Carbon Dioxide Reduction

Through Urban Forestry:

Guidelines for Professional and Volunteer Tree Planters

E. Gregory McPherson James R. Simpson

United States

Department

of Agriculture

Forest Service

Pacific Southwest

Research Station

General Technical Report

PSW-GTR-171
Abstract

McPherson, E. Gregory; Simpson, James R. 1999. Carbon dioxide reduction through urban

forestry: Guidelines for professional and volunteer tree planters. Gen. Tech. Rep. PSWGTR-171. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 237 p.

Carbon dioxide reduction through urban forestry—Guidelines for professional and volunteer

tree planters has been developed by the Pacific Southwest Research Station’s Western Center

for Urban Forest Research and Education as a tool for utilities, urban foresters and arborists,

municipalities, consultants, non-profit organizations and others to determine the effects of

urban forests on atmospheric carbon dioxide (CO2

) reduction. The calculation of CO2

reduction that can be made with the use of these Guidelines enables decision makers to

incorporate urban forestry into their efforts to protect our global climate. With these

Guidelines, they can: report current and future CO2

 reductions through a standardized

accounting process; evaluate the cost-effectiveness of urban forestry programs with CO2

reduction measures; compare benefits and costs of alternative urban forestry program

designs; and produce educational materials that assess potential CO2

 reduction benefits and

provide information on tree selection, placement, planting, and stewardship.

Retrieval Terms: urban forestry, carbon dioxide, sequestration, avoided energy

The Authors

E. Gregory McPherson and James R. Simpson are Research Forester and Research Meteorologist, respectively, in the Station’s Urban Forestry Research Unit at the Western Center

for Urban Forest Research and Education, c/o Department of Environmental Horticulture,

One Shields Avenue, University of California, Davis, CA 95616

Publisher:

Albany, California

Mailing address:

PO Box 245, Berkeley CA

94701-0245

510 559-6300

http://www.psw.fs.fed.us/

techpub.html

January 1999

Pacific Southwest Research Station

Forest Service

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to improve living conditions in rural areas

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PSW-GTR-171

General Technical ReportResearch StationPacific SouthwestForest Serviceof AgricultureDepartmentUnited States

Guidelines 

Through Urban Forestry:Carbon Dioxide Reduction

for Professional and Volunteer Tree Planters
Contents

Preface. ........................................................................................................................................... v

Acknowledgments. ................................................................................................................... vi

Guide for Users. ......................................................................................................................... vii

Chapter 1

Urban Forests and Climate Change. ............................................................................... 1

What is Climate Change? ............................................................................................ 1

Human Activities and Climate Change..................................................................... 2

How Urban Forests Can Influence Atmospheric CO2 .......................................................................2

Carbon Dioxide Sequestration .......................................................................... 3

Avoided Power Plant Emissions ........................................................................ 5

Carbon Dioxide Release...................................................................................... 7

Net Carbon Dioxide Reduction ........................................................................ 8

Potential CO2

 Reductions and Costs ....................................................................... 8

Ancillary Benefits of Shade Tree Programs............................................................. 9

Chapter 2

Program Design and Implementationy.......................................................................... 13

Program Design and Delivery..................................................................................... 13

General Guidelines for Residential Yard Trees ..................................................... 15

Location for Solar Control ................................................................................. 15

Location for Wind Control ................................................................................ 16

Selection .................................................................................................................. 17

General Guidelines—Trees in Public Places ........................................................... 18

Location and Selection ......................................................................................... 18

General Guidelines—Establishing Healthy Trees for Long-Term Benefits ..... 20

Increasing Program Cost Effectiveness .................................................................... 21

Information and Sources of Assistance .................................................................... 22

Carbon Dioxide Reduction Through Urban Forestry:

Guidelines for Professional and Volunteer Tree Planters

E. Gregory McPherson James R. Simpson

Pacific Southwest

Research Station

USDA Forest Service

General Technical

Report

PSW-GTR-171

January 1999
ii USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3

General Information about These Guidelines for Calculating CO2

Reductions from Urban Forestry Programs. .............................................................. 27

Introduction .................................................................................................................... 27

Who Should Use These Guidelines...and When? .................................................. 27

Getting Started—Frequently Asked Questions ..................................................... 27

Short Form or Long Form? ......................................................................................... 28

Collect and Record Data ............................................................................................. 30

Calculate CO2

 Reduction and Release for Mature Trees ................................... 38

Calculate CO2

 Reduction and Release for 40 Years ............................................ 39

Calculating Cost per Tonne ........................................................................................ 42

Chapter 4

Illustrative Examples. .............................................................................................................. 45

Proposed Program in Boulder City, Nevada .......................................................... 45

Background Information (Table I) ..................................................................... 46

Site and Building Data (Table II) ........................................................................ 46

Tree Data (Table III) ............................................................................................. 50

Planting and Stewardship Costs (Table IV) ..................................................... 52

Look-up Table (Short Form) (Table V)............................................................ 54

Worksheet 1 (Table VIII) .................................................................................... 56

Worksheet 2 (Table IX) ...................................................................................... 62

Boulder City Case Study Summary................................................................... 65

Existing Program in Tucson, Arizona ....................................................................... 67

Background Information (Table I) ..................................................................... 68

Site and Building Data (Table II) ........................................................................ 68

Tree Data (Table III) ............................................................................................. 70

Planting and Stewardship Costs (Table IV) ..................................................... 72

Long Form Adjustment Table (Table VI)......................................................... 74

Look-up Table (Long Form) (Table VII) .......................................................... 78

Worksheet 1 (Long Form) (Table VIII)............................................................ 82

Worksheet 2 (Table IX) ...................................................................................... 88

Tucson Case Study Summary ............................................................................. 91

References. ................................................................................................................................... 97

Appendix A. Short Form Data Input Forms and Look-up Tables. ................ 103

Appendix B. Long Form Data Input Forms and Look-up Tables. .................. 123

Appendix C. Regional Climate Information. ............................................................. 156

Instructions for Climate Region Selection ............................................................ 156
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. iii

Appendix D. Tree Information. ....................................................................................... 161

Tree Growth Zones ................................................................................................... 161

Tree Selection .............................................................................................................. 162

Tree Growth Rates, CO2 Sequestration, and Tree Decomposition .............. 168

Tree Types ............................................................................................................ 168

Tree Growth Zones ........................................................................................... 168

Develop Growth Curves ................................................................................... 168

Select Biomass Equations .................................................................................. 171

Compute CO2

 Sequestration ........................................................................... 173

CO2

 Release Through Tree Decomposition ................................................ 175

Tree Program-Related CO2

 Release....................................................................... 175

Survey of Tree-Related CO2 Emissions ......................................................... 175

Municipal Tree Care ........................................................................................... 176

Tree Production .................................................................................................. 177

Tree Program Operations ................................................................................ 178

Appendix E. Information on CO2 Emission Factors, Building

Characteristics, and Energy Performance. ................................................................ 179

Appendix F. Instructions for Adjusting Tree Distributions

to Customize Avoided Carbon Dioxide Emissions. ............................................... 183

Default Tree Distribution by Size and Location

with Respect to Buildings .......................................................................................... 183

Adjusting Avoided Carbon Dioxide Emissions Data for Tree Location ....... 185

Change in Cooling Energy Use (kg CO2 /Tree) for Each Climate

Region by Mature Tree Size, Type, Distance and Azimuth .............................. 191

Default Values for Avoided Energy Due to Climate

and Shade by Climate Region for Use in Long Form Analysis ......................... 202

Appendix G. Energy Simulation Methods. ................................................................. 212

Building Energy Use..................................................................................................... 212

Shade Effects ................................................................................................................. 213

Windbreaks ................................................................................................................... 214

Climate ........................................................................................................................... 215

Appendix H. Instructions for Adjusting Tree Age/Survival Tables. .............. 219

Tree Survival Rates ..................................................................................................... 219

Tree Age/Survival Tables ........................................................................................... 219

Custom Tree Age/Survival Tables Based on User-Supplied

Tree Survival Rates ..................................................................................................... 219

Appendix I. Glossary. ............................................................................................................ 227

Appendix J. Acronyms and Abbreviations. ................................................................ 231

Appendix K. List of Figures and Tables. ...................................................................... 232
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. v

Preface

This Forest Service publication is timely as the climate change discussion moves away from

arguments over the science toward the design of policies to limit greenhouse gas emissions.

It presents a cogent approach to evaluating the economics of urban forestry for atmospheric

carbon dioxide (CO2

) reductions. By providing this method, the authors have elevated urban and

community forestry to the same status as other CO2

 reduction measures such as rural forest

restoration, tree planting on non-forest land, and improved forest management practices. For the

first time, electric utilities, corporations, and government agencies have the tool they need to

assess the economics of investing in America’s urban and community forests. This report will

also be a valuable resource for international users interested in expanding their local urban

forests to protect global climate.

Urban and community forestry programs that are designed to maximize CO2

 reductions

should appeal to those interested in both environmental conservation and sustainable

development. Conservationists can achieve success by planting trees to protect climate, restore

urban habitats, and increase biodiversity; while businesses and industries that emit CO2

 can

offset their emissions by funding the planting and stewardship of these trees. This is a win-win

transaction and the handbook can be used as a ledger to quantify CO2 debits and credits.

Eighty percent of Americans live in towns and cities. These urban forests in which we live

provide a host of benefits that make our communities more livable. Just as importantly, they

connect people with the land and people with one another. Our Urban Resources Partnerships

and Community Forestry programs are fostering neighborhood action and a new land

stewardship ethic. This emerging stewardship ethic is essential to the successful implementation

of policies designed to protect our climate, as well as our forests.

The Forest Service is committed to working with partners to expand our urban and

community forests and to improve their health. We know today that healthy urban forests can

“grow” more sustainable communities and contribute to a more stable climate. I encourage you

to use this report to plan and manage urban and community forests to conserve energy, sequester

carbon dioxide, and deliver a full array of other products essential to a healthy environment.

Hal Salwasser

Director, Pacific Southwest Research Station, USDA Forest Service
vi USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Hashem Akbari

Lawrence Berkeley Laboratory

Berkeley, California

Gary Moll

American Forests

Washington, D.C.

Mark Trexler

Trexler and Associates

Portland, Oregon

Mark Decot

U.S. Department of Energy

Washington, D.C.

Ed Dickerhoof

USDA Forest Service

Washington, D.C.

Rebecca Spach and Ray Henning

Ohio Edison Co.

Akron, Ohio

Gary Kaster

American Electric Power Co.

McConnelsville, Ohio

Jim Clark

International Society of Arboriculture

Research Trust

Pleasanton, California

Tom Wilson

Electric Power Research Institute

Palo Alto, California

Ingrid Sather

USDA Forest Service

Athens, Georgia

Peggy Sand

Minnesota Dept. of Natural Resources

St. Paul, Minnesota

Nancy Masterson

American Forests

Metro Dade, Florida

Misha Sarkovich

Sacramento Municipal Utility District

Sacramento, California

Dr. Robert Moulton

USDA Forest Service

Research Triangle Park, North Carolina

Dr. Rowan Rowntree

USDA Forest Service

Albany, California

This study was made possible by generous funding from the U.S. Department of Energy,

Edison Electric Institute’s Utility Forest Carbon Management Program, the Electric Power

Research Institute, International Society of Arboriculture Research Trust, and the USDA Forest

Service. The Technical Advisory Committee, Project Officers, and Reviewers, all listed above,

were especially helpful throughout the course of this study. Hal Salwasser, Enoch Bell, Sylvia

Mori, Kathy Stewart, Robert Beaman, Sandy Young, Shimon Schwarzschild, and Vince Dong (all

USDA Forest Service, Pacific Southwest Research Station) provided valuable internal reviews

and directed the publication process. Klaus Scott, Paula Peper, Jason Webber, Giacomo Damonte,

and Sabrina Mathis (all USDA Forest Service, Pacific Southwest Research Station, Western Center

for Urban Forest Research and Education) assisted with various aspects of this project. Cover

illustration was provided by Matthew Faircloth.

Acknowledgments
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. vii

Guide for Users

How to Use These Guidelines

The Carbon Dioxide Reduction Through Urban Forestry—Guidelines for Professional and Volunteer

Tree Planters have been developed by the Pacific Southest Research Station’s Western Center

for Urban Forest Research and Education as a tool for utilities, urban foresters/arborists,

municipalities, consultants, non-profit organizations and others to determine the effects of urban

forests on atmospheric carbon dioxide (CO2

) reductions.

The calculations of CO2 reductions that can be made with the use of these Guidelines enables decisionmakers to incorporate urban forestry into their efforts to protect our global climate.

With these Guidelines you can:

• Report current or future CO2 reductions through a standardized accounting process

• Evaluate the cost-effectiveness of urban forestry programs with other CO2 reduction

measures

• Compare benefits and costs of alternative urban forestry program designs

• Produce educational materials that quantify potential CO2 reduction benefits and

provide guidelines on tree selection, placement, planting, and stewardship.

The four chapters and appendices in the publication will provide you with basic information

you need to calculate CO2 reductions through urban forestry programs.

Chapter 1: Urban Forests and Climate Change

Chapter 1 presents readers with background information on global climate change and the

role of urban forests as one strategy for reducing atmospheric CO2 concentrations. The implication

of global climate change on communities is described, and our current knowledge regarding

urban forestry as a CO2

 reduction measure is reviewed.

Chapter 2: Program Design and Implementation

Chapter 2 provides information on the design and implementation of urban forestry

programs specifically aimed at reducing atmospheric CO2. We share lessons learned from

previous programs that have succeeded and failed, as well as general guidelines for selecting and

locating trees to maximize energy and CO2 reduction benefits. Current information on tree

planting and stewardship techniques is presented as well as sources of technical assistance.

Chapter 3: General Information about These Guidelines for Calculating CO2 Reductions from

Urban Forestry Programs

Chapter 3 presents a general description of methods and assumptions for calculating CO2

reductions from urban forestry programs. The chapter objectives are to (1) familiarize you with

the data collection and calculation process, (2) help you determine what data are required and

how it can be obtained, and (3) explain certain key modeling assumptions.

Chapter 4. Illustrative Examples

Chapter 4 provides case studies of how to apply these guidelines. In one example, estimates

of future CO2 reductions for a proposed utility-sponsored program are described. The second

example reports future reductions from an existing planting in a residential neighborhood.

Appendices

The Appendices contain information that you will reference while applying the guidelines.

They also contain more detailed information on techniques used to develop the guidelines and

reference material, including Glossary (Appendix I), Acronyms and Abbreviations (Appendix J),

and List of Figures and Tables (Appendix K).
Chapter 1
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 1

Urban Forests and Climate Change

What Is Climate Change?

Gases that make up the Earth’s atmosphere trap the sun’s heat, creating a natural “greenhouseeffect” that makes our life on the earth possible. Recent human activity has led to an

accumulation of greenhouse gases (GHGs) in the atmosphere. Estimated U.S. emissions of

carbon dioxide (CO2) increased from 5 to 5.5 billion tonnes from 1990 to 1996 (DOE/EIA 1997).

The globally averaged temperature of the air at the Earth’s surface has warmed between 0.3 and

0.6 oC (0.5-1 oF) since 1900 (Hamburg and others 1997). Evidence of this temperature increase

includes the observed level of sea rise of 10 to 25 cm (4-10 inches), the shrinkage of mountain

glaciers, and increasing sub-surface ground temperatures.

The current best estimate of the expected rise of globally averaged surface temperature

relative to 1990 is 1 to 3.5 oC (2-6 oF) by the year 2100. This rate of warming will probably be

greater than any that has occurred in the past 10,000 years; however, specific temperature

changes will vary from region to region. This warming is expected to further increase sea level

rise by 15 to 95 cm (6-37 inches) by the year 2100. With 50 to 70 percent of the global human

population living in coastal areas, sea level rise could have significant effects. The frequency and

duration of extreme events such as heavy rains and drought are likely to increase as the climate

changes. In winter at mid-latitudes, warming is expected to increase precipitation in the form of

rain rather than snow. This is likely to increase rates of wintertime soil moisture and runoff,

while reducing summertime runoff. In spring, more flooding may result from faster runoff.

During summer, increased heating will increase the probability of severe drought and could

promote the spread of diseases formerly limited to the tropics. The number and duration of heat

waves is projected to increase, resulting in increased mortality from heat stress, especially where

air conditioning is not widely available. Even ground-level air pollutants such as ozone (smog)

could increase, because the chemical reactions that form ozone accelerate as temperatures rise.

Without humans, the Earth’s atmosphere maintains a delicate balance of GHGs. These gases

are released and removed from the atmosphere by a variety of natural sources. For example, the

natural decay of organic material in forests and grasslands, such as dead trees, results in the

release of about 196 billion tonnes of carbon dioxide (CO2

) annually (Hamburg and others 1997).

This release of CO2 is nearly balanced by physical and biological processes that remove CO2. Sea

water into which CO2 dissolves and the growth of plants are natural pools or reservoirs of CO2

(fig. 1). Approximately 97 percent of total CO2 emissions would occur even if humans were not

present on Earth.

Figure 1—Forests in and around cities are sites where CO2 can be stored.

Chapter 1
2 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 1 Urban Forests and Climate Change

Human Activities and Climate Change

Human activities add GHGs to the atmosphere at a rate of about 3 percent of annual natural

emissions. Although they are a small percentage of total emissions, human-produced GHGs are

enough to exceed the balancing effects of natural sinks. Carbon dioxide (CO2

) and methane (CH4)

are the two most important GHGs produced by people. Carbon dioxide is emitted when we burn

fossil fuels to produce energy and heat, and to power vehicles. Methane is emitted in urban areas

when garbage and waste products decompose in landfills and sewage treatment plants. Our

focus is on CO2

 rather than methane or other GHGs because urban forests can store CO2 as trees

grow.

Urban areas are population and economic centers where large quantities of energy are

consumed and CO2

 released. The total GHG emissions from the 10 largest U.S. cities account for

10 percent of total U.S. emissions. As urban centers grow both in terms of population and

geographic area, fuel consumption increases, resulting in greater GHG emissions (fig. 2).

Controlling GHG emissions to protect the climate can produce multiple benefits (ICLEI 1997).

Energy efficiency measures can provide financial savings. Strategies to reduce emissions from

the transportation sector can improve local air quality. The development of compact communities,

transit-oriented projects, and multi-use facilities can catalyze local economic development, create

new jobs, and enhance community livability.

As part of the Cities for Climate Protection Campaign, 48 U.S. cities inventoried their GHG

emissions and developed reduction targets (ICLEI 1997). Strategic tree planting has been adopted

as an emission reduction strategy in communities such as Chula Vista, Calif.; Dade County, Fla;

Austin, Texas; Portland, Ore.; and Tucson, Ariz. For example, increasing residential tree planting

in Austin from the current 4,700 to 15,000 trees per year is expected to provide annual CO2

reductions of 33,000 t after 12 years. This savings accounts for about 1 percent of Austin’s

targeted reduction of 4.5 million tonnes (Mt) (City of Austin 1997).

How Urban Forests Can Influence Atmospheric CO2

Urban forests can reduce atmospheric CO2 in two ways. As long as trees are actively growing,

their rate of uptake of CO2

 through photosynthesis is greater than their release of that gas

through respiration, and the net result is a reduction of CO2 in the atmosphere. Trees around

buildings can reduce the demand for heating and air conditioning, thereby reducing emissions

associated with production of electric power. On the other hand, CO2 is released by vehicles,

chain saws, chippers, and other equipment during the process of planting and maintaining trees.

Figure 2—As agricultural and forest land is converted to urban land uses, GHG emissions increase. These photos show urban

development in Sacramento between approximately 1970 (a) 1980 (b).

Figure 2a Figure 2b
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171 . 1999. 3

Chapter 1 Urban Forests and Climate Change

Eventually, all trees die, and most of the CO2 that has accumulated in their woody biomass is

released into the atmosphere through decomposition. Nonetheless, an urban forest can become

an important storage site for CO2

 through tree planting and stewardship that increases canopy

cover, as well as through strategic planting that cools urban heat islands and saves energy used

for space heating and air conditioning.

Carbon Dioxide Sequestration

Carbon dioxide sequestration refers to the annual rate of storage of CO2 in above- and belowground biomass over the course of one growing season. During photosynthesis, atmospheric CO2

enters the leaf through surface pores, combines with water, and is converted into cellulose,

sugars, and other materials in a chemical reaction catalyzed by sunlight. Most of these materials

become fixed as wood, although some are respired back to CO2 or used to make leaves that are

eventually shed by the tree (Larcher 1980).

Sequestration depends on tree growth and mortality, which in turn depends on species

composition, age structure, and health of the forest. Newly planted forests accumulate CO2

rapidly for several decades, and then the annual increase of sequestered CO2 declines (Harmon

and others 1990). Old-growth forests can release as much CO2 from the decay of dying trees as

they sequester from new growth. When trees are stressed, as during hot, dry weather, they can

lose their normal ability to absorb CO2

. Trees close their pores as a defensive mechanism to avoid

excess water loss. Hence, healthy, vigorous, growing trees will absorb more CO2 than will trees

that are diseased or otherwise stressed.

Because of higher tree densities, rural forests sequester about twice as much CO2

 as urban

forests per unit land area, between 4 to 8 t/ha on average (Birdsey 1992). However, because

urban trees tend to grow faster than rural trees, they sequester more CO2 on a per-tree basis (Jo

and McPherson 1995). Data on radial trunk growth were used to calculate annual sequestration

for major genera in Chicago (Jo and McPherson 1995, Nowak 1994). Sequestration can range from

16 kg/yr (35 lb/yr) for small, slow-growing trees with 8- to 15-cm dbh (3-6 inches diameter at

breast height) to 360 kg/yr (800 lb) for larger trees growing at their maximum rate.

 Although rapidly growing trees sequester more CO2

 initially than slow-growing trees, this

advantage can be lost if the rapidly growing trees die at younger ages. Figure 3 illustrates the

difference between CO2 sequestration by a rapid growing, short-lived tree such as hybrid poplar

0 

50 

100 

150 

200 

0 10 20 30 40 50 60 

Tree Age (Years)

Sugar Maple Hybrid Poplar

Figure 3—Growth rate and life span influence CO2 sequestration. In this example,

the total amount of CO2 sequestered over 60 years by the slower growing maple

(3,225 kg) is greater than the amount sequestered by the faster growing but

shorter-lived poplar (2,460 kg). Growth curves and biomass equations used to

derive these estimates are based on data from urban trees (Frelich 1992, Pillsbury

and Thompson, 1995).
4 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 1 Urban Forests and Climate Change

(Populus ‘Robusta’) and a slower growing, longer-lived tree such as sugar maple (Acer saccharum).

The poplar is estimated to sequester about 2,460 kg (5,420 lb) over 30 years, while the maple

sequesters 3,225 kg (7,100 lb) during 60 years.

Survival of urban trees is another important variable influencing long-term sequestration.

Loss rates for street and residential yard trees are on the order of 10 to 30 percent over the first 5

years of establishment, and 0.5 to 3 percent each year thereafter (Miller and Miller 1991;

McPherson 1993). One key to maximizing CO2 sequestration is to select tree species that are wellsuited to the site where they will be planted. Trees that are not well-adapted will grow slowly,

show symptoms of stress, or die at an early age. Information concerning inspecting, planting, and

caring for trees after planting is provided in Chapter 2.

Partitioning of CO2 stored in forests and trees. Carbon dioxide accumulates in pools or

reservoirs within ecosystems (sometimes called CO2 sinks). In rural forest ecosystems

approximately 63 percent of stored CO2 is in the soil, 27 percent is tree biomass, 9 percent is dead

material on the forest floor, and 1 percent is understory vegetation (Birdsey 1992). An analysis of

residential green space in Chicago found relatively more CO2 stored in the soil (78 percent) and

less in trees and shrubs (21 percent) (Jo and McPherson 1995). Removal of dead trees and lower

tree densities in cities account for relatively less CO2

 stored in woody biomass compared to rural

forests. Relatively higher levels of CO2

 stored in urban soils may be due to supplemental CO2

received in the form of compost and mulch.

The partitioning of stored CO2 for a typical forest tree is about 51percent in trunk, 30 percent

in branches and stems, and 3 percent in foliage (Birdsey 1992). About 18-24 percent of total

carbon stored in a mature forest tree is in the roots. Coarse roots (>2 mm in diameter) store about

15-20 percent of total carbon, while the amount stored in fine roots is approximately the same as

the amount stored in foliar biomass (2-5 percent) (Hendrick and Pregitzer 1993). Storage in urban

trees has received little study. Our detailed analysis of an open-grown 9-year-old Callery pear

(Pyrus calleryana ‘Bradford’) indicated that foliar biomass for open-growing urban trees may be

relatively greater than for forest trees (Xiao 1998) (fig. 4). For example, when partitioning

Figure 4—A Bradford pear similar to the one found to store

approximately 306 kg (676 lb) of CO2 in aboveground biomass

with the authors in Davis, Calif.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171 . 1999. 5

Chapter 1 Urban Forests and Climate Change

aboveground biomass only, CO2 stored in foliage is 10.6 percent for the pear and 3.6 percent for

the typical forest tree (table 1). The relatively rapid growth rates and associated CO2

 sequestration

of city trees compared to those of rural forest trees may be partially explained by their

proportionately greater amount of foliar biomass. Reduced competition, irrigation, and

fertilization are other factors that can enhance the growth rates of open-grown urban trees. In this

example, the pear tree’s leaves (about 89,000) have a surface area equivalent to the four walls and

roof of a typical one- story residence with about 93 m2

 (1,000 ft2) of floor area.

The amount of CO2 stored at any one time by trees in an urban forest is proportional to their

biomass and influenced by the amount of existing canopy cover, tree density, and the pattern of

tree diameters within a city (McPherson 1994a). For example, in heavily treed Sacramento, Calif.

CO2 storage is 172 t/ha (McPherson 1998a), whereas in more sparsely treed Oakland, Calif. it is 40

t/ha (Nowak 1993).

Avoided Power Plant Emissions

Impacts on space cooling and heating. Tree shade reduces summer air conditioning demand,

but can increase heating energy use by intercepting winter sunshine (Heisler 1986; Simpson and

McPherson 1998). Lowered air temperatures and wind speeds from increased tree cover decrease

both cooling and heating demand. Energy-saving benefits from trees around typical residences

have been measured in the field (Parker 1983; Meier 1990/91) and estimated from computer

simulations. Simulations for three cities (Sacramento, Phoenix, and Lake Charles) found that

three mature trees around energy-efficient homes cut annual air conditioning demand by 25 to 43

percent and peak cooling demand by 12 to 23 percent (Huang and others 1987). On a per tree

basis, energy simulations from 12 U.S. cities found that annual energy savings for cooling from a

well-placed 25-ft tall deciduous tree ranged from 100 to 400 kWh (10 to 15 percent), and peak

demand savings ranged from 0.3 to 0.6 kW (8 to 10 percent) (fig. 5) (McPherson and Rowntree

1993).

Greatest energy savings came from a tree on the west side of buildings in all cities, whereas

deciduous trees to the south increased heating demand more than they reduced cooling loads in

Table 1—Data from a 9 year old open-growing Bradford pear tree (Pyrus calleryana ‘Bradford’)

in Davis, CA. (from Xiao, 1998).

Tree data SI units English units

Tree dbh 22.1 cm 8.7 in

Tree height 8.5 m 27.9 ft

Average crown spread 5.7 m 18.8 ft

Crown projection area1 25.7 m2 276.1 ft2

Leaf area 178.6 m2 1,923 ft2

Leaf area index2 6.9

Number of leaves 88,908

Stem area 41.4 m2 445.6 ft2

Stem area index3 1.6

CO2

 - foliar4 36.2 kg 79.8 lb

CO2 - trunk 164.8 kg 363.3 lb

CO2 - branches + stems 141.6 kg 312.3 lb

CO2 - total aboveground 306.4 kg 675.6 lb 1

 Crown projection area is area under tree dripline.

2

 Leaf area index is ratio of leaf area (one side) to crown

projection area.

3

 Stem index area is ratio of stem area (all sides) to crown projection

area.

4

 CO2 was calculated for aboveground biomass as 50 pct of measured

dry weight and multiplied by 3.67 to convert from carbon to CO2.
6 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 1 Urban Forests and Climate Change

most cities. Planting the wrong tree species in the wrong place can increase energy use for space

conditioning. The relative importance of energy savings for cooling associated with

evapotranspiration (ET) and lower air temperatures is less certain than is the energy-saving

contribution of shading because of the complex meteorological factors associated with the

former. In computer simulations, ET cooling has accounted for one-third to two-thirds of total

annual cooling savings (McPherson and Simpson 1995).

Heisler (1986, 1990) estimated that windbreaks can reduce a typical home’s demand for space

heating by 5 to 15 percent. For single trees, simulation studies suggest that energy savings from

heating due to wind shielding range from 1 to 3 percent (0.15 to 5.5 million Btu) for a typical

energy-efficient residence. Nationally, annual energy savings for space heating and cooling from

a single 25-ft tall deciduous tree optimally sited near a well-insulated building have been

simulated to range from $5 to $50 (about 5 to 20 percent).

Impacts of building characteristics. The energy use characteristics for space heating and

cooling of different types of residential buildings (vintages) influence the amount of CO2 avoided

from tree planting. Important factors include the building’s thermal integrity, its heating,

ventilation, and air conditioning equipment, and occupant behavior. Simulated annual air

conditioning savings (kWh) for tree plantings near heavily insulated buildings were 35 to 55

percent of the savings for the same uninsulated buildings (Simpson and McPherson 1996). Also,

energy savings associated with ET cooling and wind shielding from vegetation are relatively

more important than shading benefits when heat transfer is dominated by infiltration and

conduction, as in poorly insulated buildings. However, shading benefits are relatively greater

than ET cooling savings for energy-efficient construction because of the increased importance of

solar heat gain through windows in these structures.

Impacts of climate and fuel mix. Regional variations in climate and the mix of fuels that

produce energy to heat and cool buildings influence potential CO2

 emission reductions. For

example, avoided emissions are likely to be smaller in temperate, coastally influenced climates

where energy consumed to heat and cool buildings is relatively small compared to inland

locations. Potential avoided CO2

 benefits are greatest in areas of the country where space cooling

loads are the greatest such as the South. This is because CO2 emissions associated with electrically

powered air conditioning are usually greater than those associated with heating fuels such as

natural gas.

0 

10 

20 

30 

40 

50 

60 

Heating and Cooling Savings ($)

Atlanta

Boston

Dallas

Denver

Fresno

Los Ang.

Miami

Minn.

Portland

Rk Valley

Tucson

Wash DC

Shade ET Cooling Wind Reduction

Figure 5—Simulated total annual heating and cooling savings due to shade from one 7.6-m (25-ft)

tall tree and ET cooling and wind reduction effects assumed to be associated with a 5 percent

increase in local tree cover (McPherson and Rowntree 1993).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171 . 1999. 7

Chapter 1 Urban Forests and Climate Change

Electricity from a coal-fired power plant emits about twice as much CO2 per unit of energy

produced than do fuels such as natural gas. Natural gas gets more of its energy from the

combustion of hydrogen rather than carbon, and thus has lower CO2

 emissions than coal.

Therefore, large savings of natural gas from reduced heating due to trees in northern latitude

cities frequently translate into relatively small CO2 reductions compared to electricity savings

for cooling. In summary, avoided CO2 benefits from urban forestry are likely to be greatest in

regions with large numbers of air-conditioned buildings and long cooling seasons. Also, savings

can be substantial in areas of the country where coal is the primary fuel for electric power

generation.

Ratios of avoided: sequestered CO2. The ratio of avoided emissions to sequestered CO2

varies by region and program. A ratio of 1:3 was reported for Sacramento’s existing urban forest

(McPherson 1998a). This finding differed from that in other studies that projected much higher

CO2 avoided:sequestered ratios of 15:1 and 4:1 for national urban tree planting programs (Akbari

and others 1990, Nowak 1993). However, a very low ratio of 1:28 was reported for Chicago

(Nowak 1994). The relatively low ratios for Sacramento and Chicago are due in part to local

supplies of low-emitting hydroelectric, gas turbine, and nuclear-generated electricity. Applying

the average national power plant emission factor (1,300 kg/MWh, Akbari and others 1990) in

Sacramento resulted in a nearly 1:1 ratio. Also, the low ratios for urban forests in Sacramento and

Chicago reflect the difference between energy savings from the frequently haphazard locations

of existing trees and larger savings projected for programs designed to strategically locate trees

for energy conservation purposes.

Carbon Dioxide Release

Little is known about the amount of CO2 released through tree planting and care activities.

Fallen forest trees can take 30 to 60 years to completely disappear, with stored carbon moving

into soil humus, decomposing organisms, and the atmosphere. The rate of CO2

 released through

decomposition of dead woody biomass varies with characteristics of the wood itself, fate of the

wood (e.g., left standing, chipped, burned), and local soil and climatic conditions.

Roots account for about 18-24 percent of total carbon stored in a mature forest tree. The fine

roots decompose more quickly than coarse roots. It is estimated that only about 20 percent of the

carbon stored in the root system of forest trees is released to the atmosphere as CO2, with the

remaining amount converted to other forms of carbon that remain fixed in the soil (Powers 1997).

Urban trees are usually removed soon after they die. Boles and branches are frequently

recycled as landscape mulch, sold as firewood, or salvaged for wood products. Stumps are

burned or disposed of in landfills. Burning of tree wood results in nearly complete release of

stored CO2

. Decomposition of urban waste wood that is disposed of in landfills can take decades.

Wood salvaged for use in wood products survives 50 years on the average, before becoming

landfill and gradually decomposing (Norse 1990). Wood that is chipped and applied as mulch

decomposes relatively quickly. For instance, the decomposition rate of landscape mulch in

Southern California is about 2-4 cm a year (Larson 1997). A study of red pine needle litter (Pinus

resinosa), a highly lignified material not unlike wood chips, reported that after approximately 4

years, 80 percent of the original mass was gone (Melillo and others 1989). Application of

fertilizers and irrigation hastens decomposition.

The amount of CO2 released through decomposition of wood pruned from trees depends on

pruning frequency and intensity. A study of residential green space in Chicago found that about

15 percent of the CO2 sequestered each year was eventually released back to the atmosphere

through decomposition of woody biomass pruned from trees and shrubs (Jo and McPherson

1995). By selecting tree species that are well adapted to their site in terms of size and growth the

need for pruning can be minimized.

The combustion of gasoline and diesel fuels by vehicle fleets, and by equipment such as

chainsaws, chippers, stump removers, and leaf blowers is another source of CO2 that has not

been fully quantified. The Sacramento Tree Services Division’s vehicle fleet and fossil-fuel

powered equipment released 1,720 t of CO2

 in 1996, or 0.51 kg/cm d.b.h. (McPherson 1998a).

Approximately 9,422 t of CO2

 were released annually to maintain the County’s 6 million existing

trees. This amount was 3 percent of total CO2 sequestered and avoided annually by Sacramento’s
8 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 1 Urban Forests and Climate Change

urban forest. Typically, CO2 released due to tree planting, maintenance, and other programrelated activities is about 1 to 5 percent of annual CO2

 reductions obtained through sequestration

and avoided power plant emissions.

Net Carbon Dioxide Reduction

The release of CO2 is offset by CO2 sequestered as woody biomass and CO2 emissions avoided

due to savings in space heating and cooling. A program’s net CO2 reduction is simply the

difference between CO2 reductions and releases in metric tonnes (t):

Net CO2

 Benefit = (CO2 Sequestered + CO2 Emissions Avoided) - CO2 Released (Eq. 1)

Net annual atmospheric CO2 reduction by existing urban forests in Sacramento and Chicago

was estimated as 304,000 t (1.2 t/ha) and 516,002 t (1.5 t/ha), respectively. Carbon dioxide

emitted as a byproduct of Sacramento County residents’ consumption (e.g., transportation,

electricity and natural gas use, other gas-powered machines) is estimated to be 17 million tons (17

Mt) per year. The net impact of Sacramento’s urban forest on CO2 removal is to offset these

emissions by approximately 1.8 percent.

The 8 Mt of CO2 stored in Sacramento’s trees, which took many years to accumulate, is

equivalent to nearly 50 percent of the region’s total annual emissions. This storage amount has a

relatively greater offset effect than that reported for Chicago, where CO2

 stored in tree biomass

(20 Mt) equaled the amount released from the residential sector during a 5-month period

(including transportation use) (Nowak 1994). This difference reflects regional variations in

lifestyle, commuting patterns, climate, and building energy use, as well as different urban forest

composition and structure.

Potential CO2 Reductions and Costs

Because trees are a long-term investment, decisions should be based on a systematic and

consistent approach that examines the stream of CO2 reduction and release over the project’s

duration. This approach requires identifying sources and amounts of CO2 reduction and release,

as well as program costs, for the entire life span of the project. The analysis should also indicate

the year in which these activities occur. Typically, program costs are greatest during the initial

years when trees are purchased, planted, and established. Carbon dioxide reduction benefits are

greatest later in the project when trees are vigorously growing and large enough to provide

ample shade, evapotranspirational cooling, and wind speed reductions.

Figure 6 graphs projected CO2 reduction and release, as well as program costs at 5-year

intervals for trees planted during 1990 to 1995 by the Sacramento Shade program (see Appendix

F for information on Sacramento Shade). In this example, program costs and CO2

 reduction

benefits are from the perspective of the utility (Sacramento Municipal Utility District [SMUD])

that funds the program. Most costs are incurred early, and the benefits are realized over a

number of years. The costs of tree maintenance (e.g., pruning, removal of dead trees, pest/

disease control), which can be considerable, do not appear here because they accrue to the

resident that plants the tree, not the utility.

In 1995, Portland’s Friends of Trees received funding from Portland General Electric to

identify tree planting opportunities in the metropolitan area, develop a 5-year planting and

education program, and calculate the amount of CO2

 sequestered by these trees and the cost per

ton (Friends of Trees 1995). They found room to plant 325,000 to 375,000 trees and seedlings.

Their program, expected to involve more than 40,000 volunteers, focused on plantings in parks

and natural areas, along streets, and in yards and school grounds. Once mature, their 145,000

trees and seedlings were estimated to sequester 73,000 t of CO2 at a cost of about $31/t.

Nationally, a hypothetical planting of 100 million trees would save 22 billion kWh and 33 Mt

of avoided CO2

 emissions annually after 10 years (Akbari and others 1990). In addition, the trees

would sequester nearly another 4 Mt of CO2

 as woody biomass. Assuming that CO2 reductions

accrue for 10 years and each tree cost $25 for planting and 2 years of follow-up care, the cost per

tonne of CO2

 saved is about $7. This calculation assumes that all trees survive.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171 . 1999. 9

Chapter 1 Urban Forests and Climate Change

-20 

-10 

0 

10 

20 

30 

40 

50 

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

years

Shade-Cooling Shade-Heating Climate-Cooling Climate-Heating

Sequestration Total Released Net CO2 Saved

(tons CO2)

(thousands)

Sampson and others (1992) estimated that there are approximately 225 million tree planting

opportunities along streets and on private lands in America’s 50.3 million acres of “urban and

built-up area.” A savings of 103 Mt per year was estimated from implementing opportunities on

current residential urban lands; however, this total includes CO2 storage in soil. Trexler (1991)

estimated a potential reduction of 55 Mt annually if all urban forestry planting opportunities

were exploited, but concluded a more realistic savings to be 11 to 18 Mt of CO2 per year.

Total U.S. CO2 emissions are estimated to be 5.5 billion tonnes per year. Therefore, annual

CO2

 reductions achieved through shade tree programs described above could offset about 0.2 to

2 percent of annual emissions. This potential savings is modest, especially when compared to the

3 billion tonnes per year (56 percent of current U.S. carbon emissions) that an extensive tree

planting and forest management program on rural lands is estimated to sequester (Moulton and

Richards 1990). The average cost of achieving a 10 percent CO2

 offset (476 Mt annually) through

rural forest management is about $1 to $3 per tonne depending on whether the annual rental

value of the land is included in the calculation. This amount is less than the average cost of

sequestering CO2

 through urban forestry once realistic assumptions regarding planting and

stewardship costs and tree survival are factored into calculations. Although urban forestry-based

CO2 offset projects may not be as cost-effective as rural forestry projects, they can provide many

social, economic, environmental, political, and public relations benefits to utilities and city

residents.

Ancillary Benefits of Shade Tree Programs

There are many different types of urban forestry programs, and terms can be confusing. For

example, the term “municipal urban forestry programs” usually refers to management of public

street and park trees. In this report we use the terms “urban (or community) forestry programs”

Figure 6—Projected CO2 reductions and releases from Sacramento Shade Program’s planting of 188,800 trees during 1991-95.
10 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 1 Urban Forests and Climate Change

Figure 7—Tree planting and stewardship programs provide opportunities for local residents to work

together to build better communities.

and “shade tree programs” interchangeably when referring to tree planting and stewardship

aimed at achieving CO2 reductions. Frequently, shade tree programs are partnerships between

utilities, non-profits, and local municipalities. Such programs offer opportunities for building

better communities through investment in urban and community forestry (fig. 7). Tree planting

and stewardship activities involve issues such as conservation education, neighborhood

revitalization, job training, improving air and water quality, conserving energy and water, and

recycling green waste. Forest Service research suggests that when the economic value of benefits

trees produce (e.g., removal of air pollutants, heating energy savings, reduced storm water

runoff, increased property values, scenic beauty, and biological diversity) are assessed, total

benefits can be two to three times greater than costs for tree planting and care (McPherson 1995).

In Sacramento, environmental services provided by 6 million existing trees were valued at more

than $40 million per year (McPherson 1998a, Scott and others 1998, Simpson 1998, Xiao and

others 1998). Furthermore, many of these benefits extend beyond the site where a tree grows, to

influence quality of life in the local neighborhood, community, and region. Utilities,

municipalities, and grass-root non-profit organizations can take civic leadership roles by

partnering in shade tree programs aimed at protecting global climate while improving local

environments.
Chapter 2

USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 13

Chapter 2

Program Design and Implementation

Your urban forest can become an important sink for CO2

 through strategic tree planting and

stewardship that increases canopy cover, cools urban heat islands, and saves energy used for

heating and air conditioning. This chapter provides information about developing and

implementing community forestry programs aimed at maximizing energy and CO2 reduction

benefits.

Program Design and Delivery

A shade tree program directed towards reducing atmospheric CO2 is likely to be communitywide and collaborative. Fortunately, lessons learned from urban and community programs

throughout the country can be applied to avoid pitfalls and promote success (McPherson and

others 1992). In this section we provide a checklist to consider when initiating a shade tree

program. For further information, short descriptions of successful shade tree programs are

contained in the article “Utilities Grow Energy Savings” (Anderson 1995).

• Establish the Organizing Group—Most successful programs have a core group of

people who provide the leadership needed to organize and plan specific planting and

stewardship projects. Build this coalition with an eye toward forging important

partnerships with local businesses, utility or energy organizations, politicians, service

organizations, schools, individual volunteers, and agencies, and include individuals

with expertise in the fields of planning, forestry, horticulture, design, and community

organizing. A broad-based constituency and an inclusive process that involves people

in decision-making are essential characteristics of a successful organizing group (Sand

1993).

• Draw a Road Map—A road map provides a clear picture of where the program is

headed and just as importantly, where it is not headed. Begin by establishing program

goals and objectives. Some examples of program objectives include:

- Achieve a certain number of tree plantings per year.

- Achieve a certain percentage of future tree canopy cover based on current planting

targets.

- Strategically locate trees to achieve a designated level of average CO2

 reductions per

tree planted.

- Achieve a designated survival rate each year through an active stewardship program.

- Implement an outreach program to inform the public, local decision makers, and

forestry and landscape professionals about energy savings and CO2

 reductions.

- Coordinate plantings on adjoining public and private properties to maximize mutual

benefits and minimize conflicts with utilities, sidewalks, and other aspects of the

infrastructure.

- Work with local decision makers and developers to implement tree guidelines,

ordinances, and incentives that reduce the number of trees removed or damaged

during construction.

- For rural areas, coordinate with existing state and federal programs by piggybacking

new funds with existing cost-share programs.

- Support research to quantify CO2

 reductions and develop tree planting guidelines for

the community.

Once general goals and objectives are determined, set priorities for planting projects. Identify

where genuine need exists and where there is a legitimate chance for success. For example,

identify areas where the opportunities for shade tree planting are greatest and the interest is
14 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

highest. Target these sites for planting. Concentrate on doing a few projects well to start. Take on

additional campaigns after some successful projects have been established.

• Send Roots into the Community—The social environment around a tree can be as

important to its survival and well-being as the physical environment. Research shows

that direct participation in tree planting is associated with greater satisfaction with tree

and neighborhood than when trees are planted by city, developer, or volunteer groups

without resident involvement (Sommer and others 1994). Foster active participation in

tree planting and stewardship by residents (fig. 8).

• Provide Timely, Hands-on Training and Assistance—Whether your program relies on

volunteers or paid staff, selecting, placing, planting, and establishing trees properly

requires specialized knowledge and resources. Taking the time to provide hands-on

experience pays off in the long run. Planting a tree is a far more effective educational

tool than reading a brochure or listening to a lecture about how to plant a tree.

• Nurture Your Volunteers—Most successful tree programs depend on volunteers as the

cornerstones of their efforts. Have a clear picture of how the talents and enthusiasm of

volunteers can best be put to use. Pay people to do the routine work. Have volunteers

do the inspirational work. Honor and reward your best volunteers.

• Obtain High-Quality Nursery Stock—Don’t put yourself in a hole by planting

substandard trees. Identify the best sources of nursery stock, and work with them to get

the best quality available. If you are planting large numbers of trees and have time to

order stock in advance of planting, contract for the trees to be grown to your

specifications. For more information see the American Standard for Nursery Stock

(American Association of Nurserymen 1997).

• Develop a List of Recommended Trees—Choosing trees for specific sites can be

overwhelming unless the list is narrowed down to a limited number of species that will

perform best. Enlist landscape professionals to identify species that thrive in local soils

and climates. Tree lists may be subdivided by mature tree size (e.g., large, small), life

form (e.g., deciduous, conifer), and type of site (e.g., under power lines, parking lots,

narrow side yards).

Figure 8—Direct participation in tree planting fosters increased satisfaction and a healthier urban forest.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 15

Chapter 2 Program Design and Implementacion

• Commit to Stewardship—Commitment is the key to a healthy urban forest (Lipkis and

Lipkis 1990). After the tree-planting fervor subsides, community members need to be

dedicated to the ongoing care of those trees and all that follow. Send out information

on tree care to prompt program participants to water, mulch, prune, and inspect their

trees. Establish a Shade Tree Hotline to dispense stewardship information. Select a

sample of trees to track. Monitor their survival and growth, and use the findings to

fine-tune your program. For example, the Sacramento Shade program discontinued

planting species that were found to have the lowest survival and growth rates.

• Use Self-evaluation to Improve—After every project, ask staff and volunteers to fill out

an evaluation form that lists what worked well, what did not work, and what can be

done to achieve better results. Use these evaluations to fine-tune your program on a

continuous basis.

• Educate the Public—Work with the local media to inform and involve the public in

your program. Stimulate new linkages with the community by publicizing the

program’s goals and accomplishments. Share the big picture, and show people what a

force for change they can be by working together (fig. 9).

 Tree planting is a simple act, but planning, training, selecting species, and mobilizing

resources to provide ongoing care require considerable forethought. Successful shade tree

programs will address all these issues before a single tree is planted.

General Guidelines for Residential Yard Trees

Location for Solar Control

The right tree in the right spot saves energy. In midsummer, the sun shines on the northeast and

east sides of buildings in the morning, passes over the roof near midday, then shines on the west

and northwest sides in the afternoon. Air conditioners work hardest during the afternoon when

temperatures are highest and incoming sunshine is greatest. Therefore, the west and northwest

sides of a home are the most important sides to shade. Sun shining through windows heats the

home quickly. Locate trees to shade windows so that they block incoming solar radiation, but do

not block views. In most climates the east side is the second most important side to shade (fig. 10).

Trees located to shade south walls can block winter sunshine and increase heating costs,

because during winter the sun is lower in the sky and shines on the south side of homes. The

Figure 9—The local media can be a real asset when you need to inform the public about your program.
16 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

warmth the sun provides is an asset, so do not plant evergreen trees that will block southern

exposures and solar collectors. Use solar friendly trees (listed in table 34, Appendix D) to the

south because the bare branches of these deciduous trees allow most sunlight to strike the

building (some solar unfriendly deciduous trees can reduce sunlight striking the south side of

buildings by 50 percent). To maximize summer shade and minimize winter shade, locate trees

about 3 to 6 m (10-20 ft) south of the home. As trees grow taller, prune lower branches to allow

more sun to reach the building (fig. 11).

Although the closer a tree is to the home the more shade it provides, the roots of trees that are

too close can damage the foundation. Branches that impinge on the building can make it difficult

to maintain exterior walls and windows. Keep trees at least 1.5 to 3 m (5-10 ft) from the home to

avoid these conflicts but within 9 to 15 m (30-50 ft) to effectively shade windows and walls.

Paved patios and driveways can become heat sinks that warm the home during the day.

Shade trees can make them cooler and more comfortable spaces.

Shading your air conditioner can reduce its energy use, but do not plant vegetation so close

that it will obstruct the flow of air around the unit.

Keep trees away from overhead power lines and do not plant directly above underground

water and sewer lines. Contact your local utility company before planting to determine where

underground lines are located and which tree species will not grow into power lines.

Location for Wind Control

Because of their size and porosity, trees are ideal wind filters. Locate rows of trees perpendicular

to the primary wind direction—usually along the north and west sides of the property (fig. 12).

Figure 10—Locate trees to shade west and east windows (from Sand 1993).

Figure 11—Tree south of home before and after pruning (from Sand 1993).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 17

Chapter 2 Program Design and Implementacion

Design the windbreak row to be longer than the building being sheltered because the wind

speed increases at the edge of the windbreak. Ideally, the windbreak is planted upwind about 15

m (50 ft) from the building and consists of dense evergreens that will grow to twice the height of

the building they shelter (Heisler 1984, Sand 1991). Avoid locating windbreaks that will block

sunlight to south and east walls. Trees should be spaced close enough to form a dense screen, but

not so close that they will block sunlight to each other, causing lower branches to self-prune.

