h.) 

Invasive plant species are often characterized by their vigor, ability to adapt, 

reproductive capacity, and lack of natural enemies. Th ese factors enable them to 

displace native plants and threaten natural areas.15 Seventeen of the 161 tree species 

sampled in the Chicago region are identifi ed on the state invasive species list.16 Th ese 

species comprise 38.4 percent of the tree population and though considered invasive to 

Illinois, may cause only minimal impact (Table 2). Th e three most common of these 

species are European buckthorn (28.2 percent of population), amur honeysuckle (2.1 

percent), and black locust (1.9 percent) (Figure 11).

Figure 10.—Percent of total tree 

population by area of native 

origin, Chicago region, 2010.

0

10

20

30

40

50

60

Illinois North

America

Eurasia North

America +*

Asia Unknown Americas

+**

Europe

Total Population (percent)

Area of Native Origin 

* native to North America and one other continent, excluding South America 

** native to North America and South America, and one other continent 
11

Table 2.—Inventoried species listed on the Illinois invasive species list, Chicago region, 2010

Scientific Name Common Name % of Popa % of Leaf Area

Rhamnus cathartica European buckthorn 28.2 6.55

Lonicera maackii Amur honeysuckle 2.1 0.48

Robinia pseudoacacia Black locust 1.9 1.93

Ulmus pumila Siberian elm 1.4 3.24

Acer platanoides Norway maple 1.2 3.57

Ailanthus altissima Tree-of-heaven 1.2 0.70

Morus alba White mulberry 1.0 0.84

Acer ginnala Amur maple 0.5 0.16

Frangula alnus Glossy buckthorn 0.3 0.09

Pyrus calleryana Callery pear 0.2 0.14

Populus alba White poplar 0.1 0.62

Maclura pomifera Osage orange 0.1 0.11

Elaeagnus umbellata Autumn olive 0.1 0.09

Euonymus alatus Winged burningbush 0.1 0.01

Elaeagnus angustifolia Russian olive < 0.1 0.02

Corylus avellana European filbert < 0.1 < 0.01

Ligustrum vulgare Common privet < 0.1 < 0.01

a % of Pop - Percent of tree population

Figure 11.—Number of trees by 

species on state invasive species 

list, Chicago region, 2010. 0

5

10

15

20

25

30

35

40

45

50

Number of Trees (millions)

Species 

European buckthorn and amur honeysuckle tend to be small (greater than 70 percent 

of the trees are less than 3 inches in diameter), but are relatively common. Th ese 

invasive plants have shifted the composition of the original regional forest from more 

native large tree species to more small-statured invasive tree species. Th is trend is likely 

to continue; continued monitoring of the regional forest is needed to track the extent 

to which this trend continues.
12

URBAN FOREST COVER AND LEAF AREA

Th e Chicago region has a canopy cover of 21.0 percent of which 15.5 percent was made up 

of tree species and 5.5 percent by shrub species. Common ground cover classes (including 

cover types beneath trees and shrubs) in the Chicago region include water, bare soil, 

herbaceous, duff /mulch cover, impervious surfaces (excluding buildings), and buildings. Th e 

dominant ground cover in the Chicago region include herbaceous (65.2 percent of cover), 

impervious surfaces excluding buildings (12.6 percent), and buildings (7.6 percent) (Figure 

12). Ground covers also vary within each land use. For example, agricultural land uses have 

a greater percentage of herbaceous ground cover while impervious surfaces and buildings 

dominate CTI land uses.

Many tree benefi ts are linked to the healthy leaf area of the 

plant, i.e., the greater the leaf area, the greater the benefi t. In 

the Chicago regional forest, tree species with the greatest leaf 

area are silver maple, boxelder, and green ash (Figure 13).

Tree species that contribute a relatively large amount of 

leaf area per stem (species with percent of leaf area much 

greater than percent of total population) are bur oak, silver 

maple, and black walnut. Tree species with mostly smaller 

individuals are honeysuckle species and European buckthorn 

(species with percent of leaf area much less than percentage 

of total population).

Th e importance values (IVs) are calculated using a formula that takes into account the 

relative leaf area and relative abundance. 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. Th e species in the regional forest with the greatest IVs are 

European buckthorn, boxelder, and green ash (Table 3).

Table 3.—Percent of total populationand leaf area, and importance value of species 

with the greatest importance values, Chicago region, 2010

Common name %Popa %LAb IVc

European buckthorn 28.2 6.5 34.7

Boxelder 5.5 7.9 13.4

Green ash 5.5 7.1 12.6

Silver maple 2.0 8.3 10.3

Black cherry 4.9 4.8 9.7

American elm 3.4 4.1 7.5

Black walnut 1.6 5.7 7.3

Sugar maple 2.8 3.3 6.1

Northern red oak 2.0 3.7 5.7

Bur oak 1.0 4.7 5.7

a %Pop – percent of total tree population

b %LA – percent of total leaf area

c IV = %Pop + %LA

In the Chicago regional 

forest, tree species with 

the greatest leaf area are 

silver maple, boxelder, 

and green ash.

Morton Arboretum, used with permission
13

Figure 12.—Percent of land use areas covered by ground cover classes, Chicago region, 2010.

0 20 40 60 80 100

Agriculture

CTI

Open Space

Residential

Percent of Land Use 

Land Use 

water

bare soil

herbaceous

duff/mulch cover

impervious surfaces

(excluding buildings)

buildings

Ground Cover 

Classes 

Figure 13.—Percent of total tree population and leaf area for 10 most common tree species, 

Chicago region, 2010.

0

5

10

15

20

25

30

Silver maple Boxelder Green ash European

buckthorn

Black

walnut

Black cherry Bur oak American

elm

Eastern

cottonwood

Northern

red oak

Proportion of Total Population (percent) 

Species 

Leaf area

Abundance
14

AIR POLLUTION REMOVAL BY URBAN TREES

Poor air quality is a common problem in many urban areas and can lead to human 

health problems, damage to plants and ecosystem processes, and reduced visibility. 

Th e urban forest can help improve air quality by reducing air temperature, directly 

removing pollutants from the air, and reducing energy consumption in buildings, 

which consequently reduces air pollutant emissions from power plants. Trees also 

emit volatile organic compounds (VOCs) that can contribute to ozone formation. 

However, integrative studies have revealed that an increase in tree cover leads to 

reduced ozone formation.17

Pollution removal by trees in the Chicago region was estimated using the i-Tree Eco 

model in conjunction with fi eld data and hourly pollution and weather data for the 

year 2007. Pollution removal was greatest for ozone (O3), followed by particulate 

matter less than 10 microns (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), 

and carbon monoxide (CO) (Figure 14). It is estimated that trees alone remove 18,080 

tons of air pollution (CO, NO2, O3, PM10, SO2) per year with an associated value 

of $137 million (based on 2007 national median externality costs associated with 

pollutants18). Th e eff ects of shrub cover in the Chicago region remove an additional 

estimated 6,090 tons per year ($46 million/year). Th us, tree and shrub cover combined 

remove approximately 24,170 tons of pollution per year ($183 million/year).

In 2007, trees in the Chicago region emitted 11,976 tons of VOCs (5,827 tons of 

isoprene, 2,176 tons of monoterpenes, and 3,973 tons of other VOCs). Emissions vary 

among species based on species characteristics (i.e., some genera such as oaks are high 

isoprene emitters) and amount of leaf biomass. Forty-seven percent of the region’s 

0

10

20

30

40

50

60

70

80

90

0

1

2

3

4

5

6

7

8

CO NO2 O3 PM10 SO2

Value (million dollars/year) 

Pollution Removed (thousand tons/year) 

Pollutant 

Pollution removed

Value

Figure 14.—Annual air pollution removal and value by urban trees, Chicago region, 2010.

It is estimated that 

in the Chicago 

region, trees alone 

remove 18,080 tons 

of air pollution 

per year with an 

associated value of 

$137 million.

Morton Arboretum, used with permission
15

VOC emissions were from the Quercus and Acer genera (Figure 15). Th ese VOC 

emissions have a negative eff ect on the environment as they are a precursor chemical 

to ozone formation. Th us, trees have a negative dollar value associated with these 

emissions.19

General recommendations for improving air quality with trees are given in Appendix IV.

CARBON STORAGE AND SEQUESTRATION

Climate change is an issue of global concern to many. Th e region’s trees can help 

mitigate climate change by sequestering atmospheric carbon (from carbon dioxide) in 

tissue and by reducing energy use in buildings, thus reducing carbon dioxide emissions 

from fossil-fuel based power sources.20

Trees reduce the amount of carbon in the atmosphere by sequestering carbon 

in new tissue growth. Th e amount of carbon annually sequestered is increased 

with healthier and larger diameter trees. Gross sequestration by urban trees in 

the Chicago region is about 677,000 tons of carbon per year (2.5 million tons 

per year of carbon dioxide) with an associated value of $14.0 million per year. 

Net carbon sequestration in the Chicago region is estimated at about 476,000 

tons per year (1.7 million tons per year of carbon dioxide) based on estimated 

carbon loss due to tree mortality and decomposition.

Carbon storage is another way trees can infl uence global climate change. As a tree grows, 

it stores more carbon by holding it in its accumulated tissue. As a tree dies and decays, 

it releases much of the stored carbon back into the atmosphere. Th us, carbon storage 

is an indication of the amount of carbon that can be released if trees are allowed to 

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

Ulmus

Pinus

Fraxinus

Robinia

Rhamnus

Juglans

Picea

Populus

Acer

Quercus

VOCs Emitted (thousand tons) 

Genera

Isoprene

Monoterpene

Other VOCs

VOCs Emitted 

Figure 15.—Annual volatile organic compounds (VOCs) emitted by genera with highest 

total emissions, Chicago region, 2010.

Morton Arboretum, used with permission
16

die and decompose. Maintaining healthy trees will keep the carbon stored in trees, 

but tree maintenance can contribute to carbon emissions.21 When a tree dies, using 

the wood in long-term wood products, to heat buildings, or to produce energy will 

help reduce carbon emissions from wood decomposition or from fossil-fuel or woodbased power plants. Trees in the Chicago region store an estimated 16.9 million 

tons of carbon (61.9 million tons of carbon dioxide) (valued at $349 million). Of all 

the species sampled, bur oak stores the most carbon (approximately 11.7 percent of 

total estimated carbon stored) and European buckthorn annually sequesters the most 

carbon (9.1 percent of all sequestered carbon) (Figures 16-17). Trees greater than 30 

inches in diameter store the most carbon in the region (Figures 18-19).

0

200

400

600

800

1,000

1,200

1,400

0

10

20

30

40

50

60

70

European

buckthorn

Boxelder Black cherry Silver maple Bur oak White oak Northern red

oak

Green ash Eastern

cottonwood

Black walnut

Value (thousand dollars/year)

Sequestration (thousand tons/year) 

Carbon sequestration

Value

0

5

10

15

20

25

30

35

40

45

50

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Bur oak Silver maple White oak Boxelder Eastern

cottonwood

Northern red

oak

Black cherry Green ash Siberian elm Honeylocust

Value (million dollars) 

Storage (million tons) 

Carbon storage

Value

Figure 16.—Estimated annual 

carbon sequestration and 

value for urban tree species 

with the greatest sequestration, 

Chicago region, 2010.

Figure 17.—Estimated annual 

carbon storage and value for 

urban tree species with the 

greatest storage, Chicago 

region, 2010.

Species
17

0

20

40

60

80

100

120

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0-3 3-6 6-9 9-12 12-15 15-18 18-21 21-24 24-27 27-30 30+

Total Sequestration (thousand tons/year) 

Total Storage (million tons) 

Carbon storage

Carbon sequestration

0

20

40

60

80

100

120

0

1

2

3

4

5

6

7

0-3 3-6 6-9 9-12 12-15 15-18 18-21 21-24 24-27 27-30 30+

Average Storage (thousand lbs) 

Average Sequestration (lbs/year) 

Diameter Class (d.b.h. in inches) 

Carbon storage

Carbon sequestration

Figure 18.—Estimated 

total carbon storage and 

sequestration by diameter 

class, Chicago region, 2010.

Figure 19.—Estimated 

average carbon storage and 

sequestration by diameter 

class, Chicago region, 2010.

Trees in the Chicago region 

store an estimated 16.9 

million tons of carbon.

Morton Arboretum, used with permission
18

TREES AFFECT ENERGY USE IN BUILDINGS

Trees aff ect energy consumption by shading buildings, providing evaporative cooling, 

and blocking winter winds. Trees tend to reduce building energy consumption in the 

summer months and can either increase or decrease building energy use in the winter 

months, depending on the location of trees around the building. Estimates of tree 

eff ects on energy use are based on fi eld measurements of tree distance and direction to 

space-conditioned residential buildings.11

Based on average energy costs in 200922, trees in the Chicago region reduce energy 

costs from residential buildings by an estimated $44.0 million annually (Table 4). 

Trees also provide an additional $1.3 million in value per year by reducing the amount 

of carbon released by fossil-fuel based power sources (a reduction of 63,000 tons of 

carbon emissions or 232,000 tons of carbon dioxide) (Table 5).

Table 4.—Annual monetary savingsa ($) in residential energy 

expenditures during heating and cooling seasons, Chicago region, 2010

 Heating Cooling Total

MBTUb 20,165,000 n/a 20,165,000

MWHc 1,771,000 22,049,000 23,820,000

Carbon avoided 686,900 623,000 1,309,900

a Based on 2009 statewide energy costs22

b MBTU – Million British Thermal Units (not used for cooling)

c MWH – Megawatt-hour

Table 5.—Annual energy savings (MBTU, MWH, or tons) due to trees near 

residential buildings, Chicago region, 2010

 Heating Cooling Total

MBTUa 1,809,500 n/a 1,809,500 

MWHb 15,100 187,700 202,800 

Carbon avoided (t)c 33,200 30,100 63,300 

a MBTU – Million British Thermal Units (not used for cooling)

b MWH – Megawatt-hour

c To convert carbon estimates to carbon dioxide, multiply carbon value by 3.667

Morton Arboretum, used with permission

Based on average 

energy costs in 2009, 

trees in the Chicago 

region reduce 

energy costs from 

residential buildings 

by an estimated 

$44.0 million 

annually.
19

STRUCTURAL AND FUNCTIONAL VALUES

Th e region’s forests have a structural value based on the tree itself that includes 

compensatory value and carbon storage value. Th e compensatory value is an estimate of 

the value of the forest as a structural asset (e.g., how much should one be compensated 

for the loss of the physical structure of the tree). Th e compensatory value12 of the trees 

and forests in the Chicago region is about $51.2 billion (Figure 20). For small trees, a 

replacement cost can be used; for larger trees, several estimation procedures are used.12

Th e structural value of the forest resource tends to increase with an increase in the 

number and size of healthy trees.

Forests also have functional values (either positive or negative) based on the functions 

the trees perform. Annual functional values also tend to increase with increased number 

and size of healthy trees and are usually on the order of several million dollars per year. 

Th ere are many other functional values of the forest, though they are not quantifi ed 

here (e.g., reduction in air temperatures and ultra-violet radiation, improvements in 

water quality, aesthetics, wildlife habitat, etc.). Th us the functional estimates provided 

in this report only represent a portion of the total forest functional values. Th rough 

proper management, urban and rural forest values can be increased. However, the 

values and benefi ts also can decrease as the amount of healthy tree cover declines.

Urban trees in the Chicago region have the following structural values:

• Compensatory value - $51.2 billion

• Carbon storage - $349 million

Urban trees in the Chicago region have the following annual functional values:

• Carbon sequestration - $14.0 million

• Pollution removal - $137 million 

• Reduced energy costs - $44.0 million

More detailed information on the trees and forests in the Chicago region can be 

found at http://nrs.fs.fed.us/data/urban. For information on carbon storage, carbon 

sequestration, and pollution removal by stem diameter class, see Appendix V.

Urban forests 

have a structural 

value based on 

the characteristics 

of the trees 

themselves.

Urban forests also 

have functional 

values based on the 

ecosystem functions 

the trees perform.

Large, healthy, 

long-lived trees 

provide the greatest 

structural and 

functional values.

Figure 20.—Tree species with 

the greatest compensatory value, 

Chicago region, 2010.

0

1

2

3

4

5

6

7

Bur oak White oak Silver maple Green ash Northern

red oak

European

buckthorn

Black cherry Boxelder Eastern

cottonwood

Honeylocust

Compensatory Value (billions of dollars)

Species
20

STREET TREE POPULATIONS

Street trees are defi ned as the trees located on the public right-of-way next to streets 

and roads.a

 Street trees are found throughout the Chicago region, with most street 

trees located in residential (76.0 percent) and CTI (14.5 percent) areas (Table 6). 

Suburban Cook County, Lake County, and the city of Chicago collectively have 83.2 

percent of the street tree population (Table 7).

Th e Chicago region has an estimated 2.3 million street trees. While constituting only 

1.5 percent of the region’s tree population, these street trees account for 15 percent 

of the trees in the city of Chicago (Table 7). Th e number of street trees by species can 

be found in Appendix III. Th ere is no estimate of street trees for rural Will County as 

there were no street trees in the inventoried fi eld plots.

a Street trees are located in public rights-of-way, most commonly between the sidewalk and 

the road. If there are no sidewalks, trees within 30 feet of the center of the road are included as 

are trees within 10 feet of the curb on boulevards or very wide streets. Note: i-Tree sampling 

will pick up street trees in a sample, but it is not specifi cally designed to sample street trees 

(i.e., it is not a sample of streets). In Lake County, two plots had trees along streets adjacent 

to woodlands that sampled buckthorn and other woodland trees that fell within the street tree 

defi nition. Th us the relatively large number of street trees in Lake County and buckthorn street 

trees are likely due to the low proportion of street tree sampled (small sample size) and plots 

sampling woodland trees along roads. 

Table 6.—Street trees by land use, Chicago region, 2010

Percent of

Land Use Number of 

Trees

Total 

Population

Population of 

Street Trees

Population in 

Land Use

Residential 1,783,100 1.13 76.0 3.3

CTI 340,800 0.22 14.5 2.2

Open Space 222,300 0.14 9.5 0.3

Agriculture - 0.00 0.0 0.0

Total 2,346,200 1.49 100.0 -

Table 7.—Street trees by area, Chicago region, 2010

Street Trees in County/City as a Percent of

Area Number of 

Street Trees

Total Regional 

Tree Population

Total Street 

Tree Population 

Total County/City 

Tree Population 

Suburban Cook

County

801,100 0.51 34.1 1.8

Lake County 602,800 0.38 25.7 1.8

City of Chicago 549,800 0.35 23.4 15.3

DuPage County 177,400 0.11 7.6 1.0

McHenry County 104,600 0.07 4.5 0.5

Kendall County 65,700 0.04 2.8 1.3

Kane County 44,800 0.03 1.9 0.5

Will County - - - -

Total 2,346,200 1.49 100.0 -

Morton Arboretum, used with permission
21

Morton Arboretum, used with permission

Th e most common street tree species in the Chicago region are green 

ash (12.9 percent of street trees), European buckthorn (12.7 percent), 

and Norway maple (12.2 percent) (Figure 21).

Concerns for the future of Chicago’s regional forest, such as the 

spread of pest infestations and invasive species, will have a signifi cant 

impact on the structure of the street tree population. For example, 

ash trees comprise an estimated 18 percent of the street trees in the 

region, thus the character of the streets will change dramatically as a 

result of emerald ash borer infestations.

While street trees may be planted trees, they may also be trees in the street corridor 

that have established themselves. Trees that establish themselves in street corridors can 

be a cause for concern in the Chicago region when considering the issue of invasive 

species. European buckthorn and Norway maple are among the three most common 

street tree species. Th ey are also listed on the Illinois state invasive species list. Th e 

development of a strategy (or lack thereof) to control invasive species will further aff ect 

the character of the region’s street trees.

0

2

4

6

8

10

12

14

Green ash European

buckthorn

Norway

maple

Honeylocust Silver maple White ash Littleleaf

linden

Northern

hackberry

Slippery elm Red maple

Street Tree Population (percent) 

Figure 21.—Percent of street tree population of the 10 most common street tree species, 

Chicago region, 2010.

Species

Ash trees comprise an estimated 18 percent 

of the street trees in the region, thus the 

character of the streets will change 

dramatically as a result of emerald 

ash borer infestations.
22

VARIATION IN URBAN FOREST STRUCTURE BY COUNTY

Th e Chicago region in Illinois includes 4,009 mi2 and 8.5 million residents. It has a 

diverse landscape that is heavily impacted by the city of Chicago with its extensive 

residential areas, intricate system of infrastructure, and designated open spaces. Th e 

county areas surrounding Chicago (Lake, DuPage, and suburban Cook) are suburban 

with extensive residential areas. Counties on the south and western edges (Will, 

Kendall, Kane, and McHenry) also have substantial agricultural land. Population 

density ranges from 12,482 people/mi2

 in the city of Chicago to 326 people/mi2 in 

Kendall County, which is highly agricultural (77 percent of land use) and located on 

the periphery of the region (Figure 22).

Th e highest tree density occurs in the suburban counties: Lake (112 trees/ac), suburban 

Cook (93 trees/ac), and DuPage (81 trees/ac) (Figure 23). Counties with extensive 

agricultural areas as well as the city of Chicago have lower tree densities. Suburban 

Cook County contains the greatest percentage of the regional tree population (27.6 

percent), followed by Lake (21.3 percent) and McHenry (14.2 percent) (Table 8). See 

Appendix III for more information on the tree species in each area.

Th e three most common trees in each county and the city of Chicago (Table 9) are 

among the 10 most common species of the whole Chicago region (Figure 3) with 

three exceptions: mulberry, willow species, and white spruce (Table 9). European 

buckthorn is the most common species in all areas except Kendall County and the city 

of Chicago. European buckthorn is most common in Lake, McHenry, suburban Cook, 

and DuPage Counties (greater than 25 percent of the tree population).

Th e number of trees, leaf area, and leaf area index follow a similar pattern by land 

use classifi cation across the seven counties (Figure 24). Th e suburban counties with 

a greater percentage of residential and open space land use have larger amounts and 

higher density of leaf area. Counties with large areas of agriculture and the city of 

Chicago with a large area of CTI areas have lower values.

Table 8.—Number of trees and percent of total population by area, 

Chicago region, 2010

Trees

Area Number % of Popa

Suburban Cook County 43,400,000 27.6

Lake County 33,500,000 21.3

McHenry County 22,300,000 14.2

Will County 21,900,000 13.9

DuPage County 17,300,000 11.0

Kane County 9,900,000 6.3

Kendall County 5,200,000 3.3

City of Chicago 3,600,000 2.3

Chicago Region 157,100,000 100.0

a % of Pop – Percent of total tree population

Morton Arboretum, used with permission

Morton Arboretum, used with permission

Morton Arboretum, used with permission
23

0 20 40 60 80 100

Chicago Region - 2,134

Kendall County - 326

McHenry County - 532

Will County - 819

Kane County - 984

Lake County - 1,590

DuPage County - 2,792

Suburban Cook County - 3,413

City of Chicago - 12,482

Percent of Area 

Area 

Residential

Agriculture

CTI

Open Space

Land8se 

Category 

Figure 22.—Percent of area occupied by land use categories, Chicago region, 2010. 

Population density (people/mi2) is given along y axis.

0

20

40

60

80

100

120

0

5

10

15

20

25

30

35

40

45

Suburban

Cook

County

Lake

County

McHenry

County

Will County DuPage

County

Kane

County

Kendall

County

City of

Chicago

Number of Trees (millions) 

Tree Density (trees per acre) 

Area 

Number of trees

Tree density

Figure 23.—Number of trees and tree density by area, Chicago region, 2010.

Tree size also varies by land use and area. Residential areas, particularly in the city of 

Chicago, had the greatest percent of trees greater than 18 inches diameter compared to 

other land uses (Appendix VII). Th e city of Chicago also had the greatest percentage 

of trees greater than 18 inches in open space and CTI categories compared with the 

counties. Th e relatively large trees in the city of Chicago may refl ect early settlement 

and establishment of neighborhoods, parks, forest preserves, and other areas.
24

Th e structure of forest resources varies signifi cantly across the Chicago region. 

Variations in tree and shrub cover within the city of Chicago and the seven counties 

are evident and vary among land use classifi cations (Table 10). Tree and shrub cover is 

greatest in residential and open space areas. Cover is less for CTI land uses and is the 

lowest in agricultural areas. Lake, suburban Cook, and DuPage Counties, which are 

predominantly residential and open space, have the greatest percentages of tree and 

shrub cover. Th e counties with the lowest percentage of tree and shrub cover are Will, 

Kane, and Kendall Counties, which are predominantly agricultural.

Ground cover in each county refl ects the diff erences in population density. Counties 

with greater population density have more buildings and impervious cover. 

Herbaceous cover is dominant in suburban Cook and the surrounding counties, but 

impervious cover dominates in the city of Chicago (Figure 25).

Table 9.—Percent of tree population by area and region for three most common tree 

species in each area, Chicago region, 2010

% of Population

Area Common Name Areaa Regionb

City of Chicago white ash 6.2 0.1

mulberry 5.3 0.1

green ash 4.9 0.1

DuPage County European buckthorn 25.4 2.8

boxelder 6.3 0.7

black cherry 6.1 0.7

Kane County European buckthorn 15.4 1.0

boxelder 10.4 0.7

willow 7.4 0.5

Kendall County sugar maple 12.8 0.4

mulberry 7.5 0.2

American elm 6.2 0.2

Lake County European buckthorn 40.9 8.7

green ash 5.0 1.1

white spruce 4.8 1.0

McHenry County European buckthorn 35.7 5.1

boxelder 7.0 1.0

black cherry 6.0 0.9

Suburban Cook 

County European buckthorn 31.1 8.6

black cherry 6.0 1.6

boxelder 5.3 1.5

Will County European buckthorn 12.9 1.8

sugar maple 12.7 1.8

green ash 12.4 1.7

a Percent of total population in area (e.g., 6.2 percent of trees in the city of Chicago are white ash).

b Percent of regional tree population (e.g., 0.1 of the region’s trees are white ash in the city of Chicago).

The highest tree 

density occurs 

in the suburban 

counties. Counties 

with extensive 

agricultural areas 

as well as the city 

of Chicago have 

lower tree densities.
25

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0

100

200

300

400

500

600

700

Suburban

Cook County

Lake County McHenry

County

Will County DuPage

County

Kane County Kendall

County

City of

Chicago

Leaf Area Index (LAI)

Leaf Area (thousand acres) 

Area 

Leaf area

Leaf area index

Figure 24.—Total leaf area 

and leaf area index by area, 

Chicago region, 2010.

Table 10.—Percent tree and shrub cover14 by area and land use, Chicago region, 2010

Residential Agriculture Open Space CTI Total

Population Density 

(people/mi2

)

City of Chicago 23.9 - 29.8 7.0 18.9 12,482

Suburban Cook County 30.4 6.8 49.6 9.1 29.2 3,413

DuPage County 36.7 12.0 32.5 12.6 28.6 2,792

Lake County 43.0 7.8 34.8 14.2 31.6 1,590

Kane County 36.0 1.7 25.6 10.9 13.4 984

Will County 30.1 2.7 31.4 9.2 15.4 819

McHenry County 43.1 4.1 37.3 9.3 20.4 532

Kendall County 19.2 1.9 48.5 7.7 8.7 326

Chicago Region 21.0 2,134

0 50 100

Chicago Region - 2,134

Kendall County - 326

McHenry County - 532

Will County - 819

Kane County - 984

Lake County - 1,590

DuPage County - 2,792

Suburban Cook County - 3,413

City of Chicago - 12,482

Percent of Area 

Area 

water

bare soil

herbaceous

duff/mulch cover

impervious surfaces

(excluding buildings)

buildings

Ground Cover 

Classes 

Figure 25.—Percent of areas 

covered by ground cover classes, 

Chicago region, 2010. Population 

density (people/mi2

) is provided 

along y axis.
26

CHANGING SPECIES COMPOSITION AND SIZE 

STRUCTURE

Change in species composition and tree size structure of the Chicago regional forest 

will likely have a signifi cant infl uence on the benefi ts provided by the regional forest 

for the next several decades. Th ese changes are likely to require a diff erent approach in 

aspects of forest management strategies that aff ect species composition, including pest 

management, regeneration, and restoration eff orts. Recent research reveals that urban 

forests are declining nationally at a rate of about 4 million trees/year with tree and 

shrub cover in Chicago dropping about 0.5 percent between 2005 and 2009.23

While we do not have comparable forest resource inventory information for previous 

years to examine past trends, we can look at the size and structure of the present 

forest for indications of the possible future forest. In the future, replications of the 

i-Tree inventory and assessment will provide the basis for assessing trends in the forest 

resource, its management, and the benefi ts that it provides.

Th e future forest will be determined, in part, by the trees that are currently part of the 

forest. Younger trees will grow to larger sizes and the older trees will eventually decline 

and die. By comparing the species structure of smaller (young) trees with that of the 

larger (older) trees, we can predict the change in the species composition and size 

structure of the forest over time. Other factors that will infl uence future forest structure 

include insects, disease, land use changes, climate change, changing infrastructure, and 

natural resource management.