Most conifers can be spaced about 2 m (6 ft) on center. If there is room for two or more rows, then

space rows 3 to 4 m (10-12 ft) apart.

Selection

The ideal shade tree has a fairly dense, round crown with limbs broad enough to partially shade

the roof. Given the same placement, a large tree will provide more building shade than a small

tree. Deciduous trees allow sun to shine through leafless branches in winter. Plant small trees

where nearby buildings or power lines limit aboveground space. Columnar or upright trees are

appropriate in narrow side yards. Because the best location for shade trees is relatively close to

the west and east sides of buildings, the most suitable trees will be strong, resisting storm

damage, disease, and pests (Sand 1994). Examples of trees not to select for placement near

buildings include cottonwood (Populus fremontii) because of their invasive roots, weak wood, and

large size, ginkgo (Ginkgo biloba) because of their narrow form, sparse shade, and slow growth,

and pine trees (Pinus spp.) because of their evergreen foliage.

When selecting trees, match the tree’s water requirements with those of surrounding plants.

For instance, select low water-use species for planting in areas that receive little irrigation. Also,

match the tree’s maintenance requirements with the amount of care different areas in the

landscape receive. Tree species that drop leaves and fruit may be more easily maintained in areas

where litter disappears in coarse groundcovers or in a lawn where it can be easily raked up than

in areas that are more difficult to clean. Check with your local landscape professional before

selecting trees, to make sure that they are well suited to the site’s soil and climatic conditions.

Conifers are preferred over deciduous trees for windbreaks because they provide better

wind protection (fig. 13). The ideal windbreak tree is fast growing, visually dense, and has stiff

Figure 12—Mid-winter shadows from a well-located windbreak and shade

trees do not block solar radiation on the south-facing wall (from Sand 1993).

Figure 13—Conifers guide wind over the building (from Sand 1993).
18 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

branches that do not self-prune (Heisler 1984). Norway spruce (Picea abies), white pine (Pinus

strobus), Scotch pine (Pinus sylvestris), white fir (Abies concolor), American arborvitae (Thuja

occidentalis), and Douglas fir (Pseudotsuga menziesii) are among the best windbreak trees.

General Guidelines—Trees in Public Places

Location and Selection

Locate trees in common areas, along streets, in parking lots, and commercial areas to maximize

shade on paving and parked vehicles. Shade trees reduce heat that is stored or reflected by

paved surfaces. By cooling streets and parking areas, they reduce emissions of evaporative

hydrocarbons from parked cars that are involved in smog formation (Scott and others 1999).

Large trees can shade more area than smaller trees, but should be used only where space

permits. Remember that a tree needs space for both branches and roots.

Because trees in common areas and other public places may not shelter buildings from sun

and wind, CO2

 reductions are primarily due to sequestration. Fast-growing trees sequester more

CO2

 initially than slow-growing trees, but this advantage can be lost if the fast-growing trees die

at younger ages. Large growing trees have the capacity to store more CO2 than do smaller

growing trees. To maximize CO2 sequestration, select tree species that are well-suited to the site

where they will be planted. Use information in the Tree Selection List (table 34, in Appendix D),

and consult with your local landscape professional to select the right tree for your site. Trees that

are not well-adapted will grow slowly, show symptoms of stress, or die at an early age.

Unhealthy trees do little to reduce atmospheric CO2, and can be unsightly liabilities in the

landscape.

Contact your local utility company before planting to locate underground water, sewer, gas,

and telecommunication lines. Note the location of power lines, streetlights, and traffic signs, and

select tree species that will not conflict with these aspects of the city’s infrastructure. Keep trees

at least 10 m (30 ft) away from street intersections to ensure visibility. Avoid planting shallow

rooting species near sidewalks, curbs, and paving. Tree roots can heave pavement if planted too

close to sidewalks and patios. Generally, avoid planting within 1 m (3 ft) of pavement, and

remember that trunk flare at the base of large trees can displace soil and paving for a considerable

distance. Select only small-growing trees (<7 m tall) for locations under overhead power lines,

and do not plant directly above underground water and sewer lines (fig. 14). Avoid locating

trees where they will block illumination from street lights or views of street signs in parking lots,

commercial areas, and along streets.

Maintenance requirements and public safety issues influence the type of trees selected for

public places. The ideal public tree is not susceptible to wind damage and branch drop, does not

require frequent pruning, produces little litter, is deep-rooted, has few serious pest and disease

problems, and tolerates a wide range of soil conditions, irrigation regimes, and air pollutants.

Because relatively few trees have all these traits, it is important to match the tree species to

planting site by determining what issues are most important on a case-by-case basis. For

example, parking lot trees should be tolerant of hot, dry conditions, have strong branch

attachments, and be resistant to attacks by pests that leave vehicles covered with sticky exudate.

Consult the Tree Selection List (table 34, Appendix D) and your local landscape professional for

horticultural information on tree traits.

Parks and other public landscapes serve multiple purposes. Some of the guidelines listed

below may help you maximize their ability to serve as CO2

 sinks:

• Provide as much pervious surface as possible because soil and woody plants store CO2.

• Maximize use of woody plants, especially trees, as they store more CO2

 than do

herbaceous plants and grass.

• Increase tree stocking levels where feasible, and immediately replace dead trees to

compensate for CO2

 lost through tree and stump removal.

• Create a diverse assemblage of habitats, with trees of different ages and species, to

promote a continuous canopy cover.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 19

Chapter 2 Program Design and Implementacion

Figure 14a

Figure 14c

Figure 14—(a, b) Know where power lines and other utility lines are before planting. (c) Under power lines use only small-growing

trees (“Low Zone”), and avoid planting directly above underground utilities. Larger trees may be planted where space permits

(“Medium” and “Tall” zones) (from ISA 1992).

Figure 14b
20 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

• Select species that are adapted to local climate, soils, and other growing conditions.

Adapted plants should thrive in the long run and consume relatively little CO2

through maintenance.

• Group species with similar landscape maintenance requirements together and consider

how irrigation, pruning, fertilization, weed, pest, and disease control can be minimized.

• Compost litter fall, and apply it as mulch to reduce CO2

 release associated with

irrigation and fertilization.

• Where feasible, reduce CO2

 released through landscape management by using push

mowers (not gas or electric), hand saws (not chain saws), pruners (not gas/electric

shears), rakes (not leaf blowers), and employing local landscape professionals who

do not have to travel far to your site.

• Consider the project’s life span when making species selection. Fast-growing species

will sequester more CO2

 initially than slow-growing species, but may not live as long.

• Provide a suitable soil environment for the trees in plazas, parking lots, and other

difficult sites to maximize initial CO2

 sequestration and longevity.

General Guidelines—Establishing Healthy Trees for Long-Term Benefits

Inspect your tree at the nursery or garden center before buying it to make sure that it is healthy

and well formed. If the tree is in a container, check for matted roots by sliding off the container or

feeling down the side of it. Roots should penetrate to the edge of the root ball, but not densely

circle the inside of the container or grow through drain holes. Avoid trees with dense surface

roots that circle the trunk and may girdle the tree. Gently move the trunk back and forth in the

container. If it wiggles and the soil loosens, it may not be very well anchored to the container soil.

Dig the planting hole the same depth as the root ball so that the tree will not settle after it is

watered in. The crown of the tree should be slightly above ground level. Make the hole two to

three times as wide as the container. Backfill with the native soil unless it is very sandy, in which

case you may want to add composted organic matter such as peat moss or shredded bark (fig. 15).

Use the extra backfill to build a berm outside the root ball that is 15 cm (6 inches) high and 1

m (3 ft) in diameter. Soak the tree, and gently rock it to settle it in. Cover the basin with a 10-cm (4-

inch) thick layer of mulch, but avoid placing mulch against the tree trunk. Water the new tree

twice a week for the first month and weekly thereafter for the next couple growing seasons.

Inspect your tree several times a year, and contact a local landscape professional if problems

develop. If your tree needed staking to keep it upright, remove the stake and ties as soon as the

tree can hold itself up. Reapply mulch and irrigate the tree as needed. Prune the young tree to

maintain equally spaced scaffold branches and to remove branches that cross and rub. As the tree

matures, have it pruned on a regular basis by a certified arborist. By keeping your tree healthy,

Figure 15—Prepare a broad planting area and top it off

with mulch and a berm to hold water (from Sand 1993).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 21

Chapter 2 Program Design and Implementacion

you maximize its ability to reduce atmospheric CO2 and provide other benefits. For additional

information on tree planting, establishment, and care see Principles and Practice of Planting Trees

and Shrubs (Watson and Himelick 1997) and Arboriculture (Harris 1992).

Increasing Program Cost Effectiveness

What if the program you have designed is promising in terms of CO2 reductions, volunteer

participation, and ancillary benefits, but the cost per tonne is too high? This section describes

some steps to consider that may increase benefits and reduce costs, thereby increasing cost

effectiveness.

Increasing CO2 reduction benefits

Active stewardship that increases the health and survival of recently planted trees is one strategy

for increasing cost effectiveness. An evaluation of the Sacramento Shade program found that

assumed tree survival rates had a substantial impact on projected benefits (Hildebrandt and

others 1996). Higher survival rates increase CO2

 sequestration and avoided CO2 emissions, and

reduce CO2

 released through decomposition.

Another way to increase benefits is to modify the types of locations where trees will be

planted. By increasing the proportion of trees that shade buildings you will increase CO2

emissions avoided. This can be a fruitful strategy if avoided power plant emissions are relatively

important. Areas with high cooling loads and power plants that burn coal will benefit the most

from this approach.

You can further increase avoided emissions by targeting a higher percentage of trees for

locations that produce the greatest energy savings, such as opposite west-facing walls and close

to buildings. By customizing tree locations to increase numbers in high-yield sites, CO2

 emissions

avoided can be boosted.

You can increase CO2 sequestration benefits by adjusting the distribution of trees among tree

types. Generally, deciduous trees sequester more CO2

 than similar-sized evergreens, and largegrowing trees provide more storage than small-growing trees.

Reducing program costs

Cost effectiveness is influenced by program costs as well as benefits:

Cost Effectiveness = Total Net CO2

 Benefit / Total Program Cost (Eq. 2)

and cutting these costs is one strategy to increase cost effectiveness. A substantial percentage of

total program costs occur during the first 5 years and are associated with tree planting

(McPherson 1994a). Some strategies to reduce these costs include the use of trained volunteers,

smaller tree sizes, and follow-up care to increase tree survival and reduce replacement costs.

Where growing conditions are likely to be favorable, such as yard or garden settings, it may be

cost effective to use smaller, less expensive stock or bare root trees that reduce planting costs.

However, in highly urbanized settings and sites subject to vandalism, large trees may survive

the initial establishment period better than small trees.

Investing in the resources needed to promote tree establishment during the first 5 years after

planting is usually worthwhile because once trees are established they have a high probability of

continued survival (Richards 1979). If your program has targeted trees on private property, then

encourage residents to attend tree care workshops. Develop standards of “establishment success”

for different types of tree species. Perform periodic inspections to alert residents to tree health

problems, and reward those whose trees meet your program’s establishment standards. Replace

dead trees as soon as possible, and identify ways to improve survivability.

A cadre of trained volunteers can easily maintain trees until they reach a height of about 6 m

(20 ft) and limbs are too high to prune from the ground with pole pruners. By the time trees reach

this size they are well-established. Pruning during this establishment period should result in a

desirable branching structure that will require less frequent thinning and shaping. Although

organizing and training volunteers requires labor and resources, it is usually less costly than
22 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

contracting the work. As trees grow larger, contracted pruning costs may increase on a per-tree

basis. The frequency of pruning will influence these costs, since it takes longer to prune a tree that

has not been pruned in 10 years than one that was pruned a few years ago. Although pruning

frequency varies by species and location, a return frequency of about 5 years is usually sufficient

(Miller 1997).

When evaluating the bottom line and whether trees pay, do not forget to consider other

benefits. Urban and community forestry programs have proven to produce benefits that extend

well beyond atmospheric CO2 reductions. The magnitude of benefits related to storm water

runoff reductions, increased property values, employment opportunities, job training, air quality

improvements, and enhanced human health and well-being can be substantial. Moreover, these

benefits extend beyond the site where trees are planted, furthering collaborative efforts to build

better communities. Techniques to quantify many of these benefits are now available through

organizations such as ACRT Inc., American Forests, Davey Resource Group, International Society

of Arboriculture, National Arborists Association, National Arbor Day Foundation, and the

USDA Forest Service.

Information and Sources of Assistance

Alliance for Community Trees

2121 San Jacinto, Suite 810

Dallas, TX 75201-6724

(214) 953-1187 Fax (214) 953-1986

American Forests

P.O. Box 2000

Washington, D.C. 20013

(202) 955-4500

http://www.amfor.org/

American Horticulture Society

7931 East Boulevard Drive

Alexandria, VA 22308

(703) 768-5700 Fax (703) 768-8700

http://www.members,aol.com/gardenahs

American Nursery and Landscape

Association

1250 I Street, NW

Suite 500

Washington, D.C. 20005

(202) 789-2900 Fax (202) 789-1893

http://www.anla.org

American Planning Association

1776 Massachusetts Avenue, NW

Washington, D.C. 20036

(202) 872-0611 Fax (202) 872-0643

http://www.planning.org

American Public Power Association

2301 M Street, NW

Washington, D.C. 20037

(202) 467-2900 Fax (202) 467-2910

American Society of Consulting Arborists

15245 Shady Grove Road

Suite 130

Rockville, MD 20850

(301) 947-0483 Fax (301) 990-9771

American Society of Landscape Architects

1733 Connecticut Avenue

Washington, D.C. 20009

(202) 898-2444 Fax (202) 898-1185

Association of Landscape Contractors

of America

150 Elden Street

Suite 270

Herndon, VA 20170

(703) 736-9666 Fax (703) 736-9668

http://www.alca.org

Global Releaf for New Communities

American Forests

P.O. Box 2000

Washington, D.C. 20013

(202) 955-4500 Fax (202) 955-4588

http://www.amfor.org

International Council for Local

Environmental Initiatives

ICLEI World Secretariat

City Hall, 8th Floor, East Tower,

Toronto, ON M5H 2N2

Canada

1-416-392-1462 Fax 1-416-392-1478

http://www.iclei.org/
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 23

Chapter 2 Program Design and Implementacion

International Society of Arboriculture

P.O. Box GG

Savoy, IL 61874-9902

(217) 355-9411 Fax (402) 355-9516

http://www.ag.uiuc.edu/~isa/

National Arbor Day Foundation

100 Arbor Avenue

Nebraska City, NE 68410

(402) 474-0820 Fax (402) 474-0820

http://www.arborday.org/

National Arborists Association

P.O. Box 1094

Amherst, NH 03031

(603) 673-3311 Fax (603) 672-2613

http://www.natlarb.com

National Association of State Foresters

444 N. Capitol Street, NW

Suite 540

Washington, D.C. 20001

(504) 925-4500

http://www.stateforesters.org

National Association of Towns and

Townships

National Center for Small Communities

444 North Capital Street, NW

Suite 208

Washington, D.C. 20001

(202) 624-3550 Fax (202) 624-3554

http://www.natat@ssl.org

National League of Cities

1301 Pennsylvania Ave, NW

Suite 550

Washington, D.C. 20094

(202) 626-3000 Fax (202) 626-3043

http://www.nlc.org

National Tree Trust

1120 G Street, NW

Suite 770

Washington, D.C. 20005

(202) 628-8733 or (800) 846-8733 Fax (202)

628-8735

http://home.earthlink.net/~appleseedz/

NTT.html

National Urban and Community Forestry

Advisory Council

c/o Suzanne DelVillar

1042 Park West Court

Deerwood Springs, CO 81601

(970) 928-9264 Fax (970) 945-6058

National Wildlife Federation

8925 Leesburg Pike

Vienna, VA 22184

(800) 822-9919 Fax (703) 790-4040

http://www.nwf.org/nwf/

North Central Forest Experiment Station

USDA Forest Service

845 Chicago Avenue

Suite 225

Evanston, IL 60202-2357

(847) 886-9311 Fax (847) 866-9506

http://www.ncfes.umn.edu/units/4902/

index.html

Northeastern Forest Experiment Station

USDA Forest Service

5 Moon Library

SUNY-CESF

Syracuse, NY 13210

(315) 448-3200 Fax (315) 448-3216

Society of American Foresters

5400 Grosvenor Lane

Bethesda, MD 20814-2198

(301) 897-8720 Fax (301) 897-3690

http://www.safnet.org/

Society of Municipal Arborists

City of Great Falls

P.O. Box 5021

Great Falls, MT 59403-5021

(406) 771-1265 Fax (406) 761-4055

TreeLink Homepage:

http://www.treelink.org/
24 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 2 Program Design and Implementacion

USDA Forest Service

Urban and Community Forestry

P.O. Box 96090

Washington, D.C. 20090-6090

(202) 205-6283

Western Center for Urban Forest Research

and Education

USDA Forest Service

c/o Dept of Environmental Horticulture

University of California

Davis, CA 95616-8587

(530) 752-7636 Fax (530) 752-6634

http://wcufre.ucdavis.edu
Chapter 3

USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 27

Chapter 3

General Information about These Guidelines for

Calculating CO2

 Reductions from Urban Forestry

Programs

Introduction

I

n this chapter we answer some frequently asked questions about the Guidelines. A general

description of methods and assumptions for calculating CO2 reductions from urban forestry

programs follows. Our purpose is to (1) familiarize you with the data collection and calculation

process, (2) help you determine whether to use the Short Form or Long Form for data entry, (3)

describe data required and where they can be obtained, and (4) explain certain key modeling

assumptions. Chapter 4 provides a more detailed step-by-step description of the data tabulation

and calculation process.

Who Should Use These Guidelines... and When?

The Guidelines are designed to be used by utilities, urban foresters/arborists, municipalities,

consultants, and others to determine the amount of atmospheric carbon dioxide (CO2) reductions

associated with urban forestry programs. The guidelines can be used to:

• Estimate future CO2 reductions from proposed programs

• Report annual CO2

 reductions from existing programs

• Evaluate CO2

 reductions associated with alternative programs.

Therefore, the Guidelines can be used before a program exists to assess the magnitude of CO2

reductions it will produce and the cost in $/tonne. They can be applied initially in a more

detailed fashion to design a program that will maximize cost effectiveness. By manipulating

variables such as program costs, tree types, and tree locations, the user can compare benefits and

costs of alternative programs over a 40-year period. Once a program is implemented, the

guidelines can be used to report CO2

 reductions from the date of planting to the reporting time or

for any year. Utilities or other program sponsors may claim these CO2

 reductions as credits that

partially offset CO2

 emissions associated with power production.

These Guidelines should not be applied for calculating reductions from typical afforestation

or reforestation projects where large numbers of trees are planted together.

Getting Started—Frequently Asked Questions

The thought of performing calculations can be daunting. To help get started, here are some

frequently asked questions about using these guidelines.

How Long Will an Analysis Take?

The time required to do an analysis depends on the user’s intent and the amount of complexity in

the shade tree program. If the basic information you need to calculate CO2 reductions is easily

available, and you have “crunched” numbers before, the analysis can be done in less than a day.

Otherwise, it could take longer. Using regional default values in the “Short Form” will speed up

the analysis considerably.

How Do I Know What Data to Collect for the Analysis?

The checklist in this chapter and examples in Chapter 4 describe the type of information that is

required for these calculations. A very straightforward analysis can be conducted with

information on trees (numbers by type), numbers of buildings, the local CO2

 electric emission

factor, and program costs. The specifics of your program will influence the amount and type of

information needed for the analysis.
28 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Can These Calculations Be Done in a Spreadsheet?

Manual calculations are one of the most time-consuming and error-prone aspects of this process.

Although the math is simple addition and multiplication, there is a lot of it to do, especially if the

program is complex. Creating a spreadsheet that speeds up the math work and reduces mistakes

can be worthwhile if you anticipate using these guidelines to evaluate multiple programs or test

the sensitivity of results to changes in different variables such as tree survival rates and number

of trees planted in different locations.

What Units of Measurement Are Used?

To be consistent with national and international GHG reporting conventions, information in

these Guidelines is recorded in Standard International (SI) units. Emission reductions are

reported using the full molecular weight of CO2 rather than the atomic weight of carbon

(multiply atomic weight of C by 3.67 to obtain molecular weight of CO2). Thus, CO2 reductions

are reported in terms of metric tonnes (t) (1 t = 1,000 kg) rather than short tons (2,000 lb = 1 short

ton). Conversion factors are provided.

How Accurate Are the Results?

The degree of uncertainty associated with these estimates depends on a variety of factors

including the accuracy of data collected and default values, calculations performed in the

analysis, and modeling assumptions. The error associated with estimates is likely to be high

because we know relatively little about important variables such as tree growth and survival

rates, CO2

 sequestration rates of urban trees, impacts of trees on summer air temperatures in

different climate regions, and the rate of CO2 release from decomposition and tree care activities.

One way to reduce the magnitude of estimation error is to double-check the accuracy of

mathematical calculations and data obtained from secondary sources. Another way is to repeat

calculations by varying the values of certain input variables in small increments. This allows you

to see how sensitive the estimates are to reasonable changes in the values of different variables.

Short Form or Long Form?

Before deciding what data to collect you must first determine whether to use the Short or Long

Form. The Short Form is the logical place to begin an analysis of a proposed program because it

provides a first-order approximation of net CO2 benefits.

Short Form

The Short Form simplifies the data collection process by applying regionally specific default

values for most variables. Use the Short Form if you are interested in a quick, initial analysis or if

detailed data are unavailable. As the details of a proposed program are worked out, you may

switch to the Long Form.

Long Form

Data previously recorded on the Short Form are still applied with the Long Form, but other

variables can be adjusted to more accurately reflect the program. For instance, Long Form

adjustments can be made to reflect local information concerning:

• Energy used for space heating and cooling by different types of homes

• Percentages of homes with different types of heating and cooling equipment

• Extent of benefits from shade on neighboring homes

• Locations of trees around buildings (distance and direction)

The Long Form can be used by utility analysts or others with access to detailed information

concerning building energy performance and tree locations. If you are reporting CO2 reductions

from an existing program, you may use the Long Form. Using the Long Form will increase the

number of calculations and time required to complete the analysis, but in most cases customizing

the analysis will lead to more accurate results than obtained with the Short Form. For example,

in the second example in Chapter 4 (Tucson), actual tree locations (predominately to the
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 29

Chapter 3 General Information about These Guidelines

southwest of buildings) were much different than the default and air conditioning use was much

greater (all homes had air conditioners compared to the default value of 63 percent). These

adjustments in the Long Form increased projected net CO2

 benefits compared to the Short Form.

Short and Long Form Flow Diagram

The flow diagram (fig. 16) shows links between the Short and Long Forms and related information

in the Appendices. Information in Chapter 4 and the Appendices can be used to customize the

analysis or referred to for more detailed descriptions of modeling mechanics and assumptions.

Short and Long Form tables are contained in Appendices A and B, respectively; filled-in examples

for both Short and Long Form are presented in Chapter 4. Short and Long Form Tables are

numbered using Roman numerals, while tables of supporting information are numbered using

Arabic numerals.

I. Background 

 information

II. Site & building data

III. Tree data

IV. Planting & steward-

 ship costs

Short Form: see Boulder

City example in Ch. 4.

Blank tables and forms

are found in Appendix A

C. Regional climate

 information

Long Form: see Tucson

example in Ch. 4.

Blank tables and forms

are found in Appendix B

E. CO2 emissions

 factors, building &

 energy information

D. Tree information

 - Growth zones

 - Tree selection

 - Tree growth rates,

 CO2 sequestration,

 and decomposition

VII. Long Form Look-Up

 Table

VI. Long Form

 Adjustment Table

IX. Worksheet 2

VIII. Worksheet 1

V. Short Form Look-Up

 Table

F. Avoided emissions

 adjustment for tree

 location

G. Energy simulation

 methods

H. Adjusting for tree

 age & survival

IX. Worksheet 2

VIII. Worksheet 1

I. Background 

 information

II. Site & building data

III. Tree data

IV. Planting & stewardship costs

Appendices:

Used for both Short &

Long Form

Figure 16—Flow diagram.
30 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Collect and Record Data

One of the most difficult tasks in this process is collecting data for the analysis. The Check List

(table 2) helps you identify what information is needed. Data required for the Short Form are

listed first. Additional data required for the Long Form are listed at the end of the Check List.

Copy Input Tables

Make copies of blank Input Tables I, II, III and IV from Appendix A (Short Form) or Appendix B

(Long Form).

Background Data (Table I)

Record background information (the who, why, where, when, what) in Table I.

Site and Building Data (Table II)

Approximate existing tree plus building cover (percentage) (consult table 11 for default values).

Enter percentage of homes in each vintage (consult table 11 for default values; see also

Appendix E).

Determine climate region (consult Appendix C to determine climate region of your city).

Enter electricity emissions factors and make indicated adjustments (see Appendix E for default

values by state).

Tree Data (Table III)

Total number of trees by tree type (deciduous or evergreen; small, medium and large mature

size) and location (number of trees Near buildings and Far from buildings)

Distribute trees between building vintages (consult table 12 for default distributions; see also

Appendix F).

Planting and Stewardship Costs (Table IV)

Tree planting, care, and other costs associated with tree program.

Copy Look-up Tables and Worksheets

If using the Short Form, make a copy of the Look-up Table V for your region, and Worksheets

1 and 2 (Appendix A). If using the Long Form, make a copy of the Long Form Adjustment

Table VI for your region, and Long Form Lookup Table VII, Worksheet 1 and Worksheet 2

(Appendix B).

Building Energy Use and Site Adjustments (Table VI, Long Form only)

Conditioned floor area by vintage (CFA).

Shade fraction on neighboring homes.

Cooling equipment (pct by type, typical use). Refer to table 44, Appendix E.

Heating equipment (pct by type, typical use). Refer to table 44, Appendix E.

Climate adjustments.

Long Form Look-up Table (Table VII, Long Form only)

Avoided CO2 values due to shade are taken from table 107 in Appendix F if the default tree

distribution is used, or table 61 in Appendix F if you supply your own tree distribution. In the

latter case, tables 49 through 60 in Appendix F are used to determine values in table 61.

Energy savings per tree from windbreaks are tabulated in table 108 in Appendix F.

Avoided CO2 for the given level of existing tree + building cover are linearly interpolated from

values given in table 109 in Appendix F.

Worksheet 1 (Table VIII) CALCULATE CO2 REDUCTION AND RELEASE FOR MATURE TREES:

Select sequestration, decomposition and release data (discussed in Appendix D) from Look-up

Table VII based on your tree growth zone (discussed in Appendix D). (Long Form only)

Transfer results from Look-up Table V (Short Form) or VII (Long Form) to Worksheet 1 and do

indicated calculations.

Worksheet 2 (Table IX) CALCULATE CO2 REDUCTION AND RELEASE FOR 40 YEARS:

Determine tree age/survival fractions using Appendix H and enter into Worksheet

Transfer results from Worksheet I to Worksheet 2, and do indicated calculations.

CALCULATE COST PER TONNE: bottom of Worksheet 2

Table 2—Check list of essential data.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 31

Chapter 3 General Information about These Guidelines

Copy Input Data

The initial step in the analysis is to make copies of blank input Tables I, II, III and IV from

Appendix A (Short Form) or Appendix B (Long Form).

Background Data (Table I)

Background information provides a record of the who, why, where, when, and what for each

analysis.

• Who—Names of groups and individuals involved and the project title.

• Why—Program goals and objectives.

• Where—Site location.

• When—Program start and end dates.

• What—Key program elements that influence results of the analysis such as the roles

of various participants, type of trees planted, and assumed tree survival rates.

Site and Building Data (Table II)

Existing cover. The amount of existing building and tree cover influences the extent to which

additional tree cover reduces wind speed and lowers space heating costs. As existing cover

increases, space heating benefits from additional tree cover decrease (Heisler 1990, Huang and

others 1990). Regional default values are listed in table 3. Alternatively, contact your city planner

or State Forester to determine whether cover data have been obtained for your city (see sources of

technical assistance at the end of Chapter 2). If cover data are not available for your study site,

you can obtain aerial photographs and estimate percentages of tree and building cover by

sampling dots laid on the photographs (see Bernhardt and Swiecki 1991 for information on

procedures). Another alternative is a windshield or foot survey during which periodic estimates

of cover are recorded and later tallied. Be sure to sum the percentage tree and building cover values.

Building vintages. A vintage consists of buildings of similar age, construction type, floor

area, and energy efficiency characteristics. Detailed information on each vintage is listed in

Appendix E. Although the exact characteristics of each vintage change regionally, the names

remain constant and general distinguishing features are:

• Pre-1950 vintage—low insulation levels, small conditioned floor area (CFA), large

window area:CFA ratios,

• 1950-1980 vintage—more ceiling insulation, lower window area:CFA ratios,

• Post-1980 vintage—more wall insulation, more CFA, lower window area:CFA ratios.

Home distribution by vintage (pct)

Climate region

Existing

cover (pct) Pre-1950 1950-1980 Post-1980

Tree

growth

zone

Mid-Atlantic 41 30 58 12 Central

Northern Tier 33 45 42 13 North

North Central 36 42 48 10 North

Mountains 56 42 48 10 North

Southeast 67 28 54 18 Central

South Central 52 19 63 18 Central

Pacific Northwest 54 30 58 12 Central

Gulf Coast/Hawaii 51 19 63 18 South

California Coast 44 28 54 18 South

Southwest 40 28 54 18 Central

Desert Southwest 34 19 63 18 South

Table 3—Regional default values.
32 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Percentage of homes in each vintage. Because different building vintages have different

energy efficiency characteristics, it is important to identify the proportion of dwelling units for

each vintage that will be influenced by the planting program. Usually, this is the estimated or

reported number of metered residential customers within the site, and includes homes that do

not benefit directly from program trees planted on their property. If you do not have information

on the percentage of homes by vintage, use the regional percentages listed for each vintage in

table 3.

Climate region. Select one of the eleven Climate Regions that best matches the climate of

your site. The filled-in Look-up Table V that you make from Appendix A or the Long Form

Adjustment Table VI from Appendix B should be for this Climate Region. The geographic

locations of Climate Regions, along with major U.S. cities, are shown in figure 17. Climate region

boundaries are approximate, and the climate of cities within each region can vary considerably.

Information in Appendix C and examples in Chapter 4 illustrate how to select the appropriate

Climate Region for your site. Selecting the appropriate Climate Region is important because site

climate influences space heating and cooling requirements and potential energy savings from

trees.

Electricity emissions factor. Default values for electricity emissions factor change regionally

because of local differences in the mix of fuels used to generate electricity. Contact your local

electricity supplier to obtain the most accurate values for your location. Alternatively, average

Figure 17—Climate Regions for the United States (Repeated as figure 24 in Appendix C).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 33

Chapter 3 General Information about These Guidelines

electricity emissions factor values for each state are listed in table 41, in Appendix E. The regional

default values are least accurate because emission factors can vary considerably among states.

On the basis of default and selected electricity emissions factors, calculate the indicated electricity

emissions factor adjustments for heating and cooling.

Emission factors for natural gas and fuel oil used for space heating do not change regionally

because the quality of these fuels is relatively uniform and stable. Typical emission factors for

these fuels are listed in table 42 (appendix E). Other fuels such as liquefied petroleum gas (LPG),

kerosene, and heating stoves burning wood, coal, and coke are used for residential heating.

These fuels represent a small fraction of energy used to heat buildings.

Tree Data (Table III)

Tree numbers by type. The Short and Long Forms require information on the numbers of trees

planted during the program’s first 5 years, their type, and their general location. Consider the

following definitions as you collect this information.

1. Tree Type: There are six tree types that comprise combinations of foliation period (2)

and mature size (3). Deciduous and evergreen trees can each be of three sizes (large,

medium, and small) :

• Deciduous—foliation period generally matches the duration of the cooling season

• Evergreen—year-round foliation (includes conifers and broad leaf evergreens)

• Large—mature height greater than 15 m (50+ ft)

• Medium—mature height 10-15 m (35-50 ft)

• Small—mature height 6-10 m (20-35 ft)

2. Tree Location: Tree numbers are for two types of locations and each building

vintage:

• Near—number of trees within approximately 15 m (50 ft) of target buildings so as

to provide benefits from shading and wind sheltering. Most residential yard trees

and some street trees fall into this category.

• Far—number of trees greater than approximately 15 m (50 ft) from buildings.

These trees are too distant to directly shade and shelter buildings, but in the

aggregate they provide cooling savings due to lower summertime air

temperatures and heating savings associated with neighborhood wind speed

reductions. Examples include trees planted in parks, school yards, landfill sites,

street median strips, riparian areas, and other open space.

The number of available planting sites for shade trees influences tree numbers. For potential

sites within 15 m (50 ft) of buildings it is important to consider tree direction or azimuth (compass

bearing of tree with respect to building). Generally, shading benefits are greatest for trees located

opposite west and east walls. Trees opposite south walls can increase heating costs by blocking

winter sunlight. Our Short Form default tree distribution assumes that trees are strategically

located to reduce cooling costs while at the same time to not increase heating costs (tables 4 and 5).

Note that in the default distribution there are no trees to the south, southeast, or southwest of

buildings. If you are using the Short Form do not count planting sites with these azimuths. If you

select the Long Form, you can customize the analysis to account for a variety of tree azimuths and

distances. First assess whether tree locations for your program are substantially different than

the default distribution (see Appendix F). If so, see Appendix F for guidelines on developing a

customized distribution that accounts for the effects of trees at different distances and azimuths

around each building vintage.

Steps for collecting tree data. In Chapter 4 we illustrate how to collect and record tree data

for a proposed program (Boulder City, Nev.) and an existing program (Tucson, Ariz.). Chapter 2

provides guidelines for selecting and locating trees to maximize atmospheric CO2

 reductions.
34 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Steps to follow for a proposed program are:

1. On the basis of program goals and available resources, identify the project site, and

estimate the total number of trees to plant.

2. Determine how many trees will be planted in the Near and Far locations.

3. Determine the number of trees by tree type for Near and Far locations. Consider the

distribution of deciduous and evergreen types. Remember that evergreens are best

used for protection from winter winds, but will block winter irradiance and increase

space heating costs if planted to the south and east of buildings. Also, larger trees

produce greater benefits than smaller trees, but there are planting sites that cannot

accommodate large trees, such as under utility lines and in narrow side yards and

street tree-lawns. Once you have determined the number of deciduous and evergreen

trees to plant, you can use the default distribution (tables 4, 5 and 6) to calculate the

number of trees by tree type.

4. Distribute trees among building vintages based on your program. For trees in the

Near location consider that typically:

• Tree planting opportunities and demands are greatest in newly developed areas,

but relatively small residential lot sizes may limit the percentage of large and

medium size trees.

• Trees near older homes will produce greater energy savings than those around

new energy- efficient homes, but mature landscaping may limit tree-planting

opportunities.

Tree Azimuth

Tree Distance N NE E SE S SW W NW Total

size (m) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct)

Large 3-6 0.9 0.9 5.3 0.0 0.0 0.0 7.8 3.4

6-12 3.4 9.9 19.3 0.0 0.0 0.0 32.2 11.1

12-18 0.0 1.5 2.5 0.0 0.0 0.0 0.5 1.3 100.0

Medium 3-6 0.3 3.7 5.3 0.0 0.0 0.0 7.9 3.3

6-12 3.4 10.6 21.6 0.0 0.0 0.0 25.0 15.3

12-18 0.1 1.2 1.6 0.0 0.0 0.0 0.4 0.3 100.0

Small 3-6 1.1 6.0 13.8 0.0 0.0 0.0 11.4 11.1

6-12 3.5 8.3 15.3 0.0 0.0 0.0 16.7 10.4

12-18 0.0 1.1 1.3 0.0 0.0 0.0 0.0 0.0 100.0

Tree Distance N NE E SE S SW W NW Total

size (m) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct)

Large 3-6 5.2 1.9 2.2 0.0 0.0 0.0 3.6 5.5

6-12 17.3 14.8 7.4 0.0 0.0 0.0 18.0 18.3

12-18 0.3 1.9 1.9 0.0 0.0 0.0 0.3 1.3 100.0

Medium 3-6 3.3 5.8 1.7 0.0 0.0 0.0 5.0 4.7

6-12 12.1 16.1 11.8 0.0 0.0 0.0 13.2 22.7

12-18 1.0 1.7 0.7 0.0 0.0 0.0 0.0 0.3 100.0

Small 3-6 5.4 8.6 9.0 0.0 0.0 0.0 6.6 13.8

6-12 10.3 11.0 9.1 0.0 0.0 0.0 8.4 15.3

12-18 0.0 1.1 1.3 0.0 0.0 0.0 0.0 0.0 100.0

Table 4—Default distribution for deciduous trees by size, distance and direction from building.

Table 5—Default distribution for evergreen trees by size, distance and direction from building.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 35

Chapter 3 General Information about These Guidelines

• Trees located for windbreak benefits provide greatest CO2 reductions around

buildings and in regions with the largest heating loads.

• Tree vintage distribution may follow our default, which is based on that reported

for the Sacramento Shade program, if your planting guidelines are similar (table 6).

For Far trees, consider how their distribution corresponds to the distribution of building

vintages in the community. For example, if Far trees will be planted in parks throughout the city,

distribute them among vintages in proportion to the citywide distribution of building vintages.

Alternatively, if tree planting is targeted for parks developed since 1980, record all Far tree

numbers for the Post-1980 vintage building because it is likely that these types of homes will

surround the parks.

If you are reporting CO2 emission reductions for already planted trees follow these steps:

1. Use information in the Tree Selection List (table 34, Appendix D) to assign the

appropriate tree type to each tree species (e.g., Platanus acerifolia, London plane tree =

Deciduous large).

2. Determine the number of trees by location (i.e., Near and Far) and tree type for each

building vintage. Information on tree distribution among vintages can be obtained

from aerial photographs of the project area, information recorded when trees were

planted, electric utility databases, or city information on the housing stock and its

geographic distribution. If many trees have been planted over a large area, these data

may be collected by inventorying program trees at a sample of residences. A sketch

can be drawn at each sample home to show the building “footprint,” approximate

location of program trees, and information on the building vintage. Other

information on the species, size, and condition of program trees can be collected and

compared with data recorded at the time of planting to evaluate rates of tree survival

and growth.

3. Assess whether tree azimuths and distances are substantially different than the

default distribution (tables 4 and 5), and follow guidelines in Appendix F to

customize the tree location distribution for your program if necessary.

We make several assumptions regarding tree data.

• When recording the number of program trees planted, record the total number

planted during the first 5 years of the program. A new set of calculations is required

if trees were or are expected to be planted after the first 5-year interval. These

guidelines are designed to record CO2

 benefits for 5-year intervals over a 40-year

period. Benefits are calculated for one year at the mid-point of each 5-year interval

and multiplied by 5 years to derive the 5-year total.

• Knowing tree size at the time of planting is not required. Research on tree growth

after transplanting indicates that planting size has relatively little influence on tree

size after about 10 years assuming other factors are constant (Watson 1987; Gilman

Percentage of trees by size and vintage (pct)

Size Pre-1950 1950-1980 Post-1980 Total

Large 1.2 8.2 14.7 24.1

Medium 1.7 12.1 39.3 53.1

Small 0.6 6.6 15.6 22.8

Total 3.5 26.9 69.6 100.0

Table 6—Default distribution of trees among vintages can be applied to

deciduous and evergreen plantings and is based on data from the Sacramento

Shade program.
36 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

and others 1998). Differences in tree size during the early years are relatively

insignificant because rates of CO2

 sequestration and release by decomposition from

small trees are low.

Planting and Stewardship Costs

Annual planting and stewardship costs are totaled for each of the 5-year periods. Categories

include costs for :

• Tree Planting: site preparation, trees, and other planting materials such as stakes,

backfill, mulch, as well as costs for labor and equipment (e.g., augers, tractors,

trucks).

• Tree Care: irrigation, inspection, pruning, pest/disease control, tree/stump removal,

disposal/recycling of waste wood, workshops, newsletters, and other stewardship

activities.

• Other Costs: program administration (e.g., office space, utilities, supplies), media

relations, and contingencies.

Factors that influence costs include the number, size, and location of planted trees, the roles

of contractors, paid staff, and trained volunteers, and the level of stewardship and monitoring

provided after planting.

Copy Look-up Tables and Worksheets

If using the Short Form, make a copy of the Look-up Table V for your region, and Worksheets 1

and 2 (Appendix A). If using the Long Form, make a copy of the Long Form Adjustment Table VI

for your region, and Long Form Lookup Table VII, Worksheet 1, and Worksheet 2 (Appendix B).

Building Energy Use and Site Adjustments (Table VI, Long Form Only)

The following data are only used in the Long Form.

Conditioned floor area (CFA). This is the average amount of floor area that is mechanically

cooled/heated for each vintage. You can use the regional default values or select a value that best

matches the average size of dwelling units in each vintage for your study area.

Shade fraction on neighboring homes. Non-participants may benefit from shading on their

homes by program trees planted on adjacent property. For example, the Sacramento Shade

program found that on a per-tree planted basis, 23 percent of the trees shaded neighboring

homes, resulting in an estimated energy savings equal to 15 percent of that found for participants.

This value of 15 percent is used as the Short Form default. To determine an appropriate value for

your program, consider the following factors:

• Lot size and layout (especially side yard dimensions): closer spacing of houses is

likely to increase the amount of shade on neighboring homes,

• Average number of program trees planted per property: more trees per property is

likely to produce more shade on neighboring homes (Sacramento Shade program

averaged 3.7 trees per property),

• Other program criteria that influence tree location or size: guidelines that promote

larger trees, allow planting at greater distances from target buildings, and promote

shading of east- and west-facing walls are likely to result in relatively greater

amounts of shade on neighboring homes.

Shade on neighboring homes can be estimated from aerial photographs on which mature tree

crown spread is shown for program trees. Use the factors outlined above to determine an

appropriate value for your program. On the basis of the Sacramento data, percentage of trees

shading neighboring homes divided by 1.5 gives an estimate for savings experienced by

neighboring homes. Selecting no benefit (0 pct) will result in a conservative estimate of benefits.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 37

Chapter 3 General Information about These Guidelines

Cooling equipment and base case adjustments. There are four main types of devices for

residential cooling: central air conditioners (CAC), heat pumps, evaporative coolers, and room

air conditioners. In areas where many homes are without mechanical cooling, avoided CO2

emissions can be relatively small. The amount of electricity required to produce the same amount

of cooling output varies with different types of equipment and their condition. For example, an

evaporative cooler uses about 33 percent of the electricity consumed by a central air conditioner

to produce the same amount of cooling. Information on the percentage of each building vintage

with each type of cooling equipment is needed. Regional default values are provided for each

building vintage (table 44, Appendix E; data were unavailable for evaporative coolers).

The amounts of electricity consumed annually per unit area of conditioned floor area to air

condition each of the default vintages are listed as default values under “Base Case Adjustment.”

These default values are based on computer simulations of building energy performance that

assume standard occupant behavior and the regional reference city’s climate. Reasons why these

default values may not apply to your situation are:

• The climate in your area is substantially different than the climate of the reference

city (see Appendix C to compare measures such as heating and cooling degree days),

• Computer simulations tend to over predict air conditioning loads,

• Construction characteristics of the default building vintages may not reflect those of

the homes in the study area. For example, extensive weatherization programs may

result in pre-1950 vintage buildings using less air conditioning than shown here.

• If customized vintages are selected, these default values will not apply.

Simulations for a single building tend to over predict air conditioning demand for the

average building, especially from a utility’s system-wide perspective, because not all air

conditioners are operating at the same time, thermostat settings are highly variable, and occupant

behaviors that influence demand may not be accurately modeled. The Base Case Adjustment can

be used to better depict local conditions.

Obtaining the most accurate value possible for AC use is important because these figures

have a substantial effect on subsequent calculations of CO2

 emission reductions. Review these

numbers with a representative of your local electric utility. Better estimates of annual AC

consumption may be obtained from system-wide analyses, metered data from similar types of

buildings, or computer simulations based on detailed information about each type of building.

Heating equipment and base case adjustments. There are five space heating choices: natural

gas warm-air furnace, fuel oil furnace, electric resistance (baseboard or built-in electrical units),

heat pump (reverse-cycle system), and other types (fire place, steam, portable room or space

heater, etc.). Regional default values (table 44, in Appendix E) provide the percentage of dwelling

units with each type of heating equipment for each building vintage.

Because the energy source, and hence emission factors, for each heating fuel may differ,

“combined conversion factors” (CCF’s) are determined. The CCF’s incorporate equipment and

CO2 emission factors into a single coefficient for each space heating fuel choice relative to natural

gas. This calculation incorporates differences in equipment efficiency between natural gas (the

default) and other heating fuels. We assume that fuel oil and gas furnaces have the same

efficiencies, and that conversions from natural gas to electric resistance and heat pump heating

are 0.22 and 0.11 kWh/kBtu, respectively. Even if the main heating fuel is not natural gas, this

approach converts other fuels to their natural gas equivalent. The mixture of energy sources for

heating explains the difference in treatment of heating equipment and emission factors compared

to cooling, because in the latter case electricity is the only energy source considered.

The amounts of energy (kBtu/m2 = one thousand Btu per unit conditioned floor area)

consumed annually to heat each of the default vintages are listed under “Base Case Adjustment.”

Similar to cooling, heating values are based on computer simulations of building energy

performance that assume standard occupant behavior and a natural gas furnace. These default

values may require adjustment to better reflect differences in climate or other factors that

influence space heating energy consumption. If customized vintages are selected, these default
38 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

values may not apply. Contact your local natural gas supplier to obtain estimates of annual

consumption for each vintage.

Climate adjustments. The climate cooling adjustment accounts for the decrease in air

temperature (oC) as tree canopy cover (pct) increases. We advise using the default values, which

change regionally (see table 44, Appendix E). Default values reflect research showing that

temperature depression is greatest in arid climates (as much as 0.20 oC per 1 percent increase in

canopy) and least in humid climates. Custom values may be warranted if trees are located in

unusually arid (e.g., plazas, parking lots, unirrigated sites) or humid sites (e.g., riparian or other

lush areas).

Long Form Look-up Table (Table VII, Long Form Only)

Two types of Look-up Tables are included, one for use with the Short Form and another with the

Long Form. Short Form Look-up Tables for each Climate Region are already filled in with

default CO2

 reduction and release data (Table V, Appendix A), and hence are ready to use. The

Long Form Look- up Table (Table VII, Appendix B) is similar to the Short Form versions, but it is

blank so that it can be customized by the user. This is accomplished using data derived from

Tables I to IV, VI, and the Appendices to calculate CO2 reduction and release values for a

particular program and location. Both Short and Long Form versions have three main sections:

shade and windbreak effects, climate effects, and a third section that covers sequestration, as

well as releases from decomposition, maintenance, tree production, and program operations. All

Look-up Table values are reported as metric tonnes (t) per year per mature tree and assume 100

percent survival.

Shade and windbreak effects. Short Form guidelines account for energy savings due to

cooling from deciduous trees Near buildings, as well as increased heating costs due to winter

shade from bare branches. The default distribution for evergreen trees assumes that these trees

are strategically planted to minimize costs associated with winter shade (i.e., no evergreens

located south, southeast, and southwest of buildings). Avoided CO2 emissions due to tree shade

are obtained in two different ways. Adjustments to these default values can be made using Long

Form Look-up Tables. Avoided CO2

 values are taken from table 107, in Appendix F, if the default

tree distribution is used, or table 61, in Appendix F, if you supply your own tree distribution. In

the latter case, tables 49 through 60, and 62, in Appendix F, are used to determine those values.

See Appendix G for additional information on modeling shade effects.

Evergreen trees located near buildings provide sheltering from the wind that reduces space

heating loads. Avoided CO2 emissions from evergreen windbreaks are simulated as an increase

in model wind shielding class, which is related to number and size of trees. Savings vary by

building vintage and Climate Region (table 108, in Appendix F). Larger trees provide greater CO2

benefits than smaller trees because of increased wind shielding. See Appendix G for additional

information on modeling windbreak effects.

Climate effects. Increases in neighborhood tree canopy cover can measurably reduce summer

air temperatures and winter wind speeds, thereby lowering air conditioning and space heating

demand. To estimate relations between tree cover, climate, and resulting impacts on cooling and

heating load, we rely on data published in the literature (see Appendix G). Default values in

Short Form Look-up Tables are adjusted for use in the Long Form by interpolating data in table

109, in Appendix F (see description for the Tucson example in Chapter 4).

Calculate CO2 Reduction and Release for Mature Trees

Worksheet 1 (Table VIII)

CO2 sequestration, decomposition, and release for mature (5-year average value for trees aged 36

to 40 years) trees is calculated in Worksheet 1 by multiplying the number of trees planted by

estimated CO2

 uptake or release per mature tree for each tree type. The resulting numbers

present a snapshot of annual CO2 uptake and release assuming all trees planted live to be 40

years old.

Sequestration. Sequestration, the net rate of CO2 storage in above- and belowground biomass

over the course of one growing season, is calculated with biomass equations and tree growth
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 39

Chapter 3 General Information about These Guidelines

data. We used a three-step process to derive estimates of annual CO2 sequestration: (1) develop

growth curves, (2) select biomass equations, and (3) compute sequestration (see Appendix D).

Numbers in the Look-up Tables (Short Form) are maximum rates (about 11-25 years after

planting) for tree types in the North, Central, and South Tree Growth Zones. Information

regarding CO2 sequestration by different tree types in different Tree Growth Zones is presented

in Appendix D.