Species that make up signifi cant portions of the large tree population in the present 

forest, but are not as common among the younger trees, are likely to be less common 

in the future forest. Th ese species include silver maple, white oak, bur oak, eastern 

cottonwood, northern red oak, boxelder, Norway maple, honeylocust, and Siberian elm 

(Figures 8, 9). Given the relatively large sizes of trees of these species, and the likelihood 

that they will not be as abundant in the future forest, we might expect some decrease in 

the overall tree size and the benefi ts that the forest provides. Long-lived large trees are 

Morton Arboretum, used with permission
27

essential elements in a healthy vigorous urban forest given their especially 

high potential to sequester carbon, remove air pollution, and moderate 

high temperatures through shading and evapotranspirational cooling.

Species that make up a larger proportion of the small trees than large 

trees include European buckthorn, amur honeysuckle, black cherry, 

sugar maple, American elm, ash, and mulberry. Th ese species tend to be 

prolifi c seeders that have become established in open areas and corridors 

throughout the region. We can expect these species to be more common in 

the future forest, but there will be exceptions. Not all of these species will 

become large; we can expect ash to succumb to emerald ash borer, and elm 

to succumb to Dutch elm disease. In addition, some of these species will 

not attain a large stature (e.g., buckthorn, honeysuckle). Other problems 

may emerge to aff ect the growth and development of other species in the 

future.

Trends in size by species are due, in part, to several factors. Large trees 

that often pre-date urbanization, such as oaks, are approaching the end of 

their lifespans. Native ash trees are rapidly being lost to emerald ash borer, 

while other large tree species are subject to emerging pests and pathogens 

such as Asian longhorned beetle, thousand cankers disease, and bur oak blight. In many 

cases, trees planted since urbanization have not yet attained large sizes and conditions 

are not good for regeneration of a number of important species such as the oaks. A shift 

in dominance from larger tree species, such as oaks and ashes, toward small, short-lived, 

nonnative and opportunistic species (e.g., European buckthorn) would have important 

implications for the future of the forest and its management.

Species composition and size structure vary by land use classifi cation (Table 11). Among 

the species that comprise the large trees (greater than 18 inches in diameter), silver maple 

is the most common in residential areas, but northern red oak ranks fi rst in CTI areas, 

boxelder fi rst in agricultural areas, and bur oak fi rst in open space areas.

Within the small tree category (1 to 3 inches in diameter), European buckthorn ranks 

fi rst in abundance in all land uses. It is followed by green ash in residential areas, black 

cherry in open space areas, tree-of-heaven in CTI, and mulberry in agricultural areas.

While large tree species are common among street tree plantings, street trees comprise 

only about 1.5 percent of the total tree population. Th us, street tree plantings are not 

frequent or numerous enough to help sustain the population of trees that achieve large 

sizes. Although street trees are visually prominent, they are not highly signifi cant on 

the regional scale. Open spaces (51.5 percent of trees) and residential lots (34.6 percent 

of trees) are the dominate land uses that support more than 85 percent of the tree 

population and leaf area, and their associated benefi ts. To sustain the composition of 

large trees, regeneration of species that become large, either through natural regeneration 

or tree planting, needs to be facilitated in the Chicago region, particularly in open space 

and residential lands.

Morton Arboretum, used with permission
28

Insect and Disease Impacts

Insects and diseases can infest urban forests, potentially killing trees and reducing 

the health, value, and sustainability of the urban forest. Various pests have diff erent 

tree hosts, so the potential damage or risk of each pest will diff er. Twenty-nine exotic 

insects/diseases were considered for their potential impact using range maps of these 

pests in the coterminous United States (www.foresthealth.info).24 For a complete 

analysis of the 29 exotic insects/diseases, see Appendix VI.

Although there are numerous pests that could impact Chicago’s regional forest, 

Asian longhorned beetle (ALB), gypsy moth (GM), emerald ash borer (EAB), oak 

wilt (OW), and Dutch elm disease (DED) pose the most serious threats based on the 

number of trees at risk to infestation.

Th ese fi ve insects or diseases pose a threat because they currently exist or have 

existed (ALB has been eradicated) within the Chicago region. If ALB reinfests the 

Chicago region and the infestation goes unchecked, the eff ects to the forests could be 

devastating with a potential loss greater than 41.6 million trees (greater than onefourth of the forest; $17.4 billion in compensatory value). Potential loss of trees from 

GM is 17.7 million ($18.5 billion in compensatory value), EAB is 12.7 million ($4.2 

billion in compensatory value), OW is 9.0 million ($16.0 billion), and DED is 8.2 

million ($1.6 billion) (Figure 26).

Table 11.—Three most common small and large tree species in each land use classification, 

Chicago region, 2010

Stem Diameter 1-3 in Stem Diameter >18 in

Species

Number of 

Trees % of Popa Species

Number of 

Trees % of Popa

Agriculture 3,324,180 353,724 

European buckthorn 1,484,771 45% Boxelder 148,232 42%

Mulberry spp 380,140 11% White oak 61,617 17%

Ginkgo 172,176 5% Bur oak 42,213 12%

 

CTI 8,739,710 525,549 

European buckthorn 3,639,424 42% Northern red oak 46,744 9%

Tree-of-heaven 815,705 9% White oak 44,775 9%

Sugar maple 780,027 9% Green ash 43,679 8%

 

Open Space 40,196,575 2,625,955 

European buckthorn 18,083,258 45% Bur oak 531,994 20%

Black cherry 2,061,360 5% Eastern cottonwood 470,706 18%

Amur honeysuckle 2,047,861 5% White oak 315,923 12%

 

Residential 23,658,163 3,954,961 

European buckthorn 9,725,630 41% Silver maple 705,523 18%

Green ash 1,379,618 6% White oak 427,188 11%

Boxelder 1,172,484 5% Bur oak 266,418 7%

a % of Pop – percent of tree population in land use by stem diameter class

Emerald ash borer

Photo by David Cappaert

Michigan State University,

www.invasive.org
29

Table 12 shows the current status of the fi ve insects/diseases in the Chicago region.24

Th e magnitude of threat varies by county/area (Figure 27) and land use (Figure 28), 

with the most signifi cant risk being in suburban Cook and Will Counties and in open 

space areas from ALB.

Th ese fi ve insects and diseases threaten common trees such as willow, poplar, ash, 

birch, maple, oak, and elm (Appendix VI). Of the 10 most common tree species, 

the only species not threatened by these insects and diseases are European buckthorn 

(an invasive species that comprises 28.2 percent of the total tree population), black 

cherry (the fourth most common species and 4.9 percent of the population), and amur 

honeysuckle (the eighth most common species, 2.1 percent of the population, and 

another invasive species).

Figure 26.—Number of trees at risk and associated compensatory value for five 

most threatening insects/diseases, Chicago region, 2010. See text for explanation of 

acronyms.

0

2

4

6

8

10

12

14

16

18

20

0

5

10

15

20

25

30

35

40

45

ALB GM EAB OW DED

Compensatory Value (billions of dollars) 

Number of Trees (millions) 

Insect/Disease 

Trees at risk

Compensatory value

Table 12.—Presencea of the most threatening pests, Chicago region, 2010

Area ALBb GM EAB OW DEDc

Cook Countyd

DuPage County

Kane County

Kendall County

Lake County

McHenry County

Will County

a Red indicates pest occurs within county; orange indicates pest is within 250 miles of the 

county edge

b See text for explanation of acronyms.

c Range of Dutch elm disease is based on native range of American elm

d Includes the city of Chicago

Asian longhorned 

beetle

Photo by Kenneth R. Law 

USDA APHIS PPQ, www.invasive.org

Ed Hedborn, Morton Arboretum, used with 

permission
30

Symptoms of Dutch elm disease. 

Joseph O'Brien, U.S. Forest Service

Figure 27.—Number of trees at risk to the five most significant insects/diseases by area, 

Chicago region, 2010. See text for explanation of acronyms.

Figure 28.—Number of trees at risk to the five most significant pest threats by land use, 

Chicago region, 2010. See text for explanation of acronyms.

0

2

4

6

8

10

12

City of

Chicago

Suburban

Cook

County

DuPage

County

Kane

County

Kendall

County

Lake

County

McHenry

County

Will County

Number of Host Trees (millions) 

Area 

ALB GM EAB

DED OW

Insect/Disease 

0

5

10

15

20

25

Agriculture CTI Open Space Residential

Number of Host Trees (millions) 

Land Use 

ALB GM EAB

DED OW

Insect/Disease 
31

Potential Loss of Ash Species

It is likely that the most profound change in the Chicago regional forest over 

the next 10 years will be the loss of nearly all of the 13 million ash trees (all ash 

species) to the emerald ash borer. Ash is a signifi cant tree in the Chicago region 

(Table 13). It is found in all land use categories and since it can attain a fairly 

large size, it can be a key component of the landscape. Th e contribution of ash 

to improving the urban environment is substantial in that it ranks fi rst in leaf 

area among species in the region and second only to buckthorn in number of 

trees and number of trees with a stem diameter between 1 and 3 inches. Ash is 

a prolifi c seeder and its winged seeds can scatter across signifi cant distances. Its 

high ranking in number of trees is most likely due to its prolifi c seeding habits.

Since ash grows well in urban areas, it is often planted along streets and in residential 

and CTI areas (Table 14). Among Chicago region street trees, ash (white and green) 

is the most common genus and makes up 18 percent of the total, second only 

to maple (Figure 21). Th irty-three percent of ash trees are large (greater than 18 

inches diameter), a high proportion for street trees. Land use classifi cations with the 

highest percentage of large ash trees are CTI (7.7 percent) and residential areas (7.3 

percent) across the region. Th is distribution may be due to past planting of ash trees 

in transportation corridors, in residential and commercial areas, and on corporate 

campuses, hospital grounds, and at schools. Overall, ash ranks seventh among all species 

in the region in terms of percent of trees with stem diameter greater than 18 inches.

Table 13.—Ash measurements, Chicago region, 2010

Parameter Units Value % of Total Region Rank

Population number 12,692,249 8.08 2

Density trees/acre 4.88 -- 2

Carbon stored tons 894,589 5.30 7

Carbon sequestered tons/year 42,824 6.32 3

Net carbon sequestered tons/year 32,433 6.81 3

Leaf area acres 271,878 9.57 1

Leaf biomass tons 76,465 8.10 2

Trees, diameter 1-3 in number 5,323,587 41.95a 2

Trees, diameter >18 in number 479,400 3.78a 7

Street trees number 422,662 18.01b 1

Street trees, diameter >18 in number 137,301 33.00c 1

a Percent of all ash trees

b Percent of all street trees

c Percent of ash street trees

Table 14.—Ash trees by land use, Chicago region, 2010

Land Use 

Number of 

Trees

Density 

(trees/ac)

% of All Trees 

in Land Use

% of Ash Trees in Land 

Use with d.b.h. > 18 in

Agricultural 74,724 0.1 1.1 0.0

CTI 724,326 2.0 4.7 7.7

Open Space 7,011,331 11.7 8.7 1.0

Residential 4,881,868 6.2 9.0 7.3

Chicago Region 12,692,249 4.8 8.08 3.8

Illinois Department of Agriculture
32

Th e expected loss of ash species to EAB will have a signifi cant impact on the forest 

across the entire region (Table 15). Ash is commonly found in association with other 

species, so the eff ect of its loss will be somewhat diff use. Th e impact may be especially 

great in cities where green ash has traditionally been planted due to its ability to 

do relatively well in harsh urban environments. In some residential areas and along 

transportation routes, the loss of ash will be a signifi cant loss of tree cover because large 

ash trees are a major portion of the landscape. Tree removal costs will be substantial 

for municipalities and residents. It will be important to identify other species that can 

fi ll the important role that ash has played in the Chicago regional forest in order to 

sustain the urban forest and the important benefi ts that it provides. Th is will include 

improving diffi cult sites so that a wider range of species can be planted and guarding 

against catastrophic losses of important species such as ash.

European Buckthorn Prominence

Since European buckthorn is so common in the Chicago region, it is important to 

understand its current distribution, its rank relative to other trees in the region, and its 

spread as an invasive species.

Distribution

European buckthorn is the most common species in the Chicago region based on 

the number of individual trees (28.2 percent of the total tree population). It is also 

the most dominant species in all land use categories in terms of number of trees. 

European buckthorn ranges from 24 percent of the total number of trees in residential 

to 34 percent in agricultural areas (Appendix II, Fig. 30). Th e variation in density of 

European buckthorn in diff erent land uses (Table 16) refl ects the overall diff erence in 

the number of trees in each land use. Despite its dominance in the region as a whole, 

it is not the most common tree in all parts of the region, particularly in the city of 

Chicago. It also comprises a lower proportion of the tree population in rural Kane, 

Kendall, and Will Counties.

Th e large number of European buckthorn trees could be the result of several diff erent 

scenarios: a few areas with an extremely high number of trees; many areas with a small 

number of trees; or a combination of both. European buckthorn can form very dense 

stands of trees. Th e highest density of European buckthorn trees in a plot recorded 

Table 15.—Ash trees by county, Chicago region, 2010

County/Area Number of Trees Density (trees/ac) % Trees in Area

City of Chicago 407,380 2.8 11.3

Suburban Cook County 3,240,664 7.0 7.5

DuPage County 1,539,986 7.2 8.9

Kane County 180,746 0.5 1.8

Kendall County 221,619 1.1 4.2

Lake County 3,020,392 10.1 9.0

McHenry County 1,228,076 3.1 5.5

Will County 2,853,386 5.3 13.0

Veta Bonnewell, Morton Arboretum, used with 

permission
33

in this study was 920 trees per acre. Nine percent of the study plots with European 

buckthorn had a density of greater than 500 trees/acre, while 53 percent had a density 

of 10 to 100 trees/acre.

Th e highest density of European buckthorn for the entire region occurs in the 

open space land use (41 trees/ac). In general, the counties with the lowest human 

population density and with the most agriculture (Kendall and Will) have the lowest 

density of European buckthorn (Table 17). However, the density of European 

buckthorn in McHenry County (20.4 trees/ac), a rural county, is closer to the density 

of the suburban counties (20.6 to 45.8 trees/ac) rather than the density in other 

rural counties (4.2 to 15.4). Th e distribution of European buckthorn in McHenry 

is unusual in that the density in residential land use is the highest of any county 

(34 trees/ac). Th e density in McHenry is also higher in the open space land use (50 

trees/ac) than in other rural counties (24 trees/acre). Th is suggests thatsome factor in 

addition to land use is important in European buckthorn distribution in the region.

Table 16.—Characteristics of European buckthorn by area, Chicago region, 2010

Area

Density

(trees/acre) % of Popa % Leaf Areab

City of Chicago 1.1 4.4 0.7

Suburban Cook County 28.9 31.1 7.9

DuPage County 20.6 25.4 4.2

Kane County 4.6 15.4 1.9

Kendall County 1.1 4.2 0.6

Lake County 45.8 40.9 12.0

McHenry County 20.4 35.7 7.2

Will County 5.2 12.9 3.7

Chicago Region 17.0 28.2 6.5

a % of Pop – Percent of tree population in the area. For example, European buckthorn is 4.4% of 

all the trees in the city of Chicago

b % Leaf Area – Percent of leaf area in the area. For example, the leaf area of European buckthorn 

is 0.7% of the leaf area in the city of Chicago

Table 17.—Density of European buckthorn density by land use, Chicago region, 2010

Agricultural 

(trees/ac)

CTI 

(trees/ac)

Open Space 

(trees/ac)

Residential 

(trees/ac)

All Land Use 

(trees/ac)

Chicago Region 2.8 12.5 40.9 16.4 17.0

Counties grouped by population density

Urban (Chicago) - 0.8 5.2 0.0 1.1

Suburban (DuPage, Lake, suburban Cook) 25.7 22.1 61.0 19.0 32.3

Rural (Kane, Kendall, McHenry, Will) 1.1 0.0 24.0 16.6 8.5

Counties grouped by geographic location

North (Lake, McHenry) 7.1 45.7 64.4 23.8 31.4

Middle (Kane, DuPage, suburban Cook, Chicago) 3.5 7.7 40.1 14.4 16.8

South (Will, Kendall) 0.0 0.0 9.8 12.6 4.1
34

One such factor aff ecting the distribution of European buckthorn may be geographic 

location. When the counties are grouped into three clusters roughly based on their 

north-south geographic positions, the density of European buckthorn decreases across 

all land use types moving from north to south (Table 17). Th is suggests that there may 

have been a pattern of introduction and spread of the species from north to south.

Importance and Value

While European buckthorn is a common tree in the Chicago region, its importance 

depends on which characteristic is being evaluated. European buckthorn comprises 

28 percent of stems (i.e., the most common), yet it has 2.4 percent of the total carbon 

stored by trees. Table 18 shows where European buckthorn ranks relative to other 

species in the Chicago region based on several parameters. Th e rankings refl ect how 

tree size is related to the measured characteristic. European buckthorn is a small tree 

with 95 percent of the trees having a stem diameter less than 6 inches and almost none 

greater than 12 inches. European buckthorn is the fourth most important species when 

ranked in order of the amount of leaf area (Table 3). Th e top three trees ranked by leaf 

area are silver maple, box elder, and green ash (Figure 13). Th ese three are common 

trees that can grow to a much greater size (Figure 8). Since these species have lower 

numbers but higher leaf surface area than European buckthorn, they have a greater 

average leaf area per tree. Related to the large leaf area, European buckthorn annually 

sequesters the most carbon (9.1 percent of the total estimated carbon sequestered). 

However, more carbon is stored by trees with larger trunks, so European buckthorn is 

not the top species for carbon storage.

Compensatory value is an estimate of the monetary value of a tree calculated from 

the cost of a tree of replaceable size. Using the estimate of the compensatory value, 

European buckthorn ranks as the sixth most valuable species. Awareness of the 

invasiveness of European buckthorn has increased since the data used for compensatory 

value calculations were published in 1994. Th us considering the invasive characteristics 

of this species, the compensatory value estimate is likely to be overestimated.

Other values can be calculated based on the various functions that a tree performs as 

discussed in the section “Structural and Functional Values.” Invasiveness is not a factor 

in these calculations and because the species is so common, European buckthorn ranks 

high among all species in many of these parameters (Table 18).

Table 18.—European buckthorn as percent of total and rank relative 

to other species, Chicago region, 2010

Parameter Percent of Total Rank

Number of trees 28.2 1

Carbon Sequestered 9.1 1

Net Carbon Sequestered 12.0 1

Carbon Stored 2.4 12

Leaf Area 6.5 4

Leaf Biomass 3.9 9

Compensatory Value ($) 4.3 6
35

Invasive Species Issues

As indicated by its common name, European buckthorn is not native to this area. It 

was imported to the region25 in the mid-1800s as an ornamental. Its rapid growth to 

produce dense thickets and tolerance of many soil and light conditions were attractive 

features. However, these same features combined with rapid reproduction from seed 

distributed by birds allowed European buckthorn to spread into natural areas. By the 

1930s the nursery industry recognized the problem and stopped widespread sales of 

the plant.25

Since European buckthorn is not native to Illinois, its high density in open space land 

illustrates the invasiveness of this species through natural regeneration. In 1923 Joy 

Morton collected European buckthorn on the Morton Arboretum grounds in DuPage 

County with a note that it was “spontaneous.” Th us, the current distribution of 

European buckthorn in the Chicago region is the result of at least 80, and quite likely 

more than 100, years of natural reproduction in the region. Th e pattern of distribution 

in the region suggests that the initial planting and/or subsequent reproduction have 

been successful in the residential and open spaces in suburban areas.

After so long a time, has the European buckthorn population reached a state of 

equilibrium, at least in some parts of the region? Extensive tree data in Chicago, 

suburban Cook, and DuPage Counties were collected in 1994.26 Since then, the 

number of European buckthorn trees has decreased 32 percent in the city of Chicago. 

For both suburban Cook and DuPage Counties the number of European buckthorn 

trees was 2.5 times greater in 2010 than in 1994. Th is suggests that there is the 

potential for further increase in the numbers of European buckthorn if development 

occurs in more rural areas where numbers are currently lower.

European buckthorn has long been known to be invasive and its removal from some 

natural areas, while locally signifi cant, appears to have had little impact in distribution 

across the region. Th is suggests that a signifi cant coordinated eff ort would be required 

to reduce the overall magnitude of the species in the region. Th e counties where 

European buckthorn is not as prevalent may be able to institute policies and actions to 

limit its impact as suburbanization occurs.
36

CONCLUSION

Th e Chicago regional forest contributes signifi cantly 

to the environment, the economy, and residents' 

well-being. From the core of the city to the 

agricultural areas on the periphery, 157,142,000 

trees, representing 161 species, provide a canopy 

cover of 15.5 percent across the region. Th at 

canopy, and particularly leaf surface area, provides 

a wide range of important environmental benefi ts 

including air pollution removal, reduced carbon 

emissions, carbon storage and sequestration, and 

reduced energy use for buildings, among many 

other contributions.

Th ere are a number of forces for change that are 

likely to have major, mostly negative, impacts 

on the region’s forest structure, health, and the environmental 

benefi ts provided to the region’s 9 million residents. Th ese forces include insects and disease 

infestation, invasive trees and other plants, land use change, changing infrastructure, aging and 

loss of larger trees, expansion of opportunistic species, and changes in the management and use 

of the forest. Th ese forecasted changes have prompted three Morton Arboretum researchers to 

characterize the Chicago region’s forest as being in a “transitional state” in a recent scientifi c 

paper.27 Many of the possible transition scenarios would reduce the vitality and sustainability 

of the forest and signifi cantly reduce the benefi ts provided.

To sustain and enhance the forest and the benefi ts it contributes amidst these major challenges, 

a comprehensive and integrated management strategy must be developed and implemented 

across the region. Th e strategy—the Regional Trees Initiative—will serve as a collaborative 

action roadmap to conserve, protect, enhance, and sustain the region’s forest. A coalition of 

organizations that can infl uence, or are infl uenced by, the regional forest and the benefi ts 

that it provides will be critical to the strategy. Th e coalition members will come from diverse 

areas of the public, private, not-for-profi t, and community sectors and will work together 

to better understand, communicate, and address the benefi ts and challenges of the region’s 

forest. Scientifi c knowledge, combined with current and future threats and forecasted forest 

conditions, will inform goals, opportunities, and the promise of collaborative management.

Th e primary goal of the Regional Trees Initiative is to achieve meaningful and sustained 

tree and forest improvements for the Chicago region resulting in substantial sustained 

improvements in environmental quality and human health and well-being. Th e development 

and implementation of the Regional Trees Initiative will inspire residents, landowners, and 

communities to plant and protect trees, and provide stewardship to ensure the incredible 

resources our trees provide. Th ese inspired stakeholders are the critical owners of our future 

forest and, as such, will serve as the ambassadors for this important eff ort.

Th e “Tree Census” and analysis summarized here are the platform on which to build the 

strategy—taking action for the benefi t of the entire Chicago region and beyond.

Morton Arboretum, used with permission
37

APPENDIX I. SPECIES SAMPLED IN THE CHICAGO REGIONAL FOREST

Table 19.—Speciesa sampled in the urban forest, Chicago Region, 2010

Genus Species Common Name

Number of 

Trees

Pop

%

Leaf 

Area 

% IVb

Median 

stem d.b.h.

(in)

Avg. stem 

d.b.h.

 (in)

Basal Area

(ft2

)

c

Structural 

Value

($ Millions)

Abies balsamea balsam fir 205,390 0.1 0.1 0.2 3.6 3.7 20,612 10.2

Acer ginnala amur maple 744,480 0.5 0.2 0.7 3.3 3.8 98,638 65.0

Acer negundo boxelder 8,597,890 5.5 7.9 13.4 4.4 6.7 4,049,814 1,773.5

Acer nigrum black maple 69,910 0.0 0.0 0.0 1.6 2.3 4,213 6.6

Acer palmatum Japanese maple 36,060 0.0 0.0 0.0 2.5 2.6 2,030 1.6

Acer platanoides Norway maple 1,858,800 1.2 3.6 4.8 5.7 8.6 1,319,139 1,397.9

Acer rubrum red maple 340,290 0.2 0.7 0.9 13.2 13.6 504,705 566.3

Acer saccharinum silver maple 3,209,940 2.0 8.3 10.3 10.6 13.3 5,497,028 4,330.8

Acer saccharum sugar maple 4,457,170 2.8 3.3 6.1 2.5 4.2 1,149,169 1,627.8

Acer species maple spp 1,980 0.0 0.0 0.0 19.5 19.5 4,328 4.9

Acer x freemanii Freeman maple 280,470 0.2 0.3 0.5 4.1 4.3 39,109 31.3

Aesculus glabra Ohio buckeye 64,160 0.0 0.2 0.2 8.8 17.6 179,716 149.7

Aesculus hippocastanum horsechestnut 40,250 0.0 0.0 0.0 3.5 3.2 3,293 1.6

Aesculus species buckeye spp 4,020 0.0 0.0 0.0 3.0 5.5 977 0.9

Ailanthus altissima tree-of-heaven 1,830,940 1.2 0.7 1.9 3.1 4.2 341,516 186.4

Alnus glutinosa European alder 382,610 0.2 0.2 0.4 3.0 4.1 69,725 52.4

Amelanchier arborea downy serviceberry 57,460 0.0 0.0 0.0 4.5 4.6 8,509 5.0

Amelanchier species serviceberry spp 163,110 0.1 0.0 0.1 2.3 2.4 8,003 7.6

Betula nigra river birch 552,800 0.4 0.4 0.8 3.3 5.2 146,506 168.0

Betula papyrifera paper birch 352,400 0.2 0.2 0.4 5.0 6.3 118,950 75.6

Betula populifolia gray birch 145,590 0.1 0.1 0.2 2.7 3.3 12,500 7.8

Carpinus betulus European hornbeam 99,760 0.1 0.0 0.1 3.5 3.6 10,217 4.8

Carpinus caroliniana American hornbeam 26,130 0.0 0.0 0.0 2.5 2.5 1,283 1.4

Carya alba mockernut hickory 121,430 0.1 0.0 0.1 2.7 3.3 11,596 10.3

Carya cordiformis bitternut hickory 186,540 0.1 0.1 0.2 2.8 3.6 23,163 17.7

Carya laciniosa shellbark hickory 9,750 0.0 0.0 0.0 1.5 1.5 213 0.5

Carya ovata shagbark hickory 1,711,410 1.1 0.8 1.9 3.1 4.2 316,063 319.6

Carya species hickory spp 70,090 0.0 0.0 0.0 2.5 2.8 5,374 4.5

Castanea mollissima Chinese chestnut 11,090 0.0 0.0 0.0 18.5 18.5 21,826 9.6

Catalpa species catalpa spp 7,940 0.0 0.0 0.0 18.0 19.0 17,729 14.0

Catalpa speciosa northern catalpa 59,440 0.0 0.1 0.1 3.9 14.2 124,520 102.2

Celtis occidentalis northern hackberry 1,020,060 0.6 0.9 1.5 3.3 5.7 386,617 561.3

Celtis species hackberry spp 5,950 0.0 0.0 0.0 1.3 1.3 97 0.3

Cercidiphyllum japonicum katsura tree 11,090 0.0 0.0 0.0 7.5 7.5 3,869 3.4

Cercis canadensis astern redbud 110,420 0.1 0.0 0.1 5.1 6.4 47,035 48.2

Cornus alternifolia alternateleaf dogwood 34,590 0.0 0.0 0.0 0.0 1.3 672 1.5

Cornus florida flowering dogwood 81,590 0.1 0.0 0.1 2.6 3.7 11,547 4.6

Cornus mas cornelian cherry 11,090 0.0 0.0 0.0 6.5 6.5 2,963 3.2

Cornus racemosa gray dogwood 68,010 0.0 0.0 0.0 1.5 1.5 1,484 2.7

Cornus species dogwood spp 246,200 0.2 0.0 0.2 2.1 2.4 13,165 8.3

Corylus avellana European filbert 17,440 0.0 0.0 0.0 3.5 3.5 1,522 0.6

Cotinus coggygria smoke tree 13,070 0.0 0.0 0.0 3.6 4.1 1,660 1.2

continued
38

Crataegus crus-galli cockspur hawthorn 320,200 0.2 0.1 0.3 3.1 3.8 38,567 26.3

Crataegus mollis downy hawthorn 1,203,680 0.8 0.3 1.1 3.4 4.1 190,978 132.6

Crataegus phaenopyrum Washington hawthorn 23,100 0.0 0.0 0.0 4.2 5.5 5,949 5.2

Crataegus species hawthorn spp 1,895,670 1.2 0.7 1.9 3.9 4.5 329,703 217.3

Elaeagnus angustifolia Russian olive 54,970 0.0 0.0 0.0 3.5 4.6 9,275 4.8

Elaeagnus umbellata autumn olive 228,040 0.1 0.1 0.2 3.4 3.8 28,470 22.5

Euonymus alatus winged burningbush 148,650 0.1 0.0 0.1 2.3 2.4 7,987 5.2

Euonymus atropurpurea eastern wahoo 46,320 0.0 0.0 0.0 4.9 5.1 8,501 6.7

Fagus sylvatica European beech 20,240 0.0 0.0 0.0 3.5 3.5 1,766 1.3

Forsythia species forsythia spp 104,650 0.1 0.0 0.1 1.4 1.4 1,997 4.6

Frangula alnus glossy buckthorn 500,900 0.3 0.1 0.4 2.2 2.3 24,009 16.7

Fraxinus americana white ash 4,025,410 2.6 2.5 5.1 3.4 5.0 1,172,765 1,016.8

Fraxinus nigra black ash 2,040 0.0 0.0 0.0 7.5 7.5 712 0.5

Fraxinus pennsylvanica green ash 8,657,000 5.5 7.1 12.6 3.8 5.8 3,082,162 3,180.8

Fraxinus species ash spp 9,830 0.0 0.0 0.0 1.6 2.3 561 0.3

Ginkgo biloba ginkgo 199,650 0.1 0.1 0.2 1.5 4.1 78,383 109.8

Gleditsia triacanthos honeylocust 997,510 0.6 1.3 1.9 10.9 12.2 1,274,034 1,660.9

Gymnocladus dioicus Kentucky coffeetree 33,380 0.0 0.1 0.1 23.3 17.2 74,207 83.4

Hamamelis virginiana witch hazel 206,360 0.1 0.0 0.1 2.2 2.6 14,295 7.2

Hardwood species hardwood 5,561,440 3.5 0.0 3.5 3.0 4.5 1,313,392 0.0

Hibiscus syriacus rose-of-Sharon 77,240 0.0 0.0 0.0 2.4 2.2 3,297 3.4

Juglans nigra black walnut 2,469,240 1.6 5.7 7.3 5.8 7.6 1,367,988 1,110.8

Juniperus species juniper spp 570,600 0.4 0.1 0.5 3.5 3.8 75,967 62.5

Juniperus virginiana eastern redcedar 563,500 0.4 0.2 0.6 6.1 6.6 186,138 172.3

Ligustrum species privet spp 28,830 0.0 0.0 0.0 2.2 2.1 1,134 1.3

Ligustrum vulgare common privet 7,940 0.0 0.0 0.0 2.5 2.5 411 0.4

Liquidambar styraciflua sweetgum 17,090 0.0 0.0 0.0 5.4 5.9 4,627 4.5

Liriodendron tulipifera yellow-poplar 17,440 0.0 0.1 0.1 11.5 11.5 13,698 15.3

Lonicera maackii amur honeysuckle 3,370,400 2.1 0.5 2.6 2.0 2.4 196,254 173.7

Lonicera species honeysuckle spp 1,559,430 1.0 0.2 1.2 2.1 2.6 102,200 81.3

Maclura pomifera Osage orange 80,910 0.1 0.1 0.2 11.7 14.7 123,433 139.8

Magnolia denudata Chinese magnolia 5,950 0.0 0.0 0.0 2.5 4.5 1,223 1.3

Magnolia species magnolia spp 202,990 0.1 0.1 0.2 4.1 5.4 58,234 60.2

Magnolia stellata star magnolia 69,320 0.0 0.0 0.0 3.5 3.6 6,954 4.5

Magnolia x soulangiana saucer magnolia 26,030 0.0 0.0 0.0 3.9 6.1 7,350 7.8

Malus pumila paradise apple 3,970 0.0 0.0 0.0 10.0 11.0 2,912 2.8

Malus species apple spp 1,724,980 1.1 1.4 2.5 5.8 6.8 672,523 594.1

Morus alba white mulberry 1,584,250 1.0 0.8 1.8 4.6 5.9 581,977 523.7

Morus rubra red mulberry 66,440 0.0 0.1 0.1 11.5 11.8 69,575 73.4

Morus species mulberry spp 2,653,100 1.7 1.4 3.1 3.7 5.3 843,366 704.3

Ostrya virginiana eastern hophornbeam 602,120 0.4 0.3 0.7 2.8 3.6 72,564 55.1

Other species other species 131,860 0.1 0.0 0.1 3.0 4.9 42,281 0.0

Phellodendron amurense amur corktree 66,490 0.0 0.0 0.0 3.3 5.2 15,740 16.7

continued

Appendix I.—continued

Table 19.—Speciesa sampled in the urban forest, Chicago Region, 2010

Genus Species Common Name

Number of 

Trees

Pop

%

Leaf 

Area 

% IVb

Median 

stem d.b.h.