Decomposition. CO2 released through decomposition of dead woody biomass varies with

characteristics of the wood itself, fate of the wood (e.g., left standing, chipped, burned), and local

soil and climatic conditions. Recycling of urban waste is now prevalent, and we assume here that

most material is chipped and applied as landscape mulch. For these guidelines we conservatively

estimate that dead trees are removed and mulched in the year that death occurs, and that 80

percent of their stored carbon is released to the atmosphere as CO2

 in the same year. Total annual

decomposition is based on the number of trees of each size class that die in a given year and their

biomass. Tree survival rate is the principal factor influencing decomposition. This can be adjusted

on the basis of Tree Age/Survival fractions described subsequently under Worksheet 2.

Release from tree production, program operations, and tree maintenance. A survey of

nurseries, municipal foresters, and non-profit tree groups provided data to estimate CO2

 release

rates from tree maintenance, production, and program activities (Appendix D). Specific activities

that result in the release of CO2 include heating and cooling of office space; combustion of

gasoline used by vehicles and power tools; and energy consumed in the tree production area for

water pumping, refrigeration, and greenhouse operations. Default values are found in the Lookup Tables. Because CO2

 release from tree- related activities is usually small, about 1 to 5 percent

of total CO2

 release, detailed instructions on how to calculate these values are not provided in

this document. However, customized values can be applied in the Long Form.

Calculate CO2 Reduction and Release for 40 Years

Worksheet 2 (Table IX)

Calculations in Worksheet 2 account for CO2 reductions and releases between the time of

planting and the 40-year project end date. Results from Worksheet 1 for mature trees are

transferred to Worksheet 2, and then values are calculated for each 5-year period and totaled for

a period of 40 years. The amount of CO2 avoided, stored, and released depends on tree numbers

and sizes. At a given time, tree numbers depend on cumulative mortality, whereas tree sizes

depend on tree type, age, and growth rate. To account for these effects, Tree Age-Survival

fractions are used.

Tree age fractions. Tree growth rate and survival influence the stream of benefits from CO2

sequestration and energy savings. Large, fast-growing trees provide greater benefits sooner than

small, slow-growing trees. Tree age fractions are used to estimate the rate that CO2 benefits

change during the 40-year period relative to their maximum values. Maximum values occur at

year 40, when trees are at their largest, except for sequestration, which occurs when trees are

growing their fastest (years 11-25). Thus, tree age fractions reflect growth rates and are roughly

proportional to percentages of mature tree size or maximum growth rate at any given time. Tree

age fractions are based on the default Tree Growth Zone (fig. 18, table 3) for each region (see

growth curves in Appendix D).

Tree growth rates vary by Growth Zone and tree type. Tree Growth Zones (North, Central,

and South) are based on mean length of the frost-free period. Generally, trees in the South Zone

grow faster and larger than trees in the North Zone. All growth curves are “S” shaped, reflecting

slow initial growth, rapid growth after establishment, and slower growth with maturity (fig. 19).

Growth rates and mature sizes of evergreen trees differ from those of deciduous trees (fig. 20). In

the Southern Tree Growth Zone, evergreens are assumed to grow larger than deciduous trees

because they grow nearly year round. However, mature large evergreens are smaller than large

deciduous trees in the Northern Zone. Three size classes are used for deciduous (fig. 20) and

evergreen trees in each Tree Growth Zone. Information on tree growth rates and selecting Tree

Growth Zones is in Appendix D.
40 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Tree survival fractions (Long Form Only). Projected atmospheric CO2 reductions from urban

forestry programs are very sensitive to tree survival rates. Careful consideration should be given

to selecting the most appropriate survival fractions. Unfortunately, the literature on tree survival

is sparse and deals primarily with street trees. Studies indicate that survival rates are highly

variable depending on factors related to tree planting, location, and care.

Mortality rates are usually greatest during the first 5 years when trees are becoming

established. Reported tree survival rates range from 60 to 85 percent during this establishment

Figure 18—Tree growth zones for the United States correspond with mean number of freeze-free days per year (North = < 180,

Central = 180-240, South = > 240) (Repeated as figure 25 in Appendix D).

0 

5 

10 

15 

20 

25 

30 

Height (m)

0 10 20 30 40 Years after planting

Evr-North Evr-Central Evr-South

Dec-North Dec-Central Dec-South

Large Trees

0 

5 

10 

15 

20 

Height (m)

0 10 20 30 40 

Years after planting

Large Medium Small

Deciduous Trees - North Growth Zone

Figure 19—Growth curves for large evergreen and deciduous

trees by Tree Growth Zone. Dec = deciduous; Evr = evergreen.

Figure 20—Deciduous trees of the Northern Growth Zone.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 41

Chapter 3 General Information about These Guidelines

period (Foster and Blain 1978, Nowak and others 1990, Miller and Miller 1991, Small 1997). Once

established, tree survival rates are much higher and more stable. A survey of street trees in

Urbana, Ill., found that 59 percent survived between 1932 and 1982 (Dawson and Khawaja 1985).

The average age of removed London plane (Platanus acerfolia) and Norway maple (Acer

platanoides) street trees in Jersey City, N.J., was 39 and 48 years, respectively (Polanin 1991).

On the basis of a review of tree survival literature, fractions are given for each 5-year period

for low, moderate, and high survival cases (table 7). Survival fractions can be adjusted by using

rates for low, moderate or high survival (table 7), or by applying customized rates that better

reflect expected mortality (see Appendix H).

Some factors to consider when selecting survival fractions include:

• Condition and size of tree stock: Bare root stock requires special handling that can

increase initial mortality. In areas prone to vandalism, larger trees often fare better

than smaller trees that are more easily broken.

• Planting techniques, participation, and initial care: Tree survival is likely to be

higher when individuals planting the trees are well trained and supervised to ensure

that proper planting procedures are followed. Research indicates that residents who

participate in tree planting are more satisfied with their trees than when the trees are

planted by the city or developer (Sommer and others 1994). This increased

satisfaction may be associated with greater dedication to stewardship after planting.

The extent to which transplants are properly watered, mulched, pruned, and

inspected also influences survival rates during the establishment period.

• Tree location and growing conditions: Residential yard trees may have higher

survival rates than street trees because they are subject to less damage from deicing

salts and other pollutants, autos, dogs, and vandalism.

Tree Age/Survival Fractions. Tree age and survival fractions are multiplied together to derive

Tree Age/Survival fractions for each 5-year period. Tree Age/Survival fractions are given for each

growth zone and process (shade cooling, shade heating, etc.) in Tables 113-121 in Appendix H,

which also provides instructions for customizing fractions. Tree Age-Survival fractions are

multiplied by their respective maximum values to compute the average savings/release for each 5-

year interval. The 5-year averages are summed over the entire 40-year period to determine total CO2

emissions reduced and released. Table 8 illustrates Tree Age/Survival Fractions for CO2 reductions

from sequestration and tree shade-cooling, as well CO2

 release associated with tree care.

Year 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

Moderate 0.75 0.71 0.68 0.64 0.60 0.56 0.53 0.49

High 0.85 0.83 0.80 0.78 0.75 0.72 0.70 0.67

Low 0.65 0.60 0.55 0.50 0.45 0.40 0.35 0.30

Years after Planting 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

Shade Cooling 0.04 0.17 0.29 0.39 0.47 0.50 0.53 0.54

Sequestration 0.05 0.18 0.34 0.44 0.47 0.46 0.43 0.40

Maintenance 0.07 0.18 0.28 0.36 0.42 0.45 0.48 0.49 1

Taken from table 113, Appendix H.

Table 7—Tree survival fractions list the percentage of trees planted that are assumed to be alive at each 5-year period.

Table 81

—Combined Tree Age/Survival Fractions for the North Tree Growth Zone, moderate survival rate.
42 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 3 General Information about These Guidelines

Calculating Cost per Tonne

A measure of cost effectiveness is useful for comparing return on investment in shade tree

programs with other CO2 reduction programs, or for evaluating a variety of alternative urban

forestry programs. One of the most simple techniques to compare cost effectiveness is to sum up

the “stream” of program costs and net CO2

 benefits and then calculate the dollar cost per tonne of

net CO2 reduction ($/t):

Cost Effectiveness = Total Program Cost / Total Net CO2 Benefit (Eq. 3)

Cost per tonne of avoided CO2 is calculated as total program cost divided by net CO2 benefits

(equation 3) calculated in Worksheet 2 for the 40-year period. This cost effectiveness measure

relies on the future values of costs and benefits obtained at different times. Its usefulness is

limited because it does not convert future values into their present value equivalents. In these

Guidelines we do not take this step because utilities and government agencies have specific

procedures and assumptions that they use when discounting costs and benefits to their present

values. Therefore, the cost effectiveness values derived from equation 3 should be viewed as

preliminary indicators of relative cost effectiveness, unless a more complete analysis is conducted.

Several textbooks and manuals on cost effectiveness analysis are listed in the references (Stokey

and Zeckhauser 1978; Zerbe and Dively 1994; Pekelney and others 1996).
Chapter 4

USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 45

Chapter 4

Illustrative Examples

This chapter illustrates the guidelines provided in Chapter 3 using two examples: a proposed

planting in Boulder City, Nev., and an existing planting in Tucson, Ariz.. The first example

uses the Short Form to estimate future CO2 reductions, whereas the latter case uses the Long

Form and a site-specific tree distribution to customize the analysis for trees planted between 1993

and 1997.

To help the reader determine the source of numbers in the tables that follow, each Short and

Long Form Table is labeled by Roman numeral (i.e., I, II, III, IV...), each row by number (i.e., 1, 2,

3...), and each column by letter (i.e., A, B, C...). A cell reference of (III.Bn) found in Worksheet 1

(col. A) indicates that the source of numbers is Table III (Tree Data), column B (Near trees), in row

numbers that correspond with destination row numbers (i.e. rows 1-6). When multiple rows are

referenced, but the source row numbers do not correspond with destination row numbers, the

row range is indicated using “...” For example, the reference (III.D22..27) in column K of

Worksheet 1 means that the source cells for this column, rows 1-6 are in Table III (Tree Data),

column D (Total), rows 22-27 (Total-All Vintages).

Tabular data are excerpted from the appendices to illustrate these examples. These excerpts

may be partial (e.g. table 9 contains data from table 32, Appendix C) or complete (e.g. tables 10, 11

and 12 appear in Chapter 4, as well as Appendix A and B)

Proposed Program in Boulder City, Nevada

Boulder City, Nevada, was built to house workers constructing Boulder Dam during the 1930’s. It

is located 32 km (20 miles) south of Las Vegas and has a population of 14,000. Street trees were

planted when the town was settled. Siberian elm (Ulmus pumila) and Arizona ash (Fraxinus

velutina) were the dominant species. Currently, street tree canopy cover is sparse because most of

the elms have died and not been replaced. Many of the remaining street trees are senescent. The

city hired an urban forester 2 years ago, and an active citizen group, the Green Team, has formed.

A natural gas power plant is being constructed outside Boulder City to meet the region’s

growing demand for electricity. The utility is interested in funding an urban forestry program in

Boulder City to obtain emission reduction offset credits for CO2

 released at the power plant over

a 40-year period.

Initial discussions among the utility, Boulder City, and the Clark County Public Health

Department have led to formulation of a proposed urban forestry program. The program will

plant 10,000 trees (15-gal) in Boulder City over a 5-year period. The utility will fund program

costs over the initial 5-year period, at a total of $1,000,000. Approximately $900,000 will be spent

for planting and $100,000 for program administration, public education, stewardship, and other

costs. The City Council has agreed to appropriate funds for tree maintenance. Since maintenance

costs will not accrue to the utility, they are not included in this analysis.
46 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Background Information (Table I)

Obtain copies of the blank Input Tables in Appendix A, and record information about the

project’s background.

Site and Building Data (Table II)

1 Enter the existing tree plus building cover as a percentage of site area, excluding

program trees. The default value for the Desert Southwest Region is 34 percent (table

11). However, personal observation and data for Coachella, Calif. (table 45, in

Appendix E), a similar desert city with 37 percent existing cover, suggest that cover is

greater than this. Tree cover and building cover are estimated to be 10 and 30

percent, respectively, for a total value of 40 percent in Boulder City.

2 Default vintage names, pre-entered here, are based upon year of construction.

3 If vintage names differ from the defaults, enter them here. The default names are

used here.

4 Enter the regional default percentage distribution of homes by vintage from table 11 here.

5 If a distribution of homes by vintage differs from default values, enter them here.

These percentages can be calculated as the number of homes in each vintage divided

by the total number of homes in all vintages. The default values are used in this

example.

6 Consult Appendix C to determine the appropriate climate region of the site. As

explained below, Desert Southwest is selected. The Look-up Table for the selected

climate region (climate region is noted at the top of each page) is included here.

Boulder City’s climate is similar to that of Las Vegas, Nev., the closest of the 11 reference

cities (Appendix C). Las Vegas is located in the Desert Southwest region. We need to confirm that

the climate of Las Vegas best matches the climate of the Desert Southwest region’s reference city,

which is Phoenix. Several possible reference city choices are listed in table 9. To compare the

climate of Las Vegas with Phoenix and other reference cities that may be good matches, we list

values of Cooling Degree Days (CDD’s), Heating Degree Days (HDD’s), Latent Enthalpy Hours

(LEH’s) and available sunshine (KT) (tables 31 and 32, in Appendix C). CDD’s for Las Vegas more

closely match values for Dallas and Houston than Phoenix, but these are ruled out because of

large differences in LEH’s. High LEH’s for Dallas and Houston reflect that their climates are

more humid than that of Phoenix. Although HDD’s for Las Vegas more closely match those of

Fresno than those of Phoenix, CDD’s are 57 percent less in Fresno. Our first priority is to match

CDD’s because in cooling-dominated climates air conditioning is more important than space

heating in terms of CO2 is emissions. Therefore, Phoenix is the best match, although using

Phoenix may result in overestimates of emission reductions due to cooling savings and

underestimates of reductions due to space heating savings.

7 Enter the default electricity emissions factor found in table 11 for the selected climate

region. The default value for the Desert Southwest is 0.377 tonnes CO2

 per MWh.

8 Enter the value of the electricity emissions factor to be used in the analysis. A value of

0.754 tonnes CO2

 per MWh was selected here on the basis of data from Boulder City

Municipal Utility. Contact your local electricity supplier to obtain the most accurate

value for your location. Alternatively, average electricity emissions factor values for

each state are listed in table 41 in Appendix E. The regional default values are least

accurate because emission factors can vary considerably among states.

9 Cooling emissions factor adjustment (Ec

) is the ratio of selected to default electricity

emission factors. Ec

 is calculated as:

Ec = (selected electricity emissions factor)/(Default electricity emissions factor) = 0.754/0.377 = 2.0

10 Heating emissions factor adjustment (EH) is calculated as: 1+(Ec - 1)hc, where hc is the

heating correction factor for your climate region (table 11). In this example, the Desert

Southwest has a heating correction factor of 0.32 (table 11), so that

EH = 1+(Ec

 - 1)hc = 1 + ((2.0 - 1) x 0.32) = 1.32
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 47

Chapter 4 Illustrative Examples

9 C g

City Region HDD1 CDD LEH KT

Las Vegas, Nevada Desert Southwest 2,601 2,945 199 0.704

Dallas, Texas South Central 2,290 2,754 7,951 0.536

Fresno, California Southwest 2,650 1,670 43 0.651

Houston, Texas Gulf Coast/Hawaii 1,433 2,889 18,845 0.480

Phoenix, Arizona Desert Southwest 1,552 3,506 967 0.686

 1 HDD = heating Degree Days oF day, base 65 oF); CDD = Cooling Degree Days (oF day,

 base 65 oF); LEH = Latent Enthalpy Hours (Btuh/lb of dry air) and KT = available sunshine

 (fraction).

Table 9—Climate data for Las Vegas and selected reference cities.

I. Background Information

Name: Joleen McCarthey Date: 23 January, 1998

Organization: Boulder City Municipal Utility and Boulder City Green Team

Project Title: Boulder City Case Study

Project Location: Boulder City, Nevada

Goals of the Analysis: Obtain carbon emission reduction offset credits for CO2 released at the

new power plant being constructed outside of Boulder City.

Project Description: The program will plant 10,000 trees in Boulder City over a 5-year period.

All of the trees are 15-gallon size and 50 percent will be planted along Main Street, other downtown

streets, and in parks. The remaining 5,000 trees will be planted within 50 ft of residential buildings,

primarily for shade in front yards of newer homes where streets and sidewalks are contiguous. Ten

percent of these trees will be evergreens planted for windbreak benefits. The contractor has

guaranteed replacement of all dead or dying trees after the first growing season.

 

II. Site and Building Data A B C

1 Existing Tree + Building Cover (percent) 40 pct

2 Default Home Vintage Names pre-1950 1950-80 post-1980

3 Selected Home Vintage Names pre-1950 1950-80 post-1980

4 Regional default home distribution by vintage 19 pct 63 pct 18 pct

5 Selected distribution of homes by vintage 19 pct 63 pct 18 pct

6 Climate Region Desert Southwest

7 Default electricity emissions factor 0.377

8 Selected electricity emissions factor 0.754

9 Cooling emissions factor adjustment (EC) 2.00 ( = R o w 8 / R o w 7 ) 

10 Heating emissions factor adjustment (EH) 1.32 ( = 1 + ( R o w 9 - 1 ) x h c 
48 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Climate region

Existing

cover

(pct)

Home distribution by vintage (pct)

Pre-1950 1950-1980 Post-1980

Tree

growth

zone

Electricity

emissions

factor

Heating

correction

factor (he)

Mid-Atlantic 41 30 58 12 Central .605 0.13

Northern Tier 33 45 42 13 North .612 0.03

North Central 36 42 48 10 North .635 0.09

Mountains 56 42 48 10 North .908 0.09

Southeast 67 28 54 18 Central .545 0.17

South Central 52 19 63 18 Central .671 0.32

Pacific Northwest 54 30 58 12 Central .128 0.17

Gulf Coast/Hawaii 51 19 63 18 South .655 0.32

California Coast 44 28 54 18 South .343 0.17

Southwest 40 28 54 18 Central .523 0.17

Desert Southwest 34 19 63 18 South .377 0.32

1

Reproduced in Appendices A and B.

Percentage by size and vintage (pct)

Pre-1950 1950-1980 Post-1980 Total

Large 1.2 8.2 14.7 24.1

Medium 1.7 12.1 39.3 53.1

Small 0.6 6.6 15.6 22.8

Total 3.5 26.9 69.6 100.0

 1Reproduced in Appendices A and B.

To Convert from: To: Multiply by:

acres hectares 0.4047

square miles hectares 259.01

square feet hectares 9.29 x 10-6

square kilometers hectares 100

kBtu kWh 0.293

Therm MBtu (natural gas) 0.10

1

Originally displayed in chapter 4; also reproduced in Appendix B.

Table 101—Conversion factors.

Table 111—Default values for short form by region and growth zone.

Table 121

—Distribution of Sacramento Shade trees. This distribution can be

applied to deciduous and evergreen plantings.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 49

Chapter 4 Illustrative Examples
50 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Tree Data (Table III)

Record the number of trees planted for each vintage by mature size and type. In this example,

default tree distribution by size, type, and vintage (percent, table 48, in Appendix F) are used

(provision is made in the Long Form analysis to use any tree distribution). Size choices for

deciduous and evergreen trees are: large, medium, and small. Trees are put into one of two

categories: those located Near buildings (within 15 m or 50 ft) so as to provide Shade and Climate

benefits, and those located Far from buildings (greater than 15 m or 50 ft) so as to provide Climate

benefits only. Evergreens located Near buildings are assumed to provide space heating savings

from direct sheltering of the structure.

Of the 10,000 trees to be planted, 5,000 will be planted Near residential buildings (within 15

m or 50 ft), primarily for shade in front yards of homes where streets and sidewalks are

contiguous. Five hundred of these Near trees will be evergreen windbreaks planted within 15 m

of residences to provide both wind speed reduction and shading benefits. Because trees providing

Shade benefits will be primarily planted within 15 m (50 ft) of east- and west-facing building

walls, it is reasonable to apply the Sacramento-based default values (tables 4 and 5, or tables 46

and 47, in Appendix F) for their distribution by azimuth and distance. The same tree type

distribution for deciduous and evergreens is assumed (24 percent large, 53 percent medium, 23

percent small). Similarly, we assume that the 5,000 Near trees are distributed among vintages in

proportions similar to those found for Sacramento Shade: 4 percent for pre-1950, 27 percent for

1950-80, and 70 percent for post-1980 vintage (see table 6 or table 48, in Appendix F).

A total of 4,500 deciduous trees will be planted along Main Street and other downtown

streets, and 500 evergreens will be planted in parks. We conservatively categorize these as Far

trees, assuming that they will not produce Shade benefits because they are located more than 15

m (50 ft) from buildings. In the aggregate, they will provide Climate benefits by lowering

summer air temperatures and winter wind speeds. Their distribution among vintages is assumed

to be similar to the distribution of building vintages throughout the city (19 percent for pre-1950

vintage, 63 percent for 1950-80 vintage, and 18 percent for post-1980 vintage, from Site and

Building Data Table II, row 5). To estimate the distribution of trees among tree type we assume

that deciduous and evergreens have the same distributions and that most of these street and park

trees are relatively large: 75 percent large, 20 percent medium, and 5 percent small. Percentages

shown in table 13 are obtained as the product of percentages for each vintage-size combination

(e.g., pre-1950-large = 19 pct x 75 pct = 14.2 pct). To calculate the number of deciduous Far trees to

be planted for each vintage-size combination (table 14), multiply the total number of deciduous

Far trees (4,500) by the percentages in table 13 (e.g., 14.2 pct x 4,500 = 641). Repeat this process for

the 500 evergreen Far Trees.

Percentage by size and vintage (pct)

Pre-1950 1950-1980 Post-1980 Total

Large 14.2 47.3 13.5 75.0

Medium 3.8 12.6 3.6 20.0

Small 1.0 3.1 0.9 5.0

Total 19 63 18 100

Percentage by size and vintage (pct)

Pre-1950 1950-1980 Post-1980 Total

Large 641 2,126 608 3,375

Medium 171 567 162 900

Small 43 142 40 225

Total 855 2,835 810 4,500

Table 13—Percentage distribution of Far trees for the Boulder City example.

This distribution applies to both deciduous and evergreen plantings.

Table 14—Number of deciduous Far trees for the Boulder City example.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 51

Chapter 4 Illustrative Examples

 Project Title: Boulder City case study 

III. Tree Data: Tree Numbers by Type

AB C D

Vintage: Pre-1950

Tree Type1 Near Far Total

1 Dec-Large 54 641 695

2 Dec-Med. 76 171 247

3 Dec-Small 27 43 70

4 Evr-Large 6 71 77

5 Evr-Med. 9 19 28

6 Evr-Small 358

7 Total 175 950 1,125

Vintage: 1950-1980

Tree Type Near Far Total

8 Dec-Large 369 2,126 2,495

9 Dec-Med. 544 567 1,111

10 Dec-Small 297 142 439

11 Evr-Large 41 236 277

12 Evr-Med. 61 63 124

13 Evr-Small 33 16 49

14 Total 1,345 3,150 4,495

Vintage: Post-1980

Tree Type Near Far Total

15 Dec-Large 662 608 1,270

16 Dec-Med. 1,769 162 1,931

17 Dec-Small 702 40 742

18 Evr-Large 73 68 141

19 Evr-Med. 196 18 214

20 Evr-Small 78 4 82

21 Total 3,480 900 4,380

Total - All Vintages

Tree Type Near Far Total

22 Dec-Large 1,085 3,375 4,460

23 Dec-Med. 2,389 900 3,289

24 Dec-Small 1,026 225 1,251

25 Evr-Large 120 375 495

26 Evr-Med. 266 100 366

27 Evr-Small 114 25 139

28 Total 5,000 5,000 10,000

 1 Dec = deciduous; Evr = evergreen; Med. = medium
52 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Planting and Stewardship Costs (Table IV)

Record costs for tree planting, tree care, and other associated expenditures. Table IV is divided

into five-year increments for the 40 year analysis period.

For the Boulder City case study, the utility will fund program costs over the initial 5-year

period, at a total of $1,000,000. Approximately $900,000 will be spent for planting and $100,000

for program administration, stewardship, and other costs.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 53

Chapter 4 Illustrative Examples

 Project Title: Boulder City case study 

 IV. Planting and Stewardship Costs (dollars)

A BC D E F G H

Years after planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Tree Planting 900,000

2 Tree Care 0

3 Other Costs 100,000

4 Subtotals 1,000,000 0 0 0 0 0 0 0

5 Total Costs $1,000,000
54 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Look-up Table (Short Form) (Table V)

The Short Form Look-up Table is completely filled out with regional default values specific to

each of the 11 Climate Regions (Appendix A). The Desert Southwest Region is shown here for

Boulder City. All values are for a mature tree (or maximums) and in units of t/year. These values

will be entered into Worksheet 1 (Table VIII). Because we are not using the Long Form Input or

Look-up Tables in this Short Form example, Tables VI and VII are omitted.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 55

Chapter 4 Illustrative Examples

V. Look-Up Table (Short Form) 11. Desert Southwest climate region

Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0561 -0.0019 0.04703 0.03731 0.03479 0.02565 0.00806 0.00232

2 Dec-Med. 0.0357 -0.0018 0.02099 0.01665 0.01553 0.01145 0.00360 0.00104

3 Dec-Small 0.0194 -0.0015 0.00868 0.00688 0.00642 0.00473 0.00149 0.00043

4 Evr-Large 0.0394 -0.0042 0.0125 0.05698 0.04521 0.04216 0.03108 0.00976 0.00281

5 Evr-Med. 0.0269 -0.0032 0.0088 0.02847 0.02259 0.02106 0.01553 0.00488 0.00140

6 Evr-Small 0.0068 -0.0017 0.0014 0.01076 0.00854 0.00796 0.00587 0.00184 0.00053

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.1034 -0.0033 0.11501 0.09387 0.08894 0.02067 0.00665 0.00198

8 Dec-Med 0.0658 -0.0031 0.05134 0.04190 0.03970 0.00923 0.00297 0.00088

9 Dec-Small 0.0357 -0.0027 0.02122 0.01732 0.01641 0.00381 0.00123 0.00037

10 Evr-Large 0.0726 -0.0073 0.0135 0.13937 0.11375 0.10777 0.02505 0.00805 0.00240

11 Evr-Med. 0.0495 -0.0056 0.0096 0.06962 0.05682 0.05383 0.01251 0.00402 0.00120

12 Evr-Small 0.0126 -0.0029 0.0015 0.02632 0.02148 0.02035 0.00473 0.00152 0.00045

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0897 -0.0045 0.11840 0.08722 0.07996 0.04026 0.01362 0.00437

14 Dec-Med 0.0571 -0.0042 0.05285 0.03893 0.03569 0.01797 0.00608 0.00195

15 Dec-Small 0.0309 -0.0037 0.02185 0.01609 0.01475 0.00743 0.00251 0.00081

16 Evr-Large 0.0630 -0.0101 0.0173 0.14348 0.10569 0.09690 0.04878 0.01651 0.00529

17 Evr-Med. 0.0430 -0.0078 0.0122 0.07167 0.05279 0.04840 0.02437 0.00824 0.00264

18 Evr-Small 0.0109 -0.0040 0.0019 0.02710 0.01996 0.01830 0.00921 0.00312 0.00100

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) South tree growth zone

J K L M N

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.2937 -6.019 -0.0106 -0.0007 -0.0026

2 Dec-Med. 0.1331 -2.738 -0.0082 (All tree types)

3 Dec-Small 0.0321 -0.662 -0.0049

4 Evr-Large 0.3028 -6.392 -0.0121

5 Evr-Med. 0.1049 -3.139 -0.0100

6 Evr-Small 0.0098 -0.860 -0.0064

1Reproduced from Appendix A 2 Dec = deciduous; Evr = evergreen; Med. = medium

1
56 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Worksheet 1 (Short Form) (Table VIII)

In this Worksheet you calculate impacts of trees at maturity (average value for trees at 36 to 40

years after planting) by multiplying the number of trees planted times a single mature tree’s

estimated CO2 uptake or release obtained from the Look-up Table.

Shade effects. First, tree numbers are obtained from Tree Data Table III, column B, and

entered into column A, rows 1-18 of the Worksheet. The number of trees listed as Windbreak -

Heating in Worksheet 1 (column A, rows 19-27) are copied from above (column A, rows 4-6, 10-

12, and 16-18) for each vintage. Corresponding values of CO2 uptake are copied from the

Look-up Table V (columns A-C, rows 1-18) into columns B and D of the Worksheet. Subtotals are

recorded in column C (Shade-Cooling) by multiplying values in columns A and B for each row.

Round these values to the second digit beyond the decimal point (0.01 t). However, if the analysis is for

very few trees (e.g., fewer than 10 trees per tree type) round to the third digit (0.001 t).

The subtotals for Shade-Heating are recorded in column E by multiplying values in columns

A and D. The negative values in column E reflect increased space heating consumption and CO2

release associated with obstruction of winter sunlight by tree branches. For the Windbreak -

Heating section of Worksheet 1, Look-up Table values are obtained from column C, rows 4-6, 10-

12, and 16-18 and recorded in Worksheet 1, column B, rows 19-27. The subtotals are recorded in

column C by multiplying values in columns A and B.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 57

Chapter 4 Illustrative Examples

VIII. Worksheet 1 (Short Form)1 Boulder City case study

Shade Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2)

A BC DE

 Vintage: Pre-1950 no. of Shading Shade - Cooling Shade - Heating

Trees t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type2 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

1 Dec-Large 54 0.0561 3.032 -0.0019 -0.101

2 Dec-Med. 76 0.0357 2.715 -0.0018 -0.134

3 Dec-Small 27 0.0194 0.523 -0.0015 -0.041

4 Evr-Large 6 0.0394 0.237 -0.0042 -0.025

5 Evr-Med. 9 0.0269 0.242 -0.0032 -0.029

6 Evr-Small 3 0.0068 0.021 -0.0017 -0.005

 Vintage: 1950-80 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

7 Dec-Large 369 0.1034 38.147 -0.0033 -1.208

8 Dec-Med. 544 0.0658 35.793 -0.0031 -1.668

9 Dec-Small 297 0.0357 10.591 -0.0027 -0.791

10 Evr-Large 41 0.0726 2.978 -0.0073 -0.300

11 Evr-Med. 61 0.0495 3.022 -0.0056 -0.343

12 Evr-Small 33 0.0126 0.416 -0.0029 -0.096

 Vintage: Post-1980 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

13 Dec-Large 662 0.0897 59.353 -0.0045 -2.993

14 Dec-Med. 1,769 0.0571 100.943 -0.0042 -7.493

15 Dec-Small 702 0.0309 21.711 -0.0037 -2.583

16 Evr-Large 73 0.0630 4.599 -0.0101 -0.738

17 Evr-Med. 196 0.0430 8.420 -0.0078 -1.524

18 Evr-Small 78 0.0109 0.853 -0.0040 -0.314

Windbreak - Heating

 Vintage: Pre-1950 no. of Windbreak t CO2/Tree Subtotal

Tree Type Trees (A4..6 ) (V.C4..6) (=An x Bn)

19 Evr-Large 6 0.0125 0.075

20 Evr-Med. 9 0.0088 0.079

21 Evr-Small 3 0.0014 0.004

Vintage: 1950-80 (A10..12 ) (V.C10..12) (=An x Bn)

22 Evr-Large 41 0.0135 0.555

23 Evr-Med. 61 0.0096 0.583

24 Evr-Small 33 0.0015 0.049

Vintage: Post-1980 (A16..18 ) (V.C16..18) (=An x Bn)

25 Evr-Large 73 0.0173 1.261

26 Evr-Med. 196 0.0122 2.392

27 Evr-Small 78 0.0019 0.146

1Filled in example of Table VIII taken from Appendix A. See accompanying text for explanation.

2 Dec = deciduous; Evr = evergreen; Med. = medium
58 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Worksheet 1 (Short Form) (continued)

Climate effects. This portion of Worksheet 1 gives CO2 savings (t CO2/tree/year) by vintage

due to air temperature and wind speed reductions that result from an overall increase in canopy

cover. Existing cover consists of trees and buildings pre-dating the program.

First, obtain the number of trees from the Tree Data Table III, column D, rows 1-6, 8-13 and

15-20 and enter these values into column F, rows 1-18, of Worksheet 1.

Mature tree CO2

 savings are taken from the Look-up Table (cols. D-I) for the given level of

existing tree + building cover and inserted in columns G and I of Worksheet 1. Values can be

estimated directly from the Look-up Table, or values can be calculated. In this example, existing

tree and building cover is 40 percent (Table II, Column A, Row 1), which is between Look-up

Table values of 30 percent and 60 percent (Table V, columns D-F, rows 1-18 for cooling and

columns G-I, rows 1-18 for Heating). Therefore, values for Worksheet 1 are calculated as linear

interpolations from values given in the Look- up Table. To find the interpolated value S, first

calculate the slope M of the interpolation line for each tree type:

M = (Sh - Sl)/(Ch - Cl)

where

Sh = savings value associated with existing cover percentage in the Look-up Table

that exceeds the actual cover value (60 percent in this case)

Sl = savings value associated with the existing cover percentage in the Look-up

Table that is less than the actual cover value (30 percent in this case)

Ch = fraction of existing cover from the Look-up Table that exceeds the actual cover

value (0.60 in this case)

Cl

 = fraction of existing cover from the Look-up Table that is less than the actual

cover value (0.30 in this case)

For example, interpolated cooling savings for a large deciduous tree and the 1950-1980

vintage is accomplished by calculating the slope of the line as (0.08894-0.09387)/(0.60-0.30) = -0.0164.

The value M is used in a second calculation to derive the result S

S = M(Ca

 - Cl) + Sl

where Ca is the actual existing cover fraction (0.40 in this case). In our example, S is

calculated as -0.0164 x (0.40-0.30) + 0.09387 = 0.09223, which is entered into Table VIII, column G,

row 7. This interpolation procedure is repeated for each tree type and vintage and for both

cooling and heating. If the existing cover percentage is less than 10 percent or greater than 60

percent, the slope value, M, can be extrapolated on the basis of the slope of the line between the

two closest points.

Subtotals for Cooling are recorded in column H by multiplying values in column F, rows 1-

18, by the values in column G, rows 1-18. A similar calculation is repeated for subtotaling

Heating in column J of the Worksheet. The numbers in columns H and J are metric tonnes of CO2

avoided due to Climate effects associated with increased canopy cover by mature trees, assuming

no mortality.

In the next section of this Worksheet, the sum of Shade-Cooling (col. C, rows 1-18), ShadeHeating (col. E, rows 1-18), Windbreak-Heating (col. C, rows 19-27), Climate-Cooling (col. H,

rows 1-18), Climate-Heating (col. J, rows 1-18) are totaled across building vintages and multiplied

by emissions adjustment factors obtained from Table VIII (columns G and I, row 19). The

products are recorded for Cooling (column G rows 20-31), Heating (column I, rows 20-31), and

Windbreak Heating (column J, rows 23-25). Values in the shaded cells are used in Worksheet 2.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 59

Chapter 4 Illustrative Examples

VIII. Worksheet 1 (Short Form) (continued) Project Title: Boulder City case study

Climate Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2) 40 pct existing cover

F G H IJ

 Vintage: Cooling Heating

 Pre-1950 Number of t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type1 Trees (III.D1..6) (V.D..Fn) (= Fn x Gn) (V.G..In) (= Fn x In)

1 Dec-Large 695 0.03647 25.35 0.00615 4.27

2 Dec-Med. 247 0.01628 4.02 0.00274 0.68

3 Dec-Small 70 0.00673 0.47 0.00113 0.08

4 Evr-Large 77 0.04420 3.40 0.00745 0.57

5 Evr-Med. 28 0.02208 0.62 0.00372 0.10

6 Evr-Small 8 0.00835 0.07 0.00141 0.01

 Vintage: 

1950-80 (III.D8..13)

7 Dec-Large 2,495 0.09223 230.10 0.00509 12.70

8 Dec-Med. 1,111 0.04116 45.73 0.00227 2.52

9 Dec-Small 439 0.01702 7.47 0.00094 0.41

10 Evr-Large 277 0.11176 30.96 0.00617 1.71

11 Evr-Med. 124 0.05583 6.92 0.00308 0.38

12 Evr-Small 49 0.02111 1.03 0.00116 0.06

 Vintage: 

Post-1980 (III.D15..20)

13 Dec-Large 1,270 0.08480 107.70 0.01054 13.38

14 Dec-Med. 1.931 0.03785 73.09 0.00470 9.08

15 Dec-Small 742 0.01565 11.61 0.00194 1.44

16 Evr-Large 141 0.10276 14.49 0.01277 1.80

17 Evr-Med. 214 0.05133 10.98 0.00638 1.36

18 Evr-Small 82 0.01941 1.59 0.00241 0.20

 Total Change in CO2 for all Vintages from Cooling and Heating

Emissions factor adjustment (t CO2/MWh) (t CO2/MBtu)

19 Cooling (II.A9): 2.00 Heating (II.A10): 1.33

Heating

 Shade Effects Totals Cooling Shade Windbreak

Tree Type1 (t CO2) (t CO2) (t CO2)

20 Dec-Large G19x(C1+C7+C13) 201.20 I19x(E1+E7+E13) -5.70

21 Dec-Med. G19x(C2+C8+C14) 279.10 I19x(E2+E8+E14) -12.32

22 Dec-Small G19x(C3+C9+C15) 65.70 I19x(E3+E9+E15) -4.53

23 Evr-Large G19x(C4+C10+C16) 15.64 I19x(E4+E10+E16) -1.41 2.50 I19x(C19+C22+C25) 

24 Evr-Med. G19x(C5+C11+C17) 23.38 I19x(E5+E11+E17) -2.51 4.05 I19x(C20+C23+C26) 

25 Evr-Small G19x(C6+C12+C18) 2.58 I19x(E6+E12+E18) -0.55 0.26 I19x(C21+C24+C27) 

 Climate Effects Totals

26 Dec-Large G19x(H1+H7+H13) 726.80 I19x(J1+J7+J13) 40.22

27 Dec-Med. G19x(H2+H8+H14) 245.86 I19x(J2+J8+J14) 16.27

28 Dec-Small G19x(H3+H9+H15) 39.13 I19x(J3+J9+J15) 2.56

29 Evr-Large G19x(H4+H10+H16) 97.76 I19x(J4+J10+J16) 5.41

30 Evr-Med. G19x(H5+H11+H17) 37.08 I19x(J5+J11+J17) 2.45

31 Evr-Small G19x(H6+H12+H18) 5.39 I19x(J6+J12+J18) 0.35

1 Dec = deciduous; Evr = evergreen; Med. = medium
60 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Worksheet 1 (Short Form) (continued)

Sequestration, decomposition, and tree program-related emissions. First, obtain the total

number of trees planted by tree type from the Tree Data Table III, column D, rows 22-28, and

record these numbers in column K, rows 1-7, of Worksheet 1. Next, obtain Look-up Table values

for Sequestration (column J, rows 1-6), Decomposition (column K, rows 1-6), Maintenance

(column L, rows 1-6), Tree Production (column M, row 1), and Tree Program (column N, row 1),

and enter them in columns L, N, and P of Worksheet 1. Multiply tree numbers in column K by the

corresponding values in columns L, N, and P to calculate totals for each tree type. Totals for

Decomposition, Maintenance, Tree Production, and Tree Program should be negative values

because CO2 is released. Sequestration values in column M, rows 1-6 are positive. Values in the

shaded cells are used in Worksheet 2.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 61

Chapter 4 Illustrative Examples

Sequestration, Decomposition and Program-related Emissions (Emission values are negative)

K LM NO PQ

Sequestration Decomposition Maintenance

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2 t CO2/tree Total t CO2

n Tree Type2 (III.D22..27) (V.J1..6) (= Kn x Ln) (V.K1..6) (= Kn x Nn) (V.L1..6) (= Kn x Pn)

1 Dec-Large 4,460 0.2937 1,309.69 -6.0188 -26,844 -0.0106 -47.16

2 Dec-Med. 3,289 0.1331 437.66 -2.7382 -9,006 -0.0082 -26.99

3 Dec-Small 1,251 0.0321 40.14 -0.6618 -828 -0.0049 -6.12

4 Evr-Large 495 0.3028 149.86 -6.3920 -3,164 -0.0121 -5.99

5 Evr-Med. 366 0.1049 38.40 -3.1392 -1,149 -0.0100 -3.65

6 Evr-Small 139 0.0098 1.36 -0.8603 -120 -0.0064 -0.89

Tree Production Tree Program

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2

(III.D28) (V.M7) (= K7 x L7) (V.O7) (= K7 x N7)

7 All Trees 10,000 -0.00069 -6.90 -0.0026 -26.10

1Filled in example of Table VIII taken from Appendix A. See accompanying text for explanation.

2 Dec = deciduous; Evr = evergreen; Med. = medium

Project Title: Boulder City case study

South tree growth zone

VIII. Worksheet 1 (Short Form) (continued)
62 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Worksheet 2 (Table IX)

In Worksheet 2, CO2 reductions and releases are calculated for each 5-year period and totaled for

the entire 40 years. Unless fewer than 1,000 trees are planted, all values entered into Worksheet 2

are rounded to one decimal place (t CO2). A moderate survival rate is assumed, and tree size is

based on growth curves for the appropriate Tree Growth Zones (see Appendix D).

The first step to filling in Worksheet 2 is to obtain Age/Survival fractions for the South

Growth Zone, moderate survival rate, from table 119, in Appendix H. Values from rows 1 to 7

from this table are entered into rows 1, 9, 23, 39, 47, 55, and 63, respectively, of Worksheet 2.

The next step is to obtain annual mature tree values from shaded cells in Worksheet 1,

multiply these values by 5 to derive 5-year totals, and record the resulting numbers in column J

of Worksheet 2. For example, the value for Shade Cooling in Worksheet 2, column J, row 2

(1,006.0), is obtained by multiplying the value from Worksheet 1, column G, row 20 by 5 (201.20

x 5). Shade Heating values (Worksheet 2, column J, rows 10-15) are obtained from Worksheet 1,

column I, rows 20-25. Heating-windbreak values (Worksheet 2, column J, rows 17-19) are

obtained from Worksheet 1, column J, rows 23-25. Values for Climate Effects (Worksheet 2,

column J, rows 24-29 and 31-36) are obtained from Worksheet 1, column G, rows 26-31 and

column I, rows 26-31. Similarly, values for Sequestration, Decomposition, and Maintenance are

obtained from Worksheet 1, columns M, O, and Q, rows 1-6. Tree Production and Program

values are obtained from columns M and O, row 7. Note that each value obtained from Worksheet

1 is multiplied by 5 and rounded to one decimal place.

Use the Age/Survival fractions to begin back-calculating for each 5-year period. For example,

beginning with Worksheet 2, column A, row 2, multiply the fraction in column A, row 1 or 0.09

times the value in Worksheet 2, column J, row 1 or 1006.0. The product 90.54 is rounded to one

decimal place and recorded in column A, row 2 of Worksheet 2 as 90.5. This procedure is

repeated for each 5-year time period until columns B-H are filled. The values recorded in

columns A-H, row 2, are then summed, and the total is listed in column I (90.5 + 241.4 + 372.2 +

442.6 + 503.0 + 523.1 + 533.2 + 533.2 =3239).

This process is followed for the remaining rows 3-7. In each case, the same fractions from

row 1 are multiplied by the mature tree values for each tree type in column J. Subtotals are

calculated for the Shade-Cooling category across tree types (recorded in column I) and years

after planting (recorded in row 8).

Although this procedure is repeated for each category (e.g., Shade and Windbreak-Heating,

Climate-Cooling and Heating, Sequestration, Decomposition, Maintenance, Program-Related

Emissions), a different set of Age/Survival fractions are applied. The Age/Survival fractions

appear in bold print for each category.

To calculate the cost of conserved CO2, first record total planting and stewardship costs

listed in Input Table IV in row 69 of Worksheet 2 ($1,000,000). Next, total CO2 reductions and

release are calculated in column I, row 68 to obtain total net CO2 benefit for the 40-year period.

Record this value 47,746 in row 70. Divide total program costs by total net CO2 saved, and record

the result $21 in Worksheet 2, column I, row 70.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 63

Chapter 4 Illustrative Examples

IX. Worksheet 2 5 year total CO2 Savings and Emissions (t CO2)

1 Project Title: Boulder City case study 

Moderate Survival A BCDEFGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Shade-Cooling

1 Age/survival fraction 0.09 0.24 0.37 0.44 0.50 0.52 0.53 0.53

2 Dec-Large2 90.5 241.4 372.2 442.6 503.0 523.1 533.2 533.2 3,239 1006.0

3 Dec-Medium 125.6 334.9 516.3 614.0 697.8 725.7 739.6 739.6 4,494 1395.5

4 Dec-Small 29.6 78.8 121.5 144.5 164.3 170.8 174.1 174.1 1,058 328.5

5 Evr-Large2 7.0 18.8 28.9 34.4 39.1 40.7 41.4 41.4 252 78.2

6 Evr-Medium 10.5 28.1 43.3 51.4 58.5 60.8 62.0 62.0 377 116.9

7 Evr-Small 1.2 3.1 4.8 5.7 6.5 6.7 6.8 6.8 42 12.9

8 Shade Cool subtotal 264.4 705.1 1,087.0 1,292.6 1,469.2 1,527.8 1,577.1 1,557.1 9,460

 Shade:Heating

9 Age/survival fraction 0.37 0.45 0.51 0.52 0.52 0.52 0.53 0.52

10 Dec-Large -10.5 -12.8 -14.5 -14.8 -14.8 -14.8 -15.1 -14.8 -112 -28.5 

11 Dec-Medium -22.8 -27.7 -31.4 -32.0 -32.0 -32.0 -32.6 -32.0 -243 -61.6

12 Dec-Small -8.4 -10.2 -11.6 -11.8 -11.8 -11.8 -12.0 -11.8 -89 -22.7

13 Evr-Large -2.6 -3.2 -3.6 -3.7 -3.7 -3.7 -3.8 -3.7 -28 -7.1

14 Evr-Medium -4.7 -5.7 -6.4 -6.6 -6.6 -6.6 -6.7 -6.6 -50 -12.6

15 Evr-Small -1.0 -1.3 -1.4 -1.5 -1.5 -1.5 -1.5 -1.5 -11 -2.8

16 Subtotal -50.0 -60.9 -68.9 -70.4 -70.4 -70.4 -71.7 -70.4 -533

Windbreak-Heating

17 Evr-Large 4.6 5.6 6.4 6.5 6.5 6.5 6.6 6.5 49 12.5

18 Evr-Medium 7.5 9.1 10.4 10.6 10.6 10.6 10.8 10.6 80 20.3

19 Evr-Small 0.5 0.6 0.7 0.7 0.7 0.7 0.7 0.7 5 1.3

20 Subtotal 12.6 15.3 17.5 17.8 17.8 17.8 18.1 17.8 135

21 Shade Heat subtotal -37.4 -45.6 -51.4 -52.6 -52.6 -52.6 -53.6 -52.6 -398

22 Total Shade 227.0 659.5 1,035.6 1,240.0 1,416.6 1,475.2 1,503.5 1,504.5 9,062

 Climate-Cooling

23 Age/survival fraction 0.02 0.09 0.20 0.30 0.38 0.44 0.47 0.49

24 Dec-Large 72.7 327.1 726.8 1,090.2 1,380.9 1,599.0 1,708.0 1,780.7 8,685 3,634

25 Dec-Medium 24.6 110.6 245.9 368.8 467.1 540.9 577.8 602.4 2,938 1,229.3

26 Dec-Small 3.9 17.6 39.1 58.7 74.4 86.1 92.0 95.9 468 195.7

27 Evr-Large 9.8 44.0 97.8 146.6 185.7 215.1 229.7 239.5 1,168 488.8

28 Evr-Medium 3.7 16.7 37.1 55.6 70.5 81.6 87.1 90.8 443 185.4

29 Evr-Small 0.5 2.4 5.4 8.1 10.3 11.9 12.7 13.2 65 27

30 Subtotal 115.2 518.4 1,152.1 1,728.0 2,188.9 2,534.6 2,707.3 2,822.5 13,767

 Climate-Heating

31 Dec-Large 4.0 18.1 40.2 60.3 76.4 88.5 94.5 98.5 481 201.1

32 Dec-Medium 1.6 7.3 16.3 24.4 30.9 35.8 38.3 39.9 195 81.4

33 Dec-Small 0.3 1.2 2.6 3.8 4.9 5.6 6.0 6.3 31 12.8

34 Evr-Large 0.5 2.4 5.4 8.1 10.3 11.9 12.7 13.3 65 27.1

35 Evr-Medium 0.2 1.1 2.5 3.7 4.7 5.4 5.8 6.0 29 12.3

36 Evr-Small 0.0 0.2 0.4 0.5 0.7 0.8 0.8 0.9 4 1.8

37 Subtotal 6.6 30.3 67.4 100.8 127.9 148.0 158.1 164.9 804

38 Total Climate 121.8 548.7 1,219.5 1,828.8 2,316.8 2,682.6 2,865.4 2,987.4 14,571
64 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

IX. Worksheet 2 (continued) 5 year total CO2 Savings and Emissions (t CO2) Project Title: Boulder City case study

Moderate Survival A B C D EF G H I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Sequestration

39 Age/survival fraction 0.07 0.30 0.51 0.60 0.57 0.48 0.38 0.28

40 Dec-Large 458.4 1,964.6 3,339.7 3,929.1 3,732.6 3,143.3 2,488.4 1,833.6 20.890 6,548.5

41 Dec-Medium 153.2 656.5 1,116.0 1,313.0 1,247.3 1,050.4 831.6 612.7 6,981 2,188.3

42 Dec-Small 14.0 60.2 102.4 120.4 114.4 96.3 76.3 56.2 640 200.7

43 Evr-Large 52.5 224.8 382.1 449.6 427.1 359.7 284.7 209.8 2,390 749.3

44 Evr-Medium 13.4 57.6 97.9 115.2 109.4 92.2 73.0 53.8 612 192

45 Evr-Small 0.5 2.0 3.5 4.1 3.9 3.3 2.6 1.9 22 6.8

46 Total Sequestered 692.0 2,965.7 5,041.6 5,931.4 5,634.7 4,745.2 3,756.6 2,768.8 31,535

 Tree Decomposition

47 Age/survival fraction 0.0005 0.0005 0.0014 0.0027 0.0041 0.0054 0.0066 0.0075

48 Dec-Large -67.1 -67.1 -187.9 -362.4 -550.3 -724.8 -885.8 -1,006.6 -3,852 -134,219.2

49 Dec-Medium -22.5 -22.5 -63.0 -121.6 -184.6 -243.2 -297.2 -337.7 -1,292 -45,030.5

50 Dec-Small -2.1 -2.1 -5.8 -11.2 -17.0 -22.4 -27.3 -31.0 -119 -4,139.8

51 Evr-Large -7.9 -7.9 -22.1 -42.7 -64.9 -85.4 -104.4 -118.7 -454 -15,820.1

52 Evr-Medium -2.9 -2.9 -8.0 -15.5 -23.6 -31.0 -37.9 -43.1 -165 -5,744.7

53 Evr-Small -0.3 -0.3 -0.8 -1.6 -2.5 -3.2 -3.9 -4.5 -17 -597.9

54 Decomposition Total -102.8 -102.8 -287.6 -555.0 -842.9 -1,110.0 -1,356.5 -1,541.6 -5,899

 Tree Maintenance

55 Age/survival fraction 0.10 0.23 0.35 0.43 0.48 0.50 0.50 0.49

56 Dec-Large -23.6 -54.2 -82.5 -101.4 -113.2 -117.9 -117.9 -115.5 -726 -235.8

57 Dec-Medium -13.5 -31.1 -47.3 -58.1 -64.8 -67.5 -67.5 -66.2 -416 -135

58 Dec-Small -3.1 -7.0 -10.7 -13.2 -14.7 -15.3 -15.3 -15.0 -94 -30.6

59 Evr-Large -3.0 -6.9 -10.5 -12.9 -14.4 -15.0 -15.0 -14.7 -92 -30

60 Evr-Medium -1.8 -4.2 -6.4 -7.9 -8.8 -9.2 -9.2 -9.0 -57 -18.3

61 Evr-Small -0.5 -1.0 -1.6 -1.9 -2.2 -2.3 -2.3 -2.2 -14 -4.5

62 Tree Maint. Total -45.5 -104.4 -159.0 -195.4 -218.1 -227.2 -227.2 -222.6 -1,399

 Program-related Emissions

63 Age/survival fraction 0.75 0.00 0.00 0.00 0.00 0.00 0.00 0.00

64 Tree Production -25.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -26 -34.5

65 Tree Program -97.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -98 -130.5

66 Prod/Program Total -123.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -124

67 Total Released -272.1 -207.2 -446.6 -750.4 -1,061.0 -1,337.2 -1,583.7 -1,764.2 -7,422

68 Net CO2 Saved 768.7 3,966.7 6,850.1 8,249.8 8,307.1 7,565.8 6,541.8 5,495.7 47,746

69 Cost of conserved CO2 = Total program cost (IV.A5): $1,000,000

70 divided by Net CO2 saved (I68,tonnes): 47,746 = $21/ tonne

 1 Filled in example of Table IX taken from Appendix A.

 2 Dec = deciduous; Evr = evergreen
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 65

Chapter 4 Illustrative Examples

Boulder City Case Study Summary

Projected net CO2 savings for this example is estimated at 47,746 tonnes. Savings from avoided

energy use is 49 percent (23,633) of the net benefit. Sequestration less total releases constitute 51

percent of the net savings (24,113 tonnes) (fig. 21). Cost of conserved carbon, defined as program

costs ($1,000,000) divided by net CO2 savings over the 40-year analysis period, is estimated as

$21/tonne CO2.