(in)

Avg. stem 

d.b.h.

 (in)

Basal Area

(ft2

)

c

Structural 

Value

($ Millions)
39

Picea abies Norway spruce 377,510 0.2 0.6 0.8 9.7 10.9 333,995 347.3

Picea glauca white spruce 1,786,850 1.1 0.8 1.9 4.1 4.6 312,969 177.0

Picea omorika Serbian spruce 78,160 0.0 0.0 0.0 2.0 2.0 2,810 3.9

Picea pungens blue spruce 1,107,240 0.7 1.2 1.9 5.7 6.7 436,958 467.0

Picea species spruce spp 70,810 0.0 0.0 0.0 3.4 4.6 14,230 12.4

Pinus banksiana jack pine 25,720 0.0 0.0 0.0 10.0 10.0 15,502 9.8

Pinus densiflora Japanese red pine 11,090 0.0 0.0 0.0 6.5 6.5 2,963 2.3

Pinus nigra Austrian pine 983,160 0.6 0.8 1.4 8.3 8.0 457,247 411.3

Pinus resinosa red pine 15,010 0.0 0.0 0.0 10.3 8.8 7,754 6.5

Pinus species pine spp 67,980 0.0 0.0 0.0 5.1 5.2 12,917 1.2

Pinus strobus eastern white pine 1,525,970 1.0 1.5 2.5 9.0 9.6 1,011,104 1,157.0

Pinus sylvestris scotch pine 23,500 0.0 0.0 0.0 6.5 6.5 6,281 5.0

Platanus occidentalis American sycamore 7,970 0.0 0.1 0.1 26.0 20.9 23,415 25.5

Platanus species sycamore spp 130,350 0.1 0.2 0.3 2.6 8.1 106,429 85.8

Populus alba white poplar 95,600 0.1 0.6 0.7 25.9 28.7 498,858 268.4

Populus deltoides eastern cottonwood 2,198,060 1.4 3.7 5.1 8.8 12.4 3,551,011 1,702.6

Populus species cottonwood spp 11,870 0.0 0.0 0.0 7.0 9.5 15,519 9.9

Populus tremuloides quaking aspen 230,070 0.1 0.1 0.2 3.9 3.6 22,703 10.0

Prunus americana American plum 150,100 0.1 0.0 0.1 1.9 2.7 10,923 10.1

Prunus cerasifera cherry plum 157,440 0.1 0.1 0.2 2.8 4.1 22,444 13.5

Prunus pensylvanica pin cherry 40,550 0.0 0.0 0.0 1.9 3.2 3,929 1.8

Prunus persica peach 107,320 0.1 0.0 0.1 1.9 2.2 4,786 3.4

Prunus sargentii sargent cherry 80,070 0.1 0.0 0.1 4.0 5.1 21,415 15.7

Prunus serotina black cherry 7,737,030 4.9 4.8 9.7 4.5 5.8 2,499,170 1,860.4

Prunus serrulata kwanzan cherry 14,270 0.0 0.0 0.0 9.5 9.4 9,018 5.7

Prunus species plum spp 874,810 0.6 0.2 0.8 2.2 3.1 87,634 51.8

Prunus virginiana common chokecherry 114,910 0.1 0.0 0.1 1.5 2.0 5,190 4.0

Pseudotsuga menziesii Douglas-fir 108,410 0.1 0.1 0.2 5.5 6.4 38,838 31.4

Pyrus calleryana callery pear 257,690 0.2 0.1 0.3 5.1 5.7 64,720 57.4

Pyrus communis common pear 266,140 0.2 0.2 0.4 6.5 7.9 136,883 129.8

Pyrus species pear spp 11,960 0.0 0.0 0.0 5.5 6.5 4,053 3.8

Quercus alba white oak 1,857,380 1.2 3.5 4.7 15.1 15.2 3,604,278 4,852.2

Quercus bicolor swamp white oak 104,750 0.1 0.3 0.4 19.6 17.7 256,312 430.3

Quercus ellipsoidalis northern pin oak 20,240 0.0 0.0 0.0 9.5 9.5 11,039 9.7

Quercus imbricaria shingle oak 23,500 0.0 0.0 0.0 6.5 6.5 6,281 7.1

Quercus macrocarpa bur oak 1,603,410 1.0 4.7 5.7 20.5 19.4 4,890,638 6,481.1

Quercus muehlenbergii chinkapin oak 79,770 0.1 0.1 0.2 2.9 10.6 124,659 144.0

Quercus palustris pin oak 360,430 0.2 0.6 0.8 11.6 11.6 375,959 408.1

Quercus rubra northern red oak 3,087,850 2.0 3.7 5.7 7.3 9.8 2,957,124 3,110.2

Quercus species oak spp 109,680 0.1 0.0 0.1 3.5 4.1 14,120 0.0

Quercus velutina black oak 53,670 0.0 0.0 0.0 2.7 5.3 16,320 12.0

Quercus x macnabiana Macnab’s oak 6,010 0.0 0.0 0.0 11.5 12.8 8,962 10.3

Rhamnus cathartica European buckthorn 44,281,470 28.2 6.5 34.7 2.1 2.6 2,924,581 2,198.6

continued

Appendix I.—continued

Table 19.—Speciesa sampled in the urban forest, Chicago Region, 2010

Genus Species Common Name

Number of 

Trees

Pop

%

Leaf 

Area 

% IVb

Median 

stem d.b.h.

(in)

Avg. stem 

d.b.h.

 (in)

Basal Area

(ft2

)

c

Structural 

Value

($ Millions)
40

Appendix I.—continued

Rhamnus species rhamnus spp 83,300 0.1 0.0 0.1 2.8 3.4 8,993 5.1

Rhus hirta staghorn sumac 1,980 0.0 0.0 0.0 14.5 14.5 2,435 0.4

Rhus species sumac spp 390,400 0.2 0.1 0.3 2.2 2.8 29,699 28.0

Robinia pseudoacacia black locust 2,972,090 1.9 1.9 3.8 7.2 7.3 1,225,674 852.0

Salix amygdaloides peachleaf willow 77,720 0.0 0.0 0.0 7.0 8.1 40,196 19.2

Salix discolor pussy willow 55,420 0.0 0.0 0.0 4.8 7.5 27,448 20.6

Salix exigua narrowleaf willow 2,040 0.0 0.0 0.0 1.5 1.5 44 0.1

Salix nigra black willow 44,830 0.0 0.1 0.1 18.5 17.2 77,995 58.5

Salix species willow spp 1,349,650 0.9 0.9 1.8 2.9 6.3 847,465 546.8

Salix x sepulcralis 

simonk weeping willow 11,090 0.0 0.0 0.0 18.5 18.5 21,826 17.9

Sambucus nigra s 

canadensis common elderberry 197,340 0.1 0.0 0.1 1.8 2.0 7,350 7.9

Sassafras albidum sassafras 47,370 0.0 0.0 0.0 1.5 1.5 1,033 1.9

Softwood species softwood 59,220 0.0 0.0 0.0 2.7 5.8 19,503 0.0

Syringa reticulata Japanese tree lilac 19,020 0.0 0.0 0.0 5.1 3.9 2,371 1.5

Syringa species lilac spp 789,950 0.5 0.1 0.6 2.3 2.7 54,642 48.0

Syringa vulgaris common lilac 109,050 0.1 0.0 0.1 3.2 3.2 9,338 4.1

Taxodium distichum baldcypress 26,030 0.0 0.0 0.0 4.1 3.6 2,582 2.1

Taxus species yew spp 315,130 0.2 0.1 0.3 4.4 4.5 52,862 43.2

Thuja occidentalis northern white-cedar 2,457,220 1.6 0.7 2.3 3.5 4.5 504,051 573.6

Tilia americana American basswood 822,780 0.5 0.9 1.4 6.0 7.2 411,763 438.3

Tilia cordata littleleaf linden 243,320 0.2 0.6 0.8 8.5 10.1 181,431 219.0

Tilia species basswood spp 71,040 0.0 0.1 0.1 4.9 6.2 29,354 32.2

Tilia tomentosa silver linden 3,970 0.0 0.0 0.0 4.0 14.5 7,490 9.2

Tsuga canadensis eastern hemlock 268,660 0.2 0.2 0.4 4.7 5.0 62,441 58.7

Ulmus americana American elm 5,363,030 3.4 4.1 7.5 4.0 5.4 1,631,337 653.1

Ulmus parvifolia Chinese elm 13,900 0.0 0.0 0.0 6.5 11.4 19,022 20.6

Ulmus pumila Siberian elm 2,240,590 1.4 3.2 4.6 5.5 8.0 1,610,478 939.4

Ulmus rubra slippery elm 453,470 0.3 0.2 0.5 2.8 4.7 123,691 46.0

Ulmus species elm spp 177,320 0.1 0.0 0.1 4.2 5.7 51,676 2.5

Unknown species unknown 21,920 0.0 0.0 0.0 6.2 8.5 14,295 16.7

Viburnum lentago nannyberry 69,310 0.0 0.0 0.0 1.7 1.8 2,142 2.3

Viburnum opulus v 

americanum

American 

cranberrybush 1,980 0.0 0.0 0.0 3.5 3.5 173 0.1

Viburnum prunifolium black haw 68,650 0.0 0.0 0.0 2.2 2.3 3,338 3.4

Viburnum rhytidophyllum leather leaf viburnum 17,440 0.0 0.0 0.0 1.5 1.5 381 0.6

Viburnum species viburnum spp 363,230 0.2 0.0 0.2 2.2 2.3 16,899 15.1

Zanthoxylum americanum common prickly ash 207,940 0.1 0.0 0.1 1.4 1.4 4,159 9.2

Zelkova serrata Japanese zelkova 11,090 0.0 0.0 0.0 1.5 1.5 242 0.4

a Species refers to tree species, genera, or species groups that were classified during field data collection

b IV = importance value (% population + % leaf area)

c Basal area is the cross sectional area of the tree stems measured at d.b.h.

Table 19.—Speciesa sampled in the urban forest, Chicago Region, 2010

Genus Species Common Name

Number of 

Trees

Pop

%

Leaf 

Area 

% IVb

Median 

stem d.b.h.

(in)

Avg. stem 

d.b.h.

 (in)

Basal Area

(ft2

)

c

Structural 

Value

($ Millions)
41

APPENDIX II. TREE SPECIES DISTRIBUTION

Th is appendix illustrates various species distributions for the Chicago regional forest. 

During fi eld data collection, sampled trees are identifi ed to the most specifi c classifi cation 

possible. Some trees have been identifi ed to the species or genus level. Th e designations of 

“hardwood” or “softwood” include the sampled trees that could not be identifi ed as a more 

specifi c species or genera classifi cation.

Th e species distributions for each land use are illustrated for the 20 most common species 

or all species if there are less than 20 species in the land use category (Figures 30-75). More 

detailed information on species by land use can be found at: http://nrs.fs.fed.us/data/urban.

Tree Species Distribution in the Chicago Region

Figure 29.—The 20 most common tree species as a percent of the total urban tree population, 

Chicago region, 2010.

0 5 10 15 20 25 30

White oak

Norway maple

Hawthorn spp

Eastern cottonwood

Siberian elm

Northern white-cedar

Black walnut

Mulberry spp

Black locust

Northern red oak

Silver maple

Amur honeysuckle

White ash

Sugar maple

American elm

Hardwood

Black cherry

Boxelder

Green ash

European buckthorn

Tree Population (percent) 

Species 
42

Figure 30.—The percent land use a tree population occupied for the 10 most common tree 

species, Chicago region, 2010. For example, European buckthorn comprises 34 percent of the 

Agriculture tree population.

Figure 31.—The percent county tree population occupied by the 10 most common tree species, 

Chicago region, 2010. For example, European buckthorn comprises 41 percent of the Lake 

County tree population.

0

5

10

15

20

2

0

35

European

buckthorn

Green ash Boxelder Black cherry Hardwood American

elm

Sugar maple White ash Amur

honeysuckle

Silver maple

Land Use 7UHHPopulation (percent) 

Species 

Agriculture CTI

Open Space Residential

Land8se 

0

5

10

15

20

25

30

35

40

45

European

buckthorn

Green ash Boxelder Black cherry Hardwood American

elm

Sugar maple White ash Amur

honeysuckle

Silver maple

Area 7UHHPopulation (percent) 

Species 

City of Chicago Suburban Cook County

DuPage County Kane County

Kendall County Lake County

McHenry County Will County

Area 
43

Figure 32.—The percent of tree species population in each land use category, Chicago region, 

2010. For example, 77 percent of black cherry is found within Open Space land use.

Figure 33.—The percent of species population within each area, Chicago region, 2010. For 

example, 63 percent of sugar maple is found within Will County.

0

10

20

30

40

50

60

70

80

European

buckthorn

Green ash Boxelder Black cherry Hardwood American

elm

Sugar maple White ash Amur

honeysuckle

Silver maple

7UHHSpecies Population (percent) 

Species 

Agriculture

CTI

Open Space

Residential

Land8se 

0

10

20

30

40

50

60

70

European

buckthorn

Green ash Boxelder Black cherry Hardwood American

elm

Sugar maple White ash Amur

honeysuckle

Silver maple

7UHHSpecies Population (percent) 

Species 

City of Chicago Suburban Cook County

DuPage County Kane County

Kendall County Lake County

McHenry County Will County

Area 
44

Figure 34.—Percent of trees in Residential category of land use, Chicago region, 2010.

Figure 35.—Percent of trees in Agriculture category of land use, Chicago region, 2010.

0 5 10 15 20 25

Amur honeysuckle

Lilac spp

White mulberry

Sugar maple

Blue spruce

Mulberry spp

Northern red oak

Black cherry

American elm

Apple spp

Siberian elm

Norway maple

Hardwood

White spruce

White ash

Silver maple

Northen white-cedar

Green ash

Boxelder

European buckthorn

Percent of Trees 

Species 

0 5 10 15 20 25 30 35 40

White oak

Flowering dogwood

Amur honeysuckle

Sycamore spp

Apple spp

Black walnut

Cherry plum

White spruce

White mulberry

Plum spp

Hardwood

Ginkgo

Balsam fir

Black cherry

Shagbark hickory

Eastern white pine

Siberian elm

Boxelder

Mulberry spp

European buckthorn

Percent of Trees 

Species 
45

Figure 36.—Percent of trees in Commercial/Transportation/Institution (CTI) category of land use, 

Chicago region, 2010.

Figure 37.—Percent of trees in Open Space category of land use, Chicago region, 2010.

0 5 10 15 20 25 30

Honeysuckle spp

Honeylocust

Apple spp

Black walnut

Amur honeysuckle

Slippery elm

Eastern white pine

Northen white-cedar

Hardwood

Mulberry spp

Juniper spp

Black cherry

Norway maple

Eastern cottonwood

Green ash

American elm

Boxelder

Sugar maple

Tree-of-heaven

European buckthorn

Percent of Trees 

Species 

0 5 10 15 20 25 30 35

Honeysuckle spp

Downy hawthorn

Shagbark hickory

Bur oak

White oak

Eastern cottonwood

Silver maple

Black walnut

Hawthorn spp

Northern red oak

White ash

Sugar maple

Amur honeysuckle

Black locust

American elm

Hardwood

Boxelder

Green ash

Black cherry

European buckthorn

Percent of Trees 

Species 
46

Tree Species Distribution in the City of Chicago

Figure 38.—The 20 most common tree species as a percent of the total urban tree population, 

city of Chicago, 2010.

Figure 39.—Percent of trees in Residential category of land use, city of Chicago, 2010.

01234567

Northern red oak

Yew spp

Northern hackberry

Basswood spp

Sugar maple

Rhamnus spp

Northen white-cedar

Eastern cottonwood

Honeylocust

Hawthorn spp

Boxelder

Other species

Norway maple

European buckthorn

American elm

Silver maple

Tree-of-heaven

Green ash

Mulberry spp

White ash

Tree Population (percent) 

Species 

0 2 4 6 8 10

Sugar maple

Apple spp

Eastern redcedar

Northern hackberry

Lilac spp

Honeylocust

White ash

Plum spp

Juniper spp

Boxelder

Blue spruce

Siberian elm

Yew spp

Green ash

Tree-of-heaven

American elm

Northern white-cedar

Norway maple

Silver maple

Mulberry spp

Percent of Trees 

Species 
47

Figure 40.—Percent of trees in Commercial/Transportation/Institution (CTI) category of land use, 

city of Chicago, 2010.

Figure 41.—Percent of trees in Open Space category of land use, city of Chicago, 2010.

0 2 4 6 8 10 12

Ash spp

Viburnum spp

Other species

River birch

Apple spp

Hawthorn spp

Serviceberry spp

Black haw

Norway maple

American elm

Northern hackberry

Mulberry spp

Plum spp

Green ash

Boxelder

European buckthorn

White ash

Honeylocust

Eastern cottonwood

Tree-of-heaven

Percent of Trees 

Species 

0 2 4 6 8 10 12

Northern hackberry

Norway maple

Mulberry spp

Honeylocust

Silver maple

Littleleaf linden

Black cherry

American elm

American basswood

Eastern cottonwood

Boxelder

Sugar maple

Northern red oak

Basswood spp

Green ash

Rhamnus spp

Hawthorn spp

European buckthorn

Other species

White ash

Percent of Trees 

Species 
48

Tree Species Distribution in Suburban Cook County

Figure 42.—The 20 most common tree species as a percent of the total urban tree population, 

suburban Cook County, 2010.

Figure 43.—Percent of trees in Residential category of land use, suburban Cook County, 2010.

0 5 10 15 20 25 30 35

Hawthorn spp

Honeysuckle spp

Mulberry spp

Northen white-cedar

Silver maple

Amur maple

Downy hawthorn

White oak

Amur honeysuckle

Eastern cottonwood

Northern red oak

White ash

Black locust

Tree-of-heaven

American elm

Hardwood

Green ash

Boxelder

Black cherry

European buckthorn

Tree Population (percent) 

Species 

0 5 10 15 20 25 30

Black walnut

White mulberry

Plum spp

Honeylocust

Black cherry

Tree-of-heaven

Norway maple

Blue spruce

Silver maple

Apple spp

White ash

Siberian elm

Black locust

Mulberry spp

Northern white-cedar

Hardwood

American elm

Boxelder

Green ash

European buckthorn

Percent of Trees 

Species 
49

Figure 44.—Percent of trees in Agriculture category of land use, suburban Cook County, 2010.

Figure 45.—Percent of trees in Commercial/Transportation/Institution (CTI) category of 

land use, suburban Cook County, 2010.

Figure 46.—Percent of trees in Open Space category of land use, suburban Cook County, 

2010.

0 20 40 60 80

Plum spp

Black walnut

Hawthorn spp

Hardwood

Silver maple

Black cherry

European buckthorn

Percent of Trees 

Species 

0 5 10 15 20 25 30 35 40

Sumac spp

Rose-of-Sharon

Honeylocust

Green ash

Sugar maple

Norway maple

Slippery elm

Autumn olive

Amur maple

Willow spp

Austrian pine

Mulberry spp

Magnolia spp

Honeysuckle spp

Hardwood

European buckthorn

Juniper spp

American elm

Boxelder

Tree-of-heaven

Percent of Trees 

Species 

0 10 20 30 40

Shagbark hickory

Viburnum spp

Bur oak

Honeysuckle spp

Silver maple

Hawthorn spp

American elm

Amur maple

White oak

Black locust

Downy hawthorn

Boxelder

Eastern cottonwood

White ash

Amur honeysuckle

Green ash

Hardwood

Northern red oak

Black cherry

European buckthorn

Percent of Trees 

Species
50

Tree Species Distribution in DuPage County

Figure 47.—The 20 most common tree species as a percent of the total urban tree 

population, DuPage County, 2010.

Figure 48.—Percent of trees in Residential category of land use, DuPage County, 2010.

Figure 49.—Percent of trees in Agriculture category of land use, DuPage County, 2010.

0 5 10 15 20 25 30

Honeylocust

Sumac spp

American elm

Lilac spp

Eastern white pine

Mulberry spp

European alder

Silver maple

Apple spp

Slippery elm

Siberian elm

Northen white-cedar

Norway maple

Amur honeysuckle

Green ash

Hardwood

White ash

Black cherry

Boxelder

European buckthorn

Tree Population (percent) 

Species 

0 5 10 15 20 25 30

Willow spp

Callery pear

Black cherry

American elm

European hornbeam

Hardwood

Blue spruce

Mulberry spp

White mulberry

Honeylocust

Northern white-cedar

Lilac spp

Silver maple

Siberian elm

Apple spp

Boxelder

Norway maple

Green ash

White ash

European buckthorn

Percent of Trees 

Species 

0 5 10 15 20 25 30 35 40

Boxelder

Peach

European alder

Percent of Trees 

Species
51

Figure 50.—Percent of trees in Commercial/Transportation/Institution (CTI) category of land use, 

DuPage County, 2010.

Figure 51.—Percent of trees in Open Space category of land use, DuPage County, 2010.

0 10 20 30 40 50

Siberian elm

American elm

American basswood

Pin oak

Common pear

Apple spp

Norway spruce

White ash

Honeylocust

Sumac spp

Amur honeysuckle

Hardwood

Cockspur hawthorn

Mulberry spp

Slippery elm

Black cherry

Boxelder

Eastern white pine

Northern white-cedar

European buckthorn

Percent of Trees 

Species 

0 2 4 6 8 10 12 14

Mulberry spp

Bitternut hickory

Silver maple

Bur oak

Black walnut

Sugar maple

American elm

Shagbark hickory

Paper birch

Sumac spp

Northern red oak

Green ash

Slippery elm

European alder

Amur honeysuckle

White ash

Boxelder

Hardwood

Black cherry

European buckthorn

Percent of Trees 

Species 
52

Figure 52.—The 20 most common tree species as a percent of the total urban tree population, 

Kane County, 2010.

Figure 53.—Percent of trees in Residential category of land use, Kane County, 2010.

0 2 4 6 8 10 12 14 16

Northern hackberry

Eastern cottonwood

Bur oak

Green ash

Silver maple

American elm

Eastern redcedar

Downy hawthorn

Apple spp

Northern red oak

Siberian elm

Mulberry spp

Black cherry

Black walnut

White mulberry

Amur honeysuckle

Hardwood

Willow spp

Boxelder

European buckthorn

Tree Population (percent) 

Species 

0 2 4 6 8 10

Lilac spp

Common elderberry

Eastern cottonwood

Blue spruce

Green ash

White mulberry

Bur oak

Black walnut

Mulberry spp

Downy hawthorn

Silver maple

Apple spp

Eastern redcedar

Black cherry

Amur honeysuckle

Hardwood

Northern red oak

Siberian elm

Boxelder

European buckthorn

Percent of Trees 

Species 

Tree Species Distribution in Kane County
53

Figure 54.—Percent of trees in Agriculture category of land use, Kane County, 2010.

Figure 55.—Percent of trees in Commercial/Transportation/Institution (CTI) category of land 

use, Kane County, 2010.

Figure 56.—Percent of trees in Open Space category of land use, Kane County, 2010. 

0 10 20 30 40 50 60 70

Littleleaf linden

Softwood

White mulberry

Osage orange

European buckthorn

Mulberry spp

Percent of Trees 

Species 

0 5 10 15 20

White mulberry

Apple spp

Juniper spp

Honeylocust

Northern hackberry

Norway maple

Percent of Trees 

Species 

0 5 10 15 20 25

Norway spruce

Red mulberry

White oak

Eastern cottonwood

Mulberry spp

Downy hawthorn

Gray dogwood

Northern hackberry

Apple spp

Common chokecherry

Green ash

American elm

Black cherry

White mulberry

Black walnut

Amur honeysuckle

Hardwood

Boxelder

Willow spp

European buckthorn

Percent of Trees 

Species 
54

Tree Species Distribution in Kendall County

Figure 57.—The 20 most common tree species as a percent of the total urban tree population, 

Kendall County, 2010.

Figure 58.—Percent of trees in Residential category of land use, Kendall County, 2010.

0 2 4 6 8 10 12 14

Apple spp

Northern red oak

Cherry plum

Amur honeysuckle

Green ash

White ash

Downy hawthorn

Black walnut

Black locust

American basswood

Eastern hophornbeam

Northern hackberry

European buckthorn

Black cherry

Eastern white pine

Boxelder

American elm

Hardwood

Mulberry spp

Sugar maple

Tree Population (percent) 

Species 

0 5 10 15 20 25 30 35 40

Common pear

Blue spruce

Freeman maple

Black maple

American elm

American basswood

Common lilac

Peach

American plum

Eastern white pine

Silver maple

Lilac spp

Black walnut

Northern hackberry

Callery pear

Hardwood

Norway maple

Apple spp

Boxelder

Sugar maple

Percent of Trees 

Species 
55

Figure 59.—Percent of trees in Agriculture category of land use, Kendall County, 2010.

Figure 60.—Percent of trees in Open Space category of land use, Kendall County, 2010.

0 10 20 30 40 50

Lilac spp

Eastern hophornbeam

Eastern redcedar

Honeylocust

Bur oak

Common pear

Black cherry

White mulberry

Apple spp

Amur honeysuckle

Hardwood

White ash

Black walnut

Green ash

Sycamore spp

Cherry plum

Mulberry spp

Percent of Trees 

Species 

0 2 4 6 8 10

Honeysuckle spp

Black walnut

Bitternut hickory

Northern red oak

Amur honeysuckle

Green ash

Mulberry spp

White ash

Downy hawthorn

Boxelder

Black locust

American basswood

Eastern hophornbeam

Northern hackberry

European buckthorn

Sugar maple

Black cherry

Eastern white pine

American elm

Hardwood

Percent of Trees 

Species 
56

Tree Species Distribution in Lake County

Figure 61.—The 20 most common tree species as a percent of the total urban tree population, 

Lake County, 2010.

Figure 62.—Percent of trees in Residential category of land use, Lake County, 2010.

0 10 20 30 40 50

Plum spp

Silver maple

Eastern cottonwood

Apple spp

Honeysuckle spp

Hawthorn spp

Eastern hophornbeam

Norway maple

Sugar maple

White oak

American elm

Shagbark hickory

Northern red oak

Northen white-cedar

White ash

Boxelder

Black cherry

White spruce

Green ash

European buckthorn

Tree Population (percent) 

Species 

0 5 10 15 20

Eastern white pine

Blue spruce

Silver maple

Eastern cottonwood

Austrian pine

Apple spp

Witch hazel

Norway spruce

Shagbark hickory

Sugar maple

White oak

Black cherry

Norway maple

Boxelder

Northern red oak

White ash

Green ash

Northern white-cedar

White spruce

European buckthorn

Percent of Trees 

Species 
57

Figure 63.—Percent of trees in Agriculture category of land use, Lake County, 2010.

Figure 64.—Percent of trees in Commercial/Transportation/Institution (CTI) category of 

land use, Lake County, 2010.

Figure 65.—Percent of trees in Open Space category of land use, Lake County, 2010.

0 10 20 30 40 50 60 70

Black walnut

Tree-of-heaven

Willow spp

Paper birch

Flowering dogwood

Black cherry

Mulberry spp

Boxelder

European buckthorn

Percent of Trees

Species 

0 10 20 30 40 50 60 70

White mulberry

Amur honeysuckle

Bur oak

Honeysuckle spp

Northern hackberry

Red maple

American elm

White oak

White ash

Sugar maple

Austrian pine

Serviceberry spp

Northern red oak

Apple spp

Boxelder

Shagbark hickory

Black cherry

Norway maple

Green ash

European buckthorn

Percent of Trees 

Species

0 10 20 30 40 50 60

Downy hawthorn

Cockspur hawthorn

Silver maple

Bur oak

Glossy buckthorn

Black locust

Quaking aspen

Hawthorn spp

Sugar maple

Eastern hophornbeam

Honeysuckle spp

White oak

Northern red oak

Shagbark hickory

White ash

American elm

Green ash

Boxelder

Black cherry

European buckthorn

Percent of Trees 

Species 
58

Tree Species Distribution in McHenry County

Figure 66.—The 20 most common tree species as a percent of the total urban tree population, 

McHenry County, 2010.

Figure 67.—Percent of trees in Residential category of land use, McHenry County, 2010.

0 10 20 30 40

Common prickly ash

Lilac spp

White mulberry

White oak

Austrian pine

Northern red oak

Bur oak

Mulberry spp

Amur honeysuckle

American elm

Silver maple

Shagbark hickory

Siberian elm

Eastern white pine

Hardwood

Black walnut

Green ash

Black cherry

Boxelder

European buckthorn

Tree Population (percent) 

Species 

0 10 20 30 40

Siberian elm

Mulberry spp

Eastern cottonwood

Bur oak

Eastern redcedar

Forsythia spp

River birch

White oak

Black walnut

Northern red oak

Eastern white pine

Hardwood

White mulberry

Amur honeysuckle

Lilac spp

Silver maple

Austrian pine

Black cherry

Boxelder

European buckthorn

Percent of Trees 

Species 
59

Figure 68.—Percent of trees in Agriculture category of land use, McHenry County, 2010.

Figure 69.—Percent of trees in Commercial/Transportation/Institution (CTI) category of 

land use, McHenry County, 2010.

Figure 70.—Percent of trees in Open Space category of land use, McHenry County, 2010.

0 5 10 15 20 25 30

Apple spp

White ash

Autumn olive

Blue spruce

Norway spruce

Amur honeysuckle

White oak

White mulberry

Honeysuckle spp

River birch

White spruce

Hardwood

Mulberry spp

Plum spp

Balsam fir

Shagbark hickory

Eastern white pine

Boxelder

Siberian elm

European buckthorn

Percent of Trees 

Species 

0 10 20 30 40 50

Mulberry spp

Black walnut

Amur honeysuckle

Norway maple

Percent of Trees 

Species 

0 10 20 30 40

Glossy buckthorn

White oak

Amur honeysuckle

Hawthorn spp

Mulberry spp

Dogwood spp

Common prickly ash

Siberian elm

Northern red oak

Bur oak

Eastern white pine

Shagbark hickory

Silver maple

American elm

Hardwood

Boxelder

Black walnut

Black cherry

Green ash

European buckthorn

Percent of Trees 

Species 
60

Tree Species Distribution in Will County

Figure 71.—The 20 most common tree species as a percent of the total urban tree population, 

Will County, 2010.

Figure 72.—Percent of trees in Residential category of land use, Will County, 2010.

0 2 4 6 8 10 12 14

American basswood

Siberian elm

Blue spruce

Bur oak

Honeysuckle spp

White mulberry

Northern hackberry

Black walnut

Eastern cottonwood

Hawthorn spp

Black cherry

Amur honeysuckle

Boxelder

Silver maple

Hardwood

Black locust

American elm

Green ash

Sugar maple

European buckthorn

Tree Population (percent) 

Species 

0 5 10 15 20 25 30

Bur oak

Black cherry

Austrian pine

Amur honeysuckle

Honeylocust

Norway maple

American elm

Northern white-cedar

Northern red oak

Apple spp

Freeman maple

Boxelder

American basswood

White mulberry

Hardwood

Willow spp

Blue spruce

Green ash

Silver maple

European buckthorn

Percent of Trees 

Species 
61

Figure 73.—Percent of trees in Agriculture category of land use, Will County, 2010.

Figure 74.—Percent of trees in Commercial/Transportation/Institution (CTI) category of 

land use, Will County, 2010.

Figure 75.—Percent of trees in Open Space category of land use, Will County, 2010.

0 10 20 30 40 50 60 70 80

Apple spp

Ohio buckeye

Ginkgo

Percent of Trees 

Species 

0 10 20 30 40

Northern white-cedar

Chinkapin oak

Austrian pine

Mulberry spp

Apple spp

Northern hackberry

Red maple

Osage orange

Amur honeysuckle

Hardwood

White mulberry

Tree-of-heaven

Siberian elm

American elm

Black walnut

Green ash

Eastern cottonwood

Sugar maple

Percent of Trees 

Species 

0 5 10 15 20

Common elderberry

White ash

Siberian elm

Eastern cottonwood

Austrian pine

Black walnut

Bur oak

Honeysuckle spp

Northern hackberry

Silver maple

Amur honeysuckle

Black cherry

Hawthorn spp

Boxelder

Hardwood

European buckthorn

Black locust

American elm

Sugar maple

Green ash

Percent of Trees 

Species 
62

APPENDIX III. TOTAL ESTIMATE OF TREES BY LAND USE AND AREA

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Agriculture

Amur honeysuckle 62,800 297 69 69 425.3 93.5 1,799 -

Apple spp 70,900 16,081 651 639 4,095.7 1,575.1 41,566 -

Autumn olive 20,500 161 23 23 150.7 50.3 377 -

Balsam fir 205,400 2,928 344 342 1,454.4 675.9 10,163 -

Black cherry 224,200 10,801 385 (559) 2,133.2 738.0 10,073 -

Black walnut 72,800 8,759 418 399 6,910.6 2,470.6 26,670 - 

Blue spruce 41,100 1,172 104 103 741.8 561.4 2,763 -

Boxelder 539,100 190,034 6,268 5,589 23,768.5 9,699.7 274,731 -

Bur oak 42,200 92,824 1,805 1,691 6,817.5 3,001.3 228,129 -

Cherry plum 97,500 471 123 123 626.2 169.7 2,438 -

Common pear 21,700 4,481 198 194 353.8 118.1 11,304 -

Eastern hophornbeam 10,800 5 3 3 60.5 17.7 321 -

Eastern redcedar 10,800 375 21 20 294.0 364.4 891 -

Eastern white pine 246,500 16,419 934 920 6,501.2 1,865.0 103,347 -

European alder 36,500 1,612 77 75 511.7 166.4 1,975 -

European buckthorn 2,401,900 27,060 3,528 3,366 10,440.2 2,069.9 103,314 -

Flowering dogwood 62,200 2,338 108 94 228.8 59.3 3,663 -

Ginkgo 172,200 200 88 88 303.7 59.7 6,457 -

Green ash 32,500 76 17 17 158.9 46.2 1,219 -

Hardwood 163,500 15,907 - (870 - - - -

Hawthorn spp 19,600 98 17 17 161.6 25.9 359 -

Honeylocust 10,800 59 19 19 61.3 28.6 762 -

Honeysuckle spp 61,600 220 57 57 425.5 93.5 1,713 -

Lilac spp 10,800 25 9 8 15.3 6.6 373 -

Littleleaf linden 20,900 424 79 78 355.8 118.9 2,344 -

Mulberry spp 780,600 26,525 1,963 1,915 7,683.3 2,887.6 75,542 -

Norway spruce 41,100 8,834 317 292 545.1 405.3 25,516 -

Ohio buckeye 28,700 68,776 1,232 1,185 3,352.9 1,094.4 141,572 -

Osage orange 20,900 1,014 69 64 143.1 64.1 2,224 -

Paper birch 41,400 17,014 653 614 2,022.8 631.0 35,885 -

Peach 36,500 29 17 17 25.9 9.0 913 -

Pin oak 20,500 1,788 133 132 622.9 251.5 6,059 -

Plum spp 163,400 5,767 378 352 990.1 341.7 9,719 -

River birch 61,600 1,207 165 164 445.5 154.0 3,005 -

Shagbark hickory 225,900 23,804 1,980 1,884 5,657.8 1,848.4 103,046 -

Siberian elm 390,200 70,569 1,878 1,612 10,944.3 3,325.3 89,638 -

Silver maple 39,200 178 37 36 69.2 16.2 979 -

Softwood 20,900 40 - (11) - - - -

Sycamore spp 65,000 266 68 68 589.8 120.8 1,869 -

Tree-of-heaven 20,700 282 75 75 447.5 149.4 427 -

White ash 42,200 150 50 49 259.2 65.7 1,706 -

White mulberry 104,200 1,670 210 207 553.8 180.6 5,296 -

continued

Table 20.—Estimate of trees by land use
63

White oak 61,600 100,494 1,697 616 7,081.4 2,298.0 197,181 -

White spruce 102,700 3,748 261 258 2,861.7 2,050.7 11,479 -

Willow spp 41,400 60,727 927 650 4,076.4 1,122.5 54,279 -

Total 6,967,500 785,709 27,455 22,684 115,369 41,092 1,603,085 -

Commercial/Transportation/Institution

American basswood 31,200 4,183 222 205 1,590.8 207.2 32,662 -

American elm 574,000 26,132 1,594 1,488 14,510.9 4,707.9 74,774 3,900

American hornbeam 24,100 128 30 29 91.2 24.5 1,339 -

American sycamore 2,000 2,537 81 71 594.5 128.5 9,338 2,000 

Amur corktree 24,100 2,628 168 158 389.7 130.0 14,838 - 

Amur honeysuckle 232,100 1,404 261 172 538.7 118.4 9,324 - 

Amur maple 72,400 1,490 183 176 504.1 126.6 6,178 - 

Apple spp 210,700 21,956 1,451 1,360 5,838.2 2,245.1 111,782 5,900 

Ash spp 7,900 14 5 4 25.9 10.5 249 - 

Austrian pine 173,300 6,809 453 407 2,853.0 1,226.6 63,976 - 

Autumn olive 72,400 1,681 173 158 82.0 27.4 9,225 - 

Basswood spp 3,900 3,047 86 74 567.3 117.7 15,711 - 

Black cherry 354,800 84,776 2,920 1,241 8,055.7 2,786.9 189,741 - 

Black haw 13,700 172 25 24 93.4 31.2 968 - 

Black walnut 218,300 37,830 1,878 1,730 25,888.4 9,255.4 152,402 - 

Blue spruce 2,000 15 2 2 10.1 7.6 122 - 

Boxelder 753,100 91,028 2,270 754 12,533.9 5,114.9 84,786 24,100 

Bur oak 33,100 54,523 1,033 526 2,674.1 1,177.2 221,844 - 

Callery pear 23,400 913 91 88 175.4 58.6 5,157 - 

Chinese elm 3,900 4,238 87 49 532.5 269.9 16,341 -- 

Chinkapin oak 51,400 11,846 367 357 1,223.6 538.7 30,902 - 

Cockspur hawthorn 97,500 3,887 489 422 709.7 238.5 17,205 - 

Common pear 29,300 2,876 240 194 383.3 128.0 12,667 - 

Cottonwood spp 7,900 131 19 19 47.4 14.3 927 - 

Dogwood spp 9,800 244 20 20 93.4 24.3 206 - 

Eastern cottonwood 494,600 85,619 2,140 1,972 14,084.9 4,533.5 187,819 - 

Eastern redcedar 3,900 289 11 10 145.5 180.4 2,195 - 

Eastern white pine 258,200 24,634 1,158 1,041 4,579.8 1,313.8 280,604 - 

Elm spp 2,000 5 1 1 3.7 1.1 33 - 

European buckthorn 4,520,800 34,062 4,432 4,122 14,738.5 2,922.1 163,046 48,300 

Green ash 568,000 68,266 2,482 1,646 26,370.8 7,672.8 437,943 35,900 

Hardwood 292,700 17,557 -(1,728) ---24,100 

Hawthorn spp 11,800 702 47 35 153.4 24.6 2,981 - 

Honeylocust 205,200 58,623 2,511 2,173 5,042.1 2,355.2 286,088 55,500 

Honeysuckle spp 187,800 4,901 657 508 664.0 145.9 16,377 - 

Japanese maple 24,100 112 39 39 139.1 34.9 1,125 - 

Juniper spp 311,800 1,963 334 330 971.1 1,203.1 18,542 - 

Kentucky coffeetree 3,900 22 6 6 7.4 2.5 176 3,900 

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

continued

Table 20.—Estimate of trees by land use
64

Lilac spp 3,900 109 8 5 7.4 3.2 480 - 

Littleleaf linden 52,200 6,572 357 332 3,672.4 1,227.1 56,470 28,100 

Magnolia spp 96,600 1,279 322 316 382.5 114.0 6,134 - 

Mulberry spp 293,700 15,101 877 818 3,820.4 1,435.9 46,438 - 

Northern hackberry 95,000 1,786 264 250 1,086.5 252.2 13,145 3,900 

Northern red oak 93,500 79,387 2,310 1,874 5,453.2 1,938.4 195,714 - 

Northern white-cedar 283,600 8,118 338 306 2,049.0 1,757.7 149,398 - 

Norway maple 379,900 30,381 1,611 1,502 12,922.8 3,111.4 108,737 11,800 

Norway spruce 48,800 8,246 374 357 2,602.0 1,934.5 30,898 - 

Osage orange 60,000 40,281 841 (838) 3,052.2 1,368.7 137,612 - 

Other species 9,800 19 -(5) ---- 

Paper birch 3,900 734 44 39 165.6 51.7 2,321 - 

Pin oak 40,900 11,661 427 308 2,321.3 937.2 31,523 - 

Pine spp 19,500 288 -(79) ---- 

Plum spp 41,100 328 87 81 280.5 96.8 1,609 - 

Quaking aspen 2,000 79 10 10 49.9 17.5 640 - 

Red maple 57,300 60,452 1,557 509 6,531.8 1,962.3 155,087 25,300 

Red mulberry 3,900 356 31 30 129.0 57.1 1,810 - 

Red pine 3,900 67 14 14 24.0 15.7 174 3,900 

Rhamnus spp 5,900 89 20 19 86.0 17.0 439 - 

River birch 9,800 55 17 16 55.8 19.3 455 - 

Rose-of-Sharon 48,300 219 76 74 78.1 16.8 2,143 - 

Serviceberry spp 58,500 172 66 64 138.4 46.7 3,219 - 

Shagbark hickory 126,600 2,469 301 298 1,060.3 346.4 8,833 - 

Shellbark hickory 9,800 19 7 7 37.3 8.7 463 - 

Siberian elm 155,200 12,498 874 826 5,095.2 1,548.1 44,586 5,900 

Silver maple 30,000 30,472 761 642 2,353.9 552.7 100,619 3,900 

Slippery elm 238,200 5,579 418 410 1,005.9 200.9 6,666 48,300 

Spruce spp 2,000 9 2 2 8.4 6.4 122 - 

Sugar maple 1,223,700 82,778 4,232 2,875 35,095.4 9,431.2 357,906 - 

Sumac spp 138,000 2,265 251 234 414.6 148.0 15,940 - 

Sycamore spp 19,500 55 17 16 67.0 13.7 999 - 

Tree-of-heaven 1,418,400 20,695 2,513 2,405 8,105.4 2,706.0 72,644 - 

Unknown 2,000 2,209 49 41 261.9 65.7 9,336 - 

Viburnum spp 19,600 153 23 21 58.6 19.6 1,122 - 

Washington hawthorn 2,000 126 15 15 30.9 10.4 439 - 

White ash 148,500 20,273 782 583 1,845.3 467.7 55,150 5,900 

White mulberry 127,600 12,904 504 437 1,398.1 456.3 51,319 - 

White oak 44,800 99,998 2,071 755 6,146.4 1,994.5 333,112 - 

Willow spp 98,600 2,165 170 155 216.0 59.5 1,801 - 

Yew spp 19,500 1,058 46 42 727.5 508.3 10,420 - 

Total 15,447,100 1,222,747 50,653 35,649 255,744 84,031 4,495,521 340,600 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
65

Open Space

American basswood 381,800 17,018 1,004 265 7,919.6 1,031.4 82,627 15,500 

American elm 3,572,600 151,902 10,795 8,727 68,683.7 22,283.6 366,337 - 

American plum 23,100 396 60 60 111.4 38.4 1,055 - 

American sycamore 2,000 54 11 10 29.4 6.4 166 - 

Amur corktree 42,300 253 67 66 240.9 80.5 1,879 - 

Amur honeysuckle 2,397,800 13,344 2,424 2,363 9,435.8 2,073.5 115,692 - 

Amur maple 627,700 8,415 1,739 1,717 2,151.0 540.1 26,522 - 

Apple spp 216,900 21,810 938 785 3,578.5 1,376.1 38,689 - 

Austrian pine 153,900 2,581 277 266 1,473.2 633.5 25,545 - 

Autumn olive 135,100 2,379 244 238 2,189.6 731.0 12,925 - 

Basswood spp 61,200 1,958 142 137 1,088.5 225.8 13,774 - 

Bitternut hickory 144,100 2,440 250 182 1,290.1 361.8 9,894 - 

Black ash 2,000 107 9 8 74.4 19.8 520 - 

Black cherry 5,946,300 445,604 27,181 22,239 94,103.1 32,555.1 1,189,157 - 

Black locust 2,406,900 237,110 12,273 10,864 42,646.2 10,241.9 659,662 - 

Black maple 59,000 91 39 38 88.0 22.1 3,538 - 

Black oak 53,700 6,102 264 176 1,106.8 348.9 12,008 - 

Black walnut 1,575,300 162,434 9,536 8,771 63,022.1 22,531.1 456,932 26,800 

Blue spruce 80,600 1,481 181 174 491.7 372.2 12,042 - 

Boxelder 4,030,300 454,746 17,614 11,946 90,616.3 36,979.3 579,732 - 

Buckeye spp 2,000 8 2 1 14.3 4.7 60 - 

Bur oak 1,117,700 1,196,325 20,715 15,547 84,154.6 37,048.4 3,971,594 43,300 

Callery pear 21,600 1,016 136 132 289.8 96.8 5,316 - 

Chinese elm 2,000 89 8 8 86.2 43.7 519 - 

Chinkapin oak 28,300 46,317 803 549 923.4 406.6 113,142 2,000 

Cockspur hawthorn 207,700 1,295 295 262 1,109.7 372.9 6,139 - 

Common chokecherry 109,000 494 60 3 194.7 67.4 3,369 - 

Common elderberry 111,500 329 141 140 72.6 24.2 4,111 - 

Common lilac 13,400 77 7 5 12.6 5.4 220 - 

Common pear 36,500 1,926 133 129 804.3 268.5 7,274 - 

Common prickly ash 207,900 172 131 129 767.7 256.3 9,227 - 

Cottonwood spp 2,000 5,235 90 61 218.9 66.0 8,030 - 

Dogwood spp 184,800 819 200 199 497.9 129.6 5,468 - 

Downy hawthorn 1,054,200 30,807 2,285 1,944 6,545.2 2,199.3 101,823 - 

Downy serviceberry 2,000 4 2 2 2.5 0.7 107 2,000 

Eastern cottonwood 1,207,200 871,417 13,839 7,075 58,258.3 18,751.4 1,036,825 - 

Eastern hophornbeam 462,600 5,550 762 685 4,174.5 1,215.6 33,922 - 

Eastern redcedar 147,600 5,717 345 200 1,693.6 2,098.6 36,553 - 

Eastern white pine 578,100 51,880 2,191 1,487 13,530.7 3,881.7 435,131 - 

Elm spp 136,000 4,227 48 (586) 456.4 138.6 1,918 - 

European alder 335,000 14,289 873 804 4,781.4 1,555.0 49,651 - 

European buckthorn 24,505,100 235,034 31,910 29,637 99,895.1 19,805.7 1,222,475 26,800 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
66

Freeman maple 44,700 2,221 301 291 2,444.6 613.8 10,113 - 

Glossy buckthorn 457,200 2,235 541 477 2,442.6 815.4 14,748 - 

Gray dogwood 68,000 74 36 36 122.6 26.1 2,669 - 

Green ash 4,939,300 214,234 10,224 9,038 84,785.7 24,669.1 881,832 4,100 

Hardwood 3,641,600 213,916 -(33,807) ---- 

Hawthorn spp 1,597,800 48,165 3,911 3,119 16,841.3 2,702.5 157,123 - 

Hickory spp 6,100 462 25 18 106.0 26.6 1,407 - 

Honeylocust 179,100 78,520 1,768 1,305 5,278.3 2,465.6 271,099 4,100 

Honeysuckle spp 993,900 6,721 1,319 1,258 2,503.1 550.1 50,213 - 

Horsechestnut 40,300 490 103 93 275.3 85.9 1,629 40,300 

Jack pine 25,700 2,936 100 69 660.0 245.3 9,846 

Juniper spp 21,600 210 16 16 77.3 95.7 325 - 

Kwanzan cherry 14,300 2,774 107 66 474.2 163.6 5,691 - 

Littleleaf linden 34,700 4,809 192 181 3,607.4 1,205.4 31,243 - 

Macnab’s oak 2,000 475 24 22 91.7 40.4 1,551 - 

Mulberry spp 541,200 66,643 3,184 2,838 11,692.8 4,394.4 212,941 - 

Nannyberry 69,300 135 38 37 85.7 28.6 2,297 - 

Narrowleaf willow 2,000 2 1 1 5.7 1.6 51 - 

Northern catalpa 31,300 390 57 56 277.5 75.3 1,041 4,100 

Northern hackberry 720,200 98,479 4,043 2,548 20,405.8 4,736.1 493,728 4,100 

Northern red oak 1,931,700 528,465 17,306 13,546 59,232.8 21,054.7 1,570,200 - 

Northern white-cedar 190,200 7,050 278 245 3,151.8 2,703.7 82,401 - 

Norway maple 170,200 34,376 1,443 1,247 12,509.4 3,011.9 156,181 10,200 

Norway spruce 30,500 31,646 623 552 4,538.5 3,374.3 158,999 - 

Oak spp 109,700 2,068 -(336) ---- 

Ohio buckeye 15,200 15 7 7 10.1 3.3 742 - 

Other species 112,100 9,956 -(1,608) ---- 

Paper birch 141,500 2,426 631 620 792.4 247.2 5,769 - 

Peachleaf willow 77,700 10,495 317 124 729.2 206.1 19,178 - 

Pear spp 2,000 31 8 8 11.9 3.9 131 - 

Pin cherry 23,100 88 17 17 124.0 26.7 289 -

Pin oak 223,700 51,948 2,247 1,986 7,566.4 3,054.6 170,673 - 

Plum spp 285,500 3,139 532 517 1,900.4 655.9 16,413 - 

Quaking aspen 228,100 2,234 305 280 1,399.1 491.5 9,375 - 

Red maple 104,100 45,972 1,572 1,373 5,945.2 1,786.0 225,993 - 

Red mulberry 41,600 5,563 300 276 1,395.4 618.1 20,955 - 

Rhamnus spp 75,400 1,094 116 104 505.3 100.2 4,211 - 

River birch 141,000 8,063 587 554 2,143.8 741.2 40,126 - 

Russian olive 23,100 202 65 64 347.4 116.0 1,025 - 

Sargent cherry 41,600 959 93 82 88.7 30.6 1,883 - 

Sassafras 47,400 49 21 21 85.2 18.7 1,885 - 

Serviceberry spp 13,400 9 5 5 16.6 5.6 595 - 

Shagbark hickory 1,080,700 18,265 1,963 1,910 9,066.6 2,962.0 93,704 - 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
67

Siberian elm 436,000 28,187 1,507 1,268 9,243.3 2,808.4 76,612 28,900 

Silver maple 1,280,400 473,290 12,004 9,250 63,082.2 14,810.9 1,164,069 8,200 

Slippery elm 191,200 20,859 696 567 3,660.3 731.0 34,976 - 

Softwood 38,300 2,203 -(358) ---- 

Spruce spp 21,600 271 37 36 68.2 51.5 1,665 - 

Star magnolia 43,300 503 82 81 153.0 45.6 2,353 - 

Sugar maple 2,345,000 183,335 8,730 8,000 40,247.4 10,815.7 782,534 - 

Sumac spp 158,400 841 177 174 641.0 228.7 6,947 - 

Swamp white oak 69,600 95,307 2,106 1,817 6,212.6 2,735.2 374,162 - 

Sweetgum 2,000 189 9 9 65.5 13.4 3,175 - 

Sycamore spp 22,300 22,835 573 521 3,472.7 711.6 69,597 - 

Tree-of-heaven 8,200 2,377 64 58 157.6 52.6 3,898 - 

Unknown 4,100 63 9 8 25.7 6.4 251 - 

Viburnum spp 265,200 1,201 236 221 393.9 131.4 11,178 - 

Washington hawthorn 13,200 87 21 20 136.6 46.0 631 - 

White ash 2,072,000 109,324 6,084 2,929 22,995.4 5,828.5 336,028 2,000 

White mulberry 484,500 19,656 1,577 1,408 6,714.0 2,190.9 68,669 - 

White oak 1,177,600 649,426 16,003 11,870 43,396.7 14,082.4 2,105,344 - 

White poplar 27,800 66,213 1,058 910 5,422.6 2,103.4 103,276 - 

Willow spp 725,100 80,730 2,124 1,131 6,096.9 1,678.9 172,895 - 

Winged burningbush 56,700 171 10 (13) 25.5 8.5 692 - 

Witch hazel 2,000 2 1 1 4.4 1.2 56 - 

Total 80,369,100 7,268,326 267,558 176,609 1,144,778 364,126 20,710,857 222,400 

Residential

Alternateleaf dogwood 34,600 69 32 32 23.7 7.1 1,535 - 

American basswood 409,700 51,444 2,470 2,258 15,107.0 1,967.5 322,975 15,100 

American cranberrybush 2,000 23 6 6 4.7 1.6 74 - 

American elm 1,216,400 170,439 6,462 3,069 32,205.3 10,448.6 211,944 9,900 

American hornbeam 2,000 12 3 2 5.7 1.6 55 - 

American plum 127,000 1,782 324 315 558.9 193.0 9,042 - 

American sycamore 4,000 5,825 176 154 840.9 181.7 15,989 4,000 

Amur honeysuckle 677,800 9,882 1,563 1,426 3,299.5 725.1 46,848 - 

Amur maple 44,300 8,930 525 420 1,918.7 481.7 32,328 - 

Apple spp 1,226,500 96,373 8,171 7,582 25,434.0 9,781.1 402,078 2,000 

Ash spp 2,000 78 5 5 17.5 7.0 71 - 

Austrian pine 655,900 43,285 2,911 2,715 17,317.5 7,445.5 321,756 - 

Baldcypress 26,000 208 46 45 240.9 168.3 2,110 - 

Basswood spp 6,000 379 34 32 332.1 68.9 2,739 6,000 

Bitternut hickory 42,400 2,211 164 106 464.8 130.3 7,844 - 

Black cherry 1,211,800 194,379 11,935 8,690 31,561.3 10,918.6 471,399 - 

Black haw 54,900 135 57 56 98.3 32.8 2,437 - 

Black locust 565,200 65,925 5,043 4,584 12,077.0 2,900.4 192,365 7,900 

Black maple 11,000 880 97 93 438.4 110.0 3,062 - 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
68