Net CO2

 benefits initially increase to about 8,000 t, then decrease somewhat more slowly to

5,000 t. Sequestration rates are relatively large with respect to avoided CO2 savings due to the

large number of Far trees that provide no shading benefits. In addition, the default electricity

emissions factor is relatively small.

The penalty associated with winter shade is about 10 percent of cooling savings from

summer shade. The cooling savings due to Climate modification (13,770 t) is approximately 2.5

times the cooling savings from shade (5,480 t) due in part to the large number of Far trees, that

provide climate, but no shading benefits.

Figure 21—Projected CO2 savings (+) and releases (-) for each 5-year period in Boulder City.

-2 

0 

2 

4 

6 

8 

tonnes CO2

Thousands

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

years

Shade-Cooling Shade-Heating Climate-Cooling Climate-Heating

Sequestration Total Released Net CO2 Saved
66 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 67

Chapter 4 Illustrative Examples

Existing Program in Tucson, Arizona

The Cool Communities Demonstration Project is monitoring change in the social and physical

environment of cities associated with locally based tree planting to mitigate urban heat islands.

As part of this program, 299 large trees (15 gal. containers and 24-inch boxes) were planted to

shade 104 residences in the Davis-Monthan Air Force Base’s (DM) Palo Verde South

neighborhood located in Tucson, Arizona, between 1993 and 1997 (fig. 22). The planting was

coordinated by American Forests, with Trees for Tucson providing local outreach. Tree species

were selected by consultants to American Forests in conjunction with local experts. Research to

quantify impacts of tree shade on climate and air conditioning energy use is being conducted by

Tucson Electric Power, the University of Arizona, and the USDA Forest Service.

The objectives of the project are to:

1. Monitor change in the species composition, size, age, and health of existing and

program trees, detect conditions that may be responsible for deteriorating tree health,

and identify management solutions.

2. Analyze measured kWh data from 12 sub-metered residential units at D-M to

determine impacts of shade trees on air conditioning loads.

3. Calibrate Micropas using sub-metered data, and simulate future heating/cooling

energy savings from trees as they mature.

4. Estimate other future benefits such as CO2

 reductions, as well as tree planting and

care costs to calculate present value of net benefits over 40 years.

We use the guidelines here to estimate CO2 savings for this existing tree planting. We select

the Long Form analysis, since we are given the distribution of trees with respect to location

(azimuth and distance from buildings), which we will account for using information in Appendix

F, and because all units are air conditioned, which we will account for using adjustments in Table VI.

Figure 22—Palo Verde study site at Davis-Monthan Air Force Base, Tucson, AZ (circles indicate projected

tree coverage in 40 years).
68 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Background Information (Table I)

Obtain copies of the blank Input Tables in Appendix B and record information about the

project’s background.

Site and Building Data (Table II)

1 Enter the existing tree plus building cover as a percentage of site area, excluding

program trees. The default value for the Desert Southwest Region is 34 percent (table

11). The existing tree cover is 5 percent and building cover is 6 percent, for a total

selected value of 11 percent based on aerial photo analysis (fig. 22).

2 Default vintage names, pre-entered here, are based upon year of construction.

3 If vintage names differ from the defaults, enter them here. Only the 1950-80 vintage is

used here because all homes in the Palo-Verde development were built in the 1970’s.

4 Enter the regional default percentage distribution of homes by vintage from table 11 here.

5 If a distribution of homes by vintage differs from default values, enter them here.

These percentages can be calculated as the number of homes in each vintage divided

by the total number of homes in all vintages. In this example there are 104 residences

in the 1950-1980 vintage, and none in the rest, resulting in a distribution much

different from the regional default.

6 Consult Appendix C to determine the appropriate climate region of the site. As

explained below, Desert Southwest is selected. The Long Form Adjustment Table for

the selected climate region (climate region is noted at the top of each page) is

included here.

Tucson’s climate is similar to that of Phoenix, the closest of the 11 reference cities (Appendix

C), and also the Desert Southwest region’s reference city. Both are located in the Desert Southwest

region. We need to confirm that the climate of Phoenix best matches that of Tucson’s. The

reference cities for several possible choices are listed in table 15. To compare the climate of

Tucson with these reference cities, we consider Cooling Degree Days (CDD’s), Heating Degree

Days (HDD’s), Latent Enthalpy Hours (LEH’s) and available sunshine (KT) (data from tables 31

and 32, in Appendix C). CDD’s for Tucson more closely match values for Dallas and Houston

than Phoenix, but these are ruled out because of much greater LEH’s for Dallas and Houston,

reflecting their humid climate. HDD’s for Phoenix most closely match Tucson’s. Available

sunshine in Phoenix and Tucson are similar. Given these observations, Phoenix appears to be the

best match, and the Desert Southwest climate region is selected.

7 Enter the default electricity emissions factor found in table 11 for the selected climate

region. The default value for the Desert Southwest is 0.377 tonnes CO2

 per MWh.

8 Enter the value of the electricity emissions factor to be used in the analysis. The

selected value is 1.270 tonnes CO2

 per MWh, obtained from Tucson Electric Power

(TEP), who estimate that 99 percent of their power is generated from coal, 1 percent

from natural gas/fuel oil. Actual values for electricity change regionally, reflecting

local differences in the mix of fuels used to generate electricity. Average electricity

emission factor values for each state are listed in table 41, in Appendix E. The

regional default values are least accurate because electricity emission factors can

vary considerably among states.

9 Cooling electricity emissions factor adjustment (Ec

) is the ratio of selected to default

electricity emission factors. Ec

 is calculated as:

Ec

 = (selected emissions factor)/(Default emissions factor) = 1.270/0.377 = 3.37

10 Heating electricity emissions factor adjustment for heating is set = 1.0 here. In the

Long Form, this adjustment is made in Table VI, Long Form Adjustment Table,

Heating Adjustments section.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 69

Chapter 4 Illustrative Examples

I. Background Information

Name: John Guenther Date: Feb. 2, 1998

Organization: Tucson Electric Power

Project Title: Palo Verde Phase I Tree Planting

Project Location: Davis-Monthan Air Force Base, Tucson, Arizona

Goals of the Analysis: Estimate carbon dioxide savings of an existing tree planting

Project Description: A single planting of 275 trees in November, 1993, designed to reduce air

conditioning loads in military housing at Davis-Monthan Air Force Base in Tucson, Arizona. Trees

were planted in yards to shade residences and streets. Replacement and addition of trees in 1994

to 1997 brought the total number of trees planted to 299.

 

II. Site and Building Data A B C

1 Existing Tree + Building Cover (percent) 11 pct

2 Default Home Vintage Names pre-1950 1950-80 post-1980

3 Selected Home Vintage Names 1950-80

4 Regional default home distribution by vintage 19.3 pct 62.3 pct 18.4 pct

5 Selected distribution of homes by vintage 0 100 pct 0

6 Climate Region Desert Southwest

7 Default electricity emissions factor 0.377

8 Selected electricity emissions factor 1.270

9 Cooling emissions factor adjustment (EC) 3.37 (=Row 8/ Row 7)

10 Heating emissions factor adjustment (EH) 1.0

City Region HDD1 CDD LEH KT

Tucson, Arizona Desert Southwest 1,751 2,813 1,011 0.679

Dallas, Texas South Central 2,290 2,754 7,951 0.536

Fresno, California Southwest 2,650 1,670 43 0.651

Houston, Texas Gulf Coast/Hawaii 1,433 2,889 18,845 0.480

Phoenix, Arizona Desert Southwest 1,552 3,506 967 0.686

1

 HDD = heating Degree Days (oF day, base 65 oF); CDD = Cooling Degree Days (oF day, base

65 oF); LEH = Latent Enthalpy Hours (Btuh/lb of dry air) and KT = available sunshine (fraction).

Table 15—Climate data for Tucson and selected reference cities.
70 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Tree Data (Table III)

Record the number of trees planted for each vintage by mature size and type. Size choices for

deciduous and evergreen trees are: small, medium, and large. Trees are put into one of two

categories: those located Near buildings (within 15 m or 50 ft) so as to provide Shade and Climate

benefits, and those located Far from buildings (greater than 15 m or 50 ft) so as to provide Climate

benefits only. Evergreens located Near buildings are assumed to provide space heating savings

from sheltering of the structure.

Number of trees are entered only for 1950-1980 vintage homes, because this example has no

Pre-1950 or Post-1980 vintages. In the Palo Verde project, 275 trees were originally planted in

1993, and an additional 24 trees were planted from 1994 to 1997. The distribution of trees among

tree types was obtained using information on the mature sizes of tree species in the Tree Selection

List (table 34, in Appendix D). The tree type distribution for all 299 trees is: large deciduous, 16;

medium deciduous, 152; small deciduous, 19; large evergreen, 96; medium evergreen, 16 (table

16). Of these, there were no large deciduous, 9 medium deciduous, 3 small deciduous, 4 large

evergreen, and no medium or small evergreen trees planted far from buildings. The total number

of trees planted around all three vintages is simply the 1950-1980 vintage total.

Scientific Name Common Names Number Type1

Acacia minuta Sweet acacia 14 Dec Small

Cercidium floridum Blue palo verde 5 Dec Small

Pinus halapensis Aleppo pine 19 Evr Large

Pistacia chinensis Chinese pistache 16 Dec Large

Prosopis chilensis Chilean mesquite 152 Dec Med.

Quercus virginiana ‘Heritage’ Heritage oak 77 Evr Large

Rhus lancea African sumac 16 Evr Med.

Total 299

1

 Dec = deciduous; Evr = evergreen; Med. = medium.

Table 16—Tree numbers by species and type.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 71

Chapter 4 Illustrative Examples

 Project Title: Tucson case study 

III. Tree Data: Tree Numbers by Type

AB C D

Vintage: Pre-1950

Tree Type1 Near Far Total

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

7 Total

Vintage: 1950-1980

Tree Type Near Far Total

8 Dec-Large 16 0 16

9 Dec-Med. 143 9 152

10 Dec-Small 16 3 19

11 Evr-Large 92 4 96

12 Evr-Med. 16 0 16

13 Evr-Small 0 00

14 Total 283 16 299

Vintage: Post-1980

Tree Type Near Far Total

15 Dec-Large

16 Dec-Med.

17 Dec-Small

18 Evr-Large

19 Evr-Med.

20 Evr-Small

21 Total

Total - All Vintages

Tree Type Near Far Total

22 Dec-Large 16 0 16

23 Dec-Med. 143 9 152

24 Dec-Small 16 3 19

25 Evr-Large 92 4 96

26 Evr-Med. 16 0 16

27 Evr-Small 0 00

28 Total 283 16 299

1

 Dec = deciduous; Evr = evergreen; Med. = medium
72 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Planting and Stewardship Costs. (Table IV)

Record costs for tree planting, tree care, and other associated expenditures. Table IV is divided

into 5-year increments for the 40-year analysis period.

For the Tucson case study, initial costs (years 1-5) for planting, maintenance, and education

are: $47,239, $23,650, and $5,700 respectively, or $76,589 total. These costs are based on data

reported by American Forests, Trees for Tucson, and the Davis-Monthan AFB (American Forests

1997). Subsequent costs are for maintenance only and are assumed to be $1,000 per year for

inspection and irrigation (Sumner 1997).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 73

Chapter 4 Illustrative Examples

Note: Table V, the Short Form Look-up Table is not used with Long Form, and so we skip to

Long Form Adjustment Table VI.

 Project Title: Tucson case study

 IV. Planting and Stewardship Costs (dollars)

A BCDEFGH

Years after planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Tree Planting 47,239

2 Tree Care 23,650 5,000 5,000 5,000 5,000 5,000 5,000 5,000

3 Other Costs 5,700

4 Subtotals 76,589 5,000 5,000 5,000 5,000 5,000 5,000 5,000

5 Total Costs $111,589
74 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Long Form Adjustment Table (Table VI)

To make local adjustments to regional default values, enter regional default and selected values

for factors listed. If adjustments are not required for emissions factor, CFA, shade fraction,

cooling equipment fraction, or base case, enter the value “1” for that adjustment.

1 Default vintage names from Table II, row 2, columns A..C, are pre-entered.

2 Enter selected vintage names from Table II, row 3 columns A..C. In this example it is

1950-80.

3 Default values for CFA taken from table 43, in Appendix E, are pre-entered.

4 Average CFA for 3- and 4-bedroom units at the Palo Verde site is 124.7 m2

 (1.342 ft2)

based on architectural drawings.

5 Calculate adjustment by dividing selected by default value (B4 / B3); 125 / 100 = 1.24.

6 The default value of 15 pct is based on the Sacramento study, which found that 20-25

pct of the program trees shaded neighboring buildings, resulting in a 15 pct

reduction in air conditioning use.

7 Aerial photo analysis indicates that 40 pct of the trees will shade adjacent buildings.

We assume that the ratio of default shade (20-25 pct = 22.5 pct) to savings (15 pct)

found previously is constant, so that the selected value here is 30 pct (= 40 pct x (22.5

pct/15 pct)).

8 Calculate the adjustment as (1 + A7) / (1 + A6). For this example: 1.30 / 1.15 = 1.13.

Cooling equipment adjustments. Enter fraction of units with each type of equipment, then

make adjustments based on that equipment’s relative energy use compared to central air

conditioning.

Central Air Conditioning. Default values are from table 44 in Appendix E, cooling equipment

saturations.

9 Default value is 0.70.

10 1.00 is selected since all 104 units have Central AC.

Evaporative Cooler.

11 The default value is 0.0 (table 44, in Appendix E).

12 None of the homes in this example use evaporative coolers; the selected value is 0.0.

Room AC.

13 The default value is 0.23 (table 44, in Appendix E).

14 The selected value is 0.0.

No cooling.

15 The default value is 0.07 (table 44, in Appendix E).

16 The selected value is 0.0.

Calculate cooling equipment adjustment factor.

17 The default combined equipment factor is

 (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15), or substituting values from table 44, in

 Appendix E is (0.70 + 0.33*0.0 + 0.25*0.23 + 0.0*0.07) = 0.76.

18 The selected combined equipment factor is (1.0 + 0.33*0.0 + 0.25*0.0 + 0.0*0.0) = 1.0.

19 The adjusted value is: (A..C18 / A..C17) = 1.0 /0. 69 = 1.31.

Enter base case adjustment. This adjusts default for locally available energy use data.

20 The default value is 57.5 kWh/m2

/yr based on simulation model results.

21 The selected value is 64.3 kWh/m2

/yr based on measured air conditioning energy

 use by the local utility for 12 units at the case study site.

22 Calculate adjustment by dividing selected value by default (A..C21 / A..C20); 64.3/57.5 = 1.12.

Calculate Cooling Adjustment Factor.

23 The adjustment is (A..C5 x A8 x A..C19 x A..C22) = 1.24 x 1.13 x 1.31 x 1.12 = 2.07.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 75

Chapter 4 Illustrative Examples

VI. Long Form Adjustment Table Desert Southwest Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Tucson case study Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected pre-1950 1950-1980

Conditioned Floor Area (CFA)

3 Default (m2/unit) 90.6 100.3

4 Selected (m2/unit) 0.0 124.7

5 CFA Adjustment (A..C4 / A..C3) 0.00 1.24

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected 0.30

8 Adjustment (1 + A7) / (1 + A6) 1.13

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.27 0.70

10 Selected 0.00 1.00 0.00

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 0.00 0.00 0.00

Fraction with room air conditioning

13 Default 0.59 0.23 0.05

14 Selected 0.00 0.00 0.00

Fraction with no cooling

15 Default 0.14 0.07 0.10

16 Selected 0.00 0.00 0.00

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.42 0.76 0.87

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16) 0.00 1.00 0.00

19 Adjusted (A..C18 / A..C19) 0.00 1.31 0.00

Base Case Adjustment

20 Default (kWh/m2/yr) 61.4 57.5 30.6

21 Selected (kWh/m2/yr) 0.0 64.3 0.0

22 Adjustment (A..C21 / A..C20) 0.00 1.12 0.00

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22) 0.00 2.07 0.00

post-1980

post-1980

154.2

0.0

0.00

0.86
76 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Long Form Adjustment Table (Table VI) (continued)

Heating and Climate effects. Default values are from table 44, in Appendix E, heating equipment

saturations.

24 Enter default electricity emissions factor from Table II, row 7, column A (0.377)

25 Enter selected electricity emissions factor from Table II, row 8, column A (1.270)

Combined Equipment/Emissions adjustments relative to natural gas:

26 The default percentage of units with natural gas heat is 0.62.

27 The selected value is 1.0 because all units at the Davis-Monthan site have natural gas heating.

28 The Default Combined Conversion Factor is (0.0527 x A..C26) = 0.0327.

29 The Selected Combined Conversion Factor is the product of selected natural gas emission and

equipment factors, divided by 1000 MBtu/kBtu, (0.0527 x A..C27); 0.0527x 1 = 0.0527.

30 The default percentage of units with fuel oil heat is 0.0.

31 None of the homes in this example use fuel oil, the selected value is 0.0.

32 The Default Combined Conversion Factor is (0.072 x A..C30) = 0.0.

33 The Selected Combined Conversion Factor is (0.072 x A..C31) = 0.0

34 The default percentage of 1950-1980 units with electric resistance heat is 0.17.

35 The selected value is 0 pct.

36 The Default Combined Conversion Factor is (0.22 x A24 x A..C34) = 0.0140.

37 The Selected Combined Conversion Factor is (0.22 x A25x A..C35) = 0.0.

38 The default percentage of 1950-1980 units with heat pumps is 0.10.

39 The selected value is 0 pct.

40 The Default Combined Conversion Factor is (0.11 x A24 x A..C38) = 0.0041.

41 The Selected Combined Conversion Factor is (0.11 x A25x A..C39) = 0.0.

42 The default percentage of units with other heating is 0.11.

43 The selected value is 0 pct.

44 The Default Combined Conversion Factor is (0.0527 x A..C42) = 0.0059.

45 The Selected Combined Conversion Factor is (0.0527 x A..C43) = 0.0

Combined Emissions/Equipment Adjustment.

46 The default = sum of combined default factors above: (A..C28 + A..C32 + A..C36 +

A..C40 + A..C44) = 0.057.

47 Selected value is the sum of combined selected factors above: (A..C29 + A..C33 +

A..C37 + A..C41 + A..C45) = 0.053.

48 The adjustment is the quotient of selected and default values: (A..C46 / A..C47) = 0.93

Base Case Adjustment.

49 The default value for 1950-1980 units is 102.9 (kBtu/m2

/yr) based on simulation

model results.

50 The default value of 102.9 (kBtu/m2

/yr) is selected.

51 Calculate the adjustment by dividing the selected value by the default. (A..C49 / A..C50) = 1.0.

Heating Adjustment Factor.

52 Calculate by multiplying the CFA adjustment by the percent of shade on

neighboring homes, combined emissions/equipment adjustment, and the base case

adjustment. (A..C5 x A8 x A..C48 x A..C51); 1.24 x 1.13 x 0.93 x 1.0 x 1.0 = 1.31.

Climate Cooling and Heating Adjustments

53 The default value is 0.1 %C/percentage cover increase (Table 44, in Appendix E).

54 We select the default value of 0.1 %C/percentage cover increase.

55 Calculate adjustment by dividing the selected value by the default (A60 / A59); 0.1 / 0.1 = 1.0

56 Calculate the Cooling Adjustment Factor by multiplying the electricity emission

adjustment factor by the CFA adjustment, the cooling equipment adjustment factor, and

the base case adjustment. (A..C5 x A..C19 x A..C22 x A55); 1.24 x 1.31 x 1.13 x 1.0= 1.83.

57 Calculate the Heating Adjustment Factor by dividing the heating adjustment factor by the

percent of shade on neighboring homes.(A..C5 x A..C48 x A..C51); 1.24 x 0.93 x 1.0 = 1.16.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 77

Chapter 4 Illustrative Examples

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title: Tucson case study

24 Default electricity emissions factor (t CO2/MWh) 0.377

25 Selected electricity emissions factor (t CO2/MWh) 1.270

Fraction with natural gas

26 Default 0.73 0.62 0.29

27 Selected 0.00 1.00 0.00

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0383 0.0327 0.0151

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh) 0.0000 0.0527 0.0000

Fraction with fuel oil

30 Default 0.00 0.00 0.00

31 Selected 0.00 0.00 0.00

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0000 0.0000 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh) 0.0000 0.0000 0.0000

Fraction with electric resistance

34 Default 0.11 0.17 0.42

35 Selected 0.00 0.00 0.00

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0095 0.0140 0.0348

37 Selected conversion factor (0.22 x A25 x A..C35 (t CO2/MWh) 0.0000 0.0000 0.0000

Fraction with heat pump

38 Default 0.07 0.10 0.25

39 Selected 0.00 0.00 0.00

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0028 0.0041 0.0102

41 Selected conversion factor (0.11 x A25 x A..C39 (t CO2/MWh) 0.0000 0.0000 0.0000

Fraction with other heating

42 Default 0.09 0.11 0.05

43 Selected 0.00 0.00 0.00

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0048 0.0059 0.0025

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh) 0.0000 0.0000 0.0000

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.055 0.057 0.063

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh) 0.000 0.053 0.000

48 Adjusted (A..C46/A..C47) 0.00 0.93 0.00

Base Case Adjustment 

49 Default (kWh/m2/yr) 107.0 102.9 77.1

50 Selected (kWh/m2/yr) 0.0 102.9 0.0

51 Adjustment (A..C50/A..C49) 0.00 1.00 0.00

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51) 0.00 1.31 0.00

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change ) 0.10

54 Selected (oC/%Cover change ) 0.10

55 Adjustment (A54 / A55) 1.00

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55) 0.00 1.83 0.00

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51) 0.00 1.16 0.00

Desert Southwest Region
78 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Look-up Table (Long Form) (Table VII)

Regional default values for avoided (Appendix F), sequestered, and released CO2 (Appendix D)

are entered into the Long Form Look-up Table and adjusted for local conditions with factors

calculated in the Long Form Adjustment Table VI. All values are for a mature tree (or maximums)

and in units of tonnes/year. Results from this table are entered into Worksheet 1 (Table VIII).

Shade effects. Calculate adjusted values for changes in CO2 emissions from tree shade and

windbreak effects on heating and cooling (tonnes CO2

/tree/year) by tree type and building

vintage with adjustments for local conditions. In this example adjustment factors for cooling and

heating are taken from Long Form Adjustment Table VI, column B, rows 23 (2.07) and 52 (1.31),

respectively, and entered into Table VII, columns A and D, row 7.

Because a user-supplied tree distribution is used in this example, avoided CO2 values for

shade (Table VII, columns B and E) are taken from table 61, in Appendix F, based on calculations

done using tables 49-60, and 62, in Appendix F. Filled-in examples of tables 49-60 are included at

the end of this chapter in tables 17 to 28. Tree distribution (tables 17, 20, 23, and 26) is described in

the preceding discussion of Table III. Changes in avoided CO2

 values are taken from tables 103 to

106, in Appendix F, for the Desert Southwest Climate Region. These are recorded in tables 50, 53,

56, and 59 in Appendix F, and appear as tables 18, 21, 24, and 27 in the filled-in example. Data in

tables 17, 20, 23, and 26 are multiplied cell by cell with tables 18, 21, 24, and 27, respectively,

resulting in tables 19, 22, 25, and 28 for the example (taken from tables 51, 54, 57, and 60, Appendix

F). These values are used to fill in table 61, in Appendix F (table 29 in the example), post-1980

vintage (rows 13-18). Pre-1950 and 1950-1980 vintage values (table 29, rows 1-12) are based on

post-1980 values and vintage ratios found in table 30 (reproduced from table 62, Appendix F).

In cases where the default tree distribution can be used, calculations are simplified, since

table 107, in Appendix F, would be used to fill in Table VII, columns B and E. In particular,

columns I and J, rows 19-36 of table 107 would be used for the Desert Southwest Climate Region.

In either case, the column products (A1 x Bn, D1 x En, repeated for each vintage) in Table VII

result in adjusted values of avoided CO2

 emissions.

To adjust windbreak effects on heating, apply the same adjustment factor used for shade

effects on heating (Table VII, column D). Energy savings per tree from windbreaks are found in

table 108, in Appendix F.

Because we are using only one vintage type for the Tucson case study, calculations are done

for 1950-1980 vintage only.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 79

Chapter 4 Illustrative Examples

VII. Look-Up Table (Long Form) Project Title: Tucson case study

 Shade Effects: Mature CO2 Savings/tree by Tree Type (t CO2 / tree)

ABC DEF GH

Shade - Cooling Shade - Heating Wind - Heating

Adjust- Avoided Adjusted Adjust- Avoided Adjusted Avoided Adjusted

ment CO2 CO2 ment CO2 CO2 CO2 CO2

 Vintage: Factor (t /tree) (t /tree) Factor (t /tree) (t /tree) (t /tree) (t /tree)

 Pre-1950 (Table 61 (Table 61

n Tree Type1 (VI.A23) or 107) (A1 x Bn) (VI.A52) or 107) (D1 x En) (Table 108) (D1 x Gn)

1 Dec-Large 0.00 0.0497 0.0000 0.00 -0.0041 0.0000

2 Dec-Med. 0.0293 0.0000 -0.0044 0.0000

3 Dec-Small 0.0204 0.0000 -0.0030 0.0000

4 Evr-Large 0.0525 0.0000 -0.0116 0.0000 0.0125 0.0000

5 Evr-Med. 0.0478 0.0000 -0.0172 0.0000 0.0088 0.0000

6 Evr-Small 0.0000 0.0000 0.0000 0.0000 0.0014 0.0000

 Vintage: (Table 61 (Table 61

1950-80 (VI.B23) or 107) (A7 x Bn) (VI.B52) or 107) (D7 x En) (Table 108) (D7 x Gn)

7 Dec-Large 2.07 0.0900 0.1864 1.31 -0.0077 -0.0101

8 Dec-Med. 0.0531 0.1099 -0.0084 -0.0110

9 Dec-Small 0.0369 0.0765 -0.0058 -0.0075

10 Evr-Large 0.0952 0.1970 -0.0221 -0.0289 0.0135 0.0177

11 Evr-Med. 0.0866 0.1793 -0.0326 -0.0428 0.0096 0.0125

12 Evr-Small 0.0000 0.0000 0.0000 0.0000 0.0015 0.0019

 Vintage: (Table 61 (Table 61

Post-1980 (VI.C23) or 107) (A13 x Bn) (VI.C52) or 107) (D13 x En) (Table 108) (D13 x Gn)

13 Dec-Large 0.00 0.0755 0.0000 0.00 -0.0099 0.0000

14 Dec-Med. 0.0445 0.0000 -0.0108 0.0000

15 Dec-Small 0.0310 0.0000 -0.0074 0.0000

16 Evr-Large 0.0798 0.0000 -0.0284 0.0000 0.0128 0.0000

17 Evr-Med. 0.0726 0.0000 -0.0420 0.0000 0.0111 0.0000

18 Evr-Small 0.0000 0.0000 0.0000 0.0000 0.0068 0.0000

1 Dec = deciduous; Evr = evergreen; Med. = medium
80 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Look-up Table (Long Form) (continued)

Climate effects. This portion of Table VII gives CO2 savings (t CO2/tree/year) by vintage

due to air temperature and wind speed reductions that result from an overall increase in canopy

cover. Existing cover consists of trees and buildings pre-dating the program. Results are used in

Worksheet 1.

In this example, cooling and heating adjustment factors are taken from Long Form

Adjustment Table VI, column B, rows 56 and 57 (1.83 and 1.16, respectively) and entered into

columns I and L, row 7 of the Look-up Table. Avoided CO2 values in columns J and M of the

Look-up Table can be estimated directly from table 109, in Appendix F, for existing cover values

of 10 percent, 30 percent, and 60 percent, or linearly interpolated. For example, existing tree and

building cover is 11 percent (Table II, Column A, Row 1), which is between the values of 10

percent and 30 percent listed in table 109, in Appendix F (columns Y to AA, rows 25 to 30 for

cooling). The value listed for 10 percent can be used without much loss in accuracy, but we

illustrate the interpolation process here. Interpolated cooling savings S for a large deciduous tree

and the 1950-1980 vintage is accomplished by first calculating the slope M of the interpolation

line

M = (Sh - Sl)/(Ch - Cl)

where

Sh = savings value associated with existing cover percentage in the Look-up Table that

exceeds the actual cover value (30 percent in this case)

Sl = savings value associated with the existing cover percentage in the Look-up Table that is

less than the actual cover value (10 percent in this case)

Ch= fraction of existing cover from the Look-up Table that exceeds the actual cover value

(0.30 in this case)

Cl

 = fraction of existing cover from the Look-up Table that is less than the actual cover value

(0.10 in this case)

For example, interpolated cooling savings for a large deciduous tree and the 1950-1980

vintage is accomplished by calculating the slope of the line as (0.09387-0.11501)/(0.30-0.10) =

-0.1057. The value M is used in a second calculation to derive the result S

S = M(Ca - Cl) + Sl

where Ca is the actual existing cover fraction (0.11 in this case). In our example, S is calculated

as -0.1057 x (0.11-0.10) + 0.11501 = 0.11396, which is entered into Table VII, column J, row 7. This

interpolation procedure is repeated for each tree type and vintage and for both cooling and

heating. If the existing cover percentage is less than 10 percent or greater than 60 percent, the M

value can be extrapolated on the basis of the slope of the line between the two closest points.

Sequestration, decomposition, and tree program-related emissions.

Mature values of annual sequestration, decomposition, and maintenance emissions per tree

are listed in the Look-up Table for each tree type by Tree Growth Zone. These will be used in the

next section to fill in positions of Worksheet 1 (Table VIII).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 81

Chapter 4 Illustrative Examples

VII. Look-Up Table (Long Form) (continued) Project Title: Tucson case study

Climate Effects: Mature CO2 Savings/tree (t CO2/tree) 11pct existing cover

I J K LMN

Cooling Heating

Adjust- Avoided Adjusted Adjust- Avoided Adjusted

ment CO2 CO2 ment CO2 CO2

 Vintage: Factor Factor

 Pre-1950 (t /tree) (t /tree)

n Tree Type1 (VI.A56) Table 109 (I1 x Jn) (VI.A57) Table 109 (L1 x Mn)

1 Dec-Large 0.0000 0.04654 0.0000 0.0000 0.02477 0.0000

2 Dec-Med. 0.02077 0.0000 0.01106 0.0000

3 Dec-Small 0.00859 0.0000 0.00457 0.0000

4 Evr-Large 0.05640 0.0000 0.03002 0.0000

5 Evr-Med. 0.02817 0.0000 0.01499 0.0000

6 Evr-Small 0.01065 0.0000 0.00567 0.0000

 Vintage: 

1950-80 (VI.B56) Table 109 (I7 x Jn) (VI.B57) Table 109 (L7 x Mn)

7 Dec-Large 1.8284 0.11396 0.2084 1.1585 0.01997 0.0231

8 Dec-Med. 0.05086 0.0930 0.00892 0.0103

9 Dec-Small 0.02103 0.0384 0.00369 0.0043

10 Evr-Large 0.13809 0.2525 0.02420 0.0280

11 Evr-Med. 0.06898 0.1261 0.01209 0.0140

12 Evr-Small 0.02608 0.0477 0.00457 0.0053

 Vintage: 

Post-1980 (VI.C56) Table 109 (I13 x J1n) (VI.C57) Table 109 (L13 x Mn)

13 Dec-Large 0.0000 0.11684 0.0000 0.0000 0.03892 0.0000

14 Dec-Med. 0.05215 0.0000 0.01737 0.0000

15 Dec-Small 0.02156 0.0000 0.00718 0.0000

16 Evr-Large 0.14159 0.0000 0.04717 0.0000

17 Evr-Med. 0.07073 0.0000 0.02356 0.0000

18 Evr-Small 0.02674 0.0000 0.00891 0.0000

 Sequestration, Decomposition and Maintenance Emissions at Maturity by growth zone (t CO2/tree/year)

All Vintages OPQ RST UV

Sequestration Decomposition Maintenance

n Tree Type North Central South North Central South North Central South

1 Dec Large 0.0428 0.1324 0.2937 -0.8754 -2.7107 -6.0188 -0.0051 -0.0078 -0.0106

2 Dec Med 0.0262 0.0665 0.1331 -0.5415 -1.3702 -2.7382 -0.0044 -0.0063 -0.0082

3 Dec Small 0.0055 0.0153 0.0321 -0.1138 -0.3148 -0.6618 -0.0025 -0.0037 -0.0049

4 Evr Large 0.0451 0.1204 0.3028 -0.5807 -2.4449 -6.3920 -0.0047 -0.0084 -0.0121

5 Evr Med 0.0073 0.0495 0.1049 -0.1912 -1.0598 -3.1392 -0.0032 -0.0066 -0.0100

6 Evr Small 0.0011 0.0126 0.0098 -0.0509 -0.2933 -0.8603 -0.0018 -0.0041 -0.0064

 Production and Program-related Emissions for all tree types (t CO2/tree/year)

X Y

n Production Program

1 -0.00069 -0.0026

1 Dec = deciduous; Evr = evergreen; Med. = medium

W
82 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Worksheet I (Long Form) (Table VIII)

In this Worksheet you calculate impacts of trees at maturity (average value for trees ages 36 to 40

years) by multiplying the number of trees planted by a single mature tree’s estimated CO2

uptake or release obtained from the Look-up Table value (Long Form in this example).

Shade effects. First, tree numbers are obtained from Tree Data Table III, column B, and

entered into column A, rows 1-18, of Worksheet 1. The number of trees listed as Windbreak -

Heating in Worksheet 1 (column A, rows 19-27) are copied from above (column A, rows 4-6, 10-

12, and 16-18) for each vintage. Corresponding values of CO2 uptake are copied from Look-up

Table VII, columns C, F, and H, rows 1-18 into columns B and D of the Worksheet. Subtotals are

recorded in column C (Shade-Cooling) by multiplying values in columns A and B for each row.

Round these values to the second digit beyond the decimal point (0.01 t). However, if the analysis is for

very few trees (e.g., less than 10 trees per tree type) round to the third digit (0.001 t).

The subtotals for Shade-Heating are recorded in column E by multiplying values in columns

A and D. The negative values in column E reflect increased space heating consumption and CO2

release associated with obstruction of winter sunlight by tree branches. For the Windbreak -

Heating section of Worksheet 1, Look-up Tables values are obtained from column C, rows 4-6,

10-12, and 16-18 and recorded in Worksheet 1, column B, rows 19-27. Subtotals are recorded in

column C by multiplying values in columns A and B, rows 19-27.

Worksheet I (Long Form) (continued)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 83

Chapter 4 Illustrative Examples

VIII. Worksheet 1 (Long Form)1 Project Title: Tucson case study

 Shade Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2)

A B C DE

 Vintage: no. of Shading

trees

Shade - Cooling Shade - Heating

 Pre-1950 t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type2 (III.Bn) (VII.Cn) (= An x Bn) (VII.Fn) (=An x Dn)

1 Dec-Large 0 0.0000 0.00 0.0000 0.000

2 Dec-Med. 0 0.0000 0.00 0.0000 0.000

3 Dec-Small 0 0.0000 0.00 0.0000 0.000

4 Evr-Large 0 0.0000 0.00 0.0000 0.000

5 Evr-Med. 0 0.0000 0.00 0.0000 0.000

6 Evr-Small 0 0.0000 0.00 0.0000 0.000

 Vintage: 

1950-80 (III.Bn) (VII.Cn) (= An x Bn) (VII.Fn) (=An x Dn)

7 Dec-Large 16 0.1864 2.98 -0.0101 -0.162

8 Dec-Med. 143 0.1099 15.71 -0.0110 -1.566

9 Dec-Small 16 0.0765 1.22 -0.0075 -0.121

10 Evr-Large 92 0.1970 18.12 -0.0289 -2.661

11 Evr-Med. 16 0.1793 2.87 -0.0428 -0.684

12 Evr-Small 0 0.0000 0.00 0.0000 0.000

 Vintage: 

Post-1980 (III.Bn) (VII.Cn) (= An x Bn) (VII.Fn) (=An x Dn)

13 Dec-Large 0 0.0000 0.00 0.0000 0.000

14 Dec-Med. 0 0.0000 0.00 0.0000 0.000

15 Dec-Small 0 0.0000 0.00 0.0000 0.000

16 Evr-Large 0 0.0000 0.00 0.0000 0.000

17 Evr-Med. 0 0.0000 0.00 0.0000 0.000

18 Evr-Small 0 0.0000 0.00 0.0000 0.000

Windbreak - Heating

 Vintage: 

 Pre-1950 no. of Windbreak t CO2/Tree Subtotal

Tree Type Trees (A4..6 ) (VII.H4..6) (= An x Bn)

19 Evr-Large 0 0 0.00

20 Evr-Med. 0 0 0.00

21 Evr-Small 0 0 0.00

 Vintage: 

1950-80 (A10..12 ) (VII.H10..12)

22 Evr-Large 92 0.01773 1.63

23 Evr-Med. 16 0.01253 0.20

24 Evr-Small 0 0.00193 0.00

 Vintage: 

Post-1980 (A16..18 ) (VII.H16..18)

25 Evr-Large 0 0 0.00

26 Evr-Med. 0 0 0.00

27 Evr-Small 0 0 0.00

1 Filled in example of Table VIII taken from Appendix B. See accompanying text for explanation.

2 Dec = deciduous; Evr = evergreen; Med. = medium
84 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Climate effects. This portion of Worksheet 1 gives CO2 savings (t CO2/tree/year) by vintage due

to air temperature and wind speed reductions that result from an overall increase in canopy

cover. Existing cover consists of trees and buildings pre-dating the program.

First, obtain the number of trees from Tree Data Table III, column D, rows 1-6, 8-13, and 15-

20, and enter these values into column F, rows 1-18, of Worksheet 1. Next, on the basis of existing

tree+building canopy cover (Table II, column A, row 1), corresponding values of annual CO2

uptake per tree are obtained for Cooling from Look-up Table VII, column K, rows 1-18 and for

Heating from column N, rows 1-18. Record these values in columns G and I of the Worksheet. In

the Tucson example, these values (t/tree) are for each tree type under the 1950-80 vintage and

correspond with canopy cover increase from the 11 percent existing cover.

Subtotals for Cooling are recorded in column H by multiplying values in column F, rows 1-

18, by the values in column G, rows 1-18. A similar calculation is repeated for subtotaling Heating

in column J of the Worksheet. The numbers in columns H and J are metric tonnes of CO2 avoided

due to Climate effects associated with increased canopy cover by mature trees, assuming no

mortality.

In the next section of this Worksheet, Cooling and Heating values are summed across

building vintages for Shade (columns C and E) and Climate (columns H and J) effects, then

multiplied by electricity emissions adjustment factors obtained from Table II, column A, rows 9

and 10, recorded in columns G and I, row 19 of this Worksheet. The products are recorded for

Cooling (column G rows 20-31), Heating (column I, rows 20-31), and Windbreak (column J, rows

23-25). Values in the shaded cells are used in Worksheet 2.

Worksheet I (Long Form) (continued)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 85

Chapter 4 Illustrative Examples

VIII. Worksheet 1 (Long Form) (continued) Project Title: Tucson case study

Climate Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2) 11 pct existing cover

F G H IJ

 Vintage: Cooling Heating

 Pre-1950 Number of t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type1 Trees (III.D1..6) (VII.Kn) (= Fn x Gn) (VII.Nn) (= Fn x In)

1 Dec-Large 0 0.0000 0.00 0.0000 0.00

2 Dec-Med. 0 0.0000 0.00 0.0000 0.00

3 Dec-Small 0 0.0000 0.00 0.0000 0.00

4 Evr-Large 0 0.0000 0.00 0.0000 0.00

5 Evr-Med. 0 0.0000 0.00 0.0000 0.00

6 Evr-Small 0 0.0000 0.00 0.0000 0.00

 Vintage: 

1950-80 (III.D8..13)

7 Dec-Large 16 0.2084 3.33 0.0231 0.37

8 Dec-Med. 152 0.0930 14.14 0.0103 1.57

9 Dec-Small 19 0.0384 0.73 0.0043 0.08

10 Evr-Large 96 0.2525 24.24 0.0280 2.69

11 Evr-Med. 16 0.1261 2.02 0.0140 0.22

12 Evr-Small 0 0.0477 0.00 0.0053 0.00

 Vintage: 

Post-1980 (III.D15..20)

13 Dec-Large 0 0.0000 0.00 0.0000 0.00

14 Dec-Med. 0 0.0000 0.00 0.0000 0.00

15 Dec-Small 0 0.0000 0.00 0.0000 0.00

16 Evr-Large 0 0.0000 0.00 0.0000 0.00

17 Evr-Med. 0 0.0000 0.00 0.0000 0.00

18 Evr-Small 0 0.0000 0.00 0.0000 0.00

 Total Change in CO2 for all Vintages from Cooling and Heating

Emissions factor adjustment (t CO2/MWh) (t CO2/MBtu)

19 Cooling (II.A9): 3.37 Heating (II.A10): 1.00

Heating

 Shade Effects Totals Cooling Shade Windbreak

Tree Type1 (t CO2) (t CO2) (t CO2)

20 Dec-Large G19x(C1+C7+C13) 10.06 I19x(E1+E7+E13) -0.16

21 Dec-Med. G19x(C2+C8+C14) 52.98 I19x(E2+E8+E14) -1.57

22 Dec-Small G19x(C3+C9+C15) 4.12 I19x(E3+E9+E15) -0.12

23 Evr-Large G19x(C4+C10+C16) 61.10 I19x(E4+E10+E16) -2.66 1.63 I19x(C19+C22+C25) 

24 Evr-Med. G19x(C5+C11+C17) 9.67 I19x(E5+E11+E17) -0.68 0.20 I19x(C20+C23+C26) 

25 Evr-Small G19x(C6+C12+C18) 0.00 I19x(E6+E12+E18) 0.00 0.00 I19x(C21+C24+C27) 

 Climate Effects Totals

26 Dec-Large G19x(H1+H7+H13) 11.24 I19x(J1+J7+J13) 0.37

27 Dec-Med. G19x(H2+H8+H14) 47.66 I19x(J2+J8+J14) 1.57

28 Dec-Small G19x(H3+H9+H15) 2.46 I19x(J3+J9+J15) 0.08

29 Evr-Large G19x(H4+H10+H16) 81.72 I19x(J4+J10+J16) 2.69

30 Evr-Med. G19x(H5+H11+H17) 6.80 I19x(J5+J11+J17) 0.22

31 Evr-Small G19x(H6+H12+H18) 0.00 I19x(J6+J12+J18) 0.00

1 Dec = deciduous; Evr = evergreen; Med. = medium
86 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

Sequestration, decomposition, and tree program-related emissions. First, obtain the total

number of trees planted by tree type from Tree Data Table III, column D, rows 22-28, and record

these numbers in column K, rows 1-7, of Worksheet 1. Next, obtain Look-up Table values for

Sequestration, Decomposition, Maintenance (Table VII, Long Form: columns O - W, rows 1-6; see

next paragraph for selection details), Tree Production, and Tree Program (Table VII, Long Form:

columns X and Y, row 1), and enter them in columns L, N, and P of Worksheet 1. Multiply tree

numbers in column K by the corresponding values in Columns L, N, and P to calculate totals for

each tree type. Totals for Decomposition, Maintenance, Tree Production, and Tree Program are

negative values because CO2

 is released. Sequestration values in column M, rows 1-6, are

positive.

Mature values of annual sequestration, decomposition, and maintenance emissions per tree

are listed in the Look-up Table for each tree type by Tree Growth Zone. Three Tree Growth Zones

(North, Central, and South) are shown on the basis of mean length of the frost-free period.

Default Tree Growth Zones are established for each Climate Region on the basis of geographic

and demographic similarities (tables 11, or table 33 in Appendix D). However, there are cases

where boundaries do not coincide and the default Tree Growth Zone does not match the map

(see Appendix D). Consult the Tree Growth Zone map (fig. 18, or fig. 25, in Appendix D) to

determine if the Zone for your location matches the default Zone for your Climate Region. If it

does not match, you can select a different Zone to customize the subsequent calculations. In this

example, the default Tree Growth Zone for the Desert Southwest Climate Region is South, and

this matches the Tree Growth Zone shown on the Tree Growth Zone map for Tucson.

On the basis of a South Tree Growth Zone for this example, enter data from Look-Up Table

columns Q, T and W into Worksheet 1. Adjustments are not made to tree production and

program-related emissions because they are a very small percentage of overall emissions. Hence,

values shown in Look-Up Table columns X and Y will be entered into Worksheet 1 (see Appendix

D for information on default values).

Worksheet 2 (Table IX)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 87

Chapter 4 Illustrative Examples

K LM NO PQ

Sequestration Decomposition Maintenance

Total no. of trees

Sequestration, Decomposition and Program-related Emissions (Emission values are negative)

t CO2/tree Total t CO2 t CO2/tree Total t CO2 t CO2/tree Total t CO2

n Tree Type (III.D22..27) (VII.O1..Q6) (= Kn x Ln) (VII.R1..T6) (= Kn x Nn) (V.U1..W6) (= Kn x Pn)

1 Dec-Large1 16 0.2937 4.70 -6.0188 -96 -0.0106 -0.17

2 Dec-Med. 152 0.1331 20.23 -2.7382 -416 -0.0082 -1.25

3 Dec-Small 19 0.0321 0.61 -0.6618 -13 -0.0049 -0.09

4 Evr-Large 96 0.3028 29.06 -6.3920 -614 -0.0121 -1.16

5 Evr-Med. 16 0.1049 1.68 -3.1392 -50 -0.0100 -0.16

6 Evr-Small 0 0.0098 0.00 -0.8603 0 -0.0064 0.00

Tree Production Tree Program

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2

(III.D28) (VII.X1) (= K7 x L7) (VII.Y1) (= K7 x N7)

7 All Trees 299 -0.00069 -0.21 -0.0026 -0.78

1Filled in example of Table VIII taken from Appendix A. See accompanying text for explanation.