Black walnut 602,800 198,032 8,235 6,951 66,557.6 23,795.0 474,807 - 

Black willow 44,800 23,837 1,018 926 2,629.1 742.9 58,482 - 

Blue spruce 983,600 91,203 5,551 4,826 33,493.4 25,349.0 452,033 43,700 

Boxelder 3,275,300 467,243 22,270 16,205 96,919.5 39,551.6 834,293 22,200 

Buckeye spp 2,000 184 19 18 160.4 52.4 857 2,000 

Bur oak 410,400 630,300 16,963 13,112 40,677.4 17,908.0 2,059,529 - 

Callery pear 212,600 10,898 1,239 1,191 3,440.4 1,148.5 46,910 43,800 

Catalpa spp 7,900 5,869 218 180 301.7 95.4 14,020 2,000 

Cherry plum 59,900 3,996 318 270 1,495.7 405.4 11,110 - 

Chinese chestnut 11,100 6,412 266 241 1,259.5 393.9 9,570 - 

Chinese elm 7,900 1,232 52 23 216.7 109.8 3,717 - 

Chinese magnolia 6,000 238 25 24 81.3 24.2 1,263 - 

Cockspur hawthorn 14,900 583 85 82 156.9 52.8 2,951 - 

Common chokecherry 6,000 238 28 23 35.3 12.2 633 - 

Common elderberry 85,800 199 92 91 283.4 94.7 3,807 - 

Common lilac 95,600 1,149 199 157 347.2 149.5 3,880 - 

Common pear 178,700 24,936 1,613 1,513 5,418.9 1,809.1 98,567 43,700 

Common privet 7,900 50 15 15 16.3 6.6 365 - 

Cornelian cherry 11,100 651 80 78 253.0 74.8 3,191 - 

Cottonwood spp 2,000 246 22 21 63.3 19.1 931 - 

Dogwood spp 51,600 623 154 147 377.8 98.3 2,612 - 

Douglas-fir 108,400 4,167 179 75 3,250.1 2,270.6 31,405 - 

Downy hawthorn 149,400 7,089 866 815 1,567.1 526.6 30,757 - 

Downy serviceberry 55,400 1,251 246 238 515.5 140.2 4,901 - 

Eastern cottonwood 496,300 217,252 7,461 5,907 33,307.4 10,720.4 477,937 - 

Eastern hemlock 268,700 9,213 841 751 6,015.2 2,492.4 58,659 - 

Eastern hophornbeam 128,700 4,843 686 636 3,010.9 876.8 20,883 - 

Eastern redcedar 401,100 19,634 1,402 1,260 4,669.7 5,786.4 132,616 - 

Eastern redbud 110,400 12,064 735 645 856.2 244.6 48,163 - 

Eastern wahoo 46,300 1,408 231 225 804.3 268.5 6,716 - 

Eastern white pine 443,200 44,092 2,204 1,955 17,682.5 5,072.8 337,942 2,000 

Elm spp 39,400 6,948 13 (330) 55.6 16.9 563 2,000 

European alder 11,100 232 51 50 102.8 33.4 771 - 

European beech 20,200 451 109 107 439.1 98.0 1,294 20,200 

European buckthorn 12,853,700 109,148 21,612 20,079 60,888.9 12,072.1 709,745 222,600 

European filbert 17,400 136 46 44 40.0 12.4 635 - 

European hornbeam 99,800 1,499 287 256 406.5 109.2 4,793 - 

Flowering dogwood 19,400 55 19 19 64.0 16.6 922 - 

Forsythia spp 104,600 168 92 91 367.4 122.7 4,605 - 

Freeman maple 235,700 5,533 992 966 4,680.1 1,175.0 21,227 47,000 

Ginkgo 27,500 24,909 829 733 2,244.4 441.4 103,361 27,500 

Glossy buckthorn 43,700 311 91 89 173.7 58.0 1,981 - 

Gray birch 145,600 2,224 502 493 2,029.7 537.7 7,849 - 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
69

Green ash 3,117,200 273,301 11,915 8,975 90,475.4 26,324.6 1,859,772 263,200 

Hackberry spp 6,000 7 4 4 6.7 1.7 301 - 

Hardwood 1,463,600 97,513 -(26,476) ---- 

Hawthorn spp 266,500 13,849 1,377 1,241 3,246.4 520.9 56,809 - 

Hickory spp 64,000 341 123 121 781.3 196.1 3,098 - 

Honeylocust 602,300 283,543 11,274 9,697 26,585.0 12,418.2 1,102,902 163,300 

Honeysuckle spp 316,100 1,522 419 395 984.2 216.3 12,965 - 

Japanese maple 11,900 141 27 20 154.7 38.9 481 - 

Japanese red pine 11,100 207 26 25 50.4 21.6 2,327 - 

Japanese tree lilac 19,000 383 72 70 106.7 45.9 1,477 2,000 

Japanese zelkova 11,100 12 8 8 12.8 4.3 416 - 

Juniper spp 237,200 6,158 644 618 2,500.9 3,099.4 43,598 - 

Katsura tree 11,100 826 91 83 70.4 23.5 3,445 - 

Kentucky coffeetree 29,500 27,154 859 603 3,083.3 1,029.3 83,185 6,000 

Leather leaf viburnum 17,400 15 10 10 24.7 8.3 635 - 

Lilac spp 775,200 6,985 1,502 1,428 2,260.7 972.8 47,107 - 

Littleleaf linden 135,600 19,175 1,078 990 9,048.1 3,023.4 128,931 59,400 

Macnab’s oak 4,000 3,147 103 91 136.4 60.0 8,771 - 

Magnolia spp 106,400 11,111 763 719 2,242.2 668.3 54,033 - 

Maple spp 2,000 1,303 47 42 168.8 42.4 4,905 2,000 

Mockernut hickory 121,400 2,030 377 363 1,409.2 360.3 10,328 - 

Mulberry spp 1,037,600 121,361 6,327 5,749 17,402.3 6,540.2 369,409 6, 

Northern catalpa 28,200 46,853 1,426 1,229 1,733.7 470.9 101,145 4,000 

Northern hackberry 204,800 11,741 1,061 1,011 3,116.4 723.3 54,380 66,700 

Northern pin oak 20,200 2,611 248 222 413.9 190.4 9,651 - 

Northern red oak 1,062,700 463,969 17,334 12,796 39,983.3 14,212.1 1,344,239 12,900 

Northern white-cedar 1,983,500 32,483 3,293 3,090 15,529.0 13,322.0 341,822 2,000 

Norway maple 1,308,700 317,697 14,130 11,671 75,921.7 18,279.8 1,133,008 263,800 

Norway spruce 257,200 29,545 1,573 1,130 9,519.0 7,077.3 131,846 - 

Ohio buckeye 20,200 1,769 183 165 1,114.4 363.8 7,356 - 

Other species 9,900 2,448 -(673) ---2,000 

Paper birch 165,600 12,180 1,309 1,161 4,064.1 1,267.8 31,631 - 

Paradise apple 4,000 667 48 46 132.2 50.9 2,821 - 

Peach 70,800 572 172 165 572.5 197.7 2,444 - 

Pear spp 9,900 885 76 73 138.4 46.2 3,623 - 

Pin cherry 17,400 637 117 114 175.9 37.9 1,544 - 

Pin oak 75,300 71,766 2,282 1,767 6,663.5 2,690.1 199,866 2,000 

Pine spp 48,500 645 20 (118) 56.6 24.3 1,182 - 

Plum spp 384,900 7,445 1,079 950 3,217.7 1,110.7 24,035 25,500 

Privet spp 28,800 94 35 34 47.7 19.4 1,262 - 

Pussy willow 55,400 7,163 331 315 668.2 188.8 20,567 - 

Red maple 178,900 68,339 2,657 1,722 8,782.4 2,638.4 185,171 24,900 

Red mulberry 20,900 14,855 552 495 1,598.7 708.3 50,628 - 

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
70

Red pine 11,100 1,279 98 93 220.9 144.9 6,365 - 

Rhamnus spp 2,000 267 9 -15.8 3.1 461 - 

River birch 340,300 30,049 2,532 2,407 9,075.2 3,137.9 124,432 2,000 

Rose-of-Sharon 28,900 95 35 35 59.8 12.9 1,291 4,000 

Russian olive 31,900 1,382 107 66 204.6 68.3 3,823 - 

Sargent cherry 38,400 5,317 314 263 663.2 228.9 13,838 - 

Saucer magnolia 26,000 1,554 174 168 215.7 64.4 7,818 - 

Scotch pine 23,500 665 69 62 321.7 138.3 5,046 - 

Serbian spruce 78,200 333 96 94 183.6 154.5 3,885 - 

Serviceberry spp 91,200 716 204 197 298.5 100.9 3,797 - 

Shagbark hickory 278,200 32,507 2,041 1,825 6,100.4 1,993.1 114,002 - 

Shingle oak 23,500 1,495 190 183 600.0 264.2 7,147 - 

Siberian elm 1,259,200 336,274 11,468 9,342 66,631.0 20,244.9 728,544 4,000 

Silver linden 4,000 1,682 55 49 256.2 53.2 9,235 4,000 

Silver maple 1,860,300 1,098,218 28,271 21,176 169,551.4 39,808.3 3,065,150 141,900 

Slippery elm 24,000 1,664 172 165 407.7 81.4 4,327 2,000 

Smoke tree 13,100 240 47 46 55.1 18.4 1,199 2,000 

Spruce spp 47,200 2,366 118 (63) 820.9 621.2 10,636 - 

Staghorn sumac 2,000 663 5 (87) 18.5 7.8 351 2,000 

Star magnolia 26,000 499 93 90 252.8 75.3 2,163 - 

Sugar maple 888,500 130,542 6,403 5,851 19,342.0 5,197.8 487,406 17,900 

Sumac spp 94,000 1,145 124 86 513.2 183.2 5,080 - 

Swamp white oak 35,200 17,422 695 529 970.1 427.0 56,112 - 

Sweetgum 15,100 183 29 28 153.7 31.5 1,281 2,000 

Sycamore spp 23,500 13,922 304 294 2,672.1 547.5 13,305 - 

Tree-of-heaven 383,700 55,326 3,186 2,830 11,221.6 3,746.2 109,421 2,000 

Yellow-poplar 17,400 2,560 197 186 2,695.1 708.7 15,271 - 

Unknown 15,900 1,899 131 117 485.3 121.9 7,104 2,000 

Viburnum spp 78,400 480 143 139 149.2 49.9 2,815 - 

Washington hawthorn 7,900 1,002 87 80 260.7 87.6 4,114 - 

Weeping willow 11,100 7,035 217 201 1,227.8 347.0 17,897 - 

White ash 1,762,700 208,620 11,248 9,176 44,868.9 11,372.6 623,901 111,500 

White mulberry 867,900 119,004 6,790 5,587 15,309.3 4,995.7 398,381 - 

White oak 573,300 646,222 20,272 14,171 43,831.1 14,223.4 2,216,543 33,400 

White poplar 67,800 103,650 2,865 2,307 12,298.7 4,770.8 165,172 23,500 

White spruce 1,684,200 50,849 3,454 3,057 20,046.7 14,365.9 165,571 - 

Willow spp 484,500 151,742 5,488 4,655 15,277.9 4,207.1 317,874 - 

Winged burningbush 91,900 708 191 186 259.7 86.7 4,510 - 

Witch hazel 204,300 2,182 237 7 1,047.0 274.7 7,182 - 

Yew spp 295,600 4,664 573 523 3,078.9 2,150.8 32,746 - 

Total 54,357,300 7,593,875 331,684 241,050 1,325,164 454,911 24,346,220 1,783,500 

Chicago Region 157,141,000 16,871,000 677,000 476,000 2,841,000 944,000 51,156,000 2,347,000 

a Species refers to tree species, genera, or species groups that were classified during field data collection.

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value 

($1,000)

Number 

of Street 

Trees

Appendix III.—continued

Table 20.—Estimate of trees by land use
71

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

City of Chicago

American basswood 56,800 10,785 338 300 3,297.8 429.5 61,898 6,000 

American cranberrybush 2,000 23 6 6 4.7 1.6 74 - 

American elm 165,800 27,261 934 602 4,405.1 1,429.1 30,836 13,800 

American hornbeam 2,000 12 3 2 5.7 1.6 55 - 

American sycamore 8,000 8,416 268 235 1,464.8 316.6 25,494 5,900 

Apple spp 45,800 5,138 350 327 1,379.8 530.6 20,251 7,900 

Ash spp 9,800 91 10 9 43.5 17.5 319 - 

Basswood spp 71,000 5,384 261 243 1,987.9 412.4 32,224 6,000 

Black ash 2,000 107 9 8 74.4 19.8 520 - 

Black cherry 44,700 7,924 385 317 1,326.7 458.9 18,245 - 

Black haw 13,700 172 25 24 93.4 31.2 968 - 

Black locust 16,100 6,947 254 217 881.4 211.7 14,258 7,900 

Black walnut 16,200 5,907 163 94 1,558.2 557.1 13,720 - 

Blue spruce 37,700 2,925 223 211 945.7 715.7 16,429 - 

Boxelder 124,100 14,107 499 120 1,415.1 577.5 19,122 2,000 

Buckeye spp 4,000 192 20 19 174.7 57.1 917 2,000 

Bur oak 16,000 32,504 718 616 2,018.1 888.5 116,003 - 

Callery pear 5,900 81 16 15 31.6 10.6 431 - 

Catalpa spp 7,900 5,869 218 180 301.7 95.4 14,020 2,000 

Cherry plum 2,000 118 16 15 79.1 21.5 478 - 

Chinese elm 13,900 5,559 147 79 835.4 423.5 20,578 - 

Chinese magnolia 6,000 238 25 24 81.3 24.2 1,263 - 

Chinkapin oak 2,000 5 2 2 4.9 2.2 145 2,000 

Cockspur hawthorn 10,200 101 17 17 48.7 16.3 527 - 

Common chokecherry 6,000 238 28 23 35.3 12.2 633 - 

Common privet 7,900 50 15 15 16.3 6.6 365 - 

Cottonwood spp 11,900 5,612 130 100 329.6 99.3 9,889 - 

Dogwood spp 2,000 17 6 6 10.9 2.8 88 - 

Downy serviceberry 2,000 4 2 2 2.5 0.7 107 2,000 

Eastern cottonwood 111,800 40,483 1,340 1,255 6,668.5 2,146.4 82,105 - 

Eastern redcedar 27,700 770 64 59 289.8 359.1 5,569 - 

Eastern redbud 9,900 502 46 44 116.4 33.2 2,172 - 

Eastern wahoo 2,000 6 3 2 6.2 2.1 84 - 

Eastern white pine 13,900 269 25 24 155.9 44.7 2,744 2,000 

Elm spp 24,000 288 36 36 174.5 53.0 1,377 2,000 

European buckthorn 157,200 1,059 174 123 718.6 142.5 6,240 - 

Flowering dogwood 2,000 45 10 10 21.5 5.6 148 - 

Ginkgo 4,000 260 26 25 146.8 28.9 1,388 4, 

Gray birch 2,000 117 16 15 46.2 12.2 511 - 

Green ash 176,200 33,732 976 544 8,109.8 2,359.6 223,086 47,600 

Hackberry spp 6,000 7 4 4 6.7 1.7 301 - 

Hawthorn spp 117,300 9,305 470 335 1,750.2 280.9 27,418 - 

Hickory spp 6,100 462 25 18 106.0 26.6 1,407 - 

Appendix III.—continued

continued

Table 20.—Estimate of trees by area
72

Honeylocust 113,200 43,093 1,535 1,264 2,836.5 1,324.9 170,492 57,300 

Honeysuckle spp 2,000 42 9 9 14.6 3.2 142 - 

Japanese maple 11,900 141 27 20 154.7 38.9 481 - 

Japanese tree lilac 7,900 12 6 6 9.1 3.9 269 2,000 

Juniper spp 31,800 188 37 35 74.4 92.3 1,742 - 

Kentucky coffeetree 9,900 37 12 11 15.1 5.0 449 9,900 

Kwanzan cherry 14,300 2,774 107 66 474.2 163.6 5,691 - 

Lilac spp 31,700 253 43 39 101.8 43.7 1,815 - 

Littleleaf linden 52,500 7,316 324 291 5,217.5 1,743.4 47,029 17,800 

Macnab’s oak 6,000 3,622 127 113 228.1 100.4 10,322 - 

Magnolia spp 4,000 95 19 19 62.8 18.7 366 - 

Maple spp 2,000 1,303 47 42 168.8 42.4 4,905 2,000 

Mulberry spp 189,000 65,516 2,075 1,681 6,261.0 2,353.1 154,721 6,000 

Narrowleaf willow 2,000 2 1 1 5.7 1.6 51 - 

Northern catalpa 16,100 5,639 205 166 286.4 77.8 12,705 8,000 

Northern hackberry 61,700 13,715 552 503 2,369.4 549.9 62,626 14,000 

Northern red oak 61,100 27,156 835 648 2,704.5 961.4 80,589 2,000 

Northern white-cedar 111,100 1,236 142 136 533.5 457.6 15,401 2,000 

Norway maple 143,200 52,476 2,174 1,919 12,574.4 3,027.6 198,166 119,200 

Norway spruce 9,900 3,026 125 108 856.4 636.8 14,657 - 

Other species 131,900 12,424 - (2,286) ---2,000 

Paper birch 3,900 734 44 39 165.6 51.7 2,321 - 

Paradise apple 4,000 667 48 46 132.2 50.9 2,821 - 

Peach 7,900 103 28 27 33.9 11.7 299 - 

Pear spp 12,000 916 84 80 150.2 50.1 3,754 - 

Pin oak 6,000 18,741 330 186 530.8 214.3 41,846 2,000 

Pine spp 13,900 150 20 18 56.6 24.3 1,182 - 

Plum spp 59,200 1,414 235 222 657.5 227.0 4,894 2,000 

Privet spp 13,900 42 16 16 9.6 3.9 599 - 

Quaking aspen 2,000 79 10 10 49.9 17.5 640 - 

Red maple 23,900 4,601 258 232 1,059.3 318.2 17,087 11,900 

Red mulberry 9,900 3,470 153 139 260.4 115.4 11,757 - 

Red pine 3,900 67 14 14 24.0 15.7 174 3,900 

Rhamnus spp 83,300 1,449 146 122 607.1 120.4 5,110 - 

River birch 15,800 78 24 22 71.4 24.7 672 2,000 

Rose-of-Sharon 17,900 89 30 29 48.7 10.5 799 4,000 

Russian olive 2,000 321 11 (1) 74.1 24.7 531 - 

Serviceberry spp 11,800 32 8 8 13.8 4.7 626 - 

Shagbark hickory 2,000 9 2 2 33.6 11.0 102 - 

Siberian elm 57,600 12,828 406 310 1,538.7 467.5 25,715 11,900 

Silver linden 4,000 1,682 55 49 256.2 53.2 9,235 4,000 

Silver maple 169,400 109,300 2,777 1,967 14,087.9 3,307.6 346,255 83,500 

Slippery elm 2,000 13 4 4 3.0 0.6 30 2,000 

Smoke tree 2,000 143 16 15 21.5 7.1 732 2,000 

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Appendix III.—continued

continued

Table 20.—Estimate of trees by area
73

Spruce spp 17,800 1,711 105 98 794.7 601.4 9,696 - 

Staghorn sumac 2,000 663 5 (87) 18.5 7.8 351 2,000 

Sugar maple 78,900 11,734 562 498 2,647.9 711.6 48,439 17,900 

Sumac spp 6,000 24 5 5 18.3 6.5 228 - 

Sweetgum 6,000 202 13 12 74.1 15.2 3,349 2,000 

Tree-of-heaven 174,000 25,251 1,111 942 2,983.5 996.0 44,362 2,000 

Unknown 21,900 4,172 188 166 772.9 194.1 16,690 2,000 

Viburnum spp 32,000 502 73 69 136.4 45.5 2,167 - 

Washington hawthorn 11,900 1,179 108 100 310.1 104.2 4,689 - 

White ash 221,400 26,789 1,094 786 4,313.4 1,093.2 74,114 29,800 

White mulberry 3,900 8,279 145 114 494.9 161.5 27,576 - 

White oak 28,100 14,771 488 394 1,122.1 364.1 53,370 9,900 

White poplar 6,100 3,338 69 62 56.8 22.0 6,137 - 

Willow spp 2,000 385 8 (6) 3.2 0.9 602 - 

Witch hazel 2,000 2 1 1 4.4 1.2 56 - 

Yew spp 61,500 1,006 136 129 419.1 292.8 7,460 - 

Total 3,590,500 730,094 25,535 17,952 110,177 34,265 2,333,495 550,100 

Suburban Cook County

Alternateleaf dogwood 23,500 13 13 13 5.9 1.8 1,043 - 

American basswood 21,600 177 29 29 39.0 5.1 1,136 - 

American elm 1,625,000 124,597 6,632 5,207 30,799.8 9,992.6 241,151 - 

American hornbeam 24,100 128 30 29 91.2 24.5 1,339 - 

American plum 94,000 322 123 120 83.5 28.8 3,745 - 

Amur corktree 24,100 2,628 168 158 389.7 130.0 14,838 - 

Amur honeysuckle 957,900 3,163 850 826 2,256.3 495.8 40,576 - 

Amur maple 700,100 9,905 1,922 1,894 2,655.1 666.6 32,700 - 

Apple spp 396,500 18,508 2,166 1,996 4,372.2 1,681.4 77,278 - 

Austrian pine 167,100 5,640 375 341 2,226.4 957.2 53,851 - 

Autumn olive 137,400 3,584 334 314 1,836.4 613.1 20,134 - 

Black cherry 2,586,100 161,547 10,715 8,624 24,458.0 8,461.2 451,347 - 

Black locust 1,205,900 143,302 9,393 8,628 21,153.7 5,080.3 447,515 - 

Black walnut 292,300 32,844 1,919 1,734 20,713.2 7,405.1 94,565 - 

Blue spruce 327,200 19,432 1,209 1,034 7,007.0 5,303.3 103,269 23,500 

Boxelder 2,295,500 148,958 7,591 4,834 22,019.1 8,985.8 201,729 24,100 

Bur oak 304,900 303,466 5,119 3,774 16,600.2 7,308.0 1,131,049 43,300 

Callery pear 21,600 1,016 136 132 289.8 96.8 5,316 - 

Common chokecherry 21,600 13 9 9 46.0 15.9 666 - 

Common pear 94,000 16,035 926 862 2,399.8 801.2 61,303 23,500 

Downy hawthorn 735,900 23,524 1,460 1,196 3,477.4 1,168.4 79,403 - 

Eastern cottonwood 966,000 452,170 9,445 6,576 40,230.6 12,948.9 717,542 - 

Eastern hemlock 70,500 317 91 89 97.9 40.6 4,564 - 

Eastern redcedar 23,500 1,166 90 85 646.9 801.5 7,840 - 

Eastern redbud 47,000 9,271 461 425 391.9 111.9 38,070 - 

Eastern white pine 90,900 4,286 297 278 2,301.0 660.1 45,690 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
74

Elm spp 153,400 10,892 27 (950) 341.2 103.6 1,136 - 

European alder 64,900 335 78 76 1,568.8 510.3 3,842 - 

European buckthorn 13,474,500 141,689 21,736 20,760 48,422.0 9,600.4 819,115 48,300 

Freeman maple 68,600 1,141 256 250 1,119.9 281.2 4,110 47,000 

Ginkgo 23,500 24,648 803 708 2,097.6 412.6 101,972 23,500 

Glossy buckthorn 196,700 398 54 21 490.7 163.8 4,107 - 

Green ash 2,110,800 122,383 6,163 5,224 44,860.5 13,052.6 811,340 118,200 

Hardwood 1,794,500 128,195 - (22,453) -- -24,100 

Hawthorn spp 546,500 15,074 1,224 824 1,880.9 301.8 56,808 - 

Hickory spp 23,500 49 25 25 30.4 7.6 1,175 - 

Honeylocust 368,000 174,954 5,803 4,696 13,618.9 6,361.6 684,855 94,700 

Honeysuckle spp 612,400 5,635 981 805 1,483.1 325.9 34,576 - 

Japanese maple 24,100 112 39 39 139.1 34.9 1,125 - 

Juniper spp 381,900 4,332 533 520 1,622.0 2,009.7 35,176 - 

Kentucky coffeetree 23,500 27,139 853 597 3,075.7 1,026.8 82,912 - 

Lilac spp 164,500 2,210 493 482 854.7 367.8 11,945 - 

Littleleaf linden 95,300 19,858 935 858 9,272.9 3,098.5 144,663 47,600 

Magnolia spp 143,600 8,516 729 695 1,519.2 452.8 40,050 - 

Mulberry spp 633,400 16,725 1,688 1,631 4,981.3 1,872.1 69,067 - 

Northern hackberry 157,100 4,974 638 620 1,378.8 320.0 27,135 - 

Northern red oak 1,040,800 166,015 7,469 6,752 27,489.6 9,771.3 616,375 - 

Northern white-cedar 646,900 14,821 1,134 1,080 6,253.1 5,364.4 178,321 - 

Norway maple 436,700 159,718 5,823 4,392 40,452.7 9,739.8 557,370 70,500 

Oak spp 86,600 1,992 - (324) -- -- 

Paper birch 47,000 3,694 453 438 605.6 188.9 13,780 - 

Pin oak 88,400 38,576 1,690 1,561 4,968.7 2,005.9 136,741 - 

Pine spp 23,500 196 - (54) -- -- 

Plum spp 274,400 7,941 1,029 917 3,367.7 1,162.4 24,204 23,500 

Red maple 157,100 80,948 2,821 2,311 10,021.4 3,010.6 319,597 - 

River birch 153,400 1,293 396 388 1,061.5 367.0 8,129 - 

Rose-of-Sharon 48,300 219 76 74 78.1 16.8 2,143 - 

Sargent cherry 23,500 37 23 22 46.5 16.0 881 - 

Sassafras 21,600 15 9 9 35.8 7.9 960 - 

Scotch pine 23,500 665 69 62 321.7 138.3 5,046 - 

Shagbark hickory 196,700 1,706 326 321 1,693.9 553.4 12,207 - 

Shingle oak 23,500 1,495 190 183 600.0 264.2 7,147 - 

Siberian elm 376,000 96,763 3,232 2,921 22,732.7 6,907.0 187,238 - 

Silver maple 671,900 282,342 7,983 6,165 43,033.0 10,103.6 982,832 70,500 

Slippery elm 72,400 4,829 189 185 588.6 117.5 3,283 48,300 

Spruce spp 21,600 271 37 36 68.2 51.5 1,665 - 

Star magnolia 43,300 503 82 81 153.0 45.6 2,353 - 

Sugar maple 160,200 52,516 1,674 1,219 7,064.6 1,898.5 215,677 - 

Sumac spp 48,300 1,683 154 147 76.4 27.3 11,211 - 

Swamp white oak 43,300 91,464 1,914 1,644 5,228.6 2,301.9 351,334 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
75

Sycamore spp 23,500 13,922 304 294 2,672.1 547.5 13,305 - 

Tree-of-heaven 1,490,700 49,843 4,149 3,861 14,842.3 4,955.1 131,346 - 

Viburnum spp 308,600 1,299 317 300 425.3 142.0 11,836 - 

White ash 1,129,900 85,891 5,558 4,116 22,191.1 5,624.6 296,133 23,500 

White mulberry 188,000 86,406 3,510 2,558 6,958.1 2,270.6 261,050 - 

White oak 741,500 415,732 10,998 7,947 28,193.1 9,148.8 1,407,922 23,500 

White poplar 45,100 87,310 1,792 1,421 8,557.8 3,319.7 138,320 23,500 

Willow spp 237,600 35,679 2,128 1,969 5,478.0 1,508.5 96,531 - 

Winged burningbush 66,800 123 25 13 26.9 9.0 1,638 - 

Yew spp 94,000 1,099 191 186 392.4 274.1 7,284 - 

Total 43,369,500 3,982,277 170,306 117,830 611,024 195,950 12,816,630 801,100 

DuPage County

Alternateleaf dogwood 11,100 19 19 17.8 5.3 492 - 

American basswood 64,300 12,901 603 554 2,718.3 354.0 88,351 11,100 

American elm 259,400 32,701 1,445 1,148 13,093.8 4,248.1 57,522 - 

American plum 11,100 17 11 11 24.0 8.3 416 - 

Amur corktree 12,900 134 23 23 185.3 61.9 571 - 

Amur honeysuckle 506,800 1,780 392 354 1,764.3 387.7 20,408 - 

Amur maple 44,300 8,930 525 420 1,918.7 481.7 32,328 - 

Apple spp 354,300 39,486 2,588 2,265 8,222.0 3,161.9 162,808 - 

Austrian pine 57,200 4,207 279 262 1,767.8 760.1 33,622 - 

Baldcypress 11,100 52 13 13 75.9 53.0 707 - 

Bitternut hickory 77,200 447 97 96 576.5 161.6 4,282 - 

Black cherry 1,049,600 108,322 6,041 5,118 20,850.5 7,213.3 269,438 - 

Black locust 51,400 4,860 290 263 1,248.3 299.8 13,126 - 

Black walnut 136,100 49,497 1,457 1,305 14,582.6 5,213.4 119,468 - 

Blue spruce 133,000 30,123 1,344 1,168 10,345.8 7,830.1 150,846 - 

Boxelder 1,084,500 228,088 7,828 4,359 42,302.0 17,262.9 327,060 - 

Bur oak 168,100 95,187 2,352 1,887 6,197.8 2,728.5 233,193 - 

Callery pear 86,000 8,151 667 634 2,224.4 742.6 36,521 - 

Chinese chestnut 11,100 6,412 266 241 1,259.5 393.9 9,570 - 

Chinkapin oak 22,600 46,199 782 529 867.8 382.1 112,964 - 

Cockspur hawthorn 97,500 3,887 489 422 709.7 238.5 17,205 - 

Common elderberry 11,100 32 14 13 21.5 7.2 492 - 

Common lilac 33,300 71 24 23 30.4 13.1 954 - 

Common pear 62,500 5,408 519 463 1,396.9 466.4 24,108 - 

Cornelian cherry 11,100 651 80 78 253.0 74.8 3,191 - 

Dogwood spp 31,900 285 41 41 163.3 42.5 1,190 - 

Downy serviceberry 55,400 1,251 246 238 515.5 140.2 4,901 - 

Eastern cottonwood 9,800 30,215 463 349 3,433.9 1,105.3 75,042 - 

Eastern hemlock 44,300 373 73 71 564.1 233.7 3,020 - 

Eastern redcedar 22,200 399 27 14 59.3 73.4 1,723 - 

Eastern redbud 33,300 372 84 82 216.0 61.7 2,037 - 

Eastern wahoo 44,300 1,402 229 223 798.1 266.4 6,633 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
76

Eastern white pine 289,500 28,984 1,419 1,285 5,867.6 1,683.3 318,820 - 

European alder 317,700 15,798 923 852 3,827.1 1,244.7 48,555 - 

European buckthorn 4,395,100 41,716 5,650 5,359 14,113.9 2,798.3 209,147 - 

European hornbeam 99,800 1,499 287 256 406.5 109.2 4,793 - 

Gray birch 22,200 593 127 124 300.0 79.5 1,602 - 

Green ash 606,100 75,908 3,248 2,574 30,823.7 8,968.4 558,648 99,800 

Hardwood 906,000 88,107 - (13,289) -- -- 

Hawthorn spp 23,900 723 93 85 339.5 54.5 1,830 - 

Honeylocust 246,100 93,244 4,160 3,696 8,270.9 3,863.5 394,348 33,300 

Honeysuckle spp 93,100 281 79 76 171.0 37.6 3,244 - 

Jack pine 25,700 2,936 100 69 660.0 245.3 9,846 - 

Japanese red pine 11,100 207 26 25 50.4 21.6 2,327 - 

Japanese tree lilac 11,100 372 66 65 97.6 42.0 1,208 - 

Japanese zelkova 11,100 12 8 8 12.8 4.3 416 - 

Katsura tree 11,100 826 91 83 70.4 23.5 3,445 - 

Lilac spp 266,000 626 272 267 251.5 108.2 11,309 - 

Littleleaf linden 11,100 123 30 30 53.1 17.7 747 11,100 

Magnolia spp 55,400 3,779 337 321 1,042.8 310.8 19,752 - 

Mulberry spp 317,500 14,769 1,156 1,096 2,976.1 1,118.5 58,792 - 

Northern hackberry 12,900 100 19 19 41.3 9.6 772 - 

Northern red oak 176,500 117,425 2,717 2,405 8,702.4 3,093.2 327,517 - 

Northern white-cedar 419,800 2,407 395 383 1,169.0 1,003.0 37,355 - 

Norway maple 423,000 43,909 2,727 2,471 18,096.4 4,357.1 177,821 11,100 

Norway spruce 48,800 8,246 374 357 2,602.0 1,934.5 30,898 - 

Paper birch 174,700 5,499 959 935 2,409.2 751.5 13,711 - 

Peach 47,600 52 30 30 91.9 31.8 1,329 - 

Peachleaf willow 64,300 2,928 71 (81) 66.0 18.7 3,419 - 

Pin oak 29,300 9,217 297 180 1,483.6 599.0 24,917 - 

Pine spp 30,600 587 - (161) -- -- 

Plum spp 25,700 101 25 25 70.4 24.3 757 - 

Pussy willow 55,400 7,163 331 315 668.2 188.8 20,567 - 

Red maple 22,200 1,431 175 169 773.7 232.4 6,137 - 

Red pine 11,100 1,279 98 93 220.9 144.9 6,365 - 

River birch 55,400 5,420 564 542 1,807.8 625.1 22,728 - 

Rose-of-Sharon 11,100 6 5 5 11.1 2.4 492 - 

Sassafras 25,700 35 13 12 49.4 10.8 925 - 

Saucer magnolia 11,100 1,354 121 116 194.7 58.1 6,952 - 

Serviceberry spp 33,300 109 46 45 65.5 22.2 1,476 - 

Shagbark hickory 151,200 1,422 223 219 1,744.5 569.9 10,187 - 

Shellbark hickory 9,800 19 7 7 37.3 8.7 463 - 

Siberian elm 394,600 29,577 1,470 1,318 4,838.0 1,470.0 72,435 - 

Silver maple 343,200 219,616 5,538 4,496 33,928.8 7,966.0 641,523 - 

Slippery elm 356,900 21,551 976 871 4,375.2 873.8 38,685 - 

Smoke tree 11,100 97 31 31 33.6 11.2 467 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
77

Spruce spp 11,100 631 - (173) -- -- 

Star magnolia 11,100 7 5 4 27.7 8.3 348 - 

Sugar maple 158,300 68,484 2,368 1,847 9,660.4 2,596.0 240,858 - 

Sumac spp 253,200 2,226 360 344 1,324.7 472.9 15,535 - 

Swamp white oak 12,900 3,666 170 156 930.8 409.8 22,134 - 

Sweetgum 11,100 170 26 25 145.0 29.7 1,107 - 

Sycamore spp 19,500 55 17 16 67.0 13.7 999 - 

Tree-of-heaven 55,400 2,514 361 350 1,029.2 343.5 8,838 - 

Viburnum spp 22,600 32 13 13 40.0 13.3 1,112 - 

Weeping willow 11,100 7,035 217 201 1,227.8 347.0 17,897 - 

White ash 933,800 48,690 2,524 2,117 6,247.9 1,583.6 146,663 11,100 

White mulberry 133,000 15,863 1,108 1,045 2,980.0 972.4 64,762 - 

White oak 70,500 177,916 3,409 2,834 9,882.5 3,206.9 595,767 - 

White poplar 44,300 79,214 2,062 1,734 9,106.6 3,532.5 123,991 - 

White spruce 55,400 5,463 300 137 2,451.5 1,756.8 20,755 - 

Willow spp 66,500 120 42 41 36.6 10.1 1,935 - 

Winged burningbush 33,300 412 89 87 106.3 35.5 2,101 - 

Witch hazel 22,200 12 11 11 75.1 19.7 984 - 

Yew spp 86,000 2,121 174 164 1,021.0 713.3 20,871 - 

Total 17,285,000 1,986,579 77,851 51,423 337,581 115,276 6,197,568 177,500 

Kane County

American basswood 74,700 16,683 559 498 2,571.6 334.9 96,722 - 

American elm 166,100 12,974 719 91 3,824.1 1,240.7 22,595 - 

Amur honeysuckle 589,400 7,549 1,176 1,117 2,577.0 566.3 38,509 - 

Apple spp 247,300 18,707 1,493 1,419 3,905.4 1,501.8 72,247 - 

Austrian pine 14,900 337 39 37 68.2 29.4 3,986 - 

Baldcypress 14,900 155 33 32 165.1 115.3 1,404 - 

Bitternut hickory 14,900 2,199 151 94 451.9 126.7 6,402 - 

Black cherry 422,400 31,190 2,475 2,273 4,086.3 1,413.7 84,828 - 

Black locust 59,800 2,514 372 361 1,187.8 285.3 9,506 - 

Black walnut 469,500 99,351 4,567 3,648 24,812.3 8,870.6 234,514 - 

Black willow 44,800 23,837 1,018 926 2,629.1 742.9 58,482 - 

Blue spruce 74,700 16,123 775 628 4,382.1 3,316.4 81,409 - 

Boxelder 1,027,300 90,734 3,546 818 9,721.7 3,967.2 89,440 - 

Bur oak 149,700 339,032 8,679 6,749 18,624.2 8,199.2 1,093,643 - 

Callery pear 14,900 445 84 82 177.7 59.3 1,436 - 

Cockspur hawthorn 14,900 583 85 82 156.9 52.8 2,951 - 

Common chokecherry 76,100 475 47 (10) 107.5 37.2 2,284 - 

Common elderberry 74,700 167 79 77 261.9 87.5 3,315 - 

Downy hawthorn 195,100 7,836 942 888 1,760.8 591.7 32,320 - 

Eastern cottonwood 120,400 46,094 1,867 1,600 7,979.4 2,568.2 154,203 - 

Eastern hemlock 14,900 4,317 177 136 2,372.9 983.2 26,348 - 

Eastern redcedar 179,300 15,001 934 848 2,444.1 3,028.6 105,909 - 

Eastern white pine 29,900 4,721 249 231 1,889.1 541.9 39,051 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
78

European buckthorn 1,525,100 8,093 1,585 1,509 3,336.1 661.5 68,224 - 

Gray dogwood 45,700 41 22 22 67.7 14.4 1,704 - 

Green ash 150,900 22,388 984 883 5,168.3 1,503.8 150,125 - 

Hardwood 619,500 53,781 - (13,176) -- -- 

Hawthorn spp 14,900 125 - (34) -- -- 

Honeylocust 51,900 21,496 830 744 2,988.7 1,396.1 84,768 - 

Juniper spp 81,800 2,420 255 245 1,217.5 1,508.6 15,202 - 

Lilac spp 74,700 1,473 201 194 353.6 152.1 9,107 - 

Littleleaf linden 35,800 1,349 172 166 726.0 242.6 9,525 - 

Mulberry spp 404,000 33,916 2,072 2,031 5,924.2 2,226.4 104,288 - 

Northern hackberry 82,600 1,409 239 232 377.1 87.5 10,008 

Northern red oak 269,000 11,944 1,387 1,014 2,580.7 917.3 38,991 - 

Northern white-cedar 14,900 292 36 34 117.4 100.7 2,183 - 

Norway maple 66,800 24,391 983 820 4,338.1 1,044.5 87,136 29,900 

Norway spruce 30,500 31,646 623 552 4,538.5 3,374.3 158,999 - 

Ohio buckeye 15,200 15 7 7 10.1 3.3 742 - 

Osage orange 20,900 1,014 69 64 143.1 64.1 2,224 - 

Paper birch 44,800 770 180 175 471.2 147.0 1,874 - 

Peach 29,900 276 86 85 255.7 88.3 1,065 - 

Plum spp 45,400 101 42 40 86.5 29.9 1,602 - 

Privet spp 14,900 52 19 19 38.1 15.5 663 - 

Red maple 29,900 648 146 146 347.2 104.3 1,824 14,900 

Red mulberry 45,400 17,269 716 647 2,687.7 1,190.7 61,141 - 

River birch 14,900 9,563 420 382 1,392.9 481.6 34,330 - 

Russian olive 29,900 1,061 97 67 130.5 43.5 3,293 - 

Sargent cherry 45,400 5,912 345 284 698.3 241.0 14,044 - 

Saucer magnolia 14,900 200 53 52 21.0 6.3 867 - 

Siberian elm 343,700 17,101 1,207 569 2,806.3 852.7 39,543 - 

Silver maple 164,700 126,026 3,590 2,949 14,932.7 3,506.0 381,525 - 

Softwood 36,100 49 - (13) -- -- 

Star magnolia 14,900 491 88 86 225.1 67.1 1,815 - 

Sumac spp 14,900 15 11 10 24.2 8.6 544 - 

Swamp white oak 14,900 39 18 17 29.4 12.9 897 - 

White ash 29,900 2,158 208 199 1,086.0 275.3 9,711 - 

White mulberry 482,200 19,414 1,804 1,605 4,485.9 1,463.8 76,873 - 

White oak 75,600 124,039 3,172 2,645 7,289.5 2,365.4 395,468 - 

White spruce 29,900 2,699 202 191 1,214.2 870.2 14,570 - 

Willow spp 730,400 89,850 2,751 1,610 7,852.6 2,162.3 173,694 - 

Winged burningbush 14,900 104 30 29 76.6 25.6 630 - 

Yew spp 14,900 187 34 33 44.5 31.1 1,289 - 

Total 9,877,200 1,374,841 54,750 29,759 174,240 65,947 4,221,990 44,800 

Kendall County

American basswood 178,200 13,072 744 693 5,418.4 705.7 83,690 - 

American elm 323,300 13,163 983 922 7,443.4 2,414.9 32,021 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
79

American plum 21,900 1,443 191 184 451.5 155.9 4,880 - 

Amur honeysuckle 99,800 277 71 70 358.0 78.7 3,288 - 

Apple spp 87,400 7,378 578 565 2,538.2 976.1 23,931 - 

Autumn olive 11,200 6 4 4 40.8 13.6 495 - 

Bitternut hickory 67,000 1,993 153 86 713.6 200.1 5,612 - 

Black cherry 256,100 10,897 993 961 2,598.0 898.8 38,649 - 

Black locust 145,100 7,477 518 501 3,276.5 786.9 24,056 - 

Black maple 11,000 880 97 93 438.4 110.0 3,062 - 

Black walnut 132,300 44,658 1,492 1,340 13,741.7 4,912.8 97,099 - 

Blue spruce 11,000 21 7 7 36.6 27.7 575 - 

Boxelder 265,400 61,044 3,095 2,743 17,926.1 7,315.4 115,825 - 

Bur oak 32,800 43,482 902 872 4,056.4 1,785.8 121,152 - 

Callery pear 43,800 1,843 260 250 674.3 225.1 8,475 43,800 

Cherry plum 97,500 471 123 123 626.2 169.7 2,438 - 

Common chokecherry 11,200 6 4 4 41.3 14.3 419 - 

Common lilac 21,900 677 124 121 213.7 92.0 2,252 - 

Common pear 32,600 4,873 266 260 689.2 230.0 12,546 - 

Downy hawthorn 111,600 4,693 426 399 1,919.0 644.8 13,650 - 

Eastern hophornbeam 178,300 2,207 274 267 1,187.8 345.9 13,147 - 

Eastern redcedar 10,800 375 21 20 294.0 364.4 891 - 

Eastern white pine 256,300 18,380 1,006 962 5,801.2 1,664.2 172,995 - 

European buckthorn 223,200 1,440 277 273 661.2 131.1 10,430 - 

Freeman maple 11,000 57 15 13 18.8 4.7 316 - 

Gray dogwood 22,300 33 14 14 54.9 11.7 966 - 

Green ash 110,600 2,114 216 209 2,688.4 782.2 11,620 - 

Hardwood 366,900 25,402 - (3,373) -- -- 

Hawthorn spp 44,600 1,568 142 131 227.8 36.6 4,717 - 

Honeylocust 10,800 59 19 19 61.3 28.6 762 - 

Honeysuckle spp 55,800 548 77 75 12.1 2.6 3,249 - 

Lilac spp 43,700 1,009 156 145 179.1 77.1 4,471 - 

Littleleaf linden 11,000 1,299 98 93 567.1 189.5 9,681 11,000 

Mulberry spp 392,700 20,506 1,381 1,357 6,945.7 2,610.4 56,330 - 

Northern hackberry 200,300 3,969 495 478 2,430.2 564.1 23,945 - 

Northern red oak 89,100 11,969 671 602 2,681.8 953.3 45,564 11,000 

Northern white-cedar 33,500 1,646 53 33 201.9 173.1 15,794 - 

Norway maple 55,000 4,060 299 282 1,123.3 270.5 17,087 - 

Peach 21,900 170 45 41 217.0 74.9 665 - 

Pin oak 33,300 14,668 563 501 1,500.4 605.7 48,103 - 

Plum spp 22,300 976 92 89 383.5 132.4 3,847 - 

Red mulberry 11,200 35 15 14 174.9 77.5 495 - 

River birch 11,200 6,903 237 210 1,202.1 415.6 33,231 - 

Sargent cherry 11,200 327 40 39 7.2 2.4 796 - 

Shagbark hickory 11,200 92 18 18 120.1 39.3 586 - 

Silver maple 33,100 13,953 466 413 2,353.1 552.5 41,852 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
80

Slippery elm 22,100 1,710 118 83 107.2 21.5 3,972 - 

Sugar maple 672,200 28,638 2,760 2,631 7,550.9 2,029.1 119,693 - 

Sycamore spp 87,300 23,101 641 589 4,062.6 832.4 71,467 - 

Washington hawthorn 11,200 36 15 15 118.1 39.7 495 - 

White ash 111,000 10,324 556 456 2,528.8 641.0 31,736 - 

White mulberry 77,500 1,118 221 217 1,084.3 353.8 3,718 - 

White oak 11,200 63,830 892 542 2,081.6 675.5 144,815 - 

Willow spp 11,200 27,477 488 384 1,435.2 395.2 69,341 - 

Yew spp 11,000 25 6 6 43.5 30.3 522 - 

Total 5,247,100 508,378 23,418 18,046 113,308 36,887 1,561,417 65,800 

Lake County

American basswood 94,100 2,975 339 292 2,175.0 283.3 15,964 13,400 

American elm 686,200 12,293 1,186 308 10,322.4 3,349.0 30,427 - 

Amur honeysuckle 99,200 410 123 121 451.5 99.2 3,514 - 

Apple spp 329,300 26,753 1,641 1,572 6,743.1 2,593.1 77,618 

Austrian pine 228,900 9,948 804 733 4,267.9 1,834.9 81,845 - 

Black cherry 1,360,800 178,753 7,734 3,906 19,097.6 6,606.8 368,215 - 

Black locust 228,100 41,790 1,198 909 5,328.2 1,279.6 102,645 - 

Black oak 53,700 6,102 264 176 1,106.8 348.9 12,008 - 

Black walnut 188,800 51,550 2,020 1,814 20,926.4 7,481.5 128,759 26,800 

Blue spruce 141,700 6,659 595 558 2,728.2 2,064.8 30,568 20,200 

Boxelder 1,359,800 291,727 11,666 9,647 65,369.1 26,676.3 471,907 20,200 

Bur oak 211,200 167,341 3,531 1,984 13,677.7 6,021.5 664,657 - 

Callery pear 40,500 301 94 92 174.0 58.1 1,796 - 

Cherry plum 40,500 2,322 129 88 471.2 127.7 4,551 - 

Chinkapin oak 25,100 11,839 353 345 1,194.5 525.8 29,090 - 

Cockspur hawthorn 174,400 986 213 180 868.3 291.8 4,330 - 

Common lilac 53,900 478 58 18 115.6 49.7 894 - 

Common pear 53,900 7,539 438 410 2,285.7 763.0 31,481 20,200 

Douglas-fir 81,000 3,808 146 43 2,726.5 1,904.8 26,891 - 

Downy hawthorn 161,000 1,843 323 275 955.0 320.9 7,208 - 

Eastern cottonwood 321,200 132,491 3,475 610 17,892.3 5,758.9 221,181 - 

Eastern hemlock 121,400 4,138 484 439 2,784.3 1,153.7 23,681 - 

Eastern hophornbeam 396,400 7,343 1,025 909 5,615.6 1,635.4 38,966 - 

Eastern redcedar 167,800 5,901 380 234 1,800.9 2,231.6 37,464 - 

Eastern redbud 20,200 1,919 144 94 132.0 37.7 5,885 - 

Eastern white pine 141,700 31,329 1,212 1,013 10,840.8 3,110.0 224,766 - 

European beech 20,200 451 109 107 439.1 98.0 1,294 20,200 

European buckthorn 13,708,300 132,287 17,308 15,275 67,862.6 13,454.7 592,995 249,500 

Flowering dogwood 62,200 2,338 108 94 228.8 59.3 3,663 - 

Freeman maple 40,500 874 190 186 1,285.7 322.8 2,546 - 

Glossy buckthorn 234,900 1,773 500 468 1,507.3 503.2 9,597 - 

Gray birch 121,400 1,514 360 354 1,683.5 446.0 5,737 - 

Green ash 1,665,900 103,819 4,535 2,930 35,118.1 10,217.9 569,604 20,200 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
81

Hardwood 60,500 776 - (171) -- -- 

Hawthorn spp 369,600 11,565 1,042 867 3,881.0 622.8 37,030 - 

Hickory spp 40,500 292 98 96 750.9 188.4 1,923 - 

Honeylocust 60,700 15,357 771 647 1,719.8 803.3 62,544 20,200 

Honeysuckle spp 338,800 2,703 450 427 1,945.9 427.6 19,145 - 

Horsechestnut 40,300 490 103 93 275.3 85.9 1,629 40,300 

Juniper spp 20,200 193 37 36 89.9 111.6 949 - 

Littleleaf linden 20,200 231 56 55 245.1 81.9 1,393 - 

Mockernut hickory 121,400 2,030 377 363 1,409.2 360.3 10,328 - 

Mulberry spp 158,500 2,261 357 339 903.6 339.7 8,287 - 

Northern catalpa 20,200 41,300 1,230 1,072 1,464.1 397.6 88,624 - 

Northern hackberry 151,200 8,057 696 652 3,426.3 795.3 44,541 60,700 

Northern pin oak 20,200 2,611 248 222 413.9 190.4 9,651 - 

Northern red oak 941,500 634,399 19,255 12,576 48,345.1 17,184.4 1,650,768 - 

Northern white-cedar 1,038,800 18,676 1,842 1,708 9,805.7 8,412.0 182,014 - 

Norway maple 490,600 45,438 2,703 2,265 10,596.6 2,551.4 146,252 20,200 

Norway spruce 202,400 18,515 1,045 651 4,437.2 3,299.0 77,672 - 

Ohio buckeye 20,200 1,769 183 165 1,114.4 363.8 7,356 - 

Paper birch 81,900 21,657 1,001 847 3,393.2 1,058.5 43,920 - 

Peachleaf willow 13,400 7,567 247 204 663.2 187.4 15,760 - 

Pin oak 78,800 7,688 441 410 2,217.2 895.1 24,098 - 

Plum spp 247,100 1,480 321 298 617.0 212.9 8,081 - 

Quaking aspen 228,100 2,234 305 280 1,399.1 491.5 9,375 - 

Red maple 77,300 77,810 1,995 392 5,578.0 1,675.7 173,808 23,400 

River birch 81,000 341 132 129 240.4 83.1 3,623 - 

Serbian spruce 60,700 308 85 83 151.5 127.5 3,134 - 

Serviceberry spp 100,600 550 164 157 342.5 115.8 4,733 - 

Shagbark hickory 748,600 22,876 2,138 1,970 9,094.0 2,971.0 83,475 - 

Siberian elm 107,800 107,581 3,150 2,542 19,451.0 5,909.9 237,134 26,800 

Silver maple 316,100 178,069 3,974 1,765 29,498.6 6,925.9 396,243 - 

Spruce spp 20,200 33 14 14 34.6 26.2 1,063 - 

Sugar maple 559,700 44,156 2,249 1,328 10,460.2 2,811.0 165,342 - 

Sumac spp 40,500 280 22 (7) 125.3 44.7 449 - 

Swamp white oak 33,700 17,561 699 529 993.8 437.5 55,908 - 

Tree-of-heaven 20,700 282 75 75 447.5 149.4 427 - 

White ash 1,354,500 160,604 7,498 4,362 31,060.7 7,872.7 441,010 20,200 

White mulberry 99,200 4,199 395 348 1,617.3 527.8 16,470 - 

White oak 627,000 377,258 11,491 5,598 24,460.2 7,937.5 1,182,844 - 

White spruce 1,598,800 42,687 2,953 2,729 16,381.0 11,738.9 130,246 - 

Willow spp 54,900 61,823 987 694 4,169.3 1,148.1 57,096 - 

Winged burningbush 33,700 239 57 44 75.4 25.2 833 - 

Witch hazel 182,100 2,170 225 (4) 971.8 255.0 6,198 - 

Yew spp 20,200 1,179 56 26 1,733.9 1,211.2 4,429 - 

Total 33,536,600 3,198,889 133,852 93,060 564,176 192,765 9,247,549 602,500 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
82

McHenry County

American basswood 52,300 1,038 165 160 1,130.7 147.3 7,686 - 

American elm 491,300 54,842 2,257 558 13,495.9 4,378.5 50,418 - 

American plum 23,100 396 60 60 111.4 38.4 1,055 - 

Amur honeysuckle 444,200 5,762 886 792 2,307.9 507.2 28,363 - 

Apple spp 96,000 19,514 862 771 5,026.3 1,933.0 57,753 - 

Austrian pine 284,700 24,114 1,504 1,408 8,512.3 3,659.8 168,943 - 

Autumn olive 20,500 161 23 23 150.7 50.3 377 - 

Balsam fir 205,400 2,928 344 342 1,454.4 675.9 10,163 - 

Black cherry 1,345,400 155,232 9,069 5,819 37,561.4 12,994.5 391,812 - 

Black walnut 851,500 51,711 5,136 4,858 26,453.5 9,457.4 173,941 - 

Blue spruce 76,000 2,491 271 265 1,262.7 955.7 9,266 - 

Boxelder 1,569,100 296,291 11,431 10,021 54,956.3 22,427.0 441,371 - 

Bur oak 402,400 710,230 11,877 8,662 50,683.4 22,313.0 1,937,377 - 

Callery pear 17,400 304 72 71 167.8 56.0 1,089 - 

Cherry plum 17,400 1,555 173 167 945.4 256.2 6,080 - 

Cockspur hawthorn 23,100 207 65 64 192.7 64.8 1,282 - 

Common elderberry 23,100 32 19 19 18.0 6.0 841 - 

Common pear 23,100 364 35 35 188.8 63.0 375 - 

Common prickly ash 207,900 172 131 129 767.7 256.3 9,227 - 

Dogwood spp 184,800 819 200 199 497.9 129.6 5,468 - 

Eastern cottonwood 133,400 368,035 4,372 3,221 17,492.7 5,630.3 252,130 - 

Eastern hemlock 17,400 68 15 15 196.0 81.2 1,046 - 

Eastern redcedar 104,600 1,329 196 190 621.7 770.4 8,392 - 

Eastern white pine 703,800 49,054 2,279 1,609 15,438.6 4,429.0 352,959 - 

European buckthorn 7,971,400 59,402 10,999 10,487 34,219.9 6,784.6 341,649 - 

European filbert 17,400 136 46 44 40.0 12.4 635 - 

Flowering dogwood 17,400 10 10 10 42.5 11.0 774 - 

Forsythia spp 104,600 168 92 91 367.4 122.7 4,605 - 

Freeman maple 23,100 1,541 176 169 1,616.5 405.9 8,193 - 

Glossy buckthorn 69,300 376 78 77 618.2 206.4 3,024 - 

Green ash 1,126,400 53,689 2,133 2,015 24,547.2 7,142.2 81,075 17,400 

Hardwood 768,000 22,143 - (5,681) -- -- 

Hawthorn spp 161,700 4,379 410 302 1,199.9 192.6 6,695 - 

Honeylocust 34,900 15,186 568 464 1,841.1 860.0 58,424 17,400 

Honeysuckle spp 137,000 2,087 259 256 568.8 125.0 9,645 - 

Leather leaf viburnum 17,400 15 10 10 24.7 8.3 635 - 

Lilac spp 209,300 1,549 355 314 542.6 233.5 9,313 - 

Littleleaf linden 17,400 804 91 88 601.9 201.1 5,951 - 

Mulberry spp 414,100 70,610 3,088 2,670 11,664.4 4,383.7 227,589 - 

Nannyberry 69,300 135 38 37 85.7 28.6 2,297 - 

Northern catalpa 23,100 304 48 47 260.7 70.8 857 - 

Northern red oak 370,600 37,518 2,542 2,400 5,708.0 2,029.0 131,871 - 

Northern white-cedar 52,300 1,367 105 91 692.6 594.2 12,941 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
83