2 Dec = deciduous; Evr = evergreen; Med. = medium

VIII. Worksheet 1 (Long Form) (continued) Project Title: Tucson case study

South tree growth zone
88 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

In Worksheet 2, CO2 reductions and releases are calculated for each 5-year period and totaled for

the entire 40 years. Mature tree values in Worksheet 1 are annual totals. Each value is multiplied

by 5 to compute 5-year totals, then copied into column J of Worksheet 2. For example, values for

Shade-Cooling in Worksheet 2, column J, rows 1-6, are obtained from Worksheet 1, column G,

rows 20-25. Shade-Heating values (Worksheet 2, column J, rows 10-15) are obtained from

Worksheet 1, column I, rows 20-25. Windbreak-Heating values (Worksheet 2, column J, rows 17-

19) are obtained from Worksheet 1, column J, rows 23-25. Values for Climate Effects (Worksheet

2, column J, rows 24-29 and 31-36) are obtained from Worksheet 1, column G, rows 26-31, and

column I, rows 26-31. Similarly, values for Sequestration, Decomposition, and Maintenance are

obtained from Worksheet 1, columns M, O, and Q, rows 1-6. Tree Production and Program values

are obtained from columns M and O, row 7. All values are multiplied by 5 before they are entered

into column J of Worksheet 2.

To back-calculate values for each 5-year period, Age/Survival fractions are obtained from

Appendix H and entered into rows 1, 9, 23, 39, 47, 55, and 63 of Worksheet 2. Age-survival

fractions are selected from tables 113-115, 116-118, and 119-121, in Appendix H, for North,

Central, and South Tree Growth Zones, respectively. A Tree Growth Zone is designated for each

climate region (table 11, or table 33 in Appendix D). In this example, the South Tree Growth Zone

corresponds to the Desert Southwest Climate Region, so tables 119-121, in Appendix H, are

selected.

Normally, tree mortality is greatest during the first years of establishment; the literature

indicates that nearly half of total tree mortality occurs during the initial establishment period. In

the case of the Palo Verde site in Tucson, the contractor has replaced all dead or dying trees

during the first three growing seasons. This replacement policy should result in relatively high

survival rates for the 5-year establishment period, so we select the high survival rate for this

example (table 120, in Appendix H). Appendix H can also be used to derive customized Tree AgeSurvival tables.

Application of combined tree age/survival data to mature values of CO2

 savings emissions is

illustrated by example. Beginning with Worksheet 2, column A, row 2, multiply the percentage in

column A, row 1 (0.09) times the corresponding value in Worksheet 2, column J, row 2 (50.3). The

product, 4.5, a 5-year total, is recorded in column A, row 2 of Worksheet 2. This procedure is

repeated for each 5-year time period until columns B-H are filled. The values recorded in

columns A-H, row 2, are then summed, and the total (199) is listed in column I.

This process is followed for the remaining rows. In each case, Age/Survival fractions listed

in each section of Worksheet 2 are multiplied by the mature tree values from column J of the

corresponding row in Worksheet 2. The resulting value is recorded in a Worksheet 2 cell that is in

the same column as the Age/Survival fraction and row of the CO2

 savings/emissions value.

 To calculate the cost of conserved CO2, first total the planting and stewardship costs listed in

Table IV, $111,589 in this example, and record this value in column F, row 69. Next, total the CO2

reductions and release in column I, row 68, to obtain total net CO2 benefit for the 40-year period.

Record this value 5,966 in column F, row 70. Divide total program costs by total net CO2 saved,

and record the result $19/tonne in Worksheet 2, column J, row 70.

Tucson Case Study Summary
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 89

Chapter 4 Illustrative Examples

IX. Worksheet 2 5 year total CO2 Savings and Emissions (t CO2)

1 Project Title: Tucson case study 

High Survival A BCDEFGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Shade-Cooling

1 Age/survival fraction 0.09 0.25 0.40 0.51 0.61 0.66 0.70 0.74

2 Dec-Large2 4.5 12.6 20.1 25.7 30.7 33.2 35.2 37.2 199 50.3

3 Dec-Medium 23.8 66.2 106.0 135.1 161.6 174.8 185.4 196.0 1,049 264.9

4 Dec-Small 1.9 5.2 8.2 10.5 12.6 13.6 14.4 15.2 82 20.6

5 Evr-Large2 27.5 76.4 122.2 155.8 186.4 201.6 213.9 226.1 1,210 305.5

6 Evr-Medium 4.4 12.1 19.4 24.7 29.5 31.9 33.9 35.8 192 48.4

7 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

8 Shade Cool subtotal 62.1 172.5 275.9 351.8 420.8 455.1 482.8 510.3 2,731

 Shade:Heating

9 Age/survival fraction 0.33 0.50 0.65 0.67 0.70 0.70 0.70 0.70

10 Dec-Large -0.3 -0.5 -0.7 -0.7 -0.7 -0.7 -0.7 -0.7 -5 -1

11 Dec-Medium -2.6 -4.0 -5.1 -5.3 -5.5 -5.5 -5.5 -5.5 -39 -7.9

12 Dec-Small -0.2 -0.3 -0.4 -0.4 -0.4 -0.4 -0.4 -0.4 -3 -0.6

13 Evr-Large -4.4 -6.7 -8.6 -8.9 -9.3 -9.3 -9.3 -9.3 -66 -13.3

14 Evr-Medium -1.1 -1.7 -2.2 -2.3 -2.4 -2.4 -2.4 -2.4 -17 -3.4

15 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

16 Subtotal -8.6 -13.2 -17.0 -17.6 -18.3 -18.3 -18.3 -18.3 -130

Windbreak-Heating

17 Evr-Large 2.7 4.1 5.3 5.5 5.7 5.7 5.7 5.7 40 8.2

18 Evr-Medium 0.3 0.5 0.7 0.7 0.7 0.7 0.7 0.7 5 1

19 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

20 Subtotal 3.0 4.6 6.0 6.2 6.4 6.4 6.4 6.4 45

21 Shade Heat subtotal -5.6 -8.6 -11.0 -11.4 -11.9 -11.9 -11.9 -11.9 -84

22 Total Shade 56.5 163.9 264.9 340.4 408.9 443.2 470.9 498.4 2,647

 Climate-Cooling

23 Age/survival fraction 0.02 0.11 0.23 0.36 0.47 0.56 0.63 0.68

24 Dec-Large 1.1 6.2 12.9 20.2 26.4 31.5 35.4 38.2 172 56.2

25 Dec-Medium 4.8 26.2 54.8 85.8 112.0 133.4 150.1 162.0 729 238.3

26 Dec-Small 0.2 1.4 2.8 4.4 5.8 6.9 7.7 8.4 38 12.3

27 Evr-Large 8.2 44.9 94.0 147.1 192.0 228.8 257.4 277.8 1,250 408.6

28 Evr-Medium 0.7 3.7 7.8 12.2 16.0 19.0 21.4 23.1 104 34

29 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

30 Subtotal 15.0 82.4 172.3 269.7 352.2 419.6 472.0 509.5 2,293

 Climate-Heating

31 Dec-Large 0.0 0.2 0.4 0.7 0.9 1.1 1.2 1.3 6 1.9

32 Dec-Medium 0.2 0.9 1.8 2.8 3.7 4.4 5.0 5.4 24 7.9

33 Dec-Small 0.0 0.0 0.1 0.1 0.2 0.2 0.3 0.3 1 0.4

34 Evr-Large 0.3 1.5 3.1 4.9 6.3 7.6 8.5 9.2 41 13.5

35 Evr-Medium 0.0 0.1 0.3 0.4 0.5 0.6 0.7 0.7 3 11

36 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

37 Subtotal 0.5 2.7 5.7 8.9 11.6 13.9 15.7 16.9 76

38 Total Climate 15.5 85.1 178.0 278.6 363.8 433.5 487.7 526.4 2,369
90 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

IX. Worksheet 2 (continued) 5 year total CO2 Savings and Emissions (t CO2) Project Title: Tucson case study

High Survival A B C D E F GH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Sequestration

39 Age/survival fraction 0.08 0.34 0.61 0.73 0.72 0.62 0.50 0.39

40 Dec-Large 1.9 8.0 14.3 17.2 16.9 14.6 11.8 9.2 94 23.5

41 Dec-Medium 8.1 34.4 61.7 73.9 72.9 62.7 50.6 39.5 404 101.2

42 Dec-Small 0.2 1.1 1.9 2.3 2.2 1.9 1.6 1.2 12 3.1

43 Evr-Large 11.6 49.4 88.6 106.1 104.6 90.1 72.7 56.7 580 145.3

44 Evr-Medium 0.7 2.9 5.1 6.1 6.0 5.2 4.2 3.3 33 8.4

45 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

46 Total Sequestered 22.5 95.8 171.6 205.6 202.6 174.5 140.9 109.9 1,123

 Tree Decomposition

47 Age/survival fraction 0.0003 0.0003 0.0009 0.0018 0.0028 0.0036 0.0044 0.0050

48 Dec-Large -0.1 -0.1 -0.4 -0.9 -1.3 -1.7 -2.1 -2.4 -9 -481.5

49 Dec-Medium -0.6 -0.6 -1.9 -3.7 -5.8 -7.5 -9.2 -10.4 -40 -2,081.1

50 Dec-Small 0.0 0.0 -0.1 -0.1 -0.2 -0.2 -0.3 -0.3 -1 -62.9

51 Evr-Large -0.9 -0.9 -2.8 -5.5 -8.6 -11.0 -13.5 -15.3 -59 -3,068.2

52 Evr-Medium -0.1 -0.1 -0.2 -0.5 -0.7 -0.9 -1.1 -1.3 -5 -251.2

53 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

54 Decomposition Total -1.7 -1.7 -5.4 -10.7 -16.6 -21.3 -26.2 -29.7 -113

 Tree Maintenance

55 Age/survival fraction 0.11 0.27 0.41 0.52 0.59 0.64 0.67 0.68

56 Dec-Large -0.1 -0.2 -0.4 -0.5 -0.5 -0.6 -0.6 -0.6 -4 -0.9

57 Dec-Medium -0.7 -1.7 -2.6 -3.3 -3.7 -4.0 -4.2 -4.3 -25 -6.3

58 Dec-Small -0.1 -0.1 -0.2 -0.3 -0.3 -0.3 -0.3 -0.3 -2 -0.5

59 Evr-Large -0.6 -1.6 -2.4 -3.0 -3.4 -3.7 -3.9 -3.9 -22 -5.8

60 Evr-Medium -0.1 -0.2 -0.3 -0.4 -0.5 -0.5 -0.5 -0.5 -3 -0.8

61 Evr-Small 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0

62 Tree Maint. Total -1.6 -3.8 -5.9 -7.5 -8.4 -9.1 -9.5 -9.6 -55

 Program-related Emissions

63 Age/survival fraction 0.85 0.00 0.00 0.00 0.00 0.00 0.00 0.00

64 Tree Production -0.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -1 -1.1

65 Tree Program -3.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -3 -3.9

66 Prod/Program Total -4.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -4

67 Total Released -7.5 -5.5 -11.3 -18.2 -25.0 -30.4 -35.7 -39.3 -173

68 Net CO2 Saved 87.0 339.3 603.2 806.4 950.3 1,020.8 1,063.8 1,095.4 5,966

69 Cost of conserved CO2 = Total program cost (IV.A5): $111,589

70 divided by Net CO2 saved (I68,tonnes): 5,966 = $19/ tonne

 1 Filled in example of Table IX taken from Appendix B.

 2 Dec = deciduous; Evr = evergreen
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 91

Chapter 4 Illustrative Examples

-2 

0 

2 

4 

6 

8 

10 

tonnes 

Hundreds CO2

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

years

Shade-Cooling Shade-Heating Climate-Cooling Climate-Heating

Sequestration Total Released Net CO2 Saved 

12 

Projected net CO2 savings for this example is estimated at 5,966 t. Savings from avoided energy

use are 84 percent (5,016 t) of the net benefit. Sequestration (1,123 t) less total releases (173 t)

comprise the remaining 16 percent (fig. 23). Cost of conserved carbon, defined as program costs

($111,589) divided by net CO2

 savings over the 40-year analysis period, are estimated as $19/t

CO2

. This relatively high cost reflects greater-than-normal establishment costs. Expenditures for

large boxed trees and installation of a new irrigation system might not be incurred by other

programs.

Net CO2

 benefits increase with time for the entire 40-year analysis period as trees mature. The

relatively high survival rate assumed in this example contributes to the duration of this gradual

increase. A lower survival rate would result in a slow decline in later years due to reduced

benefits from avoided emissions and sequestration, as well as increased rates of release through

decomposition.

The penalty associated with winter shade is less than 5 percent of cooling savings from

summer shade. The cooling savings due to Climate modification (2,293 tonnes) is approximately

the same magnitude as cooling savings from Shade (2,731 tonnes). This result reflects the large

canopy cover increase (34 percent) and resulting air temperature reduction expected after 40

years.

Figure 23—Projected CO2 savings (+) and releases (-) for each 5-year period in Tucson.
92 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

N NE E SE S SW W NW

A B C D E FG H

1 Large 3-6 m 0.00 0.00 6.69 0.00 7.82 31.95 8.84 3.65

2 Deciduous

3

6

6-12 m 0.00 0.00 0.00 2.02 0.00 5.45 9.07 0.00

12-18 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

4 Medium 3-6 m 0.05 0.56 2.25 1.20 5.42 11.79 10.64 0.61

5 Deciduous 6-12 m 0.00 0.02 1.31 0.39 1.23 3.19 5.04 0.16

12-18 m 0.00 0.00 0.23 0.06 0.09 0.22 0.00 0.02

7 Small 3-6 m 0.08 0.00 13.14 0.00 1.71 5.43 9.54 1.05

8 Deciduous

9

6-12 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

12-18 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m 3.0 45.0 107.1 64.6 62.6 73.0 141.4 58.5

Deciduous 6-12 m 0.6 9.2 98.0 32.4 50.6 43.6 145.1 13.9

12-18 m 0.0 0.8 72.9 14.0 20.1 24.1 117.4 5.0

Medium 3-6 m 3.6 20.2 81.7 34.8 56.2 42.7 118.7 29.5

Deciduous 6-12 m 0.0 1.4 63.1 11.4 22.3 21.0 104.4 5.9

12-18 m 0.0 0.4 33.7 4.6 6.9 10.6 68.9 3.1

Small 3-6 m 1.4 2.7 44.7 11.4 29.1 18.5 81.1 8.9

Deciduous 6-12 m 0.0 0.7 26.3 3.6 7.5 8.6 57.9 4.3

12-18 m 0.0 0.1 10.5 1.1 0.0 3.3 32.9 1.6

Calculation of mean avoided emissions from direct shading for deciduous trees

Project Title: Tucson case study

Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m 0.0 0.0 6.3 0.0 12.5 43.8 6.3 6.3

Deciduous 6-12 m 0.0 0.0 0.0 6.3 0.0 12.5 6.3 0.0

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

100

100

Medium 3-6 m 1.4 2.8 2.8 3.4 9.7 27.6 9.0 2.1

Deciduous 6-12 m 0.0 1.4 2.1 3.4 5.5 15.2 4.8 2.8

12-18 m 0.0 0.0 0.7 1.4 1.4 2.1 0.0 0.7

Small 3-6 m 5.9 0.0 29.4 0.0 5.9 29.4 11.8 11.8

Deciduous 6-12 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

12-18 m 0.0 0.0 0.0 0.0 5.9 0.0 0.0 0.0

- cooling

Table 19—Mean change in cooling (kg CO2/tree) for mature deciduous trees. Multiply Table 17 x Table 18 cell by cell, then

sum by tree size.

Completed Tables from Appendices F and H for Use with Long Form Look-up Table in

Example 2.

Tree distributions determined from aerial photos and ground sampling for the Tucson case

study are recorded in tables 17 and 23 for deciduous trees and tables 20 and 26 for evergreen trees

(based on tables 49 and 55, tables 52 and 58, respectively, in Appendix F). Each cell of these tables

is multiplied by the corresponding cell in tables 18 and 24 for deciduous trees and tables 21 and 27

for evergreen trees, in which avoided emissions per mature tree by azimuth, tree size and

direction for the post 1980 vintage are recorded (taken from tables 50 and 56, tables 53 and 59, in

Appendix F). Products are recorded in tables 19 and 25 for deciduous trees and tables 22 and 28

for evergreen trees; weighted averages result when products are summed for each tree size in

table 29. These weighted averages are entered into Long Form Lookup Tables (Table VII). Tree

Age/Survival fractions for South Growth Zone and High Survival Rate are taken from table 120,

in Appendix H.

Table 17—User supplied deciduous tree distribution (pct).

Table 18—Change in emissions from avoided cooling (kg CO2

/tree), mature deciduous trees.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 93

Chapter 4 Illustrative Examples

N NE E SE S SW W NW

3-6 m 0.00 0.61 0.00 0.92 6.86 21.55 17.01 0.79

6-12 m 0.00 1.45 5.00 0.61 0.76 5.87 7.24 1.20

12-18 m 0.00 0.05 3.83 0.25 0.00 2.59 3.00 0.19

3-6 m 0.00 0.00 0.00 3.36 18.89 15.99 18.26 2.70

6-12 m 0.00 0.00 0.00 0.00 0.00 4.59 8.38 0.45

12-18 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

3-6 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6-12 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

12-18 m 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A B C D E FG H

1 Large

2 Evergreen

3

6

4 Medium

5 Evergreen

7 Small

8 Evergreen

9

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m 3.1 56.8 119.4 85.5 79.7 95.4 158.2 73.5

Evergreen 6-12 m 1.3 19.2 116.4 56.3 71.1 68.3 168.4 28.0

12-18 m 0.0 1.0 89.0 23.2 33.6 40.2 139.6 5.8

Medium 3-6 m 3.9 30.3 103.7 53.8 75.6 64.0 146.1 43.3

Evergreen 6-12 m 0.0 2.5 83.7 21.7 43.5 36.8 134.0 7.2

12-18 m 0.0 0.6 52.8 10.7 13.6 20.0 96.0 3.6

Small 3-6 m 1.1 0.9 22.3 7.4 12.6 17.1 59.9 6.1

Evergreen 6-12 m 0.0 0.3 8.0 1.4 0.3 5.6 33.9 2.2

12-18 m 0.0 0.1 2.4 0.3 0.0 1.4 18.6 0.9

Calculation of mean avoided emissions from direct shading for evergreen trees - cooling

Project Title: Tucson case study

Mature tree (40 yr) Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m 0.0 1.1 0.0 1.1 8.6 22.6 10.8 1.1

Evergreen 6-12 m 0.0 7.5 4.3 1.1 1.1 8.6 4.3 4.3

12-18 m 1.1 5.4 4.3 1.1 0.0 6.5 2.2 3.2 100

Medium 3-6 m 0.0 0.0 0.0 6.3 25.0 25.0 12.5 6.3

Evergreen 6-12 m 0.0 0.0 0.0 0.0 0.0 12.5 6.3 6.3

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

Small 3-6 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Evergreen 6-12 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Table 22—Mean change in cooling (kg CO2/tree) for mature evergreen trees. Multiply Table 20 x Table 21 cell by cell, then

sum by tree size.

Table 21—Change in emissions from avoided cooling (kg CO2

/tree), mature evergreen trees.

Table 20—User supplied evergreen tree distribution (pct).
94 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

N NE E SE S SW W NW

3-6 m 0.000 0.000 -0.319 0.000 -1.804 -4.353 -0.484 -0.192

6-12 m 0.000 0.000 0.000 -0.676 0.000 -1.654 -0.433 0.000

12-18 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

3-6 m -0.000 -0.032 -0.184 -0.300 -1.986 -2.963 -0.867 -0.048

6-12 m 0.000 -0.000 -0.102 -0.357 -1.188 -1.808 -0.363 -0.000

12-18 m 0.000 0.000 -0.015 -0.139 -0.169 -0.232 0.000 -0.000

3-6 m -0.000 0.000 -1.894 0.000 -1.171 -3.093 -1.230 -0.000

6-12 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

12-18 m 0.000 0.000 0.000 0.000 -0.019 0.000 0.000 0.000

A B C D E FG H

1 Large

2 Deciduous

3

6

4 Medium

5 Deciduous

7 Small

8 Deciduous

9

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m -0.0 -1.6 -5.1 -8.6 -14.4 -9.9 -7.7 -3.1

Deciduous 6-12 m -0.0 -0.6 -5.3 -10.8 -25.5 -13.2 -6.9 -1.3

12-18 m -0.0 -0.0 -2.4 -12.8 -21.4 -14.2 -2.9 -0.0

Medium 3-6 m -0.0 -1.2 -6.7 -8.7 -20.6 -10.7 -9.7 -2.3

Deciduous 6-12 m -0.0 -0.0 -4.9 -10.4 -21.5 -11.9 -7.5 -0.0

12-18 m -0.0 -0.0 -2.2 -10.1 -12.2 -11.2 -3.8 -0.0

Small 3-6 m -0.0 -0.0 -6.4 -7.4 -19.9 -10.5 -10.5 -0.0

Deciduous 6-12 m -0.0 -0.0 -3.4 -7.2 -12.9 -9.5 -6.3 -0.0

12-18 m -0.0 -0.0 -0.9 -4.9 -0.3 -6.6 -2.6 -0.0

Table 24—Change in emissions from avoided heating (kg CO2/tree), mature deciduous trees.

Calculation of mean avoided emissions from direct shading for deciduous trees - heating

Project Title: Tucson case study

Tree Azimuth

Tree size Distance N NE E SE S SW W NW

Large 3-6 m 0.0 0.0 6.3 0.0 12.5 43.8 6.3 6.3

Deciduous 6-12 m 0.0 0.0 0.0 6.3 0.0 12.5 6.3 0.0

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

Medium 3-6 m 1.4 2.8 2.8 3.4 9.7 27.6 9.0 2.1

Deciduous 6-12 m 0.0 1.4 2.1 3.4 5.5 15.2 4.8 2.8

12-18 m 0.0 0.0 0.7 1.4 1.4 2.1 0.0 0.7

NW

100

Small 3-6 m 5.9 0.0 29.4 0.0 5.9 29.4 11.8 11.8

Deciduous 6-12 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

12-18 m 0.0 0.0 0.0 0.0 5.9 0.0 0.0 0.0 100

Table 25—Mean change in heating (kg CO2/tree) for mature deciduous trees. Multiply Table 23 x Table 24 cell by cell, then

sum by tree size.

Table 23—User supplied deciduous tree distribution (pct).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 95

Chapter 4 Illustrative Examples

N NE E SE S SW W NW

3-6 m 0.000 -0.051 0.000 -0.315 -4.694 -7.636 -2.708 -0.101

6-12 m 0.000 -0.190 -0.906 -0.444 -1.156 -4.007 -1.187 -0.242

12-18 m -0.000 -0.000 -0.518 -0.534 0.000 -3.428 -0.288 -0.000

3-6 m 0.000 0.000 0.000 -2.046 -19.239 -9.285 -4.060 -0.492

6-12 m 0.000 0.000 0.000 0.000 0.000 -5.471 -1.390 -0.000

12-18 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

3-6 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

6-12 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

12-18 m 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

A B C D E FG H

1 Large

2 Evergreen

3

6

4 Medium

5 Evergreen

7 Small

8 Evergreen

9

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m -0.0 -4.7 -17.7 -29.3 -54.6 -33.8 -25.2 -9.4

Evergreen 6-12 m -0.0 -2.5 -21.1 -41.3 -107.5 -46.6 -27.6 -5.6

12-18 m -0.0 -0.0 -12.0 -49.6 -94.3 -53.1 -13.4 -0.0

Medium 3-6 m -0.0 -3.9 -23.3 -32.7 -77.0 -37.1 -32.5 -7.9

Evergreen 6-12 m -0.0 -0.0 -18.4 -40.5 -95.5 -43.8 -22.2 -0.0

12-18 m -0.0 -0.0 -7.8 -41.7 -64.7 -44.2 -9.5 -0.0

Small 3-6 m -0.0 -0.0 -13.2 -14.3 -52.3 -22.7 -23.1 -0.0

Evergreen 6-12 m -0.0 -0.0 -4.6 -11.9 -3.5 -16.3 -10.4 -0.0

12-18 m -0.0 -0.0 -1.1 -5.0 -0.0 -6.1 -3.4 -0.0

Calculation of mean avoided emissions from direct shading for evergreen trees - heating

Project Title: Tucson case study

Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m 0.0 1.1 0.0 1.1 8.6 22.6 10.8 1.1

Evergreen 6-12 m 0.0 7.5 4.3 1.1 1.1 8.6 4.3 4.3

12-18 m 1.1 5.4 4.3 1.1 0.0 6.5 2.2 3.2 100

Medium 3-6 m 0.0 0.0 0.0 6.3 25.0 25.0 12.5 6.3

Evergreen 6-12 m 0.0 0.0 0.0 0.0 0.0 12.5 6.3 6.3

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

Small 3-6 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Evergreen 6-12 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

12-18 m 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

Table 28—Mean change in heating (kg CO2/tree) for mature evergreen trees. Multiply Table 26 x Table 27 cell by cell, then

sum by tree size.

Table 27—Change in emissions from avoided heating (kg CO2

/tree), mature evergreen trees.

Table 26—User supplied evergreen tree distribution (pct).
96 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Chapter 4 Illustrative Examples

A B CD

Cooling Heating

Climate Region pre-1950 1950-1980 pre-1950 1950-1980

1 Mid-Atlantic 0.74 1.13 0.99 1.22

2 Northern Tier 1.59 0.89 1.22 0.68

3 North Central 0.98 0.53 0.94 0.71

4 Mountains 0.43 0.51 0.40 0.66

5 Southeast 0.52 0.68 0.63 0.71

6 South Central 0.64 1.05 0.65 0.76

7 Pacific Northwest 0.28 0.34 1.03 0.90

8 Gulf Coast/Hawaii 0.87 1.45 0.66 0.75

9 California Coast 0.36 0.39 0.38 0.36

10 Southwest 1.35 1.61 0.68 1.25

11 Desert Southwest 0.66 1.19 0.41 0.78 1

This table is reproduced from table 62, Appendix F.

Table 30—Cooling and heating vintage factors1.

Project Title: Tucson case study

 Vintage: Pre-1950 A

n Tree Type2 Cooling

1 Large-Dec (= A13 x Table 30:An/1000) 0.0497 (= B13 x Table 30:Cn/1000) 

2 Med.-Dec (= A14 x Table 30:An/1000) 0.0293 (= B14 x Table 30:Cn/1000) 

3 Small-Dec (= A15 x Table 30:An/1000) 0.0204 (= B15 x Table 30:Cn/1000) 

4 Large Evr (= A16 x Table 30:An/1000) 0.0525 (= B16 x Table 30:Cn/1000) 

5 Med-.Evr (= A17 x Table 30:An/1000) 0.0478 (= B17 x Table 30:Cn/1000) 

6 Small-Evr (= A18 x Table 30:An/1000) 0.0000 (= B18 x Table 30:Cn/1000) 

 Vintage: 1950-80

7 Large-Dec (= A13 x Table 30:Bn/1000) 0.0900 (= B13 x Table 30:Dn/1000) 

8 Med.-Dec (= A14 x Table 30:Bn/1000) 0.0531 (= B14 x Table 30:Dn/1000) 

9 Small-Dec (= A15 x Table 30:Bn/1000) 0.0369 (= B15 x Table 30:Dn/1000) 

10 Large Evr (= A16 x Table 30:Bn/1000) 0.0952 (= B16 x Table 30:Dn/1000) 

11 Med-.Evr (= A17 x Table 30:Bn/1000) 0.0866 (= B17 x Table 30:Dn/1000) 

12 Small-Evr (= A18 x Table 30:Bn/1000) 0.0000 (= B18 x Table 30:Dn/1000) 

 Vintage: Post-1980

13 Large-Dec (= Sum Table 19:A1..H3/1000) 0.0755 (= Sum Table 25:A1..H3/1000) 

14 Med.-Dec (= Sum Table 19:A4..H6/1000) 0.0445 (= Sum Table 25:A4..H6/1000)

15 Small-Dec (= Sum Table 19:A7..H9/1000) 0.0310 (= Sum Table 25:A7..H9/1000)

16 Large Evr (= Sum Table 22:A1..H3/1000) 0.0798 (= Sum Table 28:A1..H3/1000) 

17 Med-.Evr (= Sum Table 22:A4..H6/1000) 0.0726 (= Sum Table 28:A4..H6/1000)

18 Small-Evr (= Sum Table 22:A7..H9/1000) 0.0000 (= Sum Table 28:A7..H9/1000)

1Based on Table 61, Appendix F.

2Dec = deciduous; Evr = evergreen; Med. = medium

B

Heating

-0.0041

-0.0044

-0.0030

-0.0116

-0.0172

0.0000

-0.0077

-0.0084

-0.0058

-0.0221

-0.0326

0.0000

-0.0099

-0.0108

-0.0074

-0.0284

-0.0420

0.0000

Table 29—Sum of mean change in cooling and heating (t CO2/tree) for mature trees 1.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 97

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USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 103

Appendix A

Short Form Data Input Forms and Look-up Tables

I. Background Information

Name: Date:

Organization:

Project Title:

Project Location:

Goals of the Analysis:

Project Description:

II. Site and Building Data A B C

1 Existing Tree + Building Cover (percent)

2 Default Home Vintage Names pre-1950 1950-80 post-1980

3 Selected Home Vintage Names

4 Regional default home distribution by vintage

5 Selected distribution of homes by vintage

6 Climate Region

7 Default electricity emissions factor

8 Selected electricity emissions factor

9 Cooling emissions factor adjustment (EC) (= Row8 / Row7)

10 Heating emissions factor adjustment (EH) (= 1+(Row9 -1) x hc 1.0 )
104 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

Climate region

Existing

cover

(pct)

Home distribution by vintage (pct)

Pre-1950 1950-1980 Post-1980

Tree

growth

zone

Electricity

emissions

factor

Heating

correction

factor (he)

Mid-Atlantic 41 30 58 12 Central .605 0.13

Northern Tier 33 45 42 13 North .612 0.03

North Central 36 42 48 10 North .635 0.09

Mountains 56 42 48 10 North .908 0.09

Southeast 67 28 54 18 Central .545 0.17

South Central 52 19 63 18 Central .671 0.32

Pacific Northwest 54 30 58 12 Central .128 0.17

Gulf Coast/Hawaii 51 19 63 18 South .655 0.32

California Coast 44 28 54 18 South .343 0.17

Southwest 40 28 54 18 Central .523 0.17

Desert Southwest 34 19 63 18 South .377 0.32

1

Originally displayed in chapter 4; also reproduced in Appendix B.

Percentage by size and vintage (pct)

Pre-1950 1950-1980 Post-1980 Total

Large 1.2 8.2 14.7 24.1

Medium 1.7 12.1 39.3 53.1

Small 0.6 6.6 15.6 22.8

Total 3.5 26.9 69.6 100.0 1Originally displayed in chapter 4; also reproduced

 in Appendix B.

To Convert from: To: Multiply by:

acres hectares 0.4047

square miles hectares 259.01

square feet hectares 9.29 x 10-6

square kilometers hectares 100

kBtu kWh 0.293

Therm MBtu (natural gas) 0.10

1

Originally displayed in chapter 4; also reproduced in Appendix B.

Table 101—Conversion factors.

Table 111—Default values for short form by region and growth zone.

Table 121—Distribution of Sacramento Shade trees. This distribution can be

applied to deciduous and evergreen plantings.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 105

Appendix A Short Form Data Input Forms and Look-up Tables

 Project Title: 

 III. Tree Data: Tree Numbers by Type

AB C D

Vintage: Pre-1950

Tree Type1 Near Far Total

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

7 Total

Vintage: 1950-1980

Tree Type Near Far Total

8 Dec-Large

9 Dec-Med.

10 Dec-Small

11 Evr-Large

12 Evr-Med.

13 Evr-Small

14 Total

Vintage: Post-1980

Tree Type Near Far Total

15 Dec-Large

16 Dec-Med.

17 Dec-Small

18 Evr-Large

19 Evr-Med.

20 Evr-Small

21 Total

Total - All Vintages

Tree Type Near Far Total

22 Dec-Large

23 Dec-Med.

24 Dec-Small

25 Evr-Large

26 Evr-Med.

27 Evr-Small

28 Total

1

 Dec = deciduous; Evr = evergreen; Med. = medium
106 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

Project Title: 

 IV. Planting and Stewardship Costs (dollars)

ABCDEFGH

Years after planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Tree Planting

2 Tree Care

3 Other Costs

4 Subtotals

5 Total Costs
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 107

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 1. Mid-Atlantic climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0425 -0.0487 0.02132 0.01283 0.01172 0.40755 0.16228 0.06589

2 Dec-Med. 0.0260 -0.0320 0.00996 0.00599 0.00547 0.19036 0.07580 0.03077

3 Dec-Small 0.0107 -0.0167 0.00385 0.00232 0.00212 0.07358 0.02930 0.01190

4 Evr-Large 0.0268 -0.0471 0.1931 0.02302 0.01385 0.01265 0.44008 0.17523 0.07114

5 Evr-Med. 0.0168 -0.0315 0.1294 0.01034 0.00622 0.00568 0.19772 0.07873 0.03196

6 Evr-Small 0.0036 -0.0095 0.0206 0.00421 0.00253 0.00231 0.08045 0.03203 0.01301

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0696 -0.0623 0.04992 0.03016 0.02818 0.46365 0.18062 0.07159

8 Dec-Med 0.0425 -0.0409 0.02332 0.01409 0.01316 0.21656 0.08437 0.03344

9 Dec-Small 0.0176 -0.0213 0.00901 0.00545 0.00509 0.08371 0.03261 0.01293

10 Evr-Large 0.0439 -0.0603 0.2320 0.05390 0.03257 0.03043 0.50066 0.19504 0.07731

11 Evr-Med. 0.0275 -0.0403 0.1555 0.02422 0.01463 0.01367 0.22494 0.08763 0.03473

12 Evr-Small 0.0059 -0.0121 0.0248 0.00985 0.00595 0.00556 0.09152 0.03565 0.01413

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0587 -0.0502 0.03214 0.02422 0.02366 0.41855 0.16740 0.06817

14 Dec-Med 0.0358 -0.0329 0.01501 0.01131 0.01105 0.19550 0.07819 0.03184

15 Dec-Small 0.0148 -0.0171 0.00580 0.00437 0.00427 0.07557 0.03023 0.01231

16 Evr-Large 0.0370 -0.0485 0.1985 0.03471 0.02615 0.02555 0.45196 0.18076 0.07361

17 Evr-Med. 0.0232 -0.0324 0.1330 0.01559 0.01175 0.01148 0.20306 0.08122 0.03307

18 Evr-Small 0.0050 -0.0098 0.0212 0.00634 0.00478 0.00467 0.08262 0.03304 0.01346

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) Central tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.1324 -2.711 -0.0078 -0.0007 -0.0026

2 Dec-Med. 0.0665 -1.370 -0.0063 (All tree types)

3 Dec-Small 0.0153 -0.315 -0.0037

4 Evr-Large 0.1204 -2.445 -0.0084

5 Evr-Med. 0.0495 -1.060 -0.0066

6 Evr-Small 0.0126 -0.293 -0.0041

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
108 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 2. Northern Tier climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0573 -0.0609 0.01032 0.00777 0.00724 0.37534 0.13485 0.04010

2 Dec-Med. 0.0318 -0.0392 0.00516 0.00388 0.00362 0.18757 0.06739 0.02004

3 Dec-Small 0.0109 -0.0193 0.00180 0.00136 0.00126 0.06553 0.02354 0.00700

4 Evr-Large 0.0302 -0.0461 0.1662 0.00921 0.00694 0.00646 0.33505 0.12038 0.03579

5 Evr-Med. 0.0122 -0.0227 0.1006 0.00338 0.00254 0.00237 0.12274 0.04410 0.01311

6 Evr-Small 0.0065 -0.0152 0.0690 0.00159 0.00119 0.00111 0.05771 0.02073 0.00616

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0373 -0.0378 0.01131 0.00871 0.00827 0.21312 0.07815 0.02416

8 Dec-Med 0.0207 -0.0243 0.00565 0.00435 0.00413 0.10650 0.03905 0.01207

9 Dec-Small 0.0071 -0.0120 0.00197 0.00152 0.00144 0.03721 0.01365 0.00422

10 Evr-Large 0.0196 -0.0286 0.1087 0.01009 0.00777 0.00738 0.19025 0.06976 0.02157

11 Evr-Med. 0.0079 -0.0141 0.0658 0.00370 0.00285 0.00270 0.06970 0.02556 0.00790

12 Evr-Small 0.0042 -0.0094 0.0451 0.00174 0.00134 0.00127 0.03277 0.01202 0.00371

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0420 -0.0532 0.01514 0.01132 0.01157 0.35775 0.13064 0.03985

14 Dec-Med 0.0234 -0.0342 0.00756 0.00566 0.00578 0.17878 0.06529 0.01992

15 Dec-Small 0.0080 -0.0169 0.00264 0.00198 0.00202 0.06246 0.02281 0.00696

16 Evr-Large 0.0221 -0.0403 0.1468 0.01351 0.01011 0.01033 0.31936 0.11662 0.03558

17 Evr-Med. 0.0089 -0.0198 0.0889 0.00495 0.00370 0.00378 0.11699 0.04272 0.01303

18 Evr-Small 0.0048 -0.0133 0.0609 0.00233 0.00174 0.00178 0.05500 0.02009 0.00613

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) North tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.0428 -0.875 -0.0051 -0.0007 -0.0026

2 Dec-Med. 0.0262 -0.542 -0.0044 (All tree types)

3 Dec-Small 0.0055 -0.114 -0.0025

4 Evr-Large 0.0451 -0.581 -0.0047

5 Evr-Med. 0.0073 -0.191 -0.0032

6 Evr-Small 0.0011 -0.051 -0.0018

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 109

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 3. North Central climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0487 -0.0574 0.00704 0.00573 0.00595 0.31565 0.11176 0.04279

2 Dec-Med. 0.0263 -0.0353 0.00352 0.00286 0.00297 0.15774 0.05585 0.02138

3 Dec-Small 0.0080 -0.0161 0.00123 0.00100 0.00104 0.05511 0.01951 0.00747

4 Evr-Large 0.0246 -0.0394 0.1436 0.00629 0.00511 0.00531 0.28177 0.09977 0.03820

5 Evr-Med. 0.0087 -0.0181 0.0869 0.00230 0.00187 0.00195 0.10322 0.03655 0.01399

6 Evr-Small 0.0046 -0.0117 0.0596 0.00108 0.00088 0.00091 0.04853 0.01718 0.00658

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0352 -0.0515 0.00651 0.00731 0.00710 0.24252 0.08676 0.03392

8 Dec-Med 0.0190 -0.0316 0.00325 0.00365 0.00355 0.12119 0.04335 0.01695

9 Dec-Small 0.0058 -0.0144 0.00114 0.00128 0.00124 0.04234 0.01515 0.00592

10 Evr-Large 0.0178 -0.0353 0.1306 0.00581 0.00652 0.00634 0.21649 0.07745 0.03028

11 Evr-Med. 0.0063 -0.0162 0.0791 0.00213 0.00239 0.00232 0.07931 0.02837 0.01109

12 Evr-Small 0.0034 -0.0105 0.0542 0.00100 0.00112 0.00109 0.03729 0.01334 0.00522

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0527 -0.0607 0.02546 0.01238 0.01137 0.31396 0.11185 0.04306

14 Dec-Med 0.0285 -0.0373 0.01272 0.00619 0.00568 0.15689 0.05590 0.02152

15 Dec-Small 0.0087 -0.0170 0.00445 0.00216 0.00198 0.05482 0.01953 0.00752

16 Evr-Large 0.0266 -0.0417 0.1425 0.02273 0.01105 0.01015 0.28026 0.09985 0.03844

17 Evr-Med. 0.0094 -0.0191 0.0862 0.00833 0.00405 0.00372 0.10267 0.03658 0.01408

18 Evr-Small 0.0050 -0.0124 0.0591 0.00391 0.00190 0.00175 0.04827 0.01720 0.00662

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) North tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.0428 -0.875 -0.0051 -0.0007 -0.0026

2 Dec-Med. 0.0262 -0.542 -0.0044 (All tree types)

3 Dec-Small 0.0055 -0.114 -0.0025

4 Evr-Large 0.0451 -0.581 -0.0047

5 Evr-Med. 0.0073 -0.191 -0.0032

6 Evr-Small 0.0011 -0.051 -0.0018

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
110 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 4. Mountains climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0390 -0.0353 0.02666 0.02370 0.02323 0.13285 0.04432 0.01465

2 Dec-Med. 0.0228 -0.0240 0.01332 0.01184 0.01161 0.06639 0.02215 0.00732

3 Dec-Small 0.0085 -0.0113 0.00465 0.00414 0.00406 0.02320 0.00774 0.00256

4 Evr-Large 0.0209 -0.0258 0.0538 0.02380 0.02116 0.02073 0.11859 0.03957 0.01308

5 Evr-Med. 0.0087 -0.0131 0.0326 0.00872 0.00775 0.00760 0.04345 0.01449 0.00479

6 Evr-Small 0.0047 -0.0082 0.0223 0.00410 0.00364 0.00357 0.02043 0.00681 0.00225

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0503 -0.0554 0.04631 0.04190 0.04086 0.14432 0.04734 0.01528

8 Dec-Med 0.0295 -0.0376 0.02314 0.02094 0.02042 0.07212 0.02366 0.00764

9 Dec-Small 0.0110 -0.0177 0.00809 0.00732 0.00713 0.02520 0.00827 0.00267

10 Evr-Large 0.0270 -0.0404 0.0748 0.04134 0.03741 0.03648 0.12883 0.04226 0.01364

11 Evr-Med. 0.0112 -0.0205 0.0453 0.01514 0.01370 0.01336 0.04719 0.01548 0.00500

12 Evr-Small 0.0060 -0.0129 0.0310 0.00712 0.00644 0.00628 0.02219 0.00728 0.00235

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0848 -0.0759 0.08951 0.08326 0.08267 0.22744 0.07336 0.02297

14 Dec-Med 0.0497 -0.0516 0.04473 0.04161 0.04131 0.11366 0.03666 0.01148

15 Dec-Small 0.0185 -0.0243 0.01563 0.01454 0.01443 0.03971 0.01281 0.00401

16 Evr-Large 0.0454 -0.0554 0.0861 0.07990 0.07432 0.07379 0.20303 0.06549 0.02051

17 Evr-Med. 0.0189 -0.0281 0.0521 0.02927 0.02723 0.02703 0.07438 0.02399 0.00751

18 Evr-Small 0.0102 -0.0177 0.0357 0.01376 0.01280 0.01271 0.03497 0.01128 0.00353

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) North tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.0428 -0.875 -0.0051 -0.0007 -0.0026

2 Dec-Med. 0.0262 -0.542 -0.0044 (All tree types)

3 Dec-Small 0.0055 -0.114 -0.0025

4 Evr-Large 0.0451 -0.581 -0.0047

5 Evr-Med. 0.0073 -0.191 -0.0032

6 Evr-Small 0.0011 -0.051 -0.0018

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 111

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 5. Southeast climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0586 -0.0197 0.01624 0.01186 0.01132 0.10813 0.03306 0.01006

2 Dec-Med. 0.0361 -0.0136 0.00759 0.00554 0.00529 0.05051 0.01544 0.00470

3 Dec-Small 0.0151 -0.0080 0.00293 0.00214 0.00204 0.01952 0.00597 0.00182

4 Evr-Large 0.0378 -0.0237 0.0708 0.01754 0.01281 0.01222 0.11676 0.03570 0.01086

5 Evr-Med. 0.0240 -0.0164 0.0475 0.00788 0.00576 0.00549 0.05246 0.01604 0.00488

6 Evr-Small 0.0038 -0.0047 0.0076 0.00321 0.00234 0.00223 0.02134 0.00653 0.00199

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0785 -0.0224 0.03204 0.02351 0.02229 0.10588 0.03206 0.00965

8 Dec-Med 0.0483 -0.0155 0.01496 0.01098 0.01041 0.04945 0.01498 0.00451

9 Dec-Small 0.0203 -0.0091 0.00578 0.00424 0.00403 0.01912 0.00579 0.00174

10 Evr-Large 0.0507 -0.0270 0.0784 0.03459 0.02538 0.02407 0.11433 0.03462 0.01042

11 Evr-Med. 0.0321 -0.0186 0.0526 0.01554 0.01140 0.01082 0.05137 0.01555 0.00468

12 Evr-Small 0.0052 -0.0054 0.0084 0.00632 0.00464 0.00440 0.02090 0.00633 0.00190

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0993 -0.0264 0.02910 0.02606 0.02696 0.12300 0.03684 0.01096

14 Dec-Med 0.0612 -0.0183 0.01359 0.01217 0.01259 0.05745 0.01721 0.00512

15 Dec-Small 0.0257 -0.0107 0.00525 0.00470 0.00487 0.02221 0.00665 0.00198

16 Evr-Large 0.0641 -0.0319 0.0635 0.03142 0.02814 0.02911 0.13282 0.03978 0.01183

17 Evr-Med. 0.0406 -0.0220 0.0426 0.01412 0.01264 0.01308 0.05967 0.01787 0.00532

18 Evr-Small 0.0065 -0.0063 0.0068 0.00574 0.00514 0.00532 0.02428 0.00727 0.00216

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) Central tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.1324 -2.711 -0.0078 -0.0007 -0.0026

2 Dec-Med. 0.0665 -1.370 -0.0063 (All tree types)

3 Dec-Small 0.0153 -0.315 -0.0037

4 Evr-Large 0.1204 -2.445 -0.0084

5 Evr-Med. 0.0495 -1.060 -0.0066

6 Evr-Small 0.0126 -0.293 -0.0041

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
112 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 6. South Central climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0737 -0.0091 0.03655 0.02311 0.01946 0.09481 0.03578 0.01390

2 Dec-Med. 0.0448 -0.0087 0.01707 0.01079 0.00909 0.04428 0.01671 0.00649

3 Dec-Small 0.0213 -0.0069 0.00660 0.00417 0.00351 0.01712 0.00646 0.00251

4 Evr-Large 0.0462 -0.0158 0.0482 0.03947 0.02495 0.02102 0.10238 0.03864 0.01501

5 Evr-Med. 0.0285 -0.0125 0.0323 0.01773 0.01121 0.00944 0.04600 0.01736 0.00675

6 Evr-Small 0.0093 -0.0071 0.0052 0.00721 0.00456 0.00384 0.01871 0.00706 0.00274

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.1215 -0.0113 0.08960 0.05524 0.04633 0.10036 0.03753 0.01444

8 Dec-Med 0.0738 -0.0107 0.04185 0.02580 0.02164 0.04688 0.01753 0.00674

9 Dec-Small 0.0351 -0.0085 0.01618 0.00997 0.00837 0.01812 0.00678 0.00261

10 Evr-Large 0.0761 -0.0197 0.0541 0.09676 0.05965 0.05003 0.10837 0.04053 0.01559

11 Evr-Med. 0.0470 -0.0155 0.0362 0.04347 0.02680 0.02248 0.04869 0.01821 0.00701

12 Evr-Small 0.0154 -0.0089 0.0058 0.01769 0.01090 0.00915 0.01981 0.00741 0.00285

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.1142 -0.0154 0.07210 0.04483 0.03885 0.14970 0.05686 0.02219

14 Dec-Med 0.0694 -0.0147 0.03368 0.02094 0.01815 0.06992 0.02656 0.01037

15 Dec-Small 0.0330 -0.0116 0.01302 0.00809 0.00701 0.02703 0.01027 0.00401

16 Evr-Large 0.0716 -0.0268 0.0628 0.07786 0.04841 0.04195 0.16165 0.06140 0.02397

17 Evr-Med. 0.0442 -0.0211 0.0421 0.03498 0.02175 0.01885 0.07263 0.02759 0.01077

18 Evr-Small 0.0145 -0.0121 0.0067 0.01423 0.00885 0.00767 0.02955 0.01122 0.00438

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) Central tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.1324 -2.711 -0.0078 -0.0007 -0.0026

2 Dec-Med. 0.0665 -1.370 -0.0063 (All tree types)

3 Dec-Small 0.0153 -0.315 -0.0037

4 Evr-Large 0.1204 -2.445 -0.0084

5 Evr-Med. 0.0495 -1.060 -0.0066

6 Evr-Small 0.0126 -0.293 -0.0041

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 113

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 7. Pacific Northwest climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0029 -0.0451 0.00301 0.00269 0.00266 0.12563 0.03872 0.01125

2 Dec-Med. 0.0020 -0.0366 0.00140 0.00125 0.00124 0.05868 0.01809 0.00525

3 Dec-Small 0.0009 -0.0219 0.00054 0.00048 0.00048 0.02268 0.00699 0.00203

4 Evr-Large 0.0017 -0.0337 0.1172 0.00325 0.00290 0.00288 0.13565 0.04181 0.01215

5 Evr-Med. 0.0012 -0.0282 0.0786 0.00146 0.00130 0.00129 0.06095 0.01878 0.00546

6 Evr-Small 0.0002 -0.0080 0.0125 0.00059 0.00053 0.00053 0.02480 0.00764 0.00222

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0033 -0.0382 0.00496 0.00426 0.00420 0.10531 0.03225 0.00927

8 Dec-Med 0.0023 -0.0310 0.00232 0.00199 0.00196 0.04919 0.01506 0.00433

9 Dec-Small 0.0011 -0.0185 0.00090 0.00077 0.00076 0.01901 0.00582 0.00167

10 Evr-Large 0.0020 -0.0286 0.0964 0.00536 0.00460 0.00454 0.11372 0.03482 0.01001

11 Evr-Med. 0.0014 -0.0239 0.0646 0.00241 0.00207 0.00204 0.05109 0.01565 0.00450

12 Evr-Small 0.0002 -0.0067 0.0103 0.00098 0.00084 0.00083 0.02079 0.00637 0.00183

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0074 -0.0340 0.01157 0.01090 0.01135 0.11224 0.03375 0.00942

14 Dec-Med 0.0051 -0.0275 0.00540 0.00509 0.00530 0.05243 0.01576 0.00440

15 Dec-Small 0.0024 -0.0165 0.00209 0.00197 0.00205 0.02027 0.00609 0.00170

16 Evr-Large 0.0044 -0.0254 0.0618 0.01249 0.01177 0.01225 0.12120 0.03644 0.01017

17 Evr-Med. 0.0031 -0.0213 0.0414 0.00561 0.00529 0.00551 0.05445 0.01637 0.00457

18 Evr-Small 0.0005 -0.0060 0.0066 0.00228 0.00215 0.00224 0.02216 0.00666 0.00186

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) Central tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.1324 -2.711 -0.0078 -0.0007 -0.0026

2 Dec-Med. 0.0665 -1.370 -0.0063 (All tree types)

3 Dec-Small 0.0153 -0.315 -0.0037

4 Evr-Large 0.1204 -2.445 -0.0084

5 Evr-Med. 0.0495 -1.060 -0.0066

6 Evr-Small 0.0126 -0.293 -0.0041

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
114 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 8. Gulf Coast/Hawaii climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0793 -0.0048 0.04988 0.02715 0.02203 0.09046 0.03180 0.01164

2 Dec-Med. 0.0482 -0.0043 0.02227 0.01212 0.00983 0.04038 0.01419 0.00520

3 Dec-Small 0.0254 -0.0035 0.00920 0.00501 0.00406 0.01669 0.00587 0.00215

4 Evr-Large 0.0588 -0.0108 0.0302 0.06045 0.03290 0.02669 0.10961 0.03853 0.01411

5 Evr-Med. 0.0384 -0.0082 0.0214 0.03020 0.01643 0.01333 0.05475 0.01925 0.00705

6 Evr-Small 0.0163 -0.0058 0.0033 0.01142 0.00621 0.00504 0.02070 0.00728 0.00266

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.1331 -0.0056 0.11810 0.06394 0.05084 0.09627 0.03383 0.01233

8 Dec-Med 0.0810 -0.0051 0.05271 0.02854 0.02269 0.04297 0.01510 0.00551

9 Dec-Small 0.0427 -0.0041 0.02179 0.01180 0.00938 0.01776 0.00624 0.00228

10 Evr-Large 0.0988 -0.0127 0.0328 0.14311 0.07748 0.06161 0.11665 0.04099 0.01495

11 Evr-Med. 0.0644 -0.0096 0.0232 0.07149 0.03871 0.03077 0.05827 0.02048 0.00747

12 Evr-Small 0.0273 -0.0069 0.0036 0.02703 0.01463 0.01164 0.02203 0.00774 0.00282

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0977 -0.0079 0.09227 0.05016 0.04154 0.12161 0.04222 0.01542

14 Dec-Med 0.0594 -0.0072 0.04119 0.02239 0.01854 0.05428 0.01884 0.00688

15 Dec-Small 0.0313 -0.0058 0.01702 0.00926 0.00766 0.02244 0.00779 0.00285

16 Evr-Large 0.0726 -0.0180 0.0450 0.11181 0.06079 0.05033 0.14736 0.05116 0.01869

17 Evr-Med. 0.0473 -0.0136 0.0318 0.05585 0.03037 0.02514 0.07361 0.02556 0.00934

18 Evr-Small 0.0201 -0.0097 0.0049 0.02112 0.01148 0.00951 0.02783 0.00966 0.00353

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) South tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.2937 -6.019 -0.0106 -0.0007 -0.0026

2 Dec-Med. 0.1331 -2.738 -0.0082 (All tree types)

3 Dec-Small 0.0321 -0.662 -0.0049

4 Evr-Large 0.3028 -6.392 -0.0121

5 Evr-Med. 0.1049 -3.139 -0.0100

6 Evr-Small 0.0098 -0.860 -0.0064

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 115

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 9. California Coast climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0106 -0.0174 0.00736 0.01076 0.01218 0.05264 0.01664 0.00565

2 Dec-Med. 0.0072 -0.0133 0.00329 0.00480 0.00543 0.02350 0.00743 0.00252

3 Dec-Small 0.0037 -0.0081 0.00136 0.00199 0.00225 0.00971 0.00307 0.00104

4 Evr-Large 0.0075 -0.0212 0.0376 0.00892 0.01304 0.01475 0.06379 0.02016 0.00685

5 Evr-Med. 0.0053 -0.0181 0.0266 0.00446 0.00652 0.00737 0.03186 0.01007 0.00342

6 Evr-Small 0.0015 -0.0078 0.0041 0.00168 0.00246 0.00279 0.01205 0.00381 0.00129

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0111 -0.0155 0.00976 0.01623 0.01848 0.04350 0.01360 0.00454

8 Dec-Med 0.0075 -0.0119 0.00436 0.00725 0.00825 0.01942 0.00607 0.00202

9 Dec-Small 0.0039 -0.0073 0.00180 0.00299 0.00341 0.00803 0.00251 0.00084

10 Evr-Large 0.0079 -0.0190 0.0338 0.01183 0.01967 0.02239 0.05271 0.01648 0.00550

11 Evr-Med. 0.0056 -0.0162 0.0239 0.00591 0.00983 0.01119 0.02633 0.00823 0.00275

12 Evr-Small 0.0016 -0.0070 0.0037 0.00223 0.00371 0.00423 0.00996 0.00311 0.00104

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0223 -0.0382 0.01683 0.02257 0.02428 0.09693 0.03254 0.01164

14 Dec-Med 0.0151 -0.0293 0.00751 0.01007 0.01084 0.04327 0.01452 0.00520

15 Dec-Small 0.0077 -0.0179 0.00311 0.00416 0.00448 0.01788 0.00600 0.00215

16 Evr-Large 0.0158 -0.0466 0.0229 0.02039 0.02735 0.02942 0.11746 0.03943 0.01411

17 Evr-Med. 0.0112 -0.0397 0.0162 0.01019 0.01366 0.01470 0.00587 0.00197 0.00070

18 Evr-Small 0.0032 -0.0172 0.0025 0.00385 0.00517 0.00556 0.02218 0.00745 0.00266

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) South tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.2937 -6.019 -0.0106 -0.0007 -0.0026

2 Dec-Med. 0.1331 -2.738 -0.0082 (All tree types)

3 Dec-Small 0.0321 -0.662 -0.0049

4 Evr-Large 0.3028 -6.392 -0.0121

5 Evr-Med. 0.1049 -3.139 -0.0100

6 Evr-Small 0.0098 -0.860 -0.0064

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
116 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form)1 10. Southwest climate region

 Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0598 -0.0091 0.04796 0.04117 0.03908 0.06110 0.02003 0.00549

2 Dec-Med. 0.0374 -0.0062 0.02240 0.01923 0.01826 0.02854 0.00935 0.00257

3 Dec-Small 0.0199 -0.0041 0.00866 0.00743 0.00706 0.01103 0.00362 0.00099

4 Evr-Large 0.0384 -0.0109 0.0218 0.05179 0.04446 0.04220 0.06598 0.02163 0.00593

5 Evr-Med. 0.0252 -0.0077 0.0146 0.02327 0.01998 0.01896 0.02964 0.00972 0.00267

6 Evr-Small 0.0103 -0.0049 0.0023 0.00947 0.00813 0.00771 0.01206 0.00395 0.00108

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.0758 -0.0149 0.08926 0.07587 0.07333 0.04967 0.01610 0.00439

8 Dec-Med 0.0474 -0.0102 0.04169 0.03544 0.03425 0.02320 0.00752 0.00205

9 Dec-Small 0.0252 -0.0067 0.01612 0.01370 0.01324 0.00897 0.00291 0.00079

10 Evr-Large 0.0487 -0.0178 0.0265 0.09638 0.08193 0.07918 0.05363 0.01738 0.00474

11 Evr-Med. 0.0320 -0.0126 0.0177 0.04330 0.03681 0.03558 0.02410 0.00781 0.00213

12 Evr-Small 0.0130 -0.0080 0.0028 0.01762 0.01498 0.01447 0.00980 0.00318 0.00087

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0508 -0.0124 0.10833 0.08541 0.08172 0.06955 0.02302 0.00649

14 Dec-Med 0.0318 -0.0085 0.05060 0.03989 0.03817 0.03249 0.01075 0.00303

15 Dec-Small 0.0169 -0.0055 0.01956 0.01542 0.01475 0.01256 0.00416 0.00117

16 Evr-Large 0.0327 -0.0148 0.0231 0.11698 0.09223 0.08824 0.07510 0.02486 0.00701

17 Evr-Med. 0.0214 -0.0105 0.0155 0.05256 0.04144 0.03965 0.03374 0.01117 0.00315

18 Evr-Small 0.0087 -0.0067 0.0025 0.02138 0.01686 0.01613 0.01373 0.00454 0.00128

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) Central tree growth zone

J K L MN

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.1324 -2.711 -0.0078 -0.0007 -0.0026

2 Dec-Med. 0.0665 -1.370 -0.0063 (All tree types)

3 Dec-Small 0.0153 -0.315 -0.0037

4 Evr-Large 0.1204 -2.445 -0.0084

5 Evr-Med. 0.0495 -1.060 -0.0066

6 Evr-Small 0.0126 -0.293 -0.0041

1See Chapter 4 for example of this table in use 2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 117

Appendix A Short Form Data Input Forms and Look-up Tables

V. Look-Up Table (Short Form) 11. Desert Southwest climate region

Shade Effects: Mature CO2 Savings/tree by Climate Effects: CO2 Savings by pct Existing Cover

Tree Type (t /tree/year) (t /tree/year)

ABC D E F G H I

Pct Existing Cover

 Vintage: Pre-1950 Vintage: Pre-1950

Shade Wind Cooling Heating

n Tree Type2 Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

1 Dec-Large 0.0561 -0.0019 0.04703 0.03731 0.03479 0.02565 0.00806 0.00232

2 Dec-Med. 0.0357 -0.0018 0.02099 0.01665 0.01553 0.01145 0.00360 0.00104

3 Dec-Small 0.0194 -0.0015 0.00868 0.00688 0.00642 0.00473 0.00149 0.00043

4 Evr-Large 0.0394 -0.0042 0.0125 0.05698 0.04521 0.04216 0.03108 0.00976 0.00281

5 Evr-Med. 0.0269 -0.0032 0.0088 0.02847 0.02259 0.02106 0.01553 0.00488 0.00140

6 Evr-Small 0.0068 -0.0017 0.0014 0.01076 0.00854 0.00796 0.00587 0.00184 0.00053

 Vintage: 1950-80 Vintage: 1950-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

7 Dec-Large 0.1034 -0.0033 0.11501 0.09387 0.08894 0.02067 0.00665 0.00198

8 Dec-Med 0.0658 -0.0031 0.05134 0.04190 0.03970 0.00923 0.00297 0.00088

9 Dec-Small 0.0357 -0.0027 0.02122 0.01732 0.01641 0.00381 0.00123 0.00037

10 Evr-Large 0.0726 -0.0073 0.0135 0.13937 0.11375 0.10777 0.02505 0.00805 0.00240

11 Evr-Med. 0.0495 -0.0056 0.0096 0.06962 0.05682 0.05383 0.01251 0.00402 0.00120

12 Evr-Small 0.0126 -0.0029 0.0015 0.02632 0.02148 0.02035 0.00473 0.00152 0.00045

Vintage: Post-1980 Vintage: Post-1980

Shade Wind Cooling Heating

Tree Type Cooling Heating Heating 10 pct 30 pct 60 pct 10 pct 30 pct 60 pct

13 Dec-Large 0.0897 -0.0045 0.11840 0.08722 0.07996 0.04026 0.01362 0.00437

14 Dec-Med 0.0571 -0.0042 0.05285 0.03893 0.03569 0.01797 0.00608 0.00195

15 Dec-Small 0.0309 -0.0037 0.02185 0.01609 0.01475 0.00743 0.00251 0.00081

16 Evr-Large 0.0630 -0.0101 0.0173 0.14348 0.10569 0.09690 0.04878 0.01651 0.00529

17 Evr-Med. 0.0430 -0.0078 0.0122 0.07167 0.05279 0.04840 0.02437 0.00824 0.00264

18 Evr-Small 0.0109 -0.0040 0.0019 0.02710 0.01996 0.01830 0.00921 0.00312 0.00100

 Sequestration, Decomposition and Program-related Emissions: CO2 Savings or Release 

 (t /tree/year) South tree growth zone

J K L M N

Tree size Sequestration Decomposition Maintenance Production Program

1 Dec-Large 0.2937 -6.019 -0.0106 -0.0007 -0.0026

2 Dec-Med. 0.1331 -2.738 -0.0082 (All tree types)

3 Dec-Small 0.0321 -0.662 -0.0049

4 Evr-Large 0.3028 -6.392 -0.0121

5 Evr-Med. 0.1049 -3.139 -0.0100

6 Evr-Small 0.0098 -0.860 -0.0064

1Reproduced from Appendix A 2 Dec = deciduous; Evr = evergreen; Med. = medium

1
118 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

VIII. Worksheet 1 (Short Form)1 Boulder City case study

Shade Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2)

A BC DE

 Vintage: Pre-1950 no. of Shading Shade - Cooling Shade - Heating

Trees t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type2 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

1 Dec-Large 54 0.0365 1.971 -0.0020 -0.109

2 Dec-Med. 76 0.0204 1.554 -0.0016 -0.122

3 Dec-Small 27 0.0090 0.243 -0.0012 -0.032

4 Evr-Large 6 0.0189 0.113 -0.0029 -0.018

5 Evr-Med. 9 0.0183 0.165 -0.0030 -0.027

6 Evr-Small 3 0.0076 0.023 -0.0018 -0.005

 Vintage: 1950-80 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

7 Dec-Large 369 0.0684 25.228 -0.0033 -1.208

8 Dec-Med. 544 0.0383 20.830 -0.0026 -1.410

9 Dec-Small 297 0.0169 5.006 -0.0019 -0.562

10 Evr-Large 41 0.0353 1.449 -0.0048 -0.195

11 Evr-Med. 61 0.0343 2.094 -0.0048 -0.292

12 Evr-Small 33 0.0143 0.472 -0.0029 -0.097

 Vintage: Post-1980 (III.Bn) (V.An) (= An x Bn) (V.Bn) (=An x Dn)

13 Dec-Large 662 0.0607 40.195 -0.0046 -3.057

14 Dec-Med. 1,769 0.0340 60.156 -0.0037 -6.470

15 Dec-Small 702 0.0150 10.509 -0.0027 -1.874

16 Evr-Large 73 0.0314 2.291 -0.0067 -0.490

17 Evr-Med. 196 0.0305 5.975 -0.0068 -1.325

18 Evr-Small 78 0.0127 0.991 -0.0041 -0.323

Windbreak - Heating

 Vintage: Pre-1950 no. of Windbreak t CO2/Tree Subtotal

Tree Type Trees (A4..6 ) (V.C4..6) (=An x Bn)

19 Evr-Large 6 0.0125 0.075

20 Evr-Med. 9 0.0088 0.079

21 Evr-Small 3 0.0014 0.004

Vintage: 1950-80 (A10..12 ) (V.C10..12) (=An x Bn)

22 Evr-Large 41 0.0135 0.555

23 Evr-Med. 61 0.0096 0.583

24 Evr-Small 33 0.0015 0.049

Vintage: Post-1980 (A16..18 ) (V.C16..18) (=An x Bn)

25 Evr-Large 73 0.0173 1.261

26 Evr-Med. 196 0.0122 2.392

27 Evr-Small 78 0.0019 0.146

1Filled in example of Table VIII taken from Appendix A. See accompanying text for explanation.

2 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 119

Appendix A Short Form Data Input Forms and Look-up Tables

VIII. Worksheet 1 (Short Form) (continued) Project Title: 

Climate Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2) pct existing cover

F G H IJ

 Vintage: Cooling Heating

 Pre-1950 Number of t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type1 Trees (III.D1..6) (V.D..Fn) (= Fn x Gn) (V.G..In) (= Fn x In)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

 Vintage: 

1950-80 (III.D8..13)

7 Dec-Large

8 Dec-Med.

9 Dec-Small

10 Evr-Large

11 Evr-Med.

12 Evr-Small

 Vintage: 

Post-1980 (III.D15..20)

13 Dec-Large

14 Dec-Med.

15 Dec-Small

16 Evr-Large

17 Evr-Med.

18 Evr-Small

 Total Change in CO2 for all Vintages from Cooling and Heating

Emissions factor adjustment (t CO2/MWh) (t CO2/MBtu)

19 Cooling (II.A9): Heating (II.A10):

Heating

 Shade Effects Totals Cooling Shade Windbreak

Tree Type1 (t CO2) (t CO2) (t CO2)

20 Dec-Large G19x(C1+C7+C13) I19x(E1+E7+E13) 

21 Dec-Med. G19x(C2+C8+C14) I19x(E2+E8+E14) 

22 Dec-Small G19x(C3+C9+C15) I19x(E3+E9+E15) 

23 Evr-Large G19x(C4+C10+C16) I19x(E4+E10+E16) I19x(C19+C22+C25) 

24 Evr-Med. G19x(C5+C11+C17) I19x(E5+E11+E17) I19x(C20+C23+C26) 

25 Evr-Small G19x(C6+C12+C18) I19x(E6+E12+E18) I19x(C21+C24+C27) 

 Climate Effects Totals

26 Dec-Large G19x(H1+H7+H13) I19x(J1+J7+J13) 

27 Dec-Med. G19x(H2+H8+H14) I19x(J2+J8+J14) 

28 Dec-Small G19x(H3+H9+H15) I19x(J3+J9+J15) 

29 Evr-Large G19x(H4+H10+H16) I19x(J4+J10+J16) 

30 Evr-Med. G19x(H5+H11+H17) I19x(J5+J11+J17) 

31 Evr-Small G19x(H6+H12+H18) I19x(J6+J12+J18) 

1 Dec = deciduous; Evr = evergreen; Med. = medium
120 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

Sequestration, Decomposition and Program-related Emissions (Emission values are negative)

K LM NO PQ

Sequestration Decomposition Maintenance

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2 t CO2/tree Total t CO2

n Tree Type1 (III.D22..27) (V.J1..6) (= Kn x Ln) (V.K1..6) (= Kn x Nn) (V.L1..6) (= Kn x Pn)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

Tree Production Tree Program

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2

(III.D28) (V.M7) (= K7 x L7) (V.O7) (= K7 x N7)

7 All Trees

1 Dec = deciduous; Evr = evergreen; Med. = medium

Project Title: 

 tree growth zone

VIII. Worksheet 1 (Short Form) (continued)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 121

Appendix A Short Form Data Input Forms and Look-up Tables

IX. Worksheet 2 5 year total CO2 Savings and Emissions (t CO2) Project Title:

Moderate Survival A BCDEFGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Shade-Cooling

1 Age/survival fraction

2 Dec-Large1

3 Dec-Medium

4 Dec-Small

5 Evr-Large1

6 Evr-Medium

7 Evr-Small

8 Shade Cool subtotal

 Shade:Heating

9 Age/survival fraction

10 Dec-Large

11 Dec-Medium

12 Dec-Small

13 Evr-Large

14 Evr-Medium

15 Evr-Small

16 Subtotal

Windbreak-Heating

17 Evr-Large

18 Evr-Medium

19 Evr-Small

20 Subtotal

21 Shade Heat subtotal

22 Total Shade

 Climate-Cooling

23 Age/survival fraction

24 Dec-Large

25 Dec-Medium

26 Dec-Small

27 Evr-Large

28 Evr-Medium

29 Evr-Small

30 Subtotal

 Climate-Heating

31 Dec-Large

32 Dec-Medium

33 Dec-Small

34 Evr-Large

35 Evr-Medium

36 Evr-Small

37 Subtotal

38 Total Climate
122 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix A Short Form Data Input Forms and Look-up Tables

IX. Worksheet 2 (continued) 5 year total CO2 Savings and Emissions (t CO2) Project Title:

Moderate Survival A B C D E FGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Sequestration

39 Age/survival fraction

40 Dec-Large

41 Dec-Medium

42 Dec-Small

43 Evr-Large

44 Evr-Medium

45 Evr-Small

46 Total Sequestered

 Tree Decomposition

47 Age/survival fraction

48 Dec-Large

49 Dec-Medium

50 Dec-Small

51 Evr-Large

52 Evr-Medium

53 Evr-Small

54 Decomposition Total

 Tree Maintenance

55 Age/survival fraction

56 Dec-Large

57 Dec-Medium

58 Dec-Small

59 Evr-Large

60 Evr-Medium

61 Evr-Small

62 Tree Maint. Total

 Program-related Emissions

63 Age/survival fraction

64 Tree Production

65 Tree Program

66 Prod/Program Total

67 Total Released

68 Grand Total

69 Cost of conserved CO2 = Total program cost (IV.D):

70 divided by Grand total (I68): tonnes = $ 1 Dec = deciduous; Evr = evergreen
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 123

I. Background Information

Name: Date:

Organization:

Project Title:

Project Location:

Goals of the Analysis:

Project Description:

II. Site and Building Data A B C

1 Existing Tree + Building Cover (percent)

2 Default Home Vintage Names pre-1950 1950-80 post-1980

3 Selected Home Vintage Names

4 Regional default home distribution by vintage

5 Selected distribution of homes by vintage

6 Climate Region

7 Default electricity emissions factor

8 Selected electricity emissions factor

9 Cooling emissions factor adjustment (EC) (= Row8 / Row7)

10 Heating emissions factor adjustment (EH) (= 1+(Row9 -1) x h 1.0 c)

Appendix B

Long Form Data Input Forms and Look-up Tables
124 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

Climate region

Existing

cover

(pct)

Home distribution by vintage (pct)

Pre-1950 1950-1980 Post-1980

Tree

growth

zone

Electricity

emissions

factor

Heating

correction

factor (he)

Mid-Atlantic 41 30 58 12 Central .605 0.13

Northern Tier 33 45 42 13 North .612 0.03

North Central 36 42 48 10 North .635 0.09

Mountains 56 42 48 10 North .908 0.09

Southeast 67 28 54 18 Central .545 0.17

South Central 52 19 63 18 Central .671 0.32

Pacific Northwest 54 30 58 12 Central .128 0.17

Gulf Coast/Hawaii 51 19 63 18 South .655 0.32

California Coast 44 28 54 18 South .343 0.17

Southwest 40 28 54 18 Central .523 0.17

Desert Southwest 34 19 63 18 South .377 0.32

1

Originally displayed in chapter 4; also reproduced in Appendix A.

Percentage by size and vintage (pct)

Pre-1950 1950-1980 Post-1980 Total

Large 1.2 8.2 14.7 24.1

Medium 1.7 12.1 39.3 53.1

Small 0.6 6.6 15.6 22.8

Total 3.5 26.9 69.6 100.0 1Originally displayed in chapter 4; also reproduced

 in Appendix A.

To Convert from: To: Multiply by:

acres hectares 0.4047

square miles hectares 259.01

square feet hectares 9.29 x 10-6

square kilometers hectares 100

kBtu kWh 0.293

Therm MBtu (natural gas) 0.10

1

Originally displayed in chapter 4; also reproduced in Appendix A.

Table 101—Conversion factors.

Table 111—Default values for short form by region and growth zone.

Table 121

—Distribution of Sacramento Shade trees. This distribution can be

applied to deciduous and evergreen plantings.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 125

Appendix B Long Form Data Input Forms and Look-up Tables

 Project Title: 

 III. Tree Data: Tree Numbers by Type

AB C D

Vintage: Pre-1950

Tree Type1 Near Far Total

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

7 Total

Vintage: 1950-1980

Tree Type Near Far Total

8 Dec-Large

9 Dec-Med.

10 Dec-Small

11 Evr-Large

12 Evr-Med.

13 Evr-Small

14 Total

Vintage: Post-1980

Tree Type Near Far Total

15 Dec-Large

16 Dec-Med.

17 Dec-Small

18 Evr-Large

19 Evr-Med.

20 Evr-Small

21 Total

Total - All Vintages

Tree Type Near Far Total

22 Dec-Large

23 Dec-Med.

24 Dec-Small

25 Evr-Large

26 Evr-Med.

27 Evr-Small

28 Total

1

 Dec = deciduous; Evr = evergreen; Med. = medium
126 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

Project Title: 

 IV. Planting and Stewardship Costs (dollars)

ABCDEFGH

Years after planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Tree Planting

2 Tree Care

3 Other Costs

4 Subtotals

5 Total Costs
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 127

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 1. Mid-Atlantic Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 130.1 182.1

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.42 0.61

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.35 0.27 0.07

14 Selected 

Fraction with no cooling

15 Default 0.23 0.11 0.07

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.51 0.68 0.88

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 9.5 8.3 5.0

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

194.2

0.87
128 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.605

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.49 0.54 0.53

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0256 0.0286 0.0281

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.19 0.20 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0137 0.0145 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.06 0.09 0.23

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0074 0.0118 0.0305

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.03 0.04 0.10

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0017 0.0027 0.0069

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.24 0.13 0.13

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0128 0.0068 0.0070

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.061 0.064 0.073

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 675.7 552.4 392.7

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

1. Mid- Atlantic Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 129

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 2. Northern Tier Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 146.8 102.2

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.47 0.55

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.23 0.25 0.11

14 Selected 

Fraction with no cooling

15 Default 0.30 0.20 0.11

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.53 0.62 0.81

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 10.7 7.8 3.1

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

206.2

0.78
130 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.612

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.47 0.50 0.44

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0256 0.0286 0.0281

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.20 0.25 0.11

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0145 0.0181 0.0080

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.03 0.06 0.18

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0037 0.0080 0.0248

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.01 0.01 0.04

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0004 0.0008 0.0026

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.30 0.18 0.22

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0158 0.0094 0.0117

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.059 0.063 0.071

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 1,138.9 1,007.6 598.7

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

2. Northern Tier Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 131

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 3. North Central Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 146.8 128.2

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.38 0.56

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.37 0.23 0.25

14 Selected 

Fraction with no cooling

15 Default 0.25 0.21 0.03

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.47 0.62 0.78

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 8.9 5.7 3.9

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

206.2

0.72
132 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.635

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.69 0.61 0.50

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0364 0.0320 0.0263

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.18 0.19 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0132 0.0137 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.02 0.10 0.21

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0033 0.0147 0.0290

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.00 0.02 0.04

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0003 0.0015 0.0030

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.10 0.08 0.25

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0052 0.0040 0.0132

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.058 0.066 0.071

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 815.5 752.3 470.6

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

3. North Central Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 133

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 4. Mountain Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 90.6 100.3

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.38 0.56

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.37 0.23 0.25

14 Selected 

Fraction with no cooling

15 Default 0.25 0.21 0.03

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.47 0.62 0.78

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 9.3 6.6 4.4

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

192.3

0.72
134 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.908

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.69 0.61 0.50

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0364 0.0320 0.0263

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.18 0.19 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0132 0.0137 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.02 0.10 0.21

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0047 0.0210 0.0414

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.00 0.02 0.04

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0005 0.0022 0.0043

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.10 0.08 0.25

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0052 0.0040 0.0132

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.060 0.073 0.085

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 762.1 786.9 404.5

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.20

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

4. Mountains Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 135

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 5. Southeast Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 108.2 131.5

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.39 0.59

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.36 0.23 0.14

14 Selected 

Fraction with no cooling

15 Default 0.24 0.19 0.05

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.48 0.65 0.85

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 19.3 16.3 8.3

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

202.5

0.81
136 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.545

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.70 0.61 0.52

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0367 0.0323 0.0276

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.08 0.02 0.02

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0055 0.0012 0.0017

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.06 0.13 0.20

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0075 0.0160 0.0236

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.03 0.06 0.09

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0017 0.0036 0.0053

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.14 0.18 0.17

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0072 0.0093 0.0088

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.059 0.062 0.067

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 456.9 391.2 191.4

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

5. Southeast Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 137

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 6. South Central Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 98.0 129.1

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.27 0.70

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.59 0.23 0.05

14 Selected 

Fraction with no cooling

15 Default 0.14 0.07 0.10

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.42 0.76 0.87

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 33.3 24.9 17.6

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

150.5

0.86
138 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.671

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.73 0.62 0.29

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0383 0.0327 0.0151

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.00 0.00 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0000 0.0000 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.11 0.17 0.42

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0169 0.0249 0.0621

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.07 0.10 0.25

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0050 0.0073 0.0182

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.09 0.11 0.05

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0048 0.0059 0.0025

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.065 0.071 0.098

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 278.6 217.7 157.2

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

6. South Central Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 139

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 7. Pacific Northwest Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 130.1 129.1

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.38 0.56

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.37 0.23 0.25

14 Selected 

Fraction with no cooling

15 Default 0.25 0.21 0.03

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.47 0.62 0.78

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 2.0 1.7 1.9

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

192.3

0.72
140 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.128

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.69 0.61 0.50

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0364 0.0320 0.0263

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.18 0.19 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0132 0.0137 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.02 0.10 0.21

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0007 0.0030 0.0059

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.00 0.02 0.04

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0001 0.0003 0.0006

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.10 0.08 0.25

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0052 0.0040 0.0132

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.056 0.053 0.046

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 736.5 638.8 317.1

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.20

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

7. Pacific Northwest Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 141

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 8. Gulf Coast/Hawaii Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 98.0 129.1

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.27 0.70

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.59 0.23 0.05

14 Selected 

Fraction with no cooling

15 Default 0.14 0.07 0.10

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.42 0.76 0.87

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 31.1 23.9 14.9

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

150.5

0.86
142 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.656

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.73 0.62 0.29

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0383 0.0327 0.0151

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.00 0.00 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0000 0.0000 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.11 0.17 0.42

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0165 0.0243 0.0606

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.07 0.10 0.25

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0048 0.0071 0.0177

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.09 0.11 0.05

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0048 0.0059 0.0025

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.064 0.070 0.096

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 170.3 129.0 111.0

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.05

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

8. Gulf Coast/Hawaii Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 143

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 9. California Coast Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 130.1 129.1

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.39 0.59

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.36 0.23 0.14

14 Selected 

Fraction with no cooling

15 Default 0.24 0.19 0.05

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.48 0.65 0.85

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 2.6 2.2 1.3

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

192.3

0.81
144 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.343

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.70 0.61 0.52

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0367 0.0323 0.0276

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.08 0.02 0.02

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0055 0.0012 0.0017

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.06 0.13 0.20

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0047 0.0101 0.0148

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.03 0.06 0.09

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0011 0.0023 0.0034

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.14 0.18 0.17

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0072 0.0093 0.0088

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.055 0.055 0.056

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 180.6 163.4 72.9

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.10

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

9. California Coast Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 145

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 10. Southwest Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 90.6 100.3

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.39 0.59

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.36 0.23 0.14

14 Selected 

Fraction with no cooling

15 Default 0.24 0.19 0.05

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.48 0.65 0.85

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 28.6 24.3 9.3

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

154.2

0.81
146 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.523

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.70 0.61 0.52

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0367 0.0323 0.0276

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.08 0.02 0.02

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0055 0.0012 0.0017

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.06 0.13 0.20

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0072 0.0153 0.0226

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.03 0.06 0.09

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0016 0.0035 0.0051

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.14 0.18 0.17

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0072 0.0093 0.0088

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.058 0.062 0.066

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 266.1 275.4 146.2

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.20

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

10. Southwest Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 147

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table 11. Desert Southwest Region

Site Data and Cooling Adjustments

Indicates calculated value

Project Title: Indicates Default value

Vintage Names ABC

1 Default pre-1950 1950-1980

2 Selected

Conditioned Floor Area (CFA)

3 Default (m2/unit) 90.6 100.3

4 Selected (m2/unit)

5 CFA Adjustment (A..C4 / A..C3)

Shade Fraction on Neighboring Homes

6 Default 0.15

7 Selected

8 Adjustment (1 + A7) / (1 + A6)

Cooling Equipment Adjustments

Fraction with central air conditioning or heat pump

9 Default 0.27 0.70

10 Selected 

Fraction with evaporative cooler

11 Default 0.00 0.00 0.00

12 Selected 

Fraction with room air conditioning

13 Default 0.59 0.23 0.05

14 Selected 

Fraction with no cooling

15 Default 0.14 0.07 0.10

16 Selected 

Cooling Equipment Adjustment; Shade

17 Default (A..C9+0.33*A..C11+0.25*A..C13+0.0*A..C15) 0.42 0.76 0.87

18 Selected (A..C10+0.33 x A..C12+0.25 x A..C14+ 0.0 x A..C16)

19 Adjusted (A..C18 / A..C19)

Base Case Adjustment

20 Default (kWh/m2/yr) 61.4 57.5 30.6

21 Selected (kWh/m2/yr)

22 Adjustment (A..C21 / A..C20)

Cooling Adjustment Factor (for Long Form)

23 (A..C5 x A8 x A..C19 x A..C22)

post-1980

154.2

0.86
148 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VI. Long Form Adjustment Table (continued)

Heating Adjustments A B C

Project Title:

24 Default electricity emissions factor (t CO2/MWh) 0.377

25 Selected electricity emissions factor (t CO2/MWh)

Fraction with natural gas

26 Default 0.73 0.62 0.29

27 Selected

28 Default Conversion factor (0.0527 x A..C26) (t CO2/MWh) 0.0383 0.0327 0.0151

29 Selected conversion factor (0.0527x A..C27) (t CO2/MWh)

Fraction with fuel oil

30 Default 0.00 0.00 0.00

31 Selected

32 Default Conversion factor (0.072 x A..C30) (t CO2/MWh) 0.0000 0.0000 0.0000

33 Selected conversion factor (0.072 x A..C31) (t CO2/MWh)

Fraction with electric resistance

34 Default 0.11 0.17 0.42

35 Selected

36 Default conversion factor (0.22 x A24 x A..C34) (t CO2/MWh) 0.0095 0.0140 0.0348

37 Selected conversion factor (0.22 x A25 x A..C35) (t CO2/MWh)

Fraction with heat pump

38 Default 0.07 0.10 0.25

39 Selected

40 Default conversion factor (0.11 x A24 x A..C38) (t CO2/MWh) 0.0028 0.0041 0.0102

41 Selected conversion factor (0.11 x A25 x A..C39) (t CO2/MWh)

Fraction with other heating

42 Default 0.09 0.11 0.05

43 Selected

44 Default conversion factor (0.527 x A..C42/1000) (t CO2/MWh) 0.0048 0.0059 0.0025

45 Selected conversion factor (0.527 x A..C43/1000) (t CO2/MWh)

Combined Equip/Emissions adjustment

46 Default (A..C28+A..C32+A..C36+A..C40+A..C44) (t CO2/MWh) 0.055 0.057 0.063

47 Selected (A..C29+A..C33+A..C37+A..C41+A..C45) (t CO2/MWh)

48 Adjusted (A..C46/A..C47)

Base Case Adjustment 

49 Default (kWh/m2/yr) 107.0 102.6 77.1

50 Selected (kWh/m2/yr)

51 Adjustment (A..C50/A..C49)

Heating Adjustment Factor (for Long Form)

52 ( A..C5 x A8 x A..C48 x A..C51)

Climate Cooling and Heating Adjustments

Air temperature adjustment

53 Default (oC/%Cover change) 0.10

54 Selected (oC/%Cover change) 

55 Adjustment (A54 / A55)

Cooling Adjustment Factor (for Long Form)

56 (A..C5 x A..C19 x A..C22 x A55)

Heating Adjustment Factor (for Long Form)

57 ( A..C5 x A..C48 x A..C51)

11. Desert Southwest Region
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 149

Appendix B Long Form Data Input Forms and Look-up Tables

VII. Look-Up Table (Long Form) Project Title: 

 Shade Effects: Mature CO2 Savings/tree by Tree Type (t CO2 / tree)

ABC DEF GH

Shade - Cooling Shade - Heating Wind - Heating

Adjust- Avoided Adjusted Adjust- Avoided Adjusted Avoided Adjusted

ment CO2 CO2 ment CO2 CO2 CO2 CO2

 Vintage: Factor (t /tree) (t /tree) Factor (t /tree) (t /tree) (t /tree) (t /tree)

 Pre-1950 (Table 61 (Table 61

n Tree Type1 (VI.A23) or 107) (A1 x Bn) (VI.A52) or 107) (D1 x En) (Table 108) (D1 x Gn)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

 Vintage: (Table 61 (Table 61

1950-80 (VI.B23) or 107) (A7 x Bn) (VI.B52) or 107) (D7 x En) (Table 108) (D7 x Gn)

7 Dec-Large

8 Dec-Med.

9 Dec-Small

10 Evr-Large

11 Evr-Med.

12 Evr-Small

 Vintage: (Table 61 (Table 61

Post-1980 (VI.C23) or 107) (A13 x Bn) (VI.C52) or 107) (D13 x En) (Table 108) (D13 x Gn)

13 Dec-Large

14 Dec-Med.

15 Dec-Small

16 Evr-Large

17 Evr-Med.

18 Evr-Small

1 Dec = deciduous; Evr = evergreen; Med. = medium
150 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VII. Look-Up Table (Long Form) (continued) Project Title:

Climate Effects: Mature CO2 Savings/tree (t CO2/tree) pct existing cover

I J K LMN

Cooling Heating

Adjust- Avoided Adjusted Adjust- Avoided Adjusted

ment CO2 CO2 ment CO2 CO2

 Vintage: Factor Factor

 Pre-1950 (t /tree) (t /tree)

n Tree Type1 (VI.A56) Table 109 (I1 x Jn) (VI.A57) Table 109 (L1 x Mn)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

 Vintage: 

1950-80 (VI.B56) Table 109 (I7 x Jn) (VI.B57) Table 109 (L7 x Mn)

7 Dec-Large

8 Dec-Med.

9 Dec-Small

10 Evr-Large

11 Evr-Med.

12 Evr-Small

 Vintage: 

Post-1980 (VI.C56) Table 109 (I13 x J1n) (VI.C57) Table 109 (L13 x Mn)

13 Dec-Large

14 Dec-Med.

15 Dec-Small

16 Evr-Large

17 Evr-Med.

18 Evr-Small

 Sequestration, Decomposition and Maintenance Emissions at Maturity by growth zone (t CO2/tree/year)

All Vintages OPQ RST UV

Sequestration Decomposition Maintenance

n Tree Type North Central South North Central South North Central South

1 Dec Large 0.0428 0.1324 0.2937 -0.8754 -2.7107 -6.0188 -0.0051 -0.0078 -0.0106

2 Dec Med 0.0262 0.0665 0.1331 -0.5415 -1.3702 -2.7382 -0.0044 -0.0063 -0.0082

3 Dec Small 0.0055 0.0153 0.0321 -0.1138 -0.3148 -0.6618 -0.0025 -0.0037 -0.0049

4 Evr Large 0.0451 0.1204 0.3028 -0.5807 -2.4449 -6.3920 -0.0047 -0.0084 -0.0121

5 Evr Med 0.0073 0.0495 0.1049 -0.1912 -1.0598 -3.1392 -0.0032 -0.0066 -0.0100

6 Evr Small 0.0011 0.0126 0.0098 -0.0509 -0.2933 -0.8603 -0.0018 -0.0041 -0.0064

 Production and Program-related Emissions for all tree types (t CO2/tree/year)

X Y

n Production Program

1

1 Dec = deciduous; Evr = evergreen; Med. = medium

W
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 151

Appendix B Long Form Data Input Forms and Look-up Tables

VIII. Worksheet 1 (Long Form) Project Title: 

 Shade Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2)

AB C D E

 Vintage: Pre-1950 no. of Shading Shade - Cooling Shade - Heating

n Tree Type1 Trees

(III.Bn)

t CO2/Tree

(VII.Cn)

Subtotal

( = An x Bn )

t CO2/Tree

(VII.Fn)

Subtotal

(=An x Dn)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

 Vintage: 1950-80 (III.Bn) (VII.Cn) (=An x Bn) (VII.Fn) (=An x Dn)

7 Dec-Large

8 Dec-Med.

9 Dec-Small

10 Evr-Large

11 Evr-Med.

12 Evr-Small

 Vintage: Post-1980 (III.Bn) (VII.Cn) (=An x Bn) (VII.Fn) (=An x Dn)

13 Dec-Large

14 Dec-Med.

15 Dec-Small

16 Evr-Large

17 Evr-Med.

18 Evr-Small

Windbreak - Heating

 Vintage: Pre-1950 no. of Windbreak t CO2/Tree Subtotal

Tree Type Trees (A4..6) (VII.H4..6) (=An x Bn)

19 Evr-Large

20 Evr-Med.

21 Evr-Small

 Vintage: 1950-80 (A10..12) (VII.H10..12) (=An x Bn)

22 Evr-Large

23 Evr-Med.

24 Evr-Small

 Vintage: Post-1980 (A16..18) (VII.H16..18) (=An x Bn)

25 Evr-Large

26 Evr-Med.

27 Evr-Small

1 Dec = deciduous; Evr = evergreen; Med. = medium
152 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

VIII. Worksheet 1 (Long Form) (continued) Project Title: 

Climate Effects: Mature Change in CO2 by Tree Type and Vintage (t CO2) pct existing cover

F G H IJ

 Vintage: Cooling Heating

 Pre-1950 Number of t CO2/Tree Subtotal t CO2/Tree Subtotal

n Tree Type1 Trees (III.D1..6) (V.D..Kn) (= Fn x Gn) (VII.N/n) (= Fn x In)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

 Vintage: 

1950-80 (III.D8..13)

7 Dec-Large

8 Dec-Med.

9 Dec-Small

10 Evr-Large

11 Evr-Med.

12 Evr-Small

 Vintage: 

Post-1980 (III.D15..20)

13 Dec-Large

14 Dec-Med.

15 Dec-Small

16 Evr-Large

17 Evr-Med.

18 Evr-Small

 Total Change in CO2 for all Vintages from Cooling and Heating

Emissions factor adjustment (t CO2/MWh) (t CO2/MBtu)

19 Cooling (II.A9): Heating (II.A10):

Heating

 Shade Effects Totals Cooling Shade Windbreak

Tree Type1 (t CO2) (t CO2) (t CO2)

20 Dec-Large G19x(C1+C7+C13) I19x(E1+E7+E13) 

21 Dec-Med. G19x(C2+C8+C14) I19x(E2+E8+E14) 

22 Dec-Small G19x(C3+C9+C15) I19x(E3+E9+E15) 

23 Evr-Large G19x(C4+C10+C16) I19x(E4+E10+E16) I19x(C19+C22+C25) 

24 Evr-Med. G19x(C5+C11+C17) I19x(E5+E11+E17) I19x(C20+C23+C26) 

25 Evr-Small G19x(C6+C12+C18) I19x(E6+E12+E18) I19x(C21+C24+C27) 

 Climate Effects Totals

26 Dec-Large G19x(H1+H7+H13) I19x(J1+J7+J13) 

27 Dec-Med. G19x(H2+H8+H14) I19x(J2+J8+J14) 

28 Dec-Small G19x(H3+H9+H15) I19x(J3+J9+J15) 

29 Evr-Large G19x(H4+H10+H16) I19x(J4+J10+J16) 

30 Evr-Med. G19x(H5+H11+H17) I19x(J5+J11+J17) 

31 Evr-Small G19x(H6+H12+H18) I19x(J6+J12+J18) 

1 Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 153

Appendix B Long Form Data Input Forms and Look-up Tables

Sequestration, Decomposition and Program-related Emissions (Emission values are negative)

K LM NO PQ

Sequestration Decomposition Maintenance

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2 t CO2/tree Total t CO2

n Tree Type1 (III.D22..27) (VII.O1..Q6) (= Kn x Ln) (VII.R1..T6) (= Kn x Nn) (VII.U1..W6) (= Kn x Pn)

1 Dec-Large

2 Dec-Med.

3 Dec-Small

4 Evr-Large

5 Evr-Med.

6 Evr-Small

Tree Production Tree Program

Total no. of trees t CO2/tree Total t CO2 t CO2/tree Total t CO2

(III.D28) (VII.X1) (= K7 x L7) (VII.Y1) (= K7 x N7)

7 All Trees

1 Dec = deciduous; Evr = evergreen; Med. = medium

Project Title: 

 tree growth zone

VIII. Worksheet 1 (Long Form) (continued)
154 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix B Long Form Data Input Forms and Look-up Tables

IX. Worksheet 2 5 year total CO2 Savings and Emissions (t CO2) Project Title:

Moderate Survival A BCDEFGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Shade-Cooling

1 Age/survival fraction

2 Dec-Large1

3 Dec-Medium

4 Dec-Small

5 Evr-Large1

6 Evr-Medium

7 Evr-Small

8 Shade Cool subtotal

 Shade:Heating

9 Age/survival fraction

10 Dec-Large

11 Dec-Medium

12 Dec-Small

13 Evr-Large

14 Evr-Medium

15 Evr-Small

16 Subtotal

Windbreak-Heating

17 Evr-Large

18 Evr-Medium

19 Evr-Small

20 Subtotal

21 Shade Heat subtotal

22 Total Shade

 Climate-Cooling

23 Age/survival fraction

24 Dec-Large

25 Dec-Medium

26 Dec-Small

27 Evr-Large

28 Evr-Medium

29 Evr-Small

30 Subtotal

 Climate-Heating

31 Dec-Large

32 Dec-Medium

33 Dec-Small

34 Evr-Large

35 Evr-Medium

36 Evr-Small

37 Subtotal

38 Total Climate
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 155

Appendix B Long Form Data Input Forms and Look-up Tables

IX. Worksheet 2 (continued) 5 year total CO2 Savings and Emissions (t CO2) Project Title:

Moderate Survival A B C D E FGH I J

Years After Planting Cumulative 36-40 yr

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40 Totals no mortality

 Sequestration

39 Age/survival fraction

40 Dec-Large

41 Dec-Medium

42 Dec-Small

43 Evr-Large

44 Evr-Medium

45 Evr-Small

46 Total Sequestered

 Tree Decomposition

47 Age/survival fraction

48 Dec-Large

49 Dec-Medium

50 Dec-Small

51 Evr-Large

52 Evr-Medium

53 Evr-Small

54 Decomposition Total

 Tree Maintenance

55 Age/survival fraction

56 Dec-Large

57 Dec-Medium

58 Dec-Small

59 Evr-Large

60 Evr-Medium

61 Evr-Small

62 Tree Maint. Total

 Program-related Emissions

63 Age/survival fraction

64 Tree Production

65 Tree Program

66 Prod/Program Total

67 Total Released

68 Grand Total

69 Cost of conserved CO2 = Total program cost (IV.D):

70 divided by Grand total (I68): tonnes = $ 1 Dec = deciduous; Evr = evergreen
156 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix C

Regional Climate Information

Instructions for Climate Region Selection

Climate Region can most simply be determined geographically from figure 24 (or figure 17, in

Chapter 3). This section describes an alternative process for choosing the Climate Region

that best matches your site on the basis of actual site climate. The process involves finding the

closest match between the climate of your site and that of one of the 11 reference cities. This is

important if the climate of your site differs from that of the reference city for your geographic

Climate Region. For example, as pointed out in Chapter 2, the climates of mountain communities

in Climate Regions mapped as Southeast and Southwest may more closely resemble the climate

in cities located in colder Regions mapped as Mid-Atlantic and Mountains. The reference cities

for each Climate Region are listed in table 31.

Four quantities that directly influence building energy use are used here to objectively define

climate: Heating Degree Days (HDD), Cooling Degree Days (CDD), Latent Enthalpy Hours

(LEH), and ratio of average global horizontal radiation to the average extraterrestrial horizontal

radiation (KT). These, along with average annual wind speed (WND), are given in table 32 for

125 areas in the United States with populations greater than 250,000 (Andersson and others

1986). Detailed discussion of these parameters and how they affect cooling and heating loads can

be found in that reference. In general, HDD and CDD are related to air temperature effects on

heating and cooling loads. LEH is related to relative humidity and indicates the amount of

moisture that must be removed from the air to bring it to 25 oC (77 oF) and 60 percent relative

humidity, and KT indicates amount actual of sunshine relative to cloud-free conditions and so is

related to solar gain.

The first step in the process is to find values of CDD, HDD, LEH and KT for your site. If your

site is not listed in table 32, and data are not available locally, local climatological data are

available from the National Climatic Data Center (NCDC) for about 270 U.S. cities (found online

on the World Wide Web at http://www.ncdc.noaa.gov/ol/climate/climatedata.html under

Surface Data, U.S. Climatological Averages and Normals). NCDC data include CDD, HDD and

percent possible sunshine. Average morning and afternoon relative humidity data, which are

related to LEH, are also available. Once these values are determined, locate the city in table 32

with a climate that most closely matches that of your site. Call that city your Site City.

The second step is to find the reference city in table 31 (one for each of the 11 climate regions)

whose climate most closely matches that of your Site City. The best match determines your

Climate Region. If a match of all four climate indicators is not possible, CDD should be matched

first in a cooling-dominated climate, followed by LEH, HDD and KT. In a heating-dominated

climate, HDD should be matched first, followed by CDD, LEH and KT. LEH is associated with

CDD, since relatively more cooling energy use is for dehumidification in regions with large LEH

(humid climate) compared to those with small LEH (dry climate).

Reference City Climate Region HDD1 CDD LEH KT WND LEH/CDD

Atlanta, Georgia Southeast 3,094 1,588 4,931 0.400 9.1 3.1

Dallas, Texas South Central 2,290 2,754 7,951 0.536 11.1 2.9

Denver, Colorado Mountains 6,016 625 4 0.618 9.0 0.0

Detroit, Michigan North Central 6,228 742 1,600 0.457 10.2 2.2

Fresno, California Southwest 2,650 1,670 43 0.650 6.3 0.0

Houston, Texas Gulf Coast/Hawaii 1,433 2,889 18,845 0.480 7.9 6.5

Los Angeles, California California Coast 1,818 614 109 0.588 6.5 0.2

Minneapolis, Minnesota Northern Tier 8,158 585 1,769 0.494 10.6 3.0

New York, New York Mid-Atlantic 5,033 1,022 1,533 0.465 9.4 1.5

Phoenix. Arizona Desert Southwest 1,552 3,506 967 0.686 6.1 0.3

Seattle, Washington Pacific Northwest 5,184 128 0 0.462 9.3 0.0

1

 HDD = heating Degree Days (°F day, base 65 °F); CDD = Cooling Degree Days (°F day, base 65 °F);

LEH = Latent Enthalpy Hours (Btuh/lb of dry air), KT = available sunshine (fraction), WND = annual average

wind speed (miles/hr).