Norway maple 161,200 18,622 1,013 939 5,070.0 1,220.7 77,548 34,900 

Norway spruce 58,500 9,608 395 366 1,769.2 1,315.4 27,259 - 

Oak spp 23,100 75 - (12) -- -- 

Pin cherry 40,500 724 133 131 300.0 64.6 1,833 - 

Pin oak 124,700 48,273 1,769 1,356 6,473.5 2,613.4 132,417 - 

Plum spp 143,800 4,555 271 246 977.5 337.4 6,311 - 

River birch 166,300 13,067 1,140 1,090 4,675.1 1,616.4 52,851 - 

Russian olive 23,100 202 65 64 347.4 116.0 1,025 - 

Serbian spruce 17,400 24 11 10 32.1 27.0 751 - 

Serviceberry spp 17,400 206 57 56 31.6 10.7 777 - 

Shagbark hickory 601,700 50,939 3,578 3,387 9,199.0 3,005.4 213,029 - 

Siberian elm 667,900 91,325 2,767 2,283 17,132.4 5,205.5 137,561 - 

Silver maple 555,900 520,598 10,252 8,527 65,794.8 15,447.7 1,189,626 - 

Softwood 23,100 2,193 - (356) -- -- 

Sugar maple 40,500 40,250 1,252 1,098 4,524.6 1,215.9 143,964 - 

Yellow-poplar 17,400 2,560 197 186 2,695.1 708.7 15,271 - 

White ash 101,600 2,608 426 414 1,720.8 436.1 12,108 34,900 

White mulberry 259,100 9,292 906 791 2,654.3 866.2 29,766 - 

White oak 276,100 292,561 8,539 6,513 24,442.4 7,931.7 941,599 

White spruce 102,700 3,748 261 258 2,861.7 2,050.7 11,479 - 

Total 22,344,600 3,129,498 105,522 80,696 474,978 158,882 7,818,760 104,600 

Will County

American basswood 280,600 15,015 918 202 7,266.5 946.4 82,817 - 

American elm 1,646,000 70,643 4,693 4,448 32,015.5 10,387.1 188,086 - 

Amur corktree 29,500 120 44 43 55.6 18.6 1,308 - 

Amur honeysuckle 673,000 5,987 818 752 3,984.2 875.5 39,006 - 

Apple spp 168,500 20,736 1,533 1,449 6,759.4 2,599.4 102,229 - 

Austrian pine 230,300 8,428 641 606 4,801.2 2,064.2 69,031 - 

Autumn olive 59,000 470 79 78 394.4 131.6 1,520 - 

Bitternut hickory 27,500 12 13 12 12.8 3.6 1,442 - 

Black cherry 672,000 81,695 5,009 4,594 25,874.8 8,951.4 237,835 - 

Black haw 54,900 135 57 56 98.3 32.8 2,437 - 

Black locust 1,265,600 96,144 5,291 4,568 21,647.2 5,198.8 240,921 - 

Black maple 59,000 91 39 38 88.0 22.1 3,538 - 

Black walnut 382,400 71,536 3,313 3,059 39,590.9 14,154.1 248,745 - 

Blue spruce 306,100 16,096 1,413 1,234 8,029.0 6,076.6 74,598 - 

Boxelder 872,300 72,103 2,767 1,951 10,128.9 4,133.5 107,088 - 

Bur oak 318,200 282,731 7,338 6,332 22,465.8 9,890.4 1,184,023 - 

Callery pear 27,500 685 139 136 166.1 55.4 2,318 - 

Chinkapin oak 30,000 120 33 31 79.8 35.1 1,846 - 

Common elderberry 88,400 297 122 122 54.6 18.2 3,270 - 

Dogwood spp 27,500 565 127 121 297.0 77.3 1,540 - 

Douglas-fir 27,500 360 34 32 523.6 365.8 4,514 - 

Eastern cottonwood 535,500 104,799 2,478 1,343 11,953.2 3,847.4 200,378 - 

Appendix III.—continued

continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
84

Eastern hophornbeam 27,500 847 152 148 442.6 128.9 3,013 - 

Eastern redcedar 27,500 1,074 68 40 646.2 800.7 4,467 - 

European buckthorn 2,826,700 19,618 3,752 3,420 16,628.6 3,296.9 150,780 - 

Freeman maple 137,300 4,142 657 639 3,083.8 774.2 16,175 - 

Ginkgo 172,200 200 88 88 303.7 59.7 6,457 - 

Green ash 2,710,000 141,844 6,383 5,297 50,474.6 14,686.0 775,269 - 

Hardwood 1,046,200 26,489 - (4,738) -- -- 

Hawthorn spp 617,100 20,076 1,971 1,902 11,123.5 1,784.9 82,777 - 

Honeylocust 111,900 57,356 1,886 1,665 5,629.4 2,629.6 204,658 - 

Honeysuckle spp 320,200 2,068 597 570 381.3 83.8 11,268 - 

Juniper spp 54,900 1,199 132 127 545.6 676.2 9,396 - 

Mulberry spp 143,900 5,326 533 515 942.4 354.2 25,257 - 

Northern hackberry 354,300 79,783 2,727 1,305 14,585.6 3,385.3 392,227 - 

Northern red oak 139,300 65,397 2,072 1,820 6,457.2 2,295.2 218,477 - 

Northern white-cedar 139,800 7,206 203 175 1,956.5 1,678.5 129,613 - 

Norway maple 82,400 33,840 1,463 1,332 9,102.4 2,191.6 136,545 - 

Norway spruce 27,500 7,229 325 297 3,001.3 2,231.5 37,774 - 

Ohio buckeye 28,700 68,776 1,232 1,185 3,352.9 1,094.4 141,572 - 

Osage orange 60,000 40,281 841 (838) 3,052.2 1,368.7 137,612 - 

Plum spp 56,900 112 62 61 228.6 78.9 2,080 - 

Red maple 30,000 9,323 391 355 3,479.9 1,045.4 47,797 - 

River birch 54,900 2,708 389 377 1,269.1 438.8 12,454 - 

Siberian elm 292,900 92,353 3,495 3,103 23,414.7 7,114.2 239,753 - 

Silver maple 955,800 152,254 6,493 4,824 31,427.7 7,378.8 350,960 - 

Sugar maple 2,787,200 150,876 8,500 8,105 52,776.1 14,182.6 693,874 - 

Sumac spp 27,500 23 - (6) -- -- 

Tree-of-heaven 90,000 791 141 141 629.6 210.2 1,417 - 

White ash 143,400 1,302 301 288 820.1 207.9 5,310 - 

White mulberry 341,200 8,662 992 961 3,700.3 1,207.5 43,450 - 

White oak 27,500 30,033 1,054 938 2,984.2 968.4 130,394 - 

Willow spp 247,100 80,030 2,306 1,900 6,692.5 1,842.9 147,649 - 

Yew spp 27,500 105 22 21 152.0 106.2 1,310 - 

Total 21,890,600 1,960,091 86,127 67,224 455,571 144,187 6,958,274 - 

Chicago Region 157,141,100 16,870,647 677,361 475,990 2,841,056 944,000 51,155,683 2,346,400 

a Species refers to tree species, genera, or species groups that were classified during field data collection

Appendix III.—continued

Common Namea

Number of 

Trees

Carbon 

Storage 

(tons)

Gross Carbon 

Sequestration 

(tons/yr)

Net Carbon 

Sequestration 

(tons/yr)

Leaf Area 

(ac)

Leaf 

Biomass 

(tons)

Compensatory 

Value

($US 1,000)

Number 

of Street 

Trees

Table 20.—Estimate of trees by area
85

APPENDIX IV. GENERAL RECOMMENDATIONS FOR AIR QUALITY 

IMPROVEMENT

Urban vegetation can directly and indirectly aff ect local and regional air quality by altering the urban 

atmospheric environment. Four main ways that urban trees aff ect air quality are:

Temperature reduction and other microclimatic eff ects

Removal of air pollutants

Emission of volatile organic compounds (VOC) and tree maintenance emissions

Energy conservation on buildings and consequent power plant emissions

Th e cumulative and interactive eff ects of trees on climate, pollution removal, and VOC and power plant 

emissions determine the overall impact of trees on air pollution. Cumulative studies involving urban tree 

impacts on ozone have revealed that increased urban canopy cover, particularly with low VOC emitting 

species, leads to reduced ozone concentrations in cities. Local urban forest management decisions also can 

help improve air quality.

Urban forest management strategies to help improve air quality include:

Strategy Reason

Increase the number of healthy trees Increase pollution removal

Sustain existing tree cover Maintain pollution removal levels

Maximize use of low VOC-emitting trees Reduces ozone and carbon monoxide formation

Sustain large, healthy trees Large trees have greatest per-tree eff ects

Use long-lived trees Reduce long-term pollutant emissions from planting 

 and removal

Use low maintenance trees Reduce pollutants emissions from maintenance activities

Reduce fossil fuel use in maintaining vegetation Reduce pollutant emissions

Plant trees in energy conserving locations Reduce pollutant emissions from power plants

Plant trees to shade parked cars Reduce vehicular VOC emissions

Supply ample water to vegetation Enhance pollution removal and temperature reduction

Plant trees in polluted or heavily populated areas Maximizes tree air quality benefi ts

Avoid pollutant-sensitive species Improve tree health

Utilize evergreen trees for particulate matter Year-round removal of particles
86

APPENDIX V. RELATIVE TREE EFFECTS

Th e urban forest in the Chicago region provides benefi ts that include carbon storage and sequestration, and air 

pollutant removal. To estimate a relative value of these benefi ts, tree benefi ts were compared to estimates of average 

carbon emissions in the region,28 average passenger automobile emissions,29 and average household emissions.30

General tree information:

Average tree diameter (d.b.h.) = 5.3 in

Median tree diameter (d.b.h.) = 3.1 in

Number of trees sampled = 9,731

Number of species sampled = 161

Table 21.—Average tree effects by tree diameter class (d.b.h.), Chicago region, 2010

d.b.h. 

(inch)a

Carbon storage Carbon sequestration Pollution removal

(lbs) ($) (miles) b (lbs/yr) ($/yr) (miles) b (lbs/yr) ($/yr)

1-3 6 0.06 20 1.7 0.02 6 0.04 0.15

3-6 39 0.41 140 5.3 0.05 19 0.1 0.46

6-9 135 1.40 500 10.1 0.10 37 0.3 1.07

9-12 309 3.19 1,130 17.1 0.18 63 0.5 1.95

12-15 550 5.69 2,010 22.8 0.24 84 0.8 3.00

15-18 909 9.40 3,330 33.4 0.35 122 1.0 3.81

18-21 1,333 13.79 4,880 40.3 0.42 148 1.1 4.30

21-24 1,920 19.86 7,030 51.0 0.53 187 1.3 4.88

24-27 2,432 25.16 8,910 63.5 0.66 233 1.6 6.08

27-30 3,346 34.62 12,260 72.9 0.75 267 1.6 6.01

30+ 6,158 63.71 22,550 108.5 1.12 397 2.6 9.79

a lower limit of the diameter (d.b.h.) class is greater than displayed (e.g. 3-6 is actually 3.01 to 6 inches)

b miles = number of automobile miles driven that produces emissions equivalent to tree effect

Th e trees in the Chicago region provide:

Carbon storage equivalent to:

Amount of carbon (C) emitted in region in 120 days or

Annual carbon emissions from 10,128,000 automobiles or 

Annual C emissions from 5,085,400 single family houses 

Carbon monoxide removal equivalent to:

Annual carbon monoxide emissions from 1,110 automobiles 

or 

Annual carbon monoxide emissions from 4,600 family 

houses 

Nitrogen dioxide removal equivalent to:

Annual nitrogen dioxide emissions from 213,500 

automobiles or

Annual nitrogen dioxide emissions from 142,400 single 

family houses 

Sulfur dioxide removal equivalent to:

Annual sulfur dioxide emissions from 1,406,600 automobiles 

or

Annual sulfur dioxide emissions from 23,600 single family 

houses 

Particulate matter less than 10 micron (PM10) removal 

equivalent to:

Annual PM10 emissions from 14,789,000 automobiles or

Annual PM10 emissions 1,427,700 single family houses

Annual C sequestration equivalent to:

Amount of C emitted in region in 4.8 days or

Annual C emissions from 406,600 automobiles or 

Annual C emissions from 204,200 single family home
87

APPENDIX VI. POTENTIAL INSECT AND DISEASE IMPACTS

Th e following insects and diseases were analyzed to quantify their potential impact on the Chicago 

regional forest:

• Aspen leafminer - Aspen leafminer is an insect that causes damage primarily to trembling or 

small tooth aspen by larval feeding of leaf tissue. While outbreaks of the aspen leafminer have 

been recorded throughout parts of Alaska, Canada, and the western United States, the pest is 

relatively uncommon in eastern North America.31

• Asian longhorned beetle - Asian longhorned beetle32 is an insect that bores into and kills a 

wide range of hardwood species. Th is beetle was discovered in 1996 in Brooklyn, NY, and 

has subsequently spread to Long Island, Queens, and Manhattan. In 1998, the beetle was 

discovered in the suburbs of Chicago, IL, and successfully declared eradicated in 2006. Beetles 

have also been found in Jersey City, NY (2002), Toronto/Vaughan, Ontario (2003), and 

Middlesex/Union counties, NJ (2004). In 2007, the beetle was found on Staten and Prall’s 

Islands, NY. Most recently, beetles were detected in Worcester, MA (2008) and Bethel, OH 

(2011). In addition to the eradication in Chicago, successful eradication has since occurred in 

Hudson County, NJ (2008) and Islip, NY (2011).

• Beech bark disease - Beech bark disease is an insect-disease complex that primarily impacts 

American beech. It is caused by the infestation of several diff erent species. First, the insect, 

Cryptococcus fagisuga, feeds on the sap of the beech trees. Th ese aff ected trees can become hosts 

to the nectria fungi. Th e two primary species of nectria fungi in North America are N. coccinea 

var. faginata and N. gallifena.

33

• Butternut canker - Butternut canker is caused by a fungus that infects butternut trees. Th e 

disease was fi rst discovered in 1967 in Wisconsin and has since caused signifi cant declines in 

butternut populations in the United States.34

• Chestnut blight - Th e most common hosts of the fungus that cause chestnut blight are 

American and European chestnut. Th is disease causes canker formation in host trees resulting 

in dead limbs, brown or yellowing leaves, or mortality.35

• Dogwood anthracnose - Dogwood anthracnose is a disease that aff ects dogwood species, 

specifi cally fl owering and Pacifi c dogwood. It is caused by a fungus that produces leaf spots 

and necrotic blotches and canker formation on twigs, branches, and the main stem of infected 

trees.36

• Dutch elm disease - American elm, one of the most important street trees in the 20th century, 

has been devastated by the Dutch elm disease. Since fi rst reported in the 1930s, it has killed 

more than 50 percent of the native elm population in the United States.37

• Douglas-fi r beetle - Th e Douglas-fi r beetle is a bark beetle that infests Douglas-fi r trees. 

Infestations of the Douglas-fi r beetle have been seen throughout the western United States, 

British Columbia, and Mexico often resulting in tree mortality.38

• Emerald ash borer - Since being discovered in Detroit in 2002, emerald ash borer39 has killed 

millions of ash trees in Illinois, Indiana, Kentucky, Maryland, Michigan, Minnesota, Missouri, 

New York, Ohio, Ontario, Pennsylvania, Quebec, Virginia, West Virginia, and Wisconsin.

• Fir engraver - One common pest of white fi r, grand fi r, and red fi r trees is the fi r engraver. 

Th is bark beetle is distributed primarily in the western United States.40
88

• Fusiform rust– Fusiform rust is a fungal disease that is distributed in the southern United 

States. It is particularly damaging to slash pine and loblolly pine because it infects the living 

tissue of the host’s stems and branches. Pine trees aff ected by the fungus can develop fatal galls 

and cankers.41

• Gypsy moth - Th e gypsy moth42 is a defoliator that feeds on many species causing widespread 

defoliation and tree death if outbreak conditions last several years.

• Hemlock woolly adelgid– As one of the most damaging pests to eastern hemlock and Carolina 

hemlock, hemlock woolly adelgid has played a large role in hemlock mortality in the United 

States. Since the pest was fi rst discovered in 1951, infestations have expanded to cover about 

half of the range of hemlock in the eastern United States.43

• Jeff rey pine beetle - Jeff rey pine beetle is native to North America and is distributed across 

California, Nevada, and Oregon where its only host, Jeff rey pine, also occurs. 44

• Large aspen tortrix– Quaking aspen is a principal host for the defoliator, large aspen tortrix. 

Th e insect has been found across much of the northeastern, north central, and western United 

States, as well as Alaska and Canada. Large aspen tortrix can reach outbreak levels where 

quaking aspen are abundant and will potentially strip hosts of all of their foliage.45

• Laurel wilt - Laurel wilt is a fungus-caused disease that is introduced to host trees by the 

redbay ambrosia beetle. Redbay, as well as other tree species in the Laurel family, are common 

hosts for laurel wilt which has been observed in North Carolina, South Carolina, Georgia, 

Alabama, Mississippi, and Florida.46

• Mountain pine beetle - Mountain pine beetle is a bark beetle that primarily attacks pine 

species in the western United States. Th e major host species of the mountain pine beetle, 

lodgepole pine, ponderosa pine, western white pine, sugar pine, limber pine, and whitebark 

pine, have a similar distribution as this pest.47

• Oak wilt - Oak wilt, which is caused by a fungus, is a prominent disease among oak trees 

producing leaf wilting and discoloration, heavy defoliation, or fungal mats beneath the bark. 

Th e disease has been found in 21 states throughout most of the midwestern United States and 

it is still unknown whether any species of oak are immune to it.48

• Port-Orford-cedar root disease - Port-Orford-cedar root disease is caused by a fungus. Th is 

fungus is most damaging to Port-Orford cedar and Pacifi c yew species.49

• Pine shoot beetle - Pine shoot beetle is a wood borer that attacks various pine species, though 

scotch pine is the preferred host in North America. Th e beetle has an international geographic 

distribution. In the United States it has been discovered in Illinois, Indiana, Maine, Maryland, 

Michigan, New Hampshire, New York, Ohio, Pennsylvania, Vermont, West Virginia, and 

Wisconsin, as well as in Ontario and Quebec in Canada.50

• Spruce beetle - All species of spruce that fall within the spruce beetle’s range are suitable 

hosts for attack. Th is bark beetle causes signifi cant mortality and covers large areas of Alaska, 

Canada, and the northern United States, as well as some patches through the Rocky Mountain 

range.51

• Spruce budworm - Spruce budworm is an insect that causes severe damage to balsam fi r. 

During the larval stage of the budworm’s life, it feeds primarily on the needles or expanding 

buds of its hosts. Years of heavy defoliation can ultimately lead to tree mortality. Other hosts 

for the spruce budworm include white, red, and black spruce.52
89

• Sudden oak death - Sudden oak death is a disease that is caused by a fungus. It is most 

common in British Columbia, Washington, Oregon, and California and impacts many 

diff erent species including, southern red oak, California black oak, northern red oak, pacifi c 

madrone, tanoak, and coastal live oak.53

• Southern pine beetle - Although the southern pine beetle will attack most pine species, its 

preferred hosts are loblolly, Virginia, pond, spruce, shortleaf, and sand pines. Th e range of this 

particular bark beetle covers much of the southeastern United States.54

• Sirex woodwasp - Th e sirex woodwasp is a wood borer that primarily attacks pine species. It is 

not native to the United States, but is known to cause high amounts of tree mortality among 

North American species that have been planted in countries of the southern hemisphere.55

• Th ousand cankers disease - Th ousand cankers disease is an insect-disease complex that kills 

several species of walnuts, including black walnut. It is known to occur primarily in the 

western states of Washington, Oregon, California, Idaho, Utah, Arizona, New Mexico, and 

Colorado. Tennessee is the fi rst state in the east where thousand cankers disease has been 

found. Tree mortality is the result of attacks by the walnut twig beetle and subsequent canker 

development caused by associated fungi.56

• Western pine beetle - Western pine beetle aggressively attacks ponderosa and Coulter pines. 

Th is bark beetle has caused signifi cant swaths of damage in California, Oregon, Washington, 

Idaho, British Columbia, Montana, Nevada, Utah, Colorado, Arizona, New Mexico, Texas, 

and parts of northern Mexico.57

• White pine blister rust - Since its introduction to the United States in 1900, white pine blister 

rust has had a detrimental eff ect on white pines, particularly in the Lake States.58

• Western spruce budworm - Western spruce budworm is an insect that causes defoliation in 

western conifers. It has been found in Arizona, New Mexico, Colorado, Utah, Wyoming, 

Montana, Idaho, Oregon, and Washington in the United States and British Columbia and 

Alberta in Canada. Th e western spruce budworm feeds on new foliage of its hosts. Common 

host species include Douglas-fi r, grand fi r, white fi r, subalpine fi r, corkbark fi r, blue spruce, 

Engelmann spruce, white spruce, and western larch.59
90

As each insect/disease is likely to attack diff erent host tree species, the implications for the Chicago region will 

vary. Th e number of trees at risk (Table 22) refl ects only the known host species that are likely to experience 

mortality. Th e species host lists used for these insects/diseases can be found at http://nrs.fs.fed.us/data/urban.

Table 22.—Potential risk to trees by insect or disease, Chicago region, 2010

Code Scientific Name Common Name Trees at Risk

#

Compensatory 

Value

($ millions)

AL Phyllocnistis populiella aspen leafminer 1,771,000 673

ALB Anoplophora glabripennis Asian longhorned beetle 41,641,000 17,431

BBD Cryptococcus fagisuga beech bark disease 20,000 1

BC Sirococcus clavigignentijuglandacearumbutternut canker - -

CB Cryphonectria parasitica chestnut blight - -

DA Discula destructive dogwood anthracnose 441,000 20

DED Ophiostoma novo-ulmi Dutch elm disease 8,234,000 1,641

DFB Dendroctonus pseudotsugae Douglas-fir beetle 108,000 31

EAB Agrilus planipennis emerald ash borer 12,694,000 4,198

FE Scotylus ventralis fir engraver 108,000 31

FR Cronartium fusiforme fusiform rust - -

GM Lymantria dispar gypsy moth 17,690,000 18,496

HWA Adelges tsugae hemlock woolly adelgid 269,000 59

JPB Dendroctonus jeffreyi jeffrey pine beetle - -

LAT Choristoneura conflictana large aspen tortrix 3,319,000 981

LWD Raffaelea lauricola laurel wilt 47,000 2

MPB Dendroctonus ponderosae mountain pine beetle 401,000 352

OW Ceratocystis fagacearum oak wilt 9,036,000 16,062

POCRD Phytophthora lateralis Port-Orford-cedar root disease - -

PSB Tomicus piniperda pine shoot beetle 3,138,000 1,972

SB Dendroctonus rufipennis spruce beetle 3,421,000 1,008

SBW Choristoneura fumiferana spruce budworm - -

SOD Phytophthora ramorum sudden oak death 3,448,000 3,518

SPB Dendroctonus frontalis southern pine beetle 6,342,000 2,659

SW Sirex noctilio sirex woodwasp 6,387,000 2,642

TCD Pityophthorus juglandis & 

Geosmithia spp.

thousand canker disease 2,469,000 1,111

WPB Dendroctonus brevicomis western pine beetle - -

WPBR Cronartium ribicola white pine blister rust 1,526,000 1,157

WSB Choristoneura occidentalis western spruce budworm 3,404,000 1,028

With the exception of Dutch elm disease and chestnut blight, all of the insects and diseases that were 

analyzed have existing pest range maps. Th ese range maps were used to determine the proximity of the 

insect/disease to the counties within the Chicago region. In the case of Dutch elm disease, the disease 

is known to occur in the native range of elm species. For each county in the Chicago region, it was 

determined whether the insect/disease occurs within the county, is within 250 miles of the county edge, 

is between 250 and 750 miles away, is greater than 750 miles away, or if no distance could be determined 

(no range map exists).
91

In Figure 76, the bars representing each pest are color coded according to the region’s proximity to 

the pest occurrence in the United States.23 Since the Chicago region covers multiple counties, the 

pest was color coded according to the closest proximity determined during the analysis of each county 

(i.e., if a pest is known to occur in one county within the Chicago region and be within 250 miles of 

the other counties then it will be color coded as being within the region). For more information on 

these pests and to access pest range maps, please visit www.foresthealth.info.

Based on the host tree species for each pest and the current range of the pest, it is possible to 

determine what the risk is that each tree species sampled in the Chicago region could be attacked by 

an insect or disease. In Table 23, species risk is designated as one of the following: 

• Red - tree species is at risk to at least one pest within county

• Orange - tree species has no risk to pests within county, but has a risk to at least one pest 

within 250 miles from the county

• Yellow - tree species has no risk to pests within 250 miles of county, but has a risk to at least 

pest that is 250 to 750 miles from the county

• Green - tree species has no risk to pests within 750 miles of county, but has a risk to at least 

pest that is greater than 750 miles from the county

Species that were sampled in the Chicago region, but that are not listed in this matrix, are not known 

to be hosts to any of the 29 exotic insects/diseases analyzed. Tree species at the greatest risk to existing 

pest infestations in the Chicago region are willows and poplars (Salix spp.) and Norway spruce.

Figure 76.—Number of trees at risk and associated compensatory value of insect/disease effects, 

Chicago region, 2010. See page 90, Table 22, for a description of acronyms.

0

2

4

6

8

10

12

14

16

18

20

0

5

10

15

20

25

30

35

40

45

GM

EAB

OW

DED

SB

LAT

PSB

WPBR

BC

ALB

AL

DA

BBD

SBW

SW

SPB

TCD

HWA

LWD

FR

SOD

WSB

MPB

DFB

FE

JPB

POCRD

WPB

CB

Compensatory Value (billions o fdollars) 

Number of Trees (millions) 

Trees at risk Insect/Disease 

Compensatory value

Red indicates insect/disease is within region 

Orange indicates insect/disease is within 250 miles of region 

Yellow indicates insect/disease is within 750 miles of region 

Green indicates insect/disease is outside of these ranges 

Blue indicates no data on pest range 
92

Pestc

Spp. RiskaRisk weightb

Common Name

GMEABOWDEDSBLATPSBWPBRBCALBALDABBDSBWLWDSWSPBTCDHWAFRSODWSBMPBDFBFEJPBPOCRDWPBCB

14 Willow spp 1 2 2

14 Norway spruced 3 3

14 Quaking aspen 2 2

14 Peachleaf willow 2 2

14 Pussy willow 2 2

14 Black willow 2 2

14 Weeping willow 2 2

14 Narrowleaf willow 2 2

12 Eastern white pine 3 3

11 River birch 2

11 Paper birch 2

11 Gray birch 2

10 Scotch pined 1 3 3

9 Northern red oak

9 White spruce 3 3

9 Blue spruce 3 3

9 Pin oak

9 Douglas fird 3

8 White oak

8 Apple spp

8 Bur oak

8 Austrian pine 3 3

8 Oak spp

8 Swamp white oak

8 Chinkapin oak

8 Serbian spruce 3 3

8 Spruce spp 3 3

8 Pine spp 3 3

8 Black oak

8 Jack pine 3 3

8 Shingle oak

8 Northern pin oak

8 Red pine 3 3

8 Japanese red pine 3 3

8 Macnab’s oak

8 Paradise appled

7 Green ash 2

7 American elm 2

7 Siberian elmd 2

7 Slippery elm 2

Table 23.—Potential insect and disease risk for tree species, Chicago region, 2010
93

7 Elm spp 2

7 Chinese elmd 2

4 White ash 1

4 Hawthorn spp

4 Downy hawthorn

4 American basswood

4 Eastern hophornbeam

4 European alderd

4 Cockspur hawthorn

4 Callery peard

4 Littleleaf linden

4 Witch hazel

4 Common chokecherry 1

4 White poplard

4 Basswood spp

4 Washington hawthorn

4 European filbertd

4 Sweetgum

4 Smoke tree

4 Pear spp

4 Cottonwood spp

4 Ash spp

4 Silver linden

4 Black ash

4 Staghorn sumac

3 Boxelder 2

3 Sugar maple 2

3 Silver maple 2

3 Eastern cottonwood 2

3 Norway mapled 2

3 Amur mapled 2

3 Red maple 2

3 Freeman maple 2

3 Dogwood spp 2

3 Flowering dogwood 2

3 Black maple 2

3 Gray dogwood 2

3 Ohio buckeye 2

3 Horsechestnutd 2

3 Japanese mapled 2

3 Alternateleaf dogwood 2

Table 23.—continued

Pestc

Spp. RiskaRisk weightb

Common Name

GMEABOWDEDSBLATPSBWPBRBCALBALDABBDSBWLWDSWSPBTCDHWAFRSODWSBMPBDFBFEJPBPOCRDWPBCB
94

a

Species Risk

Red indicates that tree species is at risk to at least one pest within region

Orange indicates that tree species has no risk to pests region county, but has a risk to at least one pest within 250 miles from 

the region

Yellow indicates that tree species has no risk to pests within 250 miles of region, but has a risk to at least pest that is 250 to 

750 miles from the region

Green indicates that tree species has no risk to pests within 750 miles of region, but has a risk to at least pest that is greater 

than 750 miles from the region

b

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 or blue, 2 points if yellow and 1 point if green. 

c

Pest Color Codes

Red indicates pest is within Chicago region

Orange indicates pest is within 250 miles of Chicago region

Yellow indicates pest is within 750 miles of Chicago region

Green indicates pest is outside of these ranges

Blue indicates no data on pest range

d

Species in bold text indicate that species is on the state invasive species list 

3 European beech 2

3 Katsura tree 2

3 Cornelian cherry 2

3 Buckeye spp 2

3 Maple spp 2

4 Eastern hemlock 3 3

2 Black walnut 3

2 Balsam fir 3

2 Sassafras 3

Table 23.—continued

Pestc

Spp. RiskaRisk weightb

Common Name

GMEABOWDEDSBLATPSBWPBRBCALBALDABBDSBWLWDSWSPBTCDHWAFRSODWSBMPBDFBFEJPBPOCRDWPBCB
95

APPENDIX VII. SELECTED AREA TREE DATA BY LAND USE

Table 24.—Tree population statistics by area and land use, Chicago region, 2010

Area Acres

Tree Density 

(N/ac)

Leaf Area 

(ft2

/ ac)

Valuea

($/ac)

% Illinois 

species

% Trees with d.b.h.a

Plantable 

1-3 in. >18 in. Area %

-----------------------------------------------------------Residential-------------------------------------------------------------

City of Chicago 70,800 22.8 37,800 20,300 45.6 29.9 17.9 13.5

Suburban Cook County 213,900 69.1 60,800 24,100 43.1 49.9 5.6 35.5

DuPage County 100,900 74.4 84,700 34,600 36.0 40.8 7.7 32.2

Kane County 74,700 63.8 74,100 42,800 47.3 31.0 9.4 27.2

Kendall County 24,100 46.8 51,400 16,400 72.7 32.1 5.8 37.4

Lake County 117,400 102.2 111,700 49,400 52.8 39.5 8.8 40.7

McHenry County 75,000 87.7 96,200 40,300 38.4 46.9 6.9 35.2

Will County 107,100 55.9 59,700 22,700 44.6 51.4 4.1 48.3

Total 783,900 69.3 73,600 31,100 44.9 43.5 7.3 34.9

-----------------------------------------------------------Open Space-----------------------------------------------------------

City of Chicago 21,000 63.5 68,900 27,900 58.6 43.0 7.6 33.6

Suburban Cook County 123,400 193.0 90,200 54,300 45.5 49.4 3.4 43.6

DuPage County 55,300 107.9 80,200 30,900 58.9 44.4 2.8 46.4

Kane County 57,900 80.3 33,700 17,000 39.4 58.0 3.3 67.6

Kendall County 19,000 177.7 164,900 50,800 75.2 34.1 2.6 38.1

Lake County 106,000 152.2 78,000 24,200 38.8 56.9 2.2 43.1

McHenry County 92,400 133.0 114,200 41,000 51.0 51.4 4.1 49.4

Will County 123,800 103.6 72,300 27,600 73.0 46.0 3.5 41.0

Total 598,800 134.2 83,300 34,600 51.5 50.0 3.3 45.9

-------------------------------------------Commercial/Transportation/Institution------------------------------------------

City of Chicago 55,900 11.5 12,000 5,500 55.1 44.5 6.7 9.7

Suburban Cook County 111,100 35.5 20,100 8,400 24.8 48.5 3.7 18.9

DuPage County 52,700 70.5 28,100 18,200 34.2 62.0 1.3 27.1

Kane County 30,800 4.3 1,000 800 33.3 16.7 0.0 28.9

Kendall County 4,900 - - - - - 0.0 50.0

Lake County 38,600 101.5 58,600 33,000 22.1 65.7 5.1 31.1

McHenry County 18,200 14.0 7,400 2,100 14.3 71.4 0.0 1.6

Will County 51,000 55.9 84,800 18,800 83.5 51.6 3.2 43.9

Total 363,100 42.5 30,700 12,400 38.4 56.6 3.4 23.9

------------------------------------------------------------Agricultural-------------------------------------------------------------

City of Chicago

Suburban Cook County 17,600 47.8 14,000 1,700 15.0 55.8 0.0 70.1

DuPage County 4,900 20.0 50,400 6,800 25.0 62.5 25.0 73.5

Kane County 171,300 1.9 400 100 0.0 56.3 0.0 86.7

Kendall County 158,200 4.7 3,600 1,300 22.4 65.2 4.3 90.7

Lake County 37,300 40.0 25,100 5,400 25.0 48.6 4.2 56.9

McHenry County 205,400 15.7 13,600 4,700 33.1 36.9 6.4 88.7

Will County 261,100 0.9 600 600 12.5 87.5 12.5 93.6

Total 855,800 8.1 5,900 1,900 25.7 47.7 5.1 88.3

Chicago Region 2,602,000 60.4 68,900 19,700 46.6 48.3 4.7 53.5

a Value = compensatory value

b Percent of tree population of the diameter class (d.b.h. in inches)
96

APPENDIX VIII. TREE PLANTING INDEX MAP

To determine the best locations to plant trees, tree canopy and impervious cover maps from 

National Land Cover Data60 were used in conjunction with 2000 U.S. Census data to produce an 

index of priority planting areas for the Chicago region. Index values were produced for each census 

block group; the higher the index value, the higher the priority of the area for tree planting. Th is 

index is a type of “environmental equity” index with areas with higher human population density 

and lower tree cover tending to get the higher index value. Th e criteria used to make the index were:

• Population density: the greater the population density, the greater the priority for tree 

planting

• Tree stocking levels: the lower the tree stocking level (the percent of available greenspace 

(tree, grass, and soil cover areas) that is occupied by tree canopies), the greater the priority 

for tree planting

• Tree cover per capita: the lower the amount of tree canopy cover per capita (m2

/capita), the 

greater the priority for tree planting

Each criteria was standardized61 on a scale of 0 to 1 with 1 representing the census block group with 

the highest value in relation to priority of tree planting (i.e., the census block group with highest 

population density, lowest stocking density or lowest tree cover per capita were standardized to a 

rating of 1). Individual scores were combined and standardized based on the following formula to 

produce an overall priority planting index (PPI) value between 0 and 100:

PPI = (PD * 40) + (TS * 30) + (TPC * 30)

Where PPI = index value, PD is standardized population density, TS is standardized tree stocking, 

and TPC is standardized tree cover per capita.