Table 31—Climate data for 11 reference cities (Andersson and others 1986).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 157

Appendix C Regional Climate Information

As an example, Boulder City, Nev. is 32 km (20 miles) south of Las Vegas, Nev., the closest

city on the map of climate regions (fig. 24). Las Vegas is located in the Desert-Southwest region.

We need to confirm that the climate of Las Vegas best matches the climate of the DesertSouthwest region’s reference city, which is Phoenix (table 31). To compare the climate of Las

Vegas with those of Phoenix and other reference cities that may be good matches, we list values of

CDD, HDD, LEH and KT (table 32). The CDD for Las Vegas more closely matches those for Dallas

and Houston than for Phoenix, but these cities are ruled out because of large differences in the

values of LEH. The high LEH values reflect more humid climates in Dallas and Houston than in

Phoenix. Although HDD for Las Vegas more closely matches that of Fresno than that of Phoenix,

CDD’s are 57 percent less in Fresno. Our first priority is to match CDDs. Therefore, Phoenix is the

best match, although using Phoenix may result in overestimates of emission reductions due to

cooling savings and underestimates of reductions due to space heating savings.

Figure 24—Climate Regions for the United States (Repeated as figure 17 in Chapter 3).
158 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix C Regional Climate Information

SMSA Population

(thousands) HDD CDD LEH KT WND

Albany-Schenectady, N.Y. 792 6,887 572 916 0.437 8.8

Albuquerque, N.M. 409 4,291 1,316 119 0.682 9.0

Allentown-Bethlehem, Pa./N.J. 626 5,827 770 1,466 0.454 10.0

Appleton-Oshkosh, Wis. 291 8,096 385 1,464 0.480 11.0

Atlanta, Ga. 1,852 3,094 1,588 4,931 0.495 9.1

Augusta, Ga./S.C. 291 2,547 1,994 7,675 0.500 6.0

Austin, Texas 478 1,737 2,907 1,277 0.526 10.0

Bakersfield, Calif. 365 2,183 2,178 15 0.656 6.0

Baltimore, Md. 3,145 4,729 1,107 3,764 0.476 9.5

Baton Rouge, La. 445 1,669 2,585 1,530 0.492 8.0

Beaumont-Port Arthur, Texas 364 1,517 2,797 1,974 0.499 11.0

Binghamton, N.Y./Pa. 303 7,285 369 810 0.405 11.0

Birmingham, Ala. 818 2,844 1,928 6,968 0.494 7.4

Boston-Brockton, Mass./N.H. 3,688 5,620 661 779 0.450 12.6

Bridgeport, Conn. 394 4,909 1,048 2,036 0.468 9.0

Bristol-Johnson, Tenn./Va. 411 3,478 1,568 4,767 0.479 7.3

Buffalo, N.Y. 1,303 6,926 436 1,021 0.425 12.3

Canton, Ohio 404 6,223 634 1,636 0.444 10.8

Charleston, S.C. 389 2,146 2,077 1,163 0.491 8.8

Charleston, W. Va. 261 4,590 1,055 2,313 0.435 6.5

Charlotte-Gastonia, N.C. 606 3,217 1,595 3,352 0.503 8.0

Chattanooga, Tenn./Ga. 401 3,505 1,634 2,283 0.465 6.0

Chicago-Gary, Ill./Ind. 7,678 6,125 923 2,781 0.492 10.3

Cincinnati-Ham., Ohio/Ky./Ind. 1,646 5,069 1,080 1,761 0.453 7.1

Cleveland-Akron, Ohio 2,876 6,152 612 1,636 0.439 10.8

Colorado Springs, Colo. 291 6,374 461 1 0.621 10.4

Columbia, S.C. 380 2,597 2,086 8,392 0.510 7.0

Columbus, Ohio 1,089 5,701 808 2,096 0.444 8.7

Corpus Christi, Texas 302 929 3,474 2,656 0.503 12.0

Dallas-Fort Worth, Texas 2,720 2,290 2,754 7,951 0.536 11.1

Davenport-Rock Island, Iowa/Ill. 374 6,394 893 2,944 0.493 10.0

Dayton, Ohio 834 5,639 936 1,752 0.458 11.0

Denver-Boulder, Colo. 1,505 6,016 625 4 0.618 9.0

Des Moines, Iowa 334 6,709 927 1,952 0.529 11.1

Detroit-Ann Arbor, Mich. 4,641 6,228 742 1,600 0.457 10.2

Duluth-Superior, Minn./Wis. 266 9,765 175 362 0.463 11.5

El Paso, Texas 443 2,677 2,097 70 0.687 9.6

Erie, Pa. 269 6,851 373 964 0.430 12.0

Eugene-Springfield, Ore. 258 4,851 230 5 0.476 8.0

Evansville, Ind. 295 4,628 1,363 4,466 0.487 9.0

Flint, Mich. 521 7,040 437 757 0.442 11.0

Fort Wayne, Ind. 376 6,208 747 1,760 0.450 10.0

Fresno, Calif. 479 2,650 1,670 43 0.651 6.3

Grand Rapids, Mich 585 6,800 574 1,350 0.466 10.0

Greensboro-Winston-Salem, N.C. 779 3,845 1,341 3,559 0.507 9.0

Greenville-Spartan, S.C. 541 3,163 1,571 3,352 0.502 8.0

Harrisburg, Pa. 430 5,224 1,024 2,319 0.456 7.7

Hartford-New Britain, Conn. 1,045 6,349 583 1,476 .0429 9.0

Honolulu, Hawaii 720 0 4,221 2,775 0.546 11.8

Table 32—Climate data for 125 U.S. cities with populations greater than 250,000.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 159

Appendix C Regional Climate Information

SMSA Population

(thousands) HDD CDD LEH KT WND

Houston-Galveston, Texas 2,793 1,433 2,889 18,845 0.480 7.9

Huntington-Ash., W.Va./Ky./Ohio 300 4,622 1,098 2,313 0.456 6.5

Huntsville, Ala. 293 3,505 1,634 2,283 0.465 6.0

Indianapolis, Ind. 1,156 5,576 974 2,745 0.459 11.0

Jackson, Miss. 299 2,299 2,320 1,165 0.512 7.7

Jacksonville, Fla. 702 1,327 2,596 1,432 0.514 9.0

Johnston, Pa. 265 5,929 646 890 0.425 10.0

Kalamazoo, Mich. 270 6,800 574 1,350 0.466 10.0

Kansas City, Mo./Kan. 1,325 5,357 1,283 5,807 0.525 10.2

Knoxville, Tenn. 456 3,478 1,568 4,767 0.479 7.3

Lakeland-Winter Haven, Fla 278 733 3,226 1,771 0.522 8.7

Lancaster, Pa. 351 5,224 1,024 2,319 0.456 7.7

Lansing, Mich. 458 7,040 437 757 0.442 8.0

Las Vegas, Nev. 377 2,601 2,945 199 0.704 8.9

Lexington, Ky. 300 4,729 1,197 4,021 0.471 9.7

Little Rock, Ark. 376 3,353 1,924 9,933 0.523 8.2

Los Angeles, Calif. 10,784 1,818 614 109 0.588 6.5

Louisville Ky./Ind. 887 4,644 1,267 4,511 0.470 8.4

Madison, Wis. 319 7,729 459 1,343 0.491 9.9

Manchester-Nashua, N.H. 260 7,358 347 922 0.434 6.7

Memphis, Tenn./Ark./Miss. 889 3,226 2,029 10,005 0.510 9.2

Miami-Fort Lauderdale, Fla. 2,333 205 4,037 27,753 0.506 9.1

Milwaukee-Racine, Wis. 1,594 7,443 450 1,277 0.489 11.8

Minneapolis-St.P., Minn./Wis. 2,063 8,158 585 1,769 0.494 10.6

Mobile, Ala. 435 1,683 2,576 13,155 0.495 9.3

Montgomery, Ala. 258 2,268 2,237 9,609 0.504 7.0

Nashville, Tenn. 786 3,695 1,694 5,584 0.480 7.9

New Bedford-Fall R., Mass. 472 5,791 531 779 0.450 10.8

New Haven-Waterbury, Conn. 755 4,909 1,048 2,036 0.468 8.0

New Orleans, La. 1,141 1,463 2,705 17,754 0.511 8.4

New York, N.Y./N.J./Conn. 16,285 5,033 1,022 1,533 0.465 9.4

Newport News-Hampton, Va. 361 3,487 1,440 6,902 0.505 10.6

Norfolk-Virginia Beach, Va./N.C. 800 3,487 1,440 6,902 0.505 10.6

Oklahoma City, Okla. 789 3,694 1,876 5,001 0.548 12.9

Omaha, Neb. 582 6,601 949 3,224 0.531 10.9

Orlando, Fla. 610 733 3,226 17,714 0.522 8.7

Pensacola, Fla. 276 1,683 2,576 13,155 0.495 8.0

Peoria, Ill. 361 6,394 893 2,944 0.493 10.3

Philadelphia, Pa./Del./N.J./Md. 5,603 4,864 1,103 3,168 0.461 9.6

Phoenix, Ariz. 1,293 1,552 3,506 967 0.686 6.1

Pittsburgh, Pa. 2,277 5,929 646 890 0.425 10.0

Portland, Ore./Wash. 1,140 4,792 299 35 0.455 7.8

Providence, R.I. 853 5,791 531 779 0.450 10.8

Raleigh-Durham, N.C. 494 3,514 1,393 4,790 0.488 8.0

Reading, Pa. 306 5,827 770 1,466 0.454 9.0

Richmond, Va. 612 3,938 1,353 5,144 0.479 7.6

Rochester, N.Y. 970 6,718 531 1,658 0.430 9.7

Rockford, Ill. 269 7,729 459 1,343 0.491 10.0

Sacramento, Calif. 951 2,842 1,157 43 0.638 8.3

St. Louis, Mo./Ill. 2,386 4,748 1,474 6,210 0.517 9.5
160 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix C Regional Climate Information

SMSA Population

(thousands) HDD CDD LEH KT WND

Salinas-Monterey, Calif. 276 3,042 108 0 0.597 8.7

Salt Lake City-Ogden, Utah 843 5,981 927 0 0.640 8.7

San Antonio, Texas 1,036 1,570 2,993 12,953 0.531 9.3

San Diego, Calif. 1,744 1,507 722 318 0.583 6.7

San Fran.-Oak.-San Jose, Calif. 4,717 3,042 108 0 0.597 8.7

Santa Barbara-S. Maria, Calif. 292 3,053 83 0 0.599 7.0

Santa Rosa, Calif. 274 2,909 128 0 0.591 8.7

Scranton-Wilkes-Barre, Pa. 629 6,277 607 1,466 0.437 8.4

Seattle-Tacoma, Wash. 1,905 5,184 128 0 0.462 9.3

Shreveport, La. 356 2,165 2,538 12,312 0.519 8.9

South Bend, Ind. 281 6,462 695 1,426 0.460 11.0

Spokane, Wash. 320 6,835 387 0 0.538 8.7

Springfield, Mass. 587 6,349 583 1,473 0.429 9.0

Stockton, Calif. 313 2,842 1,157 43 0.638 8.3

Syracuse, N.Y. 650 6,678 551 1,354 0.426 9.8

Tampa-St. Petersburg, Fla. 1,396 716 3,366 19,037 0.521 8.8

Toledo, Ohio/Mich. 776 6,381 684 2,546 0.457 9.5

Tucson, Ariz. 462 1,751 2,813 1,011 0.679 8.2

Tulsa, Okla. 629 3,679 1,948 8,231 0.519 10.6

Utica-Rome, N.Y. 326 6,678 551 1,354 0.426 9.8

Washington, D.C./Md./Va. 3,017 5,008 940 3,734 0.472 9.2

W. Palm Beach-Boca Raton, Fla. 487 299 3,785 24,755 0.497 9.0

Wichita, Kan. 398 4,685 1,672 5,807 0.577 12.6

Worcester-Fitchburg, Mass. 645 5,620 661 779 0.450 10.5

York, Pa. 356 5,224 1,024 2,319 0.456 7.7

Youngstown-Warren, Ohio 546 6,426 517 993 0.420 10.0

Summary of 125 largest Standard Metropolitan Statistical Areas (SMSA’s) with population in thousands

and climate information. HDD, Heating Degree Days (oF, base 65 oF); CDD, Cooling Degree Days

(oF, base 65 oF); LEH, Latent Enthalpy Hours (measure of the amount of moisture that must be removed

from outdoor air to bring it to 77 oF and 60pct relative humidity; Btuh/lb dry air); KT, Solar Radiation

(ratio of the available sunshine at the earth’s surface to the sunshine available on a parallel plane above

the atmosphere); WND, Annual Average Wind Speed (miles/hr) based on regional climate center. Taken

from Andersson and others (1986).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 161

Appendix D

Tree Information

This Appendix contains information on Tree Growth Zones, tree selection, tree growth rates,

and CO2

 sequestration, as well as CO2 release through decomposition, and program-related

activities. The purpose of this information is to explain how data used in the Guidelines were

acquired and some of the associated assumptions and limitations.

Tree Growth Zones

Tree growth rates and size influence the stream of benefits from CO2 sequestration and energy

savings, as well as CO2 release rates due to tree maintenance and decomposition. Large, fastgrowing trees provide greater benefits sooner than small, slow-growing trees. Tree growth rates

in urban landscapes are highly variable, reflecting differences among species, growing conditions,

and level of care. Relatively few studies have quantified growth rates of urban trees in different

regions of the United States. Given this lack of data on urban tree growth we identify three Tree

Growth Zones (North, Central, and South) based on mean length of the frost-free period (fig. 25,

or fig. 18, Chapter 3). Default Tree Growth Zones are established for each Climate Region based

on geographic and demographic similarities (table 33). However, there are cases in which

boundaries do not coincide, and the default Tree Growth Zone does not match the map. For

example, the default Tree Growth Zone for Fresno, Calif., is Central because it is in the Southwest

Climate Region, but the Tree Growth Zone map shows that South is a better choice. Consult the

Tree Growth Zone map to determine whether the Zone for your location matches the default

Zone for your Climate Region. If it does not match, you can select a different Zone to customize

the subsequent calculations.

Figure 25—Tree growth zones for the United States correspond with mean number of freeze-free days per year (North = < 180,

Central = 180-240, South = > 240) (Repeated as figure 18 in Chapter 3).
162 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

We explain how tree growth curves were derived for each Growth Zone in the next section of

this Appendix. Growth rates and mature sizes increase with increasing length of the frost-free

period. Growth curve data can be compared to measured tree height and diameter at breast

height (breast height = 1.4 meters), dbh, from trees of known age to evaluate which Zone’s

growth curves are most accurate for your locale.

Tree Selection

The Tree Selection List (table 34) contains information to use when selecting tree species for

planting and when assigning individual tree species to one of the six tree type categories. A

USDA Hardiness map is included (fig. 26).

Tree selection is a compromise. There is no perfect tree that matches all the criteria required

by specific sites: beautiful flowers and form, deep rooting, drought tolerance, hardiness, pest/

disease resistance, rapid growth, strong branch attachments, and so on. Finding the best tree

takes time and study. Collecting information on conditions at the site is the first step. Consider

the amount of below- and above-ground space, soil type and irrigation, microclimate, and the

type of activities occurring around the tree that will influence its growth and management (e.g,.

mowing, parking, partying). In most cases it is too expensive to alter site conditions by making

them more suitable for a specific tree species. Instead, it is more practical to identify trees with

characteristics that best match the existing site conditions, particularly those conditions that will

be most limiting to growth.

Climate Region Tree Growth Zone

Mid-Atlantic Central

Northern Tier North

North Central North

Mountains North

Southeast Central

South Central Central

Pacific Northwest Central

Gulf Coast/Hawaii South

California Coast South

Southwest Central

Desert Southwest South

Note—Tree Growth Zones correspond to mean length of the

frost-freeze period as follows: North ≤180 days, 180 <

Central < 240 days, and South ≥240 days.

Table 33—Tree Growth Zones by Climate Region.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 163

Appendix D Tree Information

Figure 26—USDA plant hardiness zones (USDA 1990).
164 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

The matrix (table 34) presents information to assist tree selection. Tree species are listed

alphabetically. Information is presented on tree type (deciduous or evergreen), mature size,

hardiness zone, growth rate, and longevity. Solar friendly tree species are noted because they are

recommended for placement south of buildings to reduce winter shading. Also, the availability

of cultivars is indicated because this may increase the likelihood of matching tree characteristics

(e.g., no fruit, disease resistance, upright form) with site requirements. Consult local landscape

professionals to obtain further information pertaining to your situation. Sources used to develop

for the tree selection matrix are listed in the References section and a key follows.

Key to the matrix:

(a): From Gilman and others (1996).

(b): Cultivars with different form, flowering and fruiting traits provide options to better

match tree traits with site requirements.

(c): Tree Type: D-L, Deciduous-Large (>15m); D-M, Deciduous-Medium (11-15m); D-S,

Deciduous-Small (<11m); E-L, Evergreen Large (>15m); E-M, Evergreen-Medium (11-15m); E-S,

Evergreen-Small (6-11m)

(d): Growth Rate: F, Fast; M, Moderate; S, Slow. Gilman and others (1996).

(e): Hardiness Zone: See fig. 25, USDA Hardiness Zone Map.

(f ): Longevity: L, Long (>50 years); M, Medium (25-50 years); S, Short (<25 years).

(g): Solar Friendly trees provide Winter solar access as well as Summer shade; Trees

numerically ranked based on crown density, time of leaf drop, time of leaf out, crown area and

growth rate; VWC, Varies with cultivar; VWS, Varies with species; NDA, No data available.

From Ames (1987).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 165

Appendix D Tree Information

Table 34—Tree Selection List (a).

Available

Cultivars

Tree

Type

Mature

Height

Mature

Spread

Growth

Rate

USDA

Hardiness

Zone

LongevitySolar

Friendly

Scientific Name Common Names (b) (c) (meter) (meter) (d) (e) (f) (g)

1 Abies concolor White Fir, Colorado Fir Y E-M 14 6 S 3A-7B L NDA

2 Acacia farnesiana Sweet Acacia, Huisache N D-S 6 6 S 9A-11 S NDA

3 Acer buergerianum Trident Maple N D-M 11 8 M 4B-9B M Y

4 Acer campestre Hedge Maple Y D-M 10 10 S 5A-8A M N

5 Acer ginnala Amur Maple Y D-S 8 7 M 3A-8B M N

6 Acer negundo Boxelder Y D-M 14 11 F 3A-8B M N

7 Acer palmatum Japanese Maple Y D-S 6 6 S 5B-8B M Y

8 Acer platanoides Norway Maple Y D-L 15 11 F 4A-7A L VWC

9 Acer pseudoplatanus Sycamore Maple, Planetree Maple Y D-L 20 15 F 5A-7B L Y

10 Acer rubrum Red Maple, Swamp Maple Y D-L 21 9 F 4A-9B L Y

11 Acer saccharinum Silver Maple Y D-L 21 15 F 3A-9B L N

12 Acer saccharum Sugar Maple Y D-L 20 13 M 3A-8A L VWC

13 Aesculus hippocastanum Horsechestnut, European Horsechestnut Y D-S 6 9 F 6B-9B S VWC

14 Albizia julibrissin Mimosa, Silktree Y D-S 6 9 F 6B-9B S Y

15 Alnus glutinosa Common, Black, and European Alder Y D-M 14 9 M 3A-7B M N

16 Alnus rhombifolia White Alder N D-L 19 11 F 8A-11 L N

17 Amelanchier canadensis Shadblow and Downy Serviceberry N D-S 7 5 M 4A-7B M Y

18 Bauhinia spp. Orchid-Tree Y E-S 8 9 F 9B-11 M NDA

19 Betula nigra River Birch Y D-M 14 9 F 4A-9A M N

20 Betula papyrifera Paper Birch, Canoe Birch N D-L 16 8 M 3A-6B S Y

21 Betula pendula European Birch Y D-M 14 9 M 3A-6B S Y

22 Brachychiton acerifolius Flame Bottle Tree N D-M 13 8 F 10A-11 L NDA

23 Bursera simaruba Gumbo-Limbo N E-M 10 10 M 10B-11 L NDA

24 Carpinus betulus European Hornbeam Y D-L 15 11 S 4A-7B M VWC

25 Carya illinoensis Pecan N D-L 26 18 M 5B-9A L Y

26 Cassia excelsa Cassia N E-S 7 8 F 10B-11 M NDA

27 Casuarina spp. Australian-Pine, Casuarina Y E-L 24 11 F 9B-11 M NDA

28 Catalpa spp. Catalpa Y D-L 17 14 F 5A-9A M Y

29 Cedrus deodara Deodar Cedar Y E-L 15 8 F 7A-9A L NDA

30 Celtis occidentalis Common Hackberry Y D-L 19 14 F 3A-9B L Y

31 Celtis sinensis Japanese Hackberry, Chinese Hackberry N D-L 15 13 F 5A-9B L NDA

32 Cercidiphyllum japonicum Katsuratree Y D-L 15 14 F 4B-8B L Y

33 Cercis canadensis Eastern Redbud Y D-S 8 6 F 4B-9A M Y

34 Cercis occidentalis Western Redbud, California Redbud N D-S 6 6 M 6A-9B M Y

35 Chilopsis linearis Desert-Willow N D-S 8 6 M 7B-11 M NDA

36 Chorisia speciosa Floss-Silk Tree Y D-M 13 14 F 9B-11 M NDA

37 Cinnamomum camphora Camphor-Tree Y E-M 14 18 F 9B-11 L NDA

38 Citrus spp. Citrus Y E-S 6 6 M 9A-11 M NDA

39 Cladrastis kentukea American Yellowwood, Virgilia N D-M 12 14 M 4A-8B M NDA

40 Cornus florida Flowering Dogwood Y D-S 8 8 M 5A-9A M Y

41 Cornus kousa Kousa Dogwood, Chinese Dogwood Y D-S 5 5 S 5A-8B M Y

42 Corylus colurna Turkish Filbert, Turkish Hazel N D-L 15 9 S 5A-7B L Y

43 Crataegus laevigata English Hawthorn Y D-S 7 6 M 4B-8B M NDA

44 Crataegus phaenopyrum Washington Hawthorn Y D-S 8 7 M 4A-8A M N

45 Crataegus x lavallei Lavalle Hawthorn N D-S 8 6 M 5A-7A M N

46 Cryptomeria japonica Japanese-Cedar Y E-L 15 5 S 6A-8B L NDA

47 Cupaniopsis anacardiopsis Carrotwood N E-S 9 9 M 10A-11 M NDA

48 Cupressus sempervirens Italian Cypress Y E-L 15 1 M 7B-11 M NDA

49 Diospyros virginiana Common Persimmon N D-L 15 8 M 4B-9B L Y

50 Elaeagnus angustifolia Russian-Olive, Oleaster N D-S 5 5 F 3A-8B S Y

51 Eucalyptus ficifolia Red-Flowering Gum Y E-M 11 6 F 10A-11 L NDA

52 Eugenia spp. Stopper, Eugenia Y E-S 7 6 M 10B-11 M NDA

53 Fagus sylvatica European Beech Y D-L 19 15 M 4A-7B L N
166 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

Available

Cultivars

Tree

Type

Mature

Height

Mature

Spread

Growth

Rate

USDA

Hardiness

Zone

LongevitySolar

Friendly

Scientific Name Common Names (b) (c) (meter) (meter) (d) (e) (f) (g)

54 Fraxinus americana White Ash Y D-L 20 15 F 3A-9A L Y

55 Fraxinus excelsior Common Ash, European Ash N D-L 21 23 F 5A-8A L Y

56 Fraxinus oxycarpa `Raywood' Raywood Ash, Claret Ash N D-M 14 8 F 5A-8B L NDA

57 Fraxinus pennsylvanica Green Ash Y D-L 20 14 F 3A-9A L Y

58 Fraxinus velutina Velvet Ash, Modesto Ash, Arizona Ash N D-M 12 16 F 7A-8B M NDA

59 Geijera parviflora Australian-Willow N E-S 10 7 F 9A-11 MM NDA

60 Ginkgo biloba Maidenhair Tree, Ginkgo Y D-L 19 17 S 3A-8A L Y

61 Gleditsia triacanthos var. inermis Thornless Honeylocust Y D-L 19 13 F 3A-8A L Y

62 Grevillea robusta Silk-Oak N E-L 24 8 F 9B-11 L NDA

63 Gymnocladus dioicus Kentucky Coffeetree N D-L 16 16 M 3B-8B L Y

64 Halesia carolina Carolina Silverbell Y D-L 15 7 M 5A-8B M Y

65 Jacaranda mimosifolia Jacaranda Y D-M 10 16 F 9B-11 M NDA

66 Juglans nigra Black Walnut Y D-L 20 18 M 5A-9A L Y

67 Koelreuteria paniculata Goldenraintree, Varnish-Tree Y D-M 11 11 M 5B-9B M Y

68 Laburnum spp. Goldenchain Tree Y D-S 7 5 M 5B-7B M Y

69 Lagerstroemia indica Crapemyrtle Y D-S 6 6 M 7A-9A M Y

70 Larix decidua European Larch, Common Larch N D-L 20 10 M 2A-6B L Y

71 Liquidambar styraciflua Sweetgum Y D-L 21 13 M 5B-10A L VWC

72 Liriodendron tulipifera Tuliptree, Tulip-Poplar, Yellow-Poplar N D-L 27 12 M 5A-9A L N

73 Magnolia acuminata Cucumbertree, Cucumber Magnolia Y D-L 21 14 F 3B-8B L Y

74 Magnolia grandiflora Southern Magnolia Y E-L 21 11 M 7A-10A L NDA

75 Magnolia kobus Kobus and Northern Japanese Magnolia Y D-M 8 9 S 5A-8A M N

76 Magnolia x soulangiana Saucer Magnolia Y D-S 7 8 M 5A-9A M Y

77 Malus spp. Crabapple Y D-S 5 5 M 4A-8A M VWC

78 Melia azedarach Chinaberry N D-M 11 6 F 7A-10B M N

79 Metasequoia glyptostroboides Dawn Redwood N D-L 24 6 F 5A-8B L Y

80 Morus alba fruitless cultivars White Mulberry N D-S 8 11 F 3B-9B M N

81 Nyssa sylvatica Blackgum, Sourgum, Black Tupelo N D-L 21 9 S 4B-9B L Y

82 Ostrya virginiana American and Eastern Hophornbeam N D-M 11 8 S 3A-9A M NDA

83 Oxydendrum arboreum Sourwood, Sorrel-Tree N D-L 15 8 S 5A-9A M Y

84 Paulownia tomentosa Princess-Tree, Empress-Tree, Paulownia N D-M 14 14 F 5B-9B M Y

85 Phellodendron amurense Amur Corktree, Chinese Corktree Y D-M 11 15 M 3B-8B L Y

86 Picea abies Norway Spruce Y E-L 27 10 S 2B-7A L NDA

87 Picea glauca White Spruce N E-L 15 5 M 2A-6B L NDA

88 Picea pungens Colorado Spruce, Blue Spruce Y E-M 12 5 S 4A-7B L NDA

89 Pinus bungeana Lacebark Pine N E-M 12 5 S 4A-8A L NDA

90 Pinus densiflora Japanese Red Pine Y E-M 12 12 M 3B-7A L NDA

91 Pinus eldarica Mondell Pine N E-M 11 8 M 6A-8B L NDA

92 Pinus nigra Austrian Pine, Black Pine N E-M 15 9 M 5A-8A S NDA

93 Pinus palustris Longleaf Pine N E-L 21 11 F 7A-10A L NDA

94 Pinus parviflora Japanese White Pine Y E-M 11 11 S 4B-7A L NDA

95 Pinus pinea Stone Pine, Italian Stone Pine, Umbrella-Pine N E-M 14 12 M 7A-11 L NDA

96 Pinus ponderosa Ponderosa Pine, Western Yellow Pine N E-L 20 8 F 3A-7B L NDA

97 Pinus strobus Eastern White Pine Y E-L 20 9 F 3B-7B L NDA

98 Pinus sylvestris Scotch Pine N E-M 14 8 M 3A-8A M NDA

99 Pinus taeda Loblolly Pine Y E-L 20 10 F 6B-9B L NDA

100 Pinus thunbergiana Japanese Black Pine N E-S 8 8 M 6A-8B M NDA

101 Pinus virginiana Virginia Pine, Scrub Pine N E-S 9 8 M 5A-8B M NDA

102 Pistacia chinensis Chinese Pistache N D-M 9 9 M 6B-9B M NDA

103 Platanus occidentalis Sycamore, American Planetree N D-L 25 18 F 4B-9A L N
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 167

Appendix D Tree Information

Available

Cultivars

Tree

Type

Mature

Height

Mature

Spread

Growth

Rate

USDA

Hardiness

Zone

LongevitySolar

Friendly

Scientific Name Common Names (b) (c) (meter) (meter) (d) (e) (f) (g)

104 Platanus x acerifolia London Planetree Y D-L 24 18 F 5A-9A L N

105 Populus alba White Poplar Y D-L 24 15 F 4A-9B M N

106 Populus deltoides Eastern Cottonwood N D-L 27 15 F 2A-9B L NDA

107 Prosopis glandulosa Mesquite, Honey Mesquite N D-M 9 9 M 6B-9B L NDA

108 Prunus cerasifera Cherry Plum, Purple-Leaf Plum Y D-S 5 4 M 5B-8A S VWC

109 Prunus sargentii Sargent Cherry Y D-M 10 10 F 5A-8A M Y

110 Prunus serrulata Flowering Cherry Y D-S 6 6 M 5B-9A S VWC

111 Pseudotsuga menziesii Douglas-Fir Y E-L 15 6 M 5A-6B L NDA

112 Pyrus calleryana Callery Pear Y D-M 12 9 F 5A-9A M N

113 Quercus acutissima Sawtooth Oak N D-M 12 13 M 5B-9A L NDA

114 Quercus alba White Oak N D-L 24 21 S 3B-8B L N

115 Quercus coccinea Scarlet Oak N D-L 21 16 M 5A-8B L Y

116 Quercus laurifolia Diamond Leaf Oak N E-L 20 12 F 6B-10A M NDA

117 Quercus macrocarpa Bur Oak N D-L 24 21 M 3A-8B L N

118 Quercus muehlenbergii Chinkapin Oak, Chestnut Oak N D-L 15 17 F 3A-8B L NDA

119 Quercus nigra Water Oak N D-L 17 20 F 6A-10A M NDA

120 Quercus palustris Pin Oak N D-L 19 11 M 4A-8A L N

121 Quercus phellos Willow Oak N D-L 21 14 F 6A-9B L N

122 Quercus robur English Oak Y D-L 17 15 M 5A-8B L N

123 Quercus rubra Northern Red Oak N D-L 20 17 F 5A-8A L N

124 Quercus shumardii Shumard Oak N D-L 21 14 F 5B-9B L N

125 Quercus velutina Black Oak N D-L 18 13 S 4B-8A L NDA

126 Quercus virginiana Southern Live Oak, Live Oak N E-L 21 27 M 7B-10B L NDA

127 Robinia pseudoacacia Black Locust, Common Locust Y D-L 17 9 F 4A-8B M VWC

128 Salix spp. Weeping Willow, Babylon Weeping Willow Y D-L 18 18 F 2A-9A M VWS

129 Sapium sebiferum Chinese Tallowtree, Popcorn Tree,

Tallowtree

N D-M 10 9 F 8A-11 S NDA

130 Sequoia sempervirens Coast Redwood N E-L 27 9 M 7A-10A L NDA

131 Sophora japonica Scholar Tree, Japanese Pagoda Tree Y D-L 17 17 M 5A-8A L NDA

132 Sorbus aucuparia European Mountain-Ash N D-M 8 6 M 3B-6B S VWC

133 Syringa reticulata Japanese Tree Lilac Y D-S 8 6 M 4A-7A M NDA

134 Tabebuia caraiba Trumpet Tree N E-S 6 4 M 10A-11 M NDA

135 Taxodium distichum Baldcypress Y D-L 21 9 F 5A-10B L NDA

136 Tibouchina granulosa Purple Glory Tree N E-S 5 5 M 10B-11 M NDA

137 Tibouchina urvilleana Princess-Flower N E-S 4 4 M 9B-11 M NDA

138 Tilia americana American Linden, Basswood, Y D-L 20 13 M 3A-8B L N

139 Tilia cordata Littleleaf Linden Y D-L 20 13 M 4A-7A L Y

140 Tipuana tipu Tipu Tree, Pride-of-Bolivia N D-M 12 20 F 9B-11 M NDA

141 Tsuga canadensis C anadian H emloc k, Easter n H emloc k Y E-L 18 13 S 4A-7A L NDA

142 Ulmus parvifolia Chinese Elm, Lacebark Elm Y D-M 14 13 M 5B-10A L N

143 Ulmus pumila Siberian Elm N D-L 18 13 F 5A-9B M Y

144 Ulmus x `Urban' `Urban' Elm N D-L 17 12 F 4B-8A UNK NDA

145 Vitex agnus-castus Chastetree, Vitex Y D-S 4 5 F 7B-11 M NDA

146 Zelkova serrata J apanes e Zelk ov a, Saw- Leaf Zelk ova Y D-L 21 19 M 5A-8B L Y

KEY:

(a): From Gilman and others (1996).

(b): Cultivars with different form, flowering and fruiting traits provide options to better match tree traits with site requirements.

(c): Tree Type: D-L, Deciduous-Large (>15m); D-M, Deciduous-Medium (11-15m); D-S, Deciduous-Small (<11m); E-L, Evergreen Large 

(d): Growth Rate: F, Fast; M, Moderate; S, Slow. Gilman and others (1996).

(e): Hardiness Zone: See fig. 25, USDA Hardiness Zone Map.

(f ): Longevity: L, Long (>50 years); M, Medium (25-50 years); S, Short (<25 years).

(g): Solar Friendly trees provide Winter solar access as well as Summer shade; Trees numerically ranked based on crown density, time of leaf drop, time of leaf

out, crown area and growth rate; VWC, Varies with cultivar; VWS, Varies with species; NDA, No data available. From Ames (1987).
168 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

Tree Growth Rates, CO2 Sequestration, and Tree Decomposition

Carbon dioxide sequestration refers to the annual rate of CO2 storage in above- and belowground

biomass over the course of one growing season. Biomass equations are used in conjunction with

tree growth data (i.e., height and dbh) to calculate CO2

 stored at any one time. Sequestration is

calculated as the difference between CO2

 stored in successive years. Although years of forest

research have produced many biomass equations and growth data sets for forest trees, relatively

few data exist for urban trees. Application of biomass formulas derived from forest trees may not

accurately reflect biomass for open-grown urban trees. A comparison of measured weight and

formula-derived weights for 30 street trees in Oak Park, Ill., found that, on average, formuladerived estimates from forest trees were 20 percent greater than actual tree weights (Nowak

1994). Growth curves derived from forest trees may not accurately reflect relations between age

and dimensions of urban trees. For example, the mean annual dbh growth rate for a sample (N =

118) of residential trees in Chicago was 1.1 cm (0.4 inches) compared to 0.4 cm (0.16 inches) for

hardwood trees growing in forest areas of Indiana and Illinois (Jo and McPherson 1995). Where

appropriate, our sequestration estimates rely on biomass equations and growth data derived

from urban trees.

We used a three-step process to derive estimates of annual CO2 sequestration: develop

growth curves, select biomass equations, and compute sequestration. Tree types and Tree Growth

Zones were used in the analysis procedure.

Tree Types

Deciduous or evergreen life forms were selected to incorporate effects of trees with different

foliation periods on building heating and cooling energy use. Large (>15 m height), medium (10-

15 m), or small (<10 m) mature sizes were selected to account for size-related impacts on CO2

sequestration potential, shading impacts, and climate modification.

Tree Growth Zones

In urban landscapes, tree growth rates are highly variable. This variability reflects the diversity

of the urban forest: its many tree species, range of growing conditions, and levels of care that vary

from neglect, to abuse, to professional pampering. Although relative growth rates have been

assigned to most species, few studies have quantified relations between tree age, dbh, height, and

other dimensional parameters. Given the dearth of data on urban tree growth and our need for a

parsimonious analysis, we used mean length of the frost-free period (i.e., growing season length)

to derive three tree growth zones for the United States (fig. 25). We assumed that the North Zone

covers the Northeast, Midwest, and Mountain West and has a mean freeze-free period of less

than 180 days. The freeze-free period of the Central Zone extends from 180 to 240 days, and this

Zone covers much of the mid-Atlantic and South Central United States. The South Zone is

assumed to be freeze-free for 240 to 340 days and ranges from Seattle to Los Angeles and Phoenix

in the West and Charleston, S.C., to Miami, Houston, and Dallas in the South. As the next section

explains, we derived “typical” growth curves for each tree type in each Tree Growth Zone (6 x 3

= 18 curves).

Develop Growth Curves

To model tree growth in the North Zone we relied on equations developed by Frelich (1992) in

Minneapolis using 221 city trees of known age comprising 12 species (9-27 trees per species). He

used non-linear regression to fit a sigmoid-shaped predictive model for dbh as a function of age

for each species. Then, predictions for tree height were modeled as a function of dbh, using the

same model as dbh versus age, or a power function with a constant. The R-square for age-dbh

relationships ranged from 0.797 to 0.967, and was greater than 0.90 for 9 of 12 species. The form of

the equations that we used is:

dbh=B0 (1-e(B1)(Age))B2 (Eq.4)

Tree Height=B0=(B1)(dbhB2) (Eq.5)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 169

Appendix D Tree Information

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Age (Years)

North Central South Minn-ash

NJ-ash Sac-ash NJ-plane Sac-plane

The constants B0, B1, and B2 are listed in table 35. There are approximately 150 frost-free

days in the Minneapolis area.

To develop curves for the South Tree Growth Zone we adjusted coefficients in the regression

equations using data from Sacramento. Sacramento has 270 frost-free days and therefore is in the

South Growth Zone (240-340 frost-free days), but many cities in this zone have more than 270 frostfree days. Two data sets were available. Tree height and dbh from 3,882 6-year-old residential yard

trees were measured by Sacramento Shade staff as part of their stewardship program (Small 1997).

With tree planting dates provided by the Sacramento Tree Services Division, our staff measured 75

30-year-old street trees. “Typical” growth curves for height and dbh were produced using measured

data points at ages 6 and 30. We defined these growth curves as “typical” of small, medium, and large

deciduous trees. We assumed that height and dbh of trees in the Central Zone fell midway between

points on curves for the Northern and Southern Zones. As an initial check, results were compared

with predicted data on the basis of surveys of street trees of known age in central New Jersey (Fleming

1988) and Milwaukee Wisconsin (Churack 1992) (figs. 27 and 28).

0 

10 

20 

30 

40 

50 

60 

70 

Height (ft)

0 10 20 30 40 Age (Years)

North Central South Minn-ash

NJ-ash Sac-ash NJ-plane Sac-plane

Figure 27—Predicted dbh curves for the “typical” large deciduous

tree in each Tree Growth Zone. These curves were calibrated

using predicted sizes based on measured ash (Fraxinus spp.) and

plane (Platanus acerifolia) trees in Minneapolis, central New Jersey,

and the Sacramento area (mean values shown). In developing the

growth curves, we assumed that trees were 2 years old when

planted.

Figure 28—Predicted height curves for the “typical” large

deciduous tree in each Tree Growth Zone.

Tree Growth dbh Height

Type Zone B0 B1 B2 B0 B1 B2

Small North 8 -0.07 1.9 0 6.5 0.585

Deciduous South 15.5 -0.07 1.9 0 6.5 0.61

Med North 14 -0.07 1.9 2 6.5 0.64

Deciduous South 26 -0.07 1.9 0 6.5 0.65

Large North 16 -0.07 1.9 0 6.5 0.76

Deciduous South 33.5 -0.07 1.9 0 6.5 0.72

Small North 13 -0.0176 1.415 1 6 0.68

Evergreen South 18.7 -0.1 1.9 0 6.5 0.592

Med North 24 -0.0176 1.415 1 6 0.67

Evergreen South 33 -0.06 1.7 -4 8.4 0.6

Large North 35 -0.0176 1.415 1 6 0.77

Evergreen South 40 -0.06 1.7 -4 8.4 0.66

Table 35—Coefficients used in growth curve equations.
170 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Large Deciduous Tree Height

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

Large Deciduous Tree DBH

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

Medium Deciduous Tree DBH

Lacking data on growth curves for evergreen trees, an initial set of curves was developed on

the basis of the Minneapolis equations for blue spruce (Picea pungens) (Frelich 1992) (N = 22, R2 =

0.929 for dbh and 0.946 for height). All growth curves were sent for review to 11 experts. We

received comments back from five reviewers (Ed Gilman, University of Florida; Don Ham,

Clemson University; James McGraw, North Carolina State University; Bob Miller, University of

Wisconsin, and Tom Perry, University of North Carolina) and modified the growth curves on the

basis of their comments (table 35). The primary adjustment was to increase the growth rates and

mature sizes of evergreen trees relative to deciduous trees in the Southern tree growth zone. As a

result of that adjustment, mature large evergreens are bigger than large deciduous trees in the

Southern Zone, about the same size in the Central Zone, and smaller in the Northern Zone (figs.

29 and 30).

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

North Central South

Small Deciduous Tree DBH

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Small Deciduous Tree Height

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Medium Deciduous Tree Height

Figure 29a Figure 29b

Figure 29c Figure 29d

Figure 29e Figure 29f

Figure 29—Growth curves for deciduous trees.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 171

Appendix D Tree Information

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

Medium Evergreen Tree DBH

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Medium Evergreen Tree Height

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

Large Evergreen Tree DBH

0 

5 

10 

15 

20 

25 

30 

35 

DBH (inches)

0 10 20 30 40 Years after Planting

North Central South

Small Evergreen Tree DBH

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Small Evergreen Tree Height

Figure 30a Figure 30b

0 

10 

20 

30 

40 

50 

60 

70 

80 

Height (feet)

0 10 20 30 40 Years after Planting

Large Evergreen Tree Height

Figure 30e Figure 30f

Figure 30c Figure 30d

Figure 30—Growth curves for evergreen trees.

Select Biomass Equations

To select the best biomass equation for estimating sequestration from a variety of deciduous tree

species planted in a CO2 reduction program we compared formula-derived estimates to

measured data from 32 trees representing eight tree species located near Davis, Calif. (Peper and

McPherson 1998) and Chicago, Ill. (Jo and McPherson 1995) (table 36). Field data were obtained

by (1) measuring tree height and dbh before tree removal, (2) felling and weighing the trees, and
172 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

dbh Height Dry weight Mean Standard

Species Number Location Range (cm) Range (m) Range (kg) DW (kg) Deviation

Acer platanoides 3 Chicago 30.5-53.3 10.7-18.3 433-1,092 811 340

Acer saccharinum 9 Chicago 53.3-99.1 15.2-19.8 1,104-4,334 2,266 1,051

Acer saccharum 1 Chicago 25.4 6.1 101 101 n/a

Fraxinus pennsylvanica 3 Chicago 25.4-86.4 6.1-21.3 125-5,687 2,215 3,028

Morus alba 6 Davis 12.9-19.4 4.5-8.1 42-140 82 36

Prunus serotina 2 Davis 20.4-20.9 7.15-7.7 104-107 106 2

Tilia sp. 1 Chicago 48.3 13.7 717 717 n/a

Ulmus americana 7 Chicago 45.7-96.5 12.2-24.4 812-4,123 2,731 1,069

Species Reference

dbh Range

(cm)

Height

Range

(m)

Mean Diff.

(kg)

Standard

Error

General Hardwoods Harris and others 1973 >10 n/a 486.2 119.2

Acer saccharum Young and others 1980 2.5-66 n/a 824.1 158.8

Celtis occidentalis Hahn 1984 n/a n/a -362.1 84.4

Fraxinus americana Brenneman and others 1978 5-51 n/a 1,086.8 213.6

Liquidambar styraciflua Pillsbury and Thompson 1995 14-54 7-20 -393.2 93.7

Platanus sp. Hahn 1984 n/a n/a -373.2 85.7

Quercus lobata Pillsbury and Kirkley 1984 10-100 6-30 390.9 111.8

Ulmus parvifolia Pillsbury and Thompson 1995 15-56 8-19 26.9 78.3

(3) drying wood samples to derive dry-weight aboveground biomass. Biomass equations (table

37) were selected for testing because they were obtained from samples of trees in urban settings

(Ulmus parvifolia, Liquidamber styraciflua), were derived from primarily open-growing trees

(Quercus lobata), and were derived from rural forest trees but applied to urban trees (general

hardwoods, Fraxinus spp., Celtis spp., Acer saccharum, Platanus spp.) in other urban forest studies

(Jo and McPherson 1995; McPherson 1998b; Nowak 1993, 1994). Formula-derived estimates of

aboveground biomass were calculated for each tree (32 total) using each biomass equation (8

total). Standard descriptive statistics were used to compare differences between formula-derived

estimates and actual biomass. The equation for Ulmus parvifolia produced the most accurate and

precise biomass estimates, on average (fig. 31). Subsequent CO2

 sequestration computations for

deciduous trees apply this equation.

Table 36—Eight species, a total of 32 trees with known dry weights (DW), were used to evaluate the accuracy of eight biomass equations.

Table 37—Attributes of biomass equations for deciduous tree species used to predict carbon dioxide storage (n/a = data not available or

variable not used in equation).

-1,500 

0 

1,500 

Mean Difference (kg), 1 Standard Error

Hdwd. Acer Celt. Frax. Liq. Plat. Quer. Ulm.

Biomass Formula

Figure 31—The accuracy and precision of predictions from

eight biomass equations are compared with actual measured

biomass from 32 urban trees representing six species.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 173

Appendix D Tree Information

The unavailability of measured woody biomass data for urban evergreen trees limited our

ability to statistically assess the accuracy and precision of alternative biomass equations. Using

the same dimensions for a medium-sized evergreen in Minnesota (Picea pungens from Frelich),

aboveground dry- weight was calculated with eight formulas (table 38). Six of the formulas were

derived from urban trees (Eucalyptus globulus, Cinnamomum camphora, Ceratonia siliqua, Quercus

ilex, Cupressus macrocarpa, Pinus radiata), and two were from rural forests but previously applied

to urban forests (general softwoods, Pinus strobus). Equations for Ceratonia siliqua and Quercus

ilex, two broadleaf evergreens, produced the highest estimates, whereas formulas for two conifer

species gave the lowest values (Cupressus macrocarpa and Pinus radiata) (fig. 32). Intermediate

values were produced by the general softwoods formula. The equation for general softwoods

was selected as most likely to produce biomass estimates representative of the mix of evergreen

species in an urban forestry planting program.

Compute CO2 Sequestration

Biomass equations for Ulmus parvifolia (Pillsbury and Thompson 1995) and general softwoods

(Monteith 1979) were used to compute total tree biomass for deciduous and evergreen tree types,

respectively. Results from the general softwoods equation (aboveground biomass as dry-weight)

were divided by 0.78 to convert to total tree biomass. This conversion factor assumes that 22

percent of total tree biomass is in the stump/root system (Husch and others 1982; Tritton and

Species Reference

dbh Range (cm) Height

Range (m)

General Softwoods Monteith 1979 2.5-55 5-30

Ceratonia siliqua Pillsbury and Thompson 1995 n/a n/a

Cinnamomum camphora Pillsbury and Thompson 1995 13-69 5-17

Cupressus macrocarpa Pillsbury and Thompson 1995 n/a n/a

Eucalyptus globulus Pillsbury and Thompson 1995 n/a n/a

Pinus radiata Pillsbury and Thompson 1995 n/a n/a

Pinus strobus Young and others 1964 15-38 14-24

Quercus ilex Pillsbury and Thompson 1995 13-52 5-17

Table 38—Attributes of biomass equations for evergreen tree species used to predict carbon dioxide storage (n/a = data not available).

0 

200 

400 

600 

800 

1000 

predicted dry weight (kg)

0 10 20 30 40 age

General Softwoods Cinnamomum camphora Eucalyptus globulus

Pinus radiata Quercus ilex Ceratonia siliqua

Cupressus macrocarpa Pinus strobus

Figure 32—This comparison shows predicted biomass obtained

from eight equations when applied to growth of the same typical

tree.
174 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

Hornbeck 1982; Wenger 1984). The equation for Ulmus parvifolia computes wood volume in cubic

feet (cf). Fresh-weight was calculated using a green weight of 864.96 kg/m3 (54 lbs/cf)

(Markwardt 1930). Fresh-weight biomass was multiplied by 0.51 to derive dry-weight biomass

on the basis of average moisture content of elms (Husch and others 1982; Markwardt 1930).

Results from these calculations were divided by 0.75 to convert to total tree biomass. This

conversion factor assumes 3 percent of the biomass in foliage and 22 percent in the stump/root

system. Total dry-weight biomass estimates for each individual tree were converted to total

carbon storage estimates by multiplying by 0.50 (Leith 1975; Whittaker and Likens 1973). Carbon

storage values were converted to CO2

 by multiplying by 3.67, the ratio of molecular weights of

CO2 to carbon. Tree dimensions associated with maximum CO2 sequestration values (t/yr) are

listed for each tree type by Tree Growth Zone in table 39.

The sequestration values resulting from this process are first-order approximations due to

the high degree of uncertainty concerning the accuracy of tree growth rates and biomass

equations. Some of the reasons why these values may have limited application in your analysis

include:

• Mature tree sizes are different than the dimensions assumed here.

• Biomass equations are available that better predict CO2

 storage than equations

used here.

• Growth rates and associated tree dimensions differ from those assumed here.

• Tree type categories are different to better depict differences among trees, and these

new categories require different CO2

 storage estimates.