Based on “environmental equity”, the Tree Planting Index gives the highest priority to tree planting 

in the city of Chicago where population density tends to be highest and tree cover the lowest 

(Figure 77).
97

Figure 77.—Priority planting areas, Chicago region, 2010. Higher index scores indicate higher priority 

areas for planting.

0 6 12 18 24 3

Miles

.

PPI

0 - 10.0

10.1 - 20.0

20.1 - 30.0

30.1 - 40.0

40.1 - 50.0

50.1 - 60.0

60.1 - 70.0

70.1 - 80.0

80.1 - 90.0

90.1 - 100.0

Priority Planting 

Index
98

REFERENCES

1 Nowak, D.J.; Crane, D.E. 2000. Th e Urban Forest Eff ects (UFORE) Model: 

quantifying urban forest structure and functions. In: Hansen, M.; Burk, T., eds. 

Integrated tools for natural resources inventories in the 21st century. Proceedings of 

IUFRO conference. Gen. Tech. Rep. NC-212. St. Paul, MN: U.S. Department of 

Agriculture, Forest Service, North Central Research Station: 714-720.

Nowak, D.J.; Hoehn, R.E.; Crane, D.E.; Stevens, J.C.; Walton, J.T; Bond, J. 2008. A 

ground-based method of assessing urban forest structure and ecosystem services.

Arboriculture and Urban Forestry. 34(6): 347-358.

2 Nowak, D.J.; Hoehn, R.E., III; Crane, D.E.; Stevens, J.C.; Leblanc Fisher, C. 2010. 

Assessing urban forest eff ects and values, Chicago’s urban forest. Resour. Bull. 

NRS-37. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northern Research Station. 27 p.

3 Chicago Metropolitan Agency for Planning (CMAP). 2005. Land-use inventory.

Chicago, IL: Chicago Metropolitan Agency for Planning. http://www.cmap.illinois.

gov/land-use-inventory

4 i-Tree. 2009. i-Tree eco manual. Version 4.1.0. Washington, DC: U.S. Department 

of Agriculture, Forest Service and Kent, OH: Davey Tree Expert Co., and other 

cooperators. 113 p. http://www.itreetools.org/resources/manuals/i-Tree%20Eco%20

Users%20Manual.pdf

5 Nowak, D.J. 1994. Atmospheric carbon dioxide reduction by Chicago’s urban 

forest. In: McPherson, E.G.; Nowak, D.J.; Rowntree, R.A., eds. Chicago’s urban 

forest ecosystem: results of the Chicago Urban Forest Climate Project. Gen. Tech. 

Rep. NE-186. Radnor, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station: 83-94.

Nowak, D.J.; Crane, D.E.; Stevens, J.C.; Ibarra, M. 2002. Brooklyn’s urban forest.

Gen. Tech. Rep. NE-290. Newtown Square, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Research Station. 107 p.

Nowak, D.J. and D.E. Crane. 2002. Carbon storage and sequestration by urban 

trees in the USA. Environmental. Pollution . 116(3):381-389.

6 Baldocchi, D. 1988. A multi-layer model for estimating sulfur dioxide deposition 

to a deciduous oak forest canopy. Atmospheric Environment. 22: 869-884.

7 Baldocchi, D.D.; Hicks, B.B.; Camara, P. 1987. A canopy stomatal resistance model 

for gaseous deposition to vegetated surfaces. Atmospheric Environment. 21: 91-101.
99

8 Bidwell, R.G.S.; Fraser, D.E. 1972. Carbon monoxide uptake and metabolism by 

leaves. Canadian Journal of Botany. 50: 1435-1439.

9 Lovett, G.M. 1994. Atmospheric deposition of nutrients and pollutants in North 

America: an ecological perspective. Ecological Applications. 4:629-650.

10 Zinke, P.J. 1967. Forest interception studies in the United States. In: Sopper, W.E.; 

Lull, H.W., eds. Forest hydrology. Oxford, UK: Pergamon Press: 137-161.

11 McPherson, E.G.; Simpson, J.R. 1999. Carbon dioxide reduction through urban 

forestry: guidelines for professional and volunteer tree planters. Gen. Tech. Rep. 

PSW-171. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacifi c 

Southwest Research Station. 237 p.

12 Nowak, D.J.; Crane, D.E.; Dwyer, J.F. 2002. Compensatory value of urban trees in 

the United States. Journal of Arboriculture. 28(4): 194-199.

13 Nowak, D.J.; Crane, D.E.; Stevens, J.C.; Ibarra, M. 2002. Brooklyn’s urban forest.

Gen. Tech. Rep. NE-290. Newtown Square, PA: U.S. Department of Agriculture, 

Forest Service, Northeastern Research Station. 107 p.

14 Based on photo-interpretation of Google EarthTM imagery (image dates circa 2008 

and 2010) of 1,000 random points in each county and the City of Chicago. Standard 

error of estimate is 0.4 percent for the Chicago region. Tree cover was estimated using 

fi eld plot estimates of tree and shrub cover, along with tree/shrub overlap. Plot cover 

estimates were prorated to equal photo-interpretation estimates of combined tree and 

shrub cover.

15 National Invasive Species Information Center. 2011. Beltsville, MD: U.S. Department 

of Agriculture, National Invasive Species Information Center. http://www.

invasivespeciesinfo.gov/plants/main.shtml

16 Illinois state invasive species list derived from: Invasive.org: Center for Invasive Species 

and Ecosystem Health. Illinois Invasive Plant List. http://www.invasive.org/species/

list.cfm?id=152

17 Nowak D.J.; Dwyer, J.F. 2000. Understanding the benefi ts and costs of urban 

forest ecosystems. In: Kuser, John E., ed. Handbook of urban and community 

forestry in the northeast. New York, NY: Kluwer Academics/Plenum: 11-22.

18 Murray, F.J.; Marsh L.; Bradford, P.A. 1994. New York state energy plan, vol. II: 

issue reports. Albany, NY: New York State Energy Offi ce. Th ese values were updated 

to 2007 dollars based on the producer price index from U.S. Department of Labor, 

Bureau of Labor Statistics. www.bls.gov/ppi
100

19 Some economic studies have estimated VOC emission costs. Th ese costs are not 

included here as there is a tendency for readers to add positive dollar estimates of 

ozone removal eff ects with negative dollar values of VOC emission eff ects to determine 

whether tree eff ects are positive or negative in relation to ozone. Th is combining of 

dollar values to determine tree eff ects should not be done, rather estimates of VOC 

eff ects on ozone formation (e.g., via photochemical models) should be conducted and 

directly contrasted with ozone removal by trees (i.e., ozone eff ects should be directly 

compared, not dollar estimates). In addition, air temperature reductions by trees have 

been shown to signifi cantly reduce ozone concentrationsa, but are not considered in 

this analysis. Photochemical modeling that integrates tree eff ects on air temperature, 

pollution removal, VOC emissions, and emissions from power plants can be used to 

determine the overall eff ect of trees on ozone concentrations.

 aCardelino, C.A.; Chameides, W.L. 1990. Natural hydrocarbons, urbanization, and 

urban ozone. Journal of Geophysical Research. 95(D9): 13,971-13,979.

 Nowak, D.J.; Civerolo, K.L.; Rao, S.T.; Sistla, S.; Luley, C.J.; Crane, D.E. 2000. A 

modeling study of the impact of urban trees on ozone. Atmospheric Environment. 

34: 1601-1613.

20 Abdollahi, K.K.; Ning, Z.H.; Appeaning, A., eds. 2000. Global climate change and 

the urban forest. Baton Rouge, LA: GCRCC and Franklin Press. 77 p.

 Carbon values are estimated at $22.8 USD per tonne based on: Fankhauser, S. 1994. 

Th e social costs of greenhouse gas emissions: an expected value approach. Th e 

Energy Journal. 15(2): 157-184.

21 Nowak, D.J.; Stevens, J.C.; Sisinni, S.M.; Luley, C.J. 2002. Eff ects of urban tree 

management and species selection on atmospheric carbon dioxide. Journal of 

Arboriculture. 28(3): 113-122.

22 Energy costs are derived from the U.S. Energy Information Administration based on 

2009 state average costs for natural gas (http://tonto.eia.doe.gov/dnav/ng/ng_pri_

sum_a_EPG0_PRS_DMcf_a.htm); 2010/2011 heating season fuel oil costs (http://

tonto.eia.doe.gov/OOG/INFO/HOPU/hopu.asp); 2009 residential electricity costs 

(http://www.eia.doe.gov/cneaf/electricity/epm/table5_3.html) and 2008 costs of wood 

(http://www.eia.doe.gov/emeu/states/sep_sum/html/sum_pr_tot.html).

23 Nowak, D.J.; Greenfi eld,E.J.; 2012. Tree and impervious cover change in U.S.

Urban Forestry and Urban Greening. 11(1): 21-30.

24 Insect/disease proximity to study area was completed using the U.S. Forest Service’s 

Forest Health Technology Enterprise Team (FHTET) database. Data includes 

distribution of pest by county FIPs code for 2004-2009. FHTET range maps are 

available at www.foresthealth.info for 2006-2010.
101

 FHTET pest range data was supplemented by:

 For ALB – Bond, S.; Antipin, J.; Smith, M.; Squibb, J. 2008. USDA and its partners 

declare victory over the Asian longhorned beetle. USDA News Release, April 17, 2008. 

0104.08.

 http://www.aphis.usda.gov/newsroom/hot_issues/alb/alb_news.shtml

 For GM – Gypsy Moth Slow the Spread Foundation, Inc. http://www.gmsts.org/

fdocs/Accomplishments_2011.pdf

 For DED – Eastern Forest Environmental Th reat Assessment Center. Dutch Elm 

Disease. http://threatsummary.forestthreats.org/threats/threatSummaryViewer.

cfm?threatID=43

25 Minnesota Department of Natural Resources. 2012. Invasive species of Minnesota: 

buckthorn. St. Paul, MN: Minnesota Department of Natural Resources. http://www.

dnr.state.mn.us/invasives/terrestrialplants/woody/buckthorn/index.html

 Wisconsin Department of Natural Resources. 2008. Common buckthorn (Rhamnus 

cathartica). Madison, WI: Wisconsin Department of Natural Resources. http://dnr.

wi.gov/topic/Invasives/fact/CommonBuckthorn.html

26 McPherson, E.G.; Nowak, D.J.; Rowntree, R.A. 1994. Chicago urban forest 

ecosystem: Results of the Chicago urban forest climate project. Gen. Tech. Rep. 

NE-186. U.S. Department of Agriculture, Northeastern Forest Experiment Station. 

201 p.

27 Fahey, R.T.; Bowles, M.L.; McBride, J.L. 2012. Origins of the Chicago urban forest: 

composition and structure in relation to pre-settlement vegetation and modern 

land-use. Arboriculture and Urban Forestry (in press).

Explanation of Calculations of Appendix V

28 Total carbon emissions were based on 2003 U.S. per capita carbon emissions, 

calculated as total U.S. carbon emissions (Energy Information Administration, 2003, 

Emissions of Greenhouse Gases in the United States 2003. http://www.eia.doe.gov/

oiaf/1605/1605aold.html ) divided by 2003 total U.S. population (www.census.gov). 

Per capita emissions were multiplied by study population to estimate total city carbon 

emissions.

29 Average passenger automobile emissions per mile were based on dividing total 2002 

pollutant emissions from light-duty gas vehicles (National Emission Trends http://

www.epa.gov/ttn/chief/trends/index.html) by total miles driven in 2002 by passenger 

cars (National Transportation Statistics http://www.bts.gov/publications/national_

transportation_statistics/2004/).
102

 Average annual passenger automobile emissions per vehicle were based on dividing 

total 2002 pollutant emissions from light-duty gas vehicles by total number of 

passenger cars in 2002 (National Transportation Statistics http://www.bts.gov/

publications/national_transportation_statistics/2004/).

 Carbon dioxide emissions from automobiles assumed 6 pounds of carbon per gallon of 

gasoline with energy costs of refi nement and transportation included (Graham, R.L.; 

Wright, L.L.; Turhollow, A.F. 1992. Th e potential for short-rotation woody crops 

to reduce U.S. CO2 emissions. Climatic Change. 22: 223-238.)

30 Average household emissions based on average electricity kWh usage, natural gas Btu 

usage, fuel oil Btu usage, kerosene Btu usage, LPG Btu usage, and wood Btu usage per 

household from: 

 Energy Information Administration. 2004. Total energy consumption in U.S. 

households by type of housing unit, 2001. Washington, DC: U.S. Department of 

Energy, Energy Information Administration. http://www.eia.gov/emeu/recs/recs2001/

ce_pdf/enduse/ce1-4c_housingunits2001.pdf

 CO2, SO2, and NOx power plant emission per KWh from:

 U.S. Environmental Protection Agency. U.S. power plant emissions total by year 

http://www.epa.gov/cleanenergy/energy-resources/egrid/index.html 

 CO emission per kWh assumes one-third of 1percent of C emissions is CO based on:

 Energy Information Administration. 1994. Energy use and carbon emissions: nonOECD countries. OE/EIA-0579(94). Washington, DC: Department of Energy, 

Energy Information Administration. http://tonto.eia.doe.gov/bookshelf

 PM10 emission per kWh from:

 Layton, M. 2004. 2005 Electricity environmental performance report: electricity 

generation and air emissions. Sacramento, CA: California Energy Commission. 

http://www.energy.ca.gov/2005_energypolicy/documents/2004-11-15_

workshop/2004-11-15_03- A_LAYTON.PDF

 CO2, NOx, SO2, PM10, and CO emission per Btu for natural gas, propane and butane 

(average used to represent LPG), Fuel #4 and #6 (average used to represent fuel oil and 

kerosene) from:

 Abraxas energy consulting. http://www.abraxasenergy.com/emissions/

 CO2 and fi ne particle emissions per Btu of wood from:

 Houck, J.E.; Tiegs, P.E.; McCrillis, R.C.; Keithley, C.; Crouch, J. 1998. Air emissions 

from residential heating: the wood heating option put into environmental perspective. 

In: Proceedings of U.S. EPA and Air and Waste Management Association conference: 

living in a global environment, V.1: 373-384.
103

 CO, NOx and SOx

 emission per Btu of wood based on total emissions from wood 

burning (tonnes) from:

 Residential Wood Burning Emissions in British Columbia. 2005. http://www.env.gov.

bc.ca/air/airquality/pdfs/wood_emissions.pdf.

 Emissions per dry tonne of wood converted to emissions per Btu based on average dry 

weight per cord of wood and average Btu per cord from:

 Kuhns, M.; Schmidt, T. 1988. Heating with wood: species characteristics and 

volumes I. NebGuide G 88-881-A. Lincoln, NE: University of Nebraska, Institute of 

Agriculture and Natural Resources, Cooperative Extension.

References of Appendix VI

31 Kruse, J.; Ambourn, A.; Zogas, K. 2007. Aspen leaf miner. Forest Health 

Protection leafl et. R10-PR-14. Juneau, AK: U. S. Department of Agriculture, Forest 

Service, Alaska Region. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/

fsbdev2_038064.pdf

32 Animal and Plant Health Inspection Service. 2010. Plant health – Asian longhorned 

beetle. Washington, DC: U.S. Department of Agriculture, Animal and Plant Health 

Inspection Service. http://www.aphis.usda.gov/plant_health/plant_pest_info/asian_

lhb/index.shtml 

 Natural Resources Canada. 2011. Trees, insects, and diseases of Canada’s forests - 

Asian longhorned beetle. Ottawa, ON: Natural Resources Canada, Canadian Forest 

Service. https://tidcf.nrcan.gc.ca/insects/factsheet/1000095

33 Houston, D.R.; O’Brien, J.T. 1983. Beech bark disease. Forest Insect & Disease 

Leafl et 75. Washington, DC: U. S. Department of Agriculture, Forest Service. 8 p. 

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043310.pdf

34 Ostry, M.E.; Mielke, M.E.; Anderson, R.L. 1996. How to identify butternut canker 

and manage butternut trees. U.S. Department of Agriculture, Forest Service, North 

Central Forest Experiment Station. http://www.na.fs.fed.us/spfo/pubs/howtos/ht_but/

ht_but.htm

35 Diller, J.D. 1965. Chestnut blight. Forest Pest Leafl et 94. U.S. Department 

of Agriculture, Forest Service. 7 p. Washington, DC: U.S. Department of 

Agriculture, Forest Service. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/

fsbdev2_043617.pdf

36 Mielke, M.E.; Daughtrey, M.L. How to identify and control dogwood anthracnose.

NA-GR-18. Broomall, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Area State and Private Forestry. http://na.fs.fed.us/spfo/pubs/howtos/

ht_dogwd/ht_dog.htm
104

37 Th e Plant Disease Diagnostic Clinic, Cornell University. 2011. Dutch elm 

disease. Ithaca, NY: Cornell University. http://plantclinic.cornell.edu/factsheets/

dutchelmdisease.pdf

38 Schmitz, R.F.; Gibson, K.E. 1996. Douglas-fi r beetle. Forest Insect & Disease Leafl et 

5. R1-96-87. Washington, DC: U.S. Department of Agriculture, Forest Service. 8 p. 

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043201.pdf

39 Michigan State University. 2010. Emerald ash borer. East Lansing, MI: Michigan 

State University [and others]. http://www.emeraldashborer.info/

40 Ferrell, G.T. 1986. Fir engraver. Forest Insect & Disease Leafl et 13. Washington, 

DC: U.S. Department of Agriculture, Forest Service. 8 p. http://www.fs.usda.gov/

Internet/FSE_DOCUMENTS/fsbdev2_042951.pdf

41 Phelps, W.R.; Czabator, F.L. 1978. Fusiform rust of southern pines. Forest Insect & 

Disease Leafl et 26. Washington, DC: U.S. Department of Agriculture, Forest Service. 

7 p. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043078.pdf

42 Northeastern Area State and Private Forestry. 2005. Gypsy moth digest. Newtown 

Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Area State 

and Private Forestry. http://www.na.fs.fed.us/fhp/gm/

43 U.S. Forest Service. 2005. Hemlock woolly adelgid. Pest Alert NA-PR-09-05. 

Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Area 

State and Private Forestry. http://na.fs.fed.us/spfo/pubs/pest_al/hemlock/hwa05.htm

44 Smith, S.L.; Borys, R.R.; Shea, P.J. 2009. Jeff rey pine beetle. Forest Insect & Disease 

Leafl et 11. Washington, DC: U.S. Department of Agriculture, Forest Service. 8 p. 

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043542.pdf

45 Ciesla, W.M.; Kruse, J.J. 2009. Large aspen tortrix. Forest Insect & Disease Leafl et 

139. Washington, DC: U.S. Department of Agriculture, Forest Service. 8 p. http://

www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_042981.pdf

46 U.S. Forest Service, Forest Health Protection. 2011. Laurel wilt. Atlanta, GA: U.S. 

Department of Agriculture, Forest Service, Forest Health Protection, Southern 

Region. http://www.fs.fed.us/r8/foresthealth/laurelwilt/

47 Gibson, K.; Kegley, S.; Bentz, B. 2009. Mountain pine beetle. Forest Insect & 

Disease Leafl et 2. Washington, DC: U.S. Department of Agriculture, Forest Service. 

12 p. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_042835.pdf
105

48 Rexrode, C.O.; Brown, H.D. 1983. Oak wilt. Forest Insect & Disease Leafl et 29. 

Washington, DC: U.S. Department of Agriculture, Forest Service. 6 p. http://www.

fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043443.pdf

49 Liebhold, A. 2010 . Personal communication on the geographical distribution of forest 

pest species in U.S. 

50 Ciesla, W.M. 2001. Tomicus piniperda. North American Forest Commission, Exotic 

Forest Pest Information System for North America (ExFor). http://spfnic.fs.fed.us/

exfor/data/pestreports.cfm?pestidval=86&langdisplay=english

51 Holsten, E.H.; Th ier, R.W.; Munson, A.S.; Gibson, K.E. 1999. Th e spruce 

beetle. Forest Insect & Disease Leafl et 127. Washington, DC: U.S. Department 

of Agriculture, Forest Service. 12 p. http://www.fs.usda.gov/Internet/FSE_

DOCUMENTS/fsbdev2_043099.pdf

52 Kucera, D.R.; Orr, P.W. 1981. Spruce budworm in the eastern United States.

Forest Pest Leafl et 160. Washington, DC: U.S. Department of Agriculture, Forest 

Service. 8 p. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_042853.

pdf

53 Kliejunas, John. 2005. Phytophthora ramorum. North American Forest Commission, 

Exotic Forest Pest Information System for North America (ExFor). http://spfnic.fs.fed.

us/exfor/data/pestreports.cfm?pestidval=62&langdisplay=english

54 Clarke, Stephen R.; Nowak, J.T. 2009. Southern pine beetle. Forest Insect & Disease 

Leafl et 49. Washington, DC: U.S. Department of Agriculture, Forest Service. 8 p. 

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_042840.pdf

55 Haugen, D.A.; Hoebeke, R.E. 2005. Sirex woodwasp – Sirex noctilio F. 

(Hymenoptera: Siricidae). Pest Alert NA-PR-07-05. Newtown Square, PA: U.S. 

Department of Agriculture, Forest Service, Northern Area State and Private Forestry. 

http://na.fs.fed.us/spfo/pubs/pest_al/sirex_woodwasp/sirex_woodwasp.htm

56 Seybold, S.; Haugen, D.; Graves, A. 2010. Th ousand cankers disease-Pest Alert. NAPR-02-10. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Area State and Private Forestry. http://na.fs.fed.us/pubs/palerts/cankers_

disease/thousand_cankers_disease_screen_res.pdf

 Cranshaw, W.; Tisserat, N. 2009. Walnut twig beetle and the thousand cankers 

disease of black walnut. Pest Alert. Ft. Collins, CO: Colorado State University. http://

www.ext.colostate.edu/pubs/insect/0812_alert.pdf
106

57 DeMars, C.J., Jr.; Roettgering, B.H. 1982. Western pine beetle. Forest Insect 

& Disease Leafl et 1. Washington, DC: U.S. Department of Agriculture, 

Forest Service. 8 p. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/

fsbdev2_043087.pdf

58 Nicholls, T.H.; Anderson, R.L. 1977. How to identify white pine blister rust 

and remove cankers. St. Paul, MN: U.S. Department of Agriculture, Forest 

Service, Northeastern Area State and Private Forestry. http://na.fs.fed.us/spfo/

pubs/howtos/ht_wpblister/toc.htm

59 Fellin, D.G.; Dewey, J.E. 1986. Western spruce budworm. Forest Insect 

& Disease Leafl et 53. Washington, DC: U.S. Department of Agriculture, 

Forest Service. 10 p. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/

fsbdev2_043445.pdf

Explanation of Calculations of Appendix VIII

60 National Land Cover Data are available at: www.epa.gov/mrlc/nlcd-2001.html 

61 Standardized value for population density was calculated as PD = (n – m) / r, 

where PD is the value (0-1), n is the value for the census block (population / 

km2

), m is the minimum value for all census blocks, and r is the range of values 

among all census blocks (maximum value – minimum value). Standardized value 

for tree stocking was calculated as TS = [1 – (t/(t+g)], where TS is the value 

(0-1), t is percent tree cover, and g is percent grass cover. Standardized value for 

tree cover per capita was calculated as TPC = 1 – [(n – m) / r], where TPC is the 

value (0-1), n is the value for the census block (m2

/capita), m is the minimum 

value for all census blocks, and r is the range of values among all census blocks 

(maximum value – minimum value).
Printed on Recycled Paper

Nowak, David J.; Hoehn, Robert E. III; Bodine, Allison R.; Crane, Daniel E.; Dwyer, 

John F.; Bonnewell, Veta; Watson, Gary. 2013. Urban trees and forests of the 

Chicago region. Resour. Bull. NRS-84. Newtown Square, PA: U.S. Department of 

Agriculture, Forest Service, Northern Research Station. 106 p.

An analysis of trees in the Chicago region of Illinois reveals that this area has about 

157,142,000 trees with tree and shrub canopy that covers 21.0 percent of the region. 

The most common tree species are European buckthorn, green ash, boxelder, black 

cherry, and American elm. Trees in the Chicago region currently store about 16.9 

million tons of carbon (61.9 million tons CO2) valued at $349 million. In addition, 

these trees remove about 677,000 tons of carbon per year (2.5 million tons CO2/year) 

($14.0 million/year) and about 18,080 tons of air pollution per year ($137 million/year). 

Chicago’s regional forest is estimated to reduce annual residential energy costs by 

$44.0 million/year. The compensatory value of the trees is estimated at $51.2 billion. 

Various invasive species, insects and diseases, and lack of adequate regeneration 

of certain species currently threaten to change the extent and composition of this 

forest. Information on the structure and functions of the regional forest can be used 

to inform forest management programs and to integrate forests into plans to improve 

environmental quality in the Chicago region. These findings can be used to improve 

and augment support for urban forest management programs and to integrate urban 

forests within plans to improve environmental quality in the Chicago region.

KEY WORDS: urban forestry, ecosystem services, air pollution removal, carbon 

sequestration, tree value

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communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s 

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(800)795-3272 (voice) or (202)720-6382 (TDD). USDA is an equal opportunity provider and employer. 
Northern Research Station

www.nrs.fs.fed.us