Tree Growth Zone/

Tree Type

dbh

cm (in)

height

m (ft)

CO2 uptake

kg/yr (lb/yr)

North Zone

Large-Dec 27.5 (10.8) 12.1 (39.7) 42.9 (94.7)

Med.-Dec 24.0 (9.5) 9.0 (29.4) 26.4 (58.1)

Small-Dec 13.7 (5.4) 5.3 (17.4) 5.5 (12.2)

Large-Evr 20.6 (8.1) 9.5 (31.1) 22.0 (48.4)

Med.-Evr 14.1 (5.6) 6.1 (19.9) 7.3 (16.0)

Small-Evr 4.5 (1.8) 3.0 ( 9.9) 1.1 (2.5)

Central Zone

Large-Dec 42.5 (16.7) 15.4 (50.6) 132.8 (292.5)

Med.-Dec 34.3 (13.5) 10.9 (35.6) 66.8 (147.3)

Small-Dec 20.2 (7.9) 6.8 (22.3) 15.3 (33.8)

Large-Evr 43.4 (17.1) 15.1 (49.6) 109.3 (240.9)

Med.-Evr 34.4 (13.5) 10.5 (34.4) 47.1 (103.7)

Small-Evr 17.7 (7.0) 5.9 (19.2) 12.6 (27.7)

South Zone

Large-Dec 57.5 (22.6) 18.7 (61.4) 294.7 (649.8)

Med.-Dec 44.6 (17.6) 12.8 (41.9) 133.7 (294.8)

Small-Dec 26.6 (10.5) 8.3 (27.2) 32.3 (71.1)

Large-Evr 66.1 (26.0) 20.8 (68.2) 302.8 (667.5)

Med.-Evr 54.6 (21.5) 14.9 (48.9) 147.0 (324.2)

Small-Evr 30.9 (12.2) 8.7 (28.6) 46.6 (102.8)

Table 39—Tree dimensions and CO2 sequestration values when trees are sequestering CO2 at their maximum

rate.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 175

Appendix D Tree Information

CO2 Release Through Tree Decomposition

The rate of CO2 released through decomposition of dead woody biomass varies with

characteristics of the wood itself, fate of the wood (e.g., left standing, chipped, burned), and local

soil and climatic conditions. Tree roots comprise about 18 percent of total carbon stored in a

mature tree. Fine roots account for approximately 75 percent of total root biomass, and decompose

more quickly than the larger roots. It is estimated that only about 20 percent of the carbon stored

in the root system is released to the atmosphere as CO2, with the remaining amount converted to

other forms of carbon (Powers 1997).

Fallen forest trees can take 30 to 60 years or longer to completely disappear, with stored

carbon moving into soil humus, decomposing organisms, and the atmosphere. Recycling of

urban waste is now prevalent, and most material is chipped and applied as landscape mulch.

This process, combined with applications of fertilizers and irrigation, hastens decomposition. A

study of red pine needle litter reported that after approximately 4 years, 80 percent of the original

mass was gone (Melillo and others 1989). The decomposition rate of landscape mulch in Southern

California is about 2-4 cm a year (Larson 1997). For these guidelines we conservatively estimate

that dead trees are removed and mulched in the year in which death occurs, and that 80 percent

of their stored carbon is released to the atmosphere as CO2

 in the same year. The scientific

underpinnings for assumptions regarding both the percentage of stored CO2

 released to the

atmosphere and the rate of release over time are weak because of little research on this aspect of

urban forestry.

Calculations of total annual decomposition are based on the number of trees in each size class

that die in a given year and their woody biomass. Tree survival rate is the principal factor

influencing decomposition. You can select from among three tree survival rates provided in

Appendix H or create your own rate for each 5-year period.

Tree Program-Related CO2 Release

Three types of tree program-related CO2 emissions are accounted for in this analysis: municipal

tree maintenance, tree nursery production, and non-profit program operations. Our default

values are based on a survey of wholesale nurseries, non-profit tree programs, and municipal

forestry programs. The CO2 emission rates were highly variable among programs, suggesting

that these values may not accurately reflect the actual values for your program. On the other

hand, some error in estimating these emission rates is acceptable because total program-related

emissions are only on the order of 5 percent of total CO2

 sequestered and avoided (Simpson and

McPherson 1998).

Survey of Tree-Related CO2 Emissions

Questionnaires were mailed to a geographically diverse sample of 14 wholesale nurseries

(contacts provided by Craig Regelbrugge, American Nursery and Landscape Association), 18

non-profit tree programs (Jennifer Barsotti, Alliance for Community Trees), and 16 municipal

forestry departments (Bob Benjamin, Society of Municipal Arborists). Responses were received

from 5 nurseries (36 percent response rate), 12 non-profit programs (67 percent response), and 13

municipal programs (81 percent response).

Estimates of CO2 release associated with annual consumption of gasoline and diesel fuel by

motor vehicles, chain saws, chippers, and other equipment were obtained using CO2 coefficients

of 8.62 kg CO2

 / gal. of gasoline and 10.66 kg CO2 / gal. of diesel (City of Austin 1997). Emissions

associated with electricity and natural gas used to heat and cool buildings, light office space,

power pumps, heat water, and for other purposes were obtained using a CO2

 coefficient of 0.59

kg CO2

 / therm of natural gas (DOE/EIA 1992) and average coefficients for electricity by state

(table 41, in Appendix D). Annual energy consumption was reported directly (kWh and therms),

estimated from reported annual expenditures using current prices, or calculated from reported

conditioned floor areas (CFA) using energy intensity data (e.g., kWh/sq ft CFA) for five U.S.

climate zones (DOE/EIA 1994).

As costs for tree care activities such as pruning and removal increase with tree size (usually

dbh), CO2

 emissions similarly increase. Survey data from municipal forestry programs are used
176 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

to calculate an average base emission value on a per cm dbh basis. This base value is multiplied

by the 40-yr size of each tree type in each Tree Growth Zone to account for size differences. These

mature tree values are back-calculated to derive emissions for each 5-year period. The equation

for calculating the base value M is:

where:

Gi = emissions from gasoline fuel consumed at municipal program i

Ei = emissions from diesel fuel consumed at municipal program i

Di = average dbh (cm) of all trees managed by municipal program i

Ti = total number of trees managed by municipal program i

The equation to calculate the weighted average CO2 emissions (kg) per tree produced N at

nurseries is:

where:

Vi = emissions from vehicles at nursery i

Bi =emissions from heating, cooling, and other building/greenhouse operations at

nursery i

Pi = emissions from fossil fuel consuming equipment in the production area at nursery i

Ti = average number of trees in the inventory of nursery i at any one time

Ri = average number of trees sold annually at nursery i

A similar equation calculates the weighted average of annual CO2 emissions per tree planted

G by non- profit programs:

where the term i refers to each program.

Results. Data from the survey are listed in table 40. Municipal programs release on average

approximately 0.14 kg CO2 annually per cm of dbh for each tree that they manage. This amounts

to 11.6 kg annually for a large, mature deciduous tree (83 cm dbh). Carbon dioxide released via

tree care is the greatest single source of CO2 release because it accrues on an annual basis. On

average for this sample, 0.7 and 2.6 kg of CO2 are emitted annually per tree produced at nurseries

and planted by non- profit programs, respectively. Emissions from tree production are accounted

for on a one-time basis, as is often the case with emissions from non-profit program operations.

Municipal Tree Care

Tree care that involves the use of vehicles, chain saws, chippers, and other equipment powered

by gasoline or diesel results in the release of CO2. Default values are based on a survey of street

tree managers. When evaluating the applicability of the default values to your program, consider

the level of care program trees are likely to receive over the 40-year period. Will trees be

maintained by contractors, property owners/tenants, volunteers, or trained staff? Will vehicle

use be extensive? Will trees be pruned regularly? If, on average, street trees receive more

 Gj

+Ej

 Tj+Dj

M=

 Vj+Bj+Pj

 Tj+Rj

N=

 Vj+Bj

 Tj

M=
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 177

Appendix D Tree Information

intensive care than the trees planted by your program, the default values may overstate your

program’s CO2 release rates. Look-up Table values are a product of the average base release rate

(0.14 kg/cm dbh) and the dbh size of each tree type at year 40.

Tree Production

The survey findings suggest that CO2 release associated with tree production is relatively

modest. The analysis accounts for CO2 release through heating and cooling of nursery office

40a. Municipal tree care. Result = 0.14

# Trees Average Total fuel

City, State managed dbh (cm) kg CO2/yr

Wellesley Hills, MA 5,759 61.0 21,126

Dallas, TX 10,000 76.2 102,731

Mesquite, TX 10,000 10.2 145,620

Colorado Springs, CO 100,000 45.7 144,600

Lompoc, CA 19,503 26.7 77,300

Portland, OR 150,000 20.3 231,360

Ithaca, NY 11,000 27.9 87,629

Sarasota, FL 12,300 20.3 90,567

Salt Lake City, UT 72,000 40.6 32,205

Sacramento, CA 97,000 61.0 346,184

Modesto, CA 95,000 30.5 395,089

Milwaukee, WI 200,000 25.4 353,635

Minneapolis, MN 275,000 30.5 3,007,680

1,057,562 5,035,727

40b. Tree production. Result = 0.69 avg. kg CO2 per tree

pct Annual Vehicle Office Production Total

Name City, State # Trees turnover kg CO2/yr kg CO2/yr kg CO2/yr kg CO2/yr

Glacier Nursery Kalispell, MT 50,000 25 pct 17,714 5,283 68,725 91,722

Cherry Lake Farms Groveland, FL 800,000 25 pct 1,042,900 22,360 9,433 1,074,693

Forrest Keeling Nursery Elsberry, MO 4,000,000 75 pct 146,080 94,299 286,897 527,276

High Ranch Nursery Sacramento, CA 12,500 100 pct 156,022 9,901 7,853 173,776

KF Evergreen Osseo, WI 1,000,000 8 pct 275,840 44,368 88,736 408,944

5,862,500 2,276,410

40c. Non-profit programs. Result = 2.62 avg. kg CO2 per tree

# Trees Vehicle Office Total

Name City, State Planted/Yr kg CO2/yr kg CO2/yr kg CO2/yr

TreeUtah Salt Lake City, UT 5,000 0 0 0

Trees for Tucson Tucson, AZ 3,600 8,620 1,703 10,323

Savannah Tree Foundation Savannah, GA 100 0 2,344 2,344

Twin Cities Tree Trust St. Louis Park, MN 4,000 229,867 19,649 249,516

Trees Atlanta Atlanta, GA 2,000 6,896 19,563 26,459

Treemendous Seattle Seattle, WA 5,500 1,327 4,262 5,590

People for Trees San Diego, CA 1,500 28,733 2,125 30,858

Treefolks Austin, TX 600 0 4,446 4,446

Sacramento Tree Foundation Sacramento, CA 188,588 138,463 48,225 186,689

Trees New Jersey Bordentown, NJ 25 0 1,138 1,138

Openlands Project Chicago, IL 300 0 24,439 24,439

TreePeople Beverly Hills, CA 12,000 18,276 25,166 43,441

223,213 585,241

avg. kg CO2/cm dbh

Table 40—Survey results of annual CO2 release by tree-related activities.
178 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix D Tree Information

space, gasoline used by vehicles, and energy consumed in the tree production area for water

pumping, refrigeration, and other greenhouse operations. Although CO2 release related to tree

production occurs over a number of years prior to planting, our calculations account for it on a

per-tree basis at the time of planting.

Tree Program Operations

Many non-profit tree programs are relatively small and, therefore, the amount of CO2 released

through office space conditioning and motor vehicle use is minor. However, if the program is

responsible for planting tens of thousands of trees each year, a substantial amount of CO2

 can be

released by vehicles and lesser amounts released through office heating and cooling. To simplify

the analysis we account at the time of planting for all present and future program-related CO2

release on a per-tree planted basis. This value may overstate actual CO2 release for program trees

if it incorporates releases associated with other program activities not directly related to tree

planting. Also, it may understate actual CO2 release if it neglects emissions associated with future

stewardship activities.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 179

Appendix E

Information on CO2 Emission Factors, Building

Characteristics, and Energy Performance

Electric emission factors by state are given in table 41 as an option to the regional defaults intable 44. Regional default data given here (tables 43 and 44) are primarily related to buildings.

Regional electric utility emissions factors, as well as estimates of air temperature and wind speed

adjustments due to increased canopy cover, are also given. Emissions factors for other fuels that

do not vary by region are given in table 42. Table 45 contains estimates of existing tree and

building cover for various cities.

State EEF (t CO2/MWh) Region Encompassed

Alabama 0.6215 Southeast, South Central, Gulf Coast/Hawaii

Arizona 0.3623 Southwest, Desert Southwest

Arkansas 0.5839 Southeast

California 0.3432 California Coast, Southwest, Desert Southwest

Colorado 0.9085 Mountains

Conn. 0.3246 North Central, North Central

Delaware 0.8422 North Central

Florida 0.5875 Gulf Coast/Hawaii

Georgia 0.5539 Southeast

Idaho 0.1221 Northern Tier, Mountains

Illinois 0.3932 North Central, North Central

Indiana 0.9857 North Central, North Central

Iowa 0.7655 North Central

Kansas 0.7732 Mountains, North Central

Kentucky 0.8762 North Central

Louisiana 0.6302 South Central, Gulf Coast/Hawaii

Maine 0.4386 North Central

Maryland 0.6156 North Central, Southeast

Mass. 0.6624 North Central

Michigan 0.7155 Northern Tier, North Central

Minnesota 0.7387 Northern Tier

Mississippi 0.4881 Southeast, South Central, Gulf Coast/Hawaii

Missouri 0.8095 North Central

Montana 0.7051 Northern Tier

Nebraska 0.5848 Mountains, North Central

Nevada 0.8513 Mountains, Southwest, Desert Southwest

New Hampshire 0.3868 North Central

New Jersey 0.3514 North Central

New Mexico 0.6379 Southwest, Desert Southwest

New York 0.4704 North Central, North Central

North Carolina 0.6129 Southeast

North Dakota 1.0456 Northern Tier

Ohio 0.8204 Great Lakes, North Central

Oklahoma 0.7591 Southwest, South Central

Oregon 0.1067 Pacific Northwest, Northern Tier, Mountains

Pennsylvania 0.5839 Great Lakes, North Central

Rhode Island 0.4953 North Central

South Carolina 0.3124 Southeast

South Dakota 0.4141 Northern Tier

Tennessee 0.6061 Southeast

Texas 0.7046 Southwest, South Central, Gulf Coast/Hawaii

Utah 0.9035 Mountains

Vermont 0.0722 North Central

Virginia 0.5026 Southeast

Washington 0.1389 Pacific Northwest, Northern Tier

West Virginia 0.9103 North Central

Wisconsin 0.6097 Northern Tier

Wyoming 0.9961 Mountains

1

DOE/EIA (1992)

Table 41—Electric emissions factors (EEF) by state1.
180 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix E Information on CO2 Emission Factors, Building Characteristics, and Energy Performance

Table 43—Building data by climate region1

.

Table 42—CO2

 emission factors (EF) for other fuels.

Fuel Type EF (tonnes CO2 per MBtu)

Natural gas 0.0527

Fuel oil 0.0720

Other heating equipment types 0.0527

Motor gasoline 0.0705

Diesel engine fuel 0.0720

kg CO2 per gallon gasoline 8.6

kg CO2 per gallon diesel 10.7 1

DOE/EIA (1992)

CFA Glazing Wall Found R Values

Climate Region Vintage Stories (m2

) (m2) panes Type Type Wall Ceiling Floor Found.

Mid-Atlantic Pre-1950 2 130.1 21.1 2 Wood Bsmt 7 7 0 0

New York 1950-80 2 182.1 35.8 2 Wood Bsmt 7 22 0 0

Post-1980 2 194.2 22.6 2 Wood Bsmt 13 27 0 0

Northern Tier Pre-1950 2 146.8 28.8 2 Wood Bsmt 7 7 0 0

Minneapolis 1950-80 1 102.2 20.1 2 Wood Bsmt 7 22 0 0

Post-1980 2 206.2 22.5 2 Wood Bsmt 19 32 0 5

North Central Pre-1950 2 146.8 27.9 2 Wood Bsmt 7 11 0 0

Detroit 1950-80 1 128.2 24.5 2 Brick Bsmt 7 19 0 0

Post-1980 2 206.2 25.5 2 Alum Bsmt 13 32 0 0

Mountains Pre-1950 1 90.6 16.4 2 Wood Bsmt 7 11 0 0

Denver 1950-80 1 100.3 18.2 2 Brick Slab 7 11 0 0

Post-1980 2 192.3 24.4 2 Wood Bsmt 13 31 11 0

Southeast Pre-1950 1 108.2 19.2 2 Wood Crawl 7 7 0 0

Atlanta 1950-80 1 131.5 23.1 2 Brick Crawl 7 11 0 0

Post-1980 2 205.5 24.5 2 Wood Bsmt 11 27 19 0

South Central Pre-1950 1 98.0 20.1 2 Wood Slab 7 7 0 0

Dallas 1950-80 1 129.1 26.6 2 Brick Slab 7 19 0 0

Post-1980 1 150.5 19.9 1 Wood Slab 11 27 0 5

Pacific Pre-1950 1 130.1 22.7 2 Wood Crawl 7 11 0 0

Northwest 1950-80 1 129.1 22.5 2 Wood Crawl 7 19 0 0

Seattle Post-1980 2 192.3 35.6 2 Wood Crawl 11 32 19 0

Gulf Coast/ Pre-1950 1 98.0 20.1 2 Wood Slab 7 7 0 0

Hawaii 1950-80 1 129.1 26.6 2 Brick Slab 7 19 0 0

Houston Post-1980 1 150.5 19.9 1 Brick Slab 11 19 0 0

California Coast Pre-1950 1 130.1 22.7 1 Wood Crawl 7 7 0 0

Los Angeles 1950-80 1 129.1 22.5 1 Stucc Crawl 7 11 0 0

Post-1980 2 192.3 30.2 2 Stucc Slab 11 25 0 0

Southwest Pre-1950 1 90.6 16.4 2 Wood Bsmt 7 11 0 0

El Paso/Fresno 1950-80 1 100.3 18.2 2 Brick Slab 7 11 0 0

Post-1980 1 154.2 16.6 2 Stucc Slab 13 29 0 5

Desert Pre-1950 1 90.6 16.4 2 Wood Bsmt 7 11 0 0

Southwest 1950-80 1 100.3 18.2 2 Brick Slab 7 11 0 0

Phoenix Post-1980 1 154.2 16.6 2 Stucc Slab 13 27 0 0

1

Ritschard and others 1992
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 181

Appendix E Information on CO2 Emission Factors, Building Characteristics, and Energy Performance

Percent Elec emis. Air Cooling Heating

Coo ling e quipme nt

saturatio n (pct)1

Heating Equipment

Saturation (pct)1

Climate by Factor2 Temp SEER AFUE Evap Room No Natural Elec. Heat Fuel Other

Region Vintage vintage1 (t CO2/MWh) Adj. CAC Cooler AC Cooling Gas Res. Pump Oil Heating

Mid- pre-1950 30 .605 0.05 8 0.75 42 0 35 23 49 6 3 19 24

Atlantic 1950-80 58 8 0.75 61 0 27 11 54 9 4 20 13

post-1980 12 10 0.78 87 0 7 7 53 23 10 0 13

Northern pre-1950 45 .612 0.05 8 0.75 47 0 23 30 47 3 1 20 30

Tier 1950-80 42 8 0.75 55 0 25 20 50 6 1 25 18

post-1980 13 10 0.78 78 0 11 11 44 18 4 11 22

North pre-1950 43 .635 0.05 8 0.75 38 0 37 25 69 2 0 18 10

Central 1950-80 48 8 0.75 56 0 23 21 61 10 2 19 8

post-1980 10 10 0.78 72 0 25 3 50 21 4 0 25

Mountains pre-1950 43 .908 0.2 8 0.75 38 0 37 25 69 2 0 18 10

1950-80 48 8 0.75 56 0 23 21 61 10 2 19 8

post-1980 10 10 0.78 72 0 25 3 50 21 4 0 25

Southeast pre-1950 28 .545 0.05 8 0.75 39 0 36 24 70 6 3 8 14

1950-80 53 8 0.75 59 0 23 19 61 13 6 2 18

post-1980 18 10 0.78 81 0 14 5 52 20 9 2 17

South pre-1950 19 .671 0.05 8 0.75 27 0 59 14 73 11 7 0 9

Central 1950-80 62 8 0.75 70 0 23 7 62 17 10 0 11

post-1980 18 10 0.78 86 0 5 10 29 42 25 0 5

Pacific pre-1950 30 .128 0.2 8 0.75 38 0 37 25 69 2 0 18 10

Northwest 1950-80 58 8 0.75 56 0 23 21 61 10 2 19 8

post-1980 12 10 0.78 72 0 25 3 50 21 4 0 25

Gulf Coast/ pre-1950 19 .655 0.05 8 0.75 27 0 59 14 73 11 7 0 9

Hawaii 1950-80 62 8 0.75 70 0 23 7 62 17 10 0 11

post-1980 18 10 0.78 86 0 5 10 29 42 25 0 5

California pre-1950 28 .343 0.1 8 0.75 39 0 36 24 70 6 3 8 14

Coast 1950-80 53 8 0.75 59 0 23 19 61 13 6 2 18

post-1980 18 10 0.78 81 0 14 5 52 20 9 2 17

Southwest pre-1950 28 .523 0.2 8 0.75 39 0 36 24 70 6 3 8 14

1950-80 53 8 0.75 59 0 23 19 61 13 6 2 18

post-1980 18 10 0.78 81 0 14 5 52 20 9 2 17

Desert pre-1950 19 .376 0.1 8 0.75 27 0 59 14 73 11 7 0 9

Southwest 1950-80 62 8 0.75 70 0 23 7 62 17 10 0 11

post-1980 18 10 0.78 86 0 5 10 29 42 25 0 5 1

 DOE/EIA (1993)

2

 Population-weighted averages of states in each region from DOE/EIA (1992)

Table 44—Other building data by climate region.
182 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix E Information on CO2 Emission Factors, Building Characteristics, and Energy Performance

City Population pct

Cover

Atlanta, GA 437,000 67

Boston, MA 520,000 49

Chicago 2,780,000 38

Cook County 3,320,000 35

Dallas, TX 1,000,000 52

Denver, CO 468,000 56

DuPage County 78,000 28

Miami, FL 359,000 51

Minneapolis, MN 375,000 33

Portland, OR 440,000 54

Rock Valley, IA 3,000 26

Tucson, AZ 405,000 34

Washington, DC 623,000 34

California Cities

Atherton 7,300 62

Bakersfield 212,700 39

Cathedral City 35,450 33

Chico 47,200 46

Coachella 21,050 37

Desert Hot Springs 14,850 25

Escondido 118,300 43

Eureka 27,500 37

Fresno 400,400 51

Lancaster 121,000 3

Los Angeles 3,638,100 44

Menlo Park 30,200 17

Merced 61,000 32

Palm Springs 41,700 45

Pasadena 137,100 54

Poway 45,450 35

Redding 76,700 40

Sacramento 384,800 52

Santa Maria 68,900 42

South Lake Tahoe 23,100 66

Victorville 60,000 26

Visalia 91,300 42

Yuba City 33,900 45

Table 45—Total tree and building cover percentages (from McPherson

and others 1993, USDA Forest Service 1997).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 183

Instructions for Adjusting Tree Distributions to

Customize Avoided Carbon Dioxide Emissions.

Default Tree Distribution by Size and Location with Respect to Buildings

Energy and CO2

 savings depend on tree size and location (distance and direction, or azimuth)

with respect to buildings. Short Form calculations use a tree distribution adapted from that

found for Sacramento Shade from 1991 to 1995 (Simpson 1998). The Sacramento Municipal

Utility District, in collaboration with the Sacramento Tree Foundation (STF), is implementing this

energy conservation program through the planting of shade trees. Planting guidelines in effect

for Sacramento Shade during planting of the initial 100,000 trees specified that: “Trees must be

placed in a position to shade the house at some point during the day”. Tree-siting guidelines for

the next approximately 120,000 trees were more specific, as follows (SMUD 1995):

• Trees may be planted only in west, east, or southern locations;

• Trees must be sited no farther than 12 m (35 ft) from the house;

• Trees cannot be sited where they interfere with power lines;

• Smaller trees must be sited a minimum of 2.4 m (8 ft) away from the house, whereas

larger trees must be 4.6 m (15 ft) away from the house;

• Trees must be sited at least 2 m (6 ft) from sidewalks, patios, driveways, or any other

concrete surfaces; and

• Smaller trees must be spaced a minimum of 2.4 m (8 ft) apart, whereas larger trees

must be 4.6 m (15 ft) apart.

The resulting tree distribution serves as a basis for determining the default distribution used

in the Short Form Look-up tables. The distribution of all tree sizes among azimuth reflects the

program goal of maximizing cooling savings because few trees are located to the north, northeast,

and northwest. Also, the distribution differs as a function of distance between size classes.

Smaller trees are more common closer to buildings, and large and medium sized trees are more

common farther away.

The default distribution for deciduous and evergreen trees (tables 46 and 47) assumes the

same distribution of trees among distances from the buildings, but modifies the distribution with

respect to azimuth to reduce heating costs associated with trees opposite south-facing walls that

obstruct winter solar access. Even the bare branches of deciduous trees can attenuate 30 to 60

percent of sunlight during the heating period. SMUD and STF did not view this as a liability

because their goal was to reduce only energy used for air conditioning. However, shade tree

programs aimed at reducing CO2 emissions should consider impacts of trees on both space

heating and cooling.

The net change in CO2 emissions due to shade (cooling minus heating) was calculated for

single large, medium and small deciduous trees at each location used in tables 46 and 47 to

evaluate the effect of tree size and location on net emissions. Trees to the south, southeast or

southwest produced a net increase in emissions, with the exception of some large or medium

trees close to buildings in cooling dominated climates, which reduced net emissions. In heating

dominated climates, east and west trees produced a net increase in emissions in some cases. A

default deciduous tree distribution was developed from that found for Sacramento Shade by

moving trees located south of buildings to more favorable locations. Deciduous trees located

opposite south-facing walls were divided between east and west locations. Deciduous trees to

the southeast were divided between east and northeast locations; those to the southwest between

west and northwest locations (table 46). More drastic limits on tree location based on shading

only would limit emissions reductions from climate effects and sequestration. For shading,

reduced emissions due to cooling were diminished relative to increases from heating due to the

smaller number of residences with cooling compared to heating (equipment saturations, table 44,

Appendix E).

Appendix F
184 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Tree Distance N NE E SE S SW W NW Total

size (m) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct)

Large 3-6 5.2 1.9 2.2 0.0 0.0 0.0 3.6 5.5

6-12 17.3 14.8 7.4 0.0 0.0 0.0 18.0 18.3

12-18 0.3 1.9 1.9 0.0 0.0 0.0 0.3 1.3 100.0

Medium 3-6 3.3 5.8 1.7 0.0 0.0 0.0 5.0 4.7

6-12 12.1 16.1 11.8 0.0 0.0 0.0 13.2 22.7

12-18 1.0 1.7 0.7 0.0 0.0 0.0 0.0 0.3 100.0

Small 3-6 5.4 8.6 9.0 0.0 0.0 0.0 6.6 13.8

6-12 10.3 11.0 9.1 0.0 0.0 0.0 8.4 15.3

12-18 0.0 1.1 1.3 0.0 0.0 0.0 0.0 0.0 100.0

Evergreen trees are assumed to be used primarily for windbreaks, and therefore located

where they will not increase heating loads by obstructing winter irradiance. Trees located

opposite south-facing walls were moved opposite the north-facing wall. Trees to the southeast

were located to the northeast; those to the southwest located to the northwest (table 47).

Evergreens may or may not provide benefits from shade depending on their location. Trees may

be distributed by size and vintage on the basis of Sacramento data (table 48).

Table 47—Default evergreen tree distribution by size, distance and direction from building.

Percentage by size and vintage ( pct)

Pre-1950 1950-1980 Post-1980 Total

Large 1.2 8.2 14.7 24.1

Medium 1.7 12.1 39.3 53.1

Small 0.6 6.6 15.6 22.8

Total 3.5 26.9 69.6 100.0

Table 48—Distribution of trees planted by Sacramento Shade by size and

building vintage. This distribution can be applied to deciduous and evergreen

plantings.

Tree Azimuth

Tree Distance N NE E SE S SW W NW Total

size (m) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct) (pct)

Large 3-6 0.9 0.9 5.3 0.0 0.0 0.0 7.8 3.4

6-12 3.4 9.9 19.3 0.0 0.0 0.0 32.2 11.1

12-18 0.0 1.5 2.5 0.0 0.0 0.0 0.5 1.3 100.0

Medium 3-6 0.3 3.7 5.3 0.0 0.0 0.0 7.9 3.3

6-12 3.4 10.6 21.6 0.0 0.0 0.0 25.0 15.3

12-18 0.1 1.2 1.6 0.0 0.0 0.0 0.4 0.3 100.0

Small 3-6 1.1 6.0 13.8 0.0 0.0 0.0 11.4 11.1

6-12 3.5 8.3 15.3 0.0 0.0 0.0 16.7 10.4

12-18 0.0 1.1 1.3 0.0 0.0 0.0 0.0 0.0 100.0

Table 46—Default deciduous tree distribution by size, distance and direction from building.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 185

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Adjusting Avoided Carbon Dioxide Emissions Data for Tree Location

Avoided emissions for each region by tree size and vintage provided in the lookup tables are precalculated averages of avoided emissions per tree simulated at 24 locations (three distances and

eight azimuths) weighted by relative occurrence of trees at each location. This section provides

the information necessary to perform the calculations to account for tree location distributions

that differ from the default location distribution (tables 4 and 5, in Chapter 3, tables 46 and 47) as

part of the Long Form analysis.

Tree distributions supplied by the user are recorded in tables 49 and 55 for deciduous trees

and tables 52 and 58 for evergreen trees. Each cell of these tables is multiplied by the

corresponding cell in tables 50, 56, 53 and 59 respectively, in which avoided emissions per mature

tree by azimuth, tree size, and direction for the post 1980 vintage are recorded from tables 63 to

106 for the selected Climate Region. Products are recorded in tables 51, 57, 54 and 60, respectively;

weighted averages result when products are summed for each tree size in table 61. Results for

pre-1950 and 1950-1980 vintages are constant factors of post 1980 avoided emissions per tree

given in table 62, which our analysis has shown to be similar over tree size and age in each

Climate Region. These weighted averages are entered into Table VII, in Appendix B.

Note: values expressed as percentages in table 50, 53, 56 and 59 must be divided by 100 when

doing computations to convert percentages to fractional values.
186 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Calculation of mean avoided cooling energy from tree shade (kg CO2/tree): deciduous trees

Project Title: 

Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m

Deciduous 6-12 m

12-18 m 100

100

100

Medium 3-6 m

Deciduous 6-12 m

12-18 m

Small 3-6 m

Deciduous 6-12 m

12-18 m

x

Table 49—User supplied deciduous tree distribution (pct).

N NE E SE S SW W NW

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

A B C D E FG H

1 Large

2 Deciduous

3

6

4 Medium

5 Deciduous

7 Small

8 Deciduous

9

Table 51—Mean change in cooling (kg CO2/tree) for mature deciduous trees. Multiply Table 49 x Table 50 cell by cell, then

sum by tree size).

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m

Deciduous 6-12 m

12-18 m

Medium 3-6 m

Deciduous 6-12 m

12-18 m

Small 3-6 m

Deciduous 6-12 m

12-18 m

=

Table 50—Change in emissions from avoided cooling (kg CO2/tree), mature deciduous trees.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 187

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Project Title: 

Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m

Evergreen 6-12 m

12-18 m 100

Medium 3-6 m

Evergreen 6-12 m

12-18 m 100

Small 3-6 m

Evergreen 6-12 m

12-18 m 100

Calculation of mean avoided cooling energy from tree shade (kg CO2/tree): evergreen trees

x

Table 52—User supplied evergreen tree distribution (pct).

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m

Evergreen 6-12 m

12-18 m

Medium 3-6 m

Evergreen 6-12 m

12-18 m

Small 3-6 m

Evergreen 6-12 m

12-18 m

=

Table 53—Change in emissions from avoided cooling (kg CO2/tree), mature evergreen trees.

N NE E SE S SW W NW

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

A B C D E FG H

1 Large

2 Evergreen

3

6

4 Medium

5 Evergreen

7 Small

8 Evergreen

9

Table 54—Mean change in cooling (kg CO2/tree) for mature evergreen trees. Multiply Table 52 x Table 53 cell by cell, then

sum by tree size).
188 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

N NE E SE S SW W NW

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

A B C D E FG H

1 Large

2 Deciduous

3

6

4 Medium

5 Deciduous

7 Small

8 Deciduous

9

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m

Deciduous 6-12 m

12-18 m

Medium 3-6 m

Deciduous 6-12 m

12-18 m

Small 3-6 m

Deciduous 6-12 m

12-18 m

=

Project Title: 

Tree Azimuth

Tree size Distance N NE E SE S SW W NW

Large 3-6 m

Deciduous 6-12 m

12-18 m 100

Medium 3-6 m

Deciduous 6-12 m

12-18 m

NW

100

Small 3-6 m

Deciduous 6-12 m

12-18 m 100

Calculation of mean avoided heating energy from tree shading (kg CO2/tree): deciduous trees

x

Table 55—User supplied deciduous tree distribution (pct).

Table 56—Change in emissions from avoided heating (kg CO2/tree), mature deciduous trees.

Table 57—Mean change in heating (kg CO2/tree) for mature deciduous trees. Multiply Table 55 x Table 56 cell by cell, then

sum by tree size).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 189

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

N NE E SE S SW W NW

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

3-6 m

6-12 m

12-18 m

A B C D E FG H

1 Large

2 Evergreen

3

6

4 Medium

5 Evergreen

7 Small

8 Evergreen

9

Table 60—Mean change in heating (kg CO2/tree) for mature evergreen trees. Multiply Table 58 x Table 59 cell by cell, then

sum by tree size).

post-1980 Vintage

N NE E SE S SW W NW

Large 3-6 m

Evergreen 6-12 m

12-18 m

Medium 3-6 m

Evergreen 6-12 m

12-18 m

Small 3-6 m

Evergreen 6-12 m

12-18 m

=

Table 59—Change in emissions from avoided heating (kg CO2/tree), mature evergreen tree.

Project Title: 

Tree Azimuth

Tree size Distance N NE E SE S SW W NW Total

Large 3-6 m

Evergreen 6-12 m

12-18 m 100

Medium 3-6 m

Evergreen 6-12 m

12-18 m 100

Small 3-6 m

Evergreen 6-12 m

12-18 m 100

Calculation of mean avoided heating energy from tree shading (kg CO2/tree): evergreen trees

 

x

Table 58—User supplied evergreen tree distribution (pct).
190 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Project Title: 

 Vintage: Pre-1950 A

n Tree Type2 Cooling Sum

1 Large-Dec (= A13 x Table 62:An/1000) (= B13 x Table 62:Cn/1000) 

2 Med.-Dec (= A14 x Table 62:An/1000) (= B14 x Table 62:Cn/1000) 

3 Small-Dec (= A15 x Table 62:An/1000) (= B15 x Table 62:Cn/1000) 

4 Large Evr (= A16 x Table 62:An/1000) (= B16 x Table 62:Cn/1000) 

5 Med-.Evr (= A17 x Table 62:An/1000) (= B17 x Table 62:Cn/1000) 

6 Small-Evr (= A18 x Table 62:An/1000) (= B18 x Table 62:Cn/1000) 

 Vintage: 1950-80

7 Large-Dec (= A13 x Table 62:Bn/1000) (= B13 x Table 62:Dn/1000) 

8 Med.-Dec (= A14 x Table 62:Bn/1000) (= B14 x Table 62:Dn/1000) 

9 Small-Dec (= A15 x Table 62:Bn/1000) (= B15 x Table 62:Dn/1000) 

10 Large Evr (= A16 x Table 62:Bn/1000) (= B16 x Table 62:Dn/1000) 

11 Med-.Evr (= A17 x Table 62:Bn/1000) (= B17 x Table 62:Dn/1000) 

12 Small-Evr (= A18 x Table 62:Bn/1000) (= B18 x Table 62:Dn/1000) 

 Vintage: Post-1980

13 Large-Dec (= Sum Table 51:A1..H3/1000) (= Sum Table 57:A1..H3/1000) 

14 Med.-Dec (= Sum Table 51:A4..H6/1000) (= Sum Table 57:A4..H6/1000)

15 Small-Dec (= Sum Table 51:A7..H9/1000) (= Sum Table 57:A7..H9/1000)

16 Large Evr (= Sum Table 54:A1..H3/1000) (= Sum Table 60:A1..H3/1000) 

17 Med-.Evr (= Sum Table 54:A4..H6/1000) (= Sum Table 60:A4..H6/1000)

18 Small-Evr (= Sum Table 54:A7..H9/1000) (= Sum Table 60:A7..H9/1000)

1For an example of this table in use, see table 29, Chapter 4 2Dec = deciduous; Evr = evergreen; Med. = medium

B

Heating Sum

Table 61—Sum of mean change in cooling and heating (t CO2/tree) for mature trees1.

A BCD

Cooling Heating

Climate Region pre-1950 1950-1980 pre-1950 1950-1980

1 Mid-Atlantic 0.74 1.13 0.99 1.22

2 Northern Tier 1.59 0.89 1.22 0.68

3 North Central 0.98 0.53 0.94 0.71

4 Mountains 0.43 0.51 0.40 0.66

5 Southeast 0.52 0.68 0.63 0.71

6 South Central 0.64 1.05 0.65 0.76

7 Pacific Northwest 0.28 0.34 1.03 0.90

8 Gulf Coast/Hawaii 0.87 1.45 0.66 0.75

9 California Coast 0.36 0.39 0.38 0.36

10 Southwest 1.35 1.61 0.68 1.25

11 Desert Southwest 0.66 1.19 0.41 0.78

1

This table is reproduced for illustration as table 30, Chapter 4.

Table 62—Cooling and heating vintage factors1.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 191

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Change in Cooling Energy Use (kg CO2 /Tree) for Each Climate Region

by Mature Tree Size, Type, Distance and Azimuth.

The following tables all titled “Change from avoided cooling/heating (kg CO2/tree) for mature

deciduous/evergreen trees” (tables 63-106) provide data for different climate regions and are

used as input for tables 50, 53, 56 and 59 to adjust avoided energy data for tree locations different

than the default. Tables 50, 53, 56, 59, and 62 are in turn used to complete table 61.

Table 63—Change from avoided cooling (kg CO2/tree) for mature deciduous trees.

Table 64—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 65—Change from avoided heating (kg CO2

/tree) for mature deciduous trees.

Table 66—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.

Region 01: Mid-Atlantic, New York post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 6.2 35.9 55.9 67.9 70.5 79.2 110.5 58.5

Deciduous Near 0.1 1.3 47.4 20.9 38.1 32.9 103.9 8.5

Far 0.0 0.3 27.7 4.6 5.5 9.0 73.2 3.8

Medium Adjacent 3.2 11.8 45.2 32.3 55.0 41.9 96.3 27.8

Deciduous Near 0.0 0.6 26.0 5.7 7.2 9.8 69.4 7.5

Far 0.0 0.1 10.3 0.4 0.1 1.3 36.1 2.3

Small Adjacent 1.0 0.8 19.1 5.7 10.7 10.3 49.7 9.3

Deciduous Near 0.0 0.2 6.3 0.2 0.1 1.0 24.0 3.9

Far 0.0 0.0 1.6 0.0 0.0 0.6 10.0 1.1

N NE E SE S SW W NW

Large Adjacent 6.5 38.4 59.6 72.2 76.6 85.6 119.5 62.8

Evergreen Near 0.1 1.4 50.5 22.9 43.7 36.7 113.4 8.9

Far 0.0 0.4 30.3 5.5 6.5 11.1 80.2 4.4

Medium Adjacent 3.3 12.6 48.2 34.5 59.5 45.3 103.1 29.4

Evergreen Near 0.0 0.6 28.0 6.1 8.0 10.9 73.8 7.7

Far 0.0 0.1 10.9 0.4 0.1 1.4 38.0 2.7

Small Adjacent 1.4 0.3 6.0 4.4 0.9 20.8 33.7 4.1

Evergreen Near 0.0 0.1 1.4 0.1 0.0 0.7 13.4 1.6

Far 0.0 0.0 0.3 0.0 0.0 0.0 5.7 0.8

N NE E SE S SW W NW

Large Adjacent -1.7 -30.8 -74.6 -105.2 -170.7 -133.8 -96.5 -41.5

Deciduous Near 0.0 -0.5 -59.1 -65.4 -157.8 -93.1 -75.4 -1.4

Far 0.0 -0.1 -35.6 -46.4 -89.5 -73.2 -41.7 -0.1

Medium Adjacent -0.3 -12.5 -64.7 -73.6 -165.3 -102.6 -88.9 -18.1

Deciduous Near 0.0 -0.2 -37.5 -42.7 -98.8 -68.7 -51.3 -0.6

Far 0.0 0.0 -18.5 -25.7 -40.4 -46.7 -25.8 -0.1

Small Adjacent 0.0 -0.3 -34.1 -31.6 -96.5 -56.4 -52.5 -1.1

Deciduous Near 0.0 0.0 -12.7 -15.2 -28.2 -33.5 -25.5 -0.3

Far 0.0 0.0 -3.9 -6.1 -0.6 -18.4 -8.9 0.0

N NE E SE S SW W NW

Large Adjacent -1.8 -52.7 -133.3 -205.7 -390.3 -251.8 -179.9 -69.1

Evergreen Near 0.0 -0.5 -102.0 -144.6 -382.6 -204.8 -139.2 -1.5

Far 0.0 -0.1 -52.7 -122.9 -240.8 -178.6 -72.8 -0.1

Medium Adjacent -0.4 -19.4 -117.1 -152.4 -386.7 -208.5 -170.8 -29.0

Evergreen Near 0.0 -0.2 -60.2 -105.7 -245.6 -159.4 -90.7 -0.6

Far 0.0 0.0 -26.5 -62.0 -97.9 -106.4 -41.9 -0.1

Small Adjacent -0.2 -0.1 -22.9 -39.7 -91.5 -111.0 -72.3 -1.7

Evergreen Near 0.0 0.0 -5.4 -13.4 -9.6 -40.3 -25.2 0.0

Far 0.0 0.0 -1.4 -4.2 0.0 -17.7 -8.2 0.0
192 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Region 02: Northern Tier, Minneapolis post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 4.7 15.8 40.6 32.5 49.8 41.3 89.9 31.3

Deciduous Near 0.0 0.9 29.7 9.2 15.3 15.5 75.9 6.5

Far 0.0 0.2 15.2 1.5 1.6 2.6 49.3 2.2

Medium Adjacent 2.0 3.0 25.8 12.9 31.5 19.6 69.1 12.4

Deciduous Near 0.0 0.4 14.9 2.0 2.4 3.2 47.3 4.9

Far 0.0 0.1 6.0 0.2 -0.1 0.4 23.9 1.0

Small Adjacent 0.1 0.4 8.3 1.3 2.5 2.4 28.5 6.0

Deciduous Near 0.0 0.1 2.5 -0.0 -0.1 0.1 13.8 2.0

Far 0.0 0.0 0.6 0.0 0.0 0.0 5.2 0.4

N NE E SE S SW W NW

Large Adjacent 3.9 12.4 38.7 28.5 48.4 36.4 89.7 27.0

Evergreen Near 0.0 0.7 24.9 5.6 8.0 8.8 70.2 6.3

Far 0.0 0.2 12.5 0.9 0.5 1.8 41.6 1.7

Medium Adjacent 1.1 0.9 17.7 5.4 11.5 9.0 51.3 8.4

Evergreen Near 0.0 0.2 7.5 0.5 0.4 0.7 29.4 3.3

Far 0.0 0.1 1.9 -0.0 0.0 0.2 12.5 0.7

Small Adjacent 1.2 0.3 6.3 3.0 1.2 10.4 30.9 3.7

Evergreen Near 0.0 0.1 1.7 0.0 0.0 0.2 13.7 1.5

Far 0.0 0.0 0.4 -0.1 0.0 0.0 5.7 0.2

N NE E SE S SW W NW

Large Adjacent -1.0 -23.5 -76.1 -98.2 -190.3 -140.9 -125.8 -28.6

Deciduous Near 0.0 -0.6 -52.6 -63.3 -146.6 -111.2 -83.4 -1.2

Far 0.0 -0.1 -32.3 -39.9 -74.1 -82.0 -41.8 -0.3

Medium Adjacent -0.3 -4.1 -58.9 -59.4 -159.8 -107.0 -102.5 -5.9

Deciduous Near 0.0 -0.3 -33.3 -35.1 -89.1 -79.1 -59.9 -0.9

Far 0.0 -0.1 -15.3 -20.9 -24.5 -53.6 -27.0 -0.1

Small Adjacent 0.0 -0.3 -23.8 -21.8 -69.8 -56.6 -56.8 -1.8

Deciduous Near 0.0 -0.1 -9.1 -9.7 -13.5 -35.6 -32.6 -0.4

Far 0.0 0.0 -2.9 -4.0 -0.2 -24.3 -10.8 -0.1

N NE E SE S SW W NW

Large Adjacent -0.6 -23.9 -119.1 -160.0 -409.2 -253.1 -219.8 -36.0

Evergreen Near 0.0 -0.4 -66.7 -112.1 -306.8 -212.1 -117.8 -1.1

Far 0.0 -0.1 -33.7 -73.7 -133.8 -155.3 -51.5 -0.2

Medium Adjacent -0.2 -0.9 -64.0 -81.9 -280.6 -167.7 -139.2 -2.3

Evergreen Near 0.0 -0.1 -26.2 -43.9 -99.6 -107.7 -62.9 -0.6

Far 0.0 0.0 -9.0 -20.5 -14.3 -64.4 -22.6 -0.1

Small Adjacent -0.2 -0.3 -25.6 -39.6 -118.5 -129.1 -100.9 -0.7

Evergreen Near 0.0 -0.1 -7.9 -16.4 -19.6 -63.7 -40.0 -0.2

Far 0.0 0.0 -2.5 -6.4 0.0 -35.2 -12.0 -0.1

Table 69—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Table 68—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 67—Change from avoided cooling (kg CO2

/tree) for mature deciduous trees.

Table 70—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 193

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Region 03: North Central, Detroit post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 6.1 20.7 49.9 46.4 73.7 67.0 119.3 46.9

Deciduous Near 0.0 0.5 34.4 10.1 17.3 20.8 94.8 9.1

Far 0.0 -0.2 16.6 1.0 0.3 5.7 58.3 2.0

Medium Adjacent 3.3 3.8 32.9 18.9 44.3 34.6 89.0 16.1

Deciduous Near 0.0 0.1 16.5 1.3 2.6 6.3 57.5 5.9

Far 0.0 -0.3 4.6 0.1 0.1 1.5 24.6 1.1

Small Adjacent 0.1 0.1 8.1 1.3 4.3 4.5 35.1 7.0

Deciduous Near 0.0 -0.3 2.2 0.0 0.1 1.5 13.8 1.4

Far 0.0 0.0 0.2 0.0 0.0 0.3 4.8 0.4

N NE E SE S SW W NW

Large Adjacent 5.2 14.8 45.0 37.2 66.8 56.2 111.8 40.2

Evergreen Near 0.0 0.4 27.8 6.1 7.5 13.4 82.6 8.2

Far 0.0 -0.2 10.8 0.5 0.3 3.2 46.1 1.6

Medium Adjacent 0.4 0.5 19.5 7.2 13.1 13.2 60.5 10.6

Evergreen Near 0.0 -0.2 5.9 0.2 0.2 2.1 30.3 3.4

Far 0.0 0.0 1.4 0.0 0.0 1.5 9.7 0.6

Small Adjacent 1.7 0.0 5.3 3.0 2.9 18.9 37.7 4.7

Evergreen Near 0.0 -0.3 1.1 0.0 0.0 1.6 13.1 0.8

Far 0.0 0.0 -0.0 0.0 0.0 0.3 4.9 0.2

N NE E SE S SW W NW

Large Adjacent -1.5 -26.1 -96.5 -102.8 -196.4 -148.1 -141.0 -38.0

Deciduous Near 0.0 -1.4 -68.7 -63.8 -131.8 -103.5 -87.0 -2.5

Far 0.0 -0.1 -45.0 -39.5 -59.9 -73.8 -50.0 -0.4

Medium Adjacent -1.1 -6.2 -70.6 -65.5 -155.0 -108.1 -102.6 -7.9

Deciduous Near 0.0 -0.4 -43.8 -34.1 -68.2 -67.4 -58.8 -1.9

Far 0.0 -0.1 -20.4 -18.7 -15.3 -46.1 -32.6 -0.2

Small Adjacent -0.1 -0.9 -28.8 -21.8 -56.7 -49.2 -52.4 -2.2

Deciduous Near 0.0 -0.1 -11.0 -8.7 -8.6 -30.8 -29.9 -0.5

Far 0.0 0.0 -3.1 -3.3 0.0 -8.6 -8.9 -0.2

N NE E SE S SW W NW

Large Adjacent -1.4 -26.9 -132.4 -161.4 -382.4 -242.2 -214.9 -45.7

Evergreen Near 0.0 -1.2 -77.7 -109.2 -256.3 -176.7 -114.2 -2.2

Far 0.0 -0.1 -42.3 -65.2 -104.0 -123.2 -57.9 -0.3

Medium Adjacent -0.1 -1.5 -70.0 -80.1 -236.6 -141.8 -124.1 -3.6

Evergreen Near 0.0 -0.2 -30.2 -37.9 -72.9 -82.2 -57.9 -0.7

Far 0.0 0.0 -9.8 -16.0 -5.1 -36.4 -19.1 -0.2

Small Adjacent -0.4 -0.7 -27.6 -38.4 -91.0 -117.3 -86.6 -1.5

Evergreen Near 0.0 -0.1 -8.5 -12.8 -11.5 -47.9 -36.1 -0.2

Far 0.0 0.0 -2.4 -4.7 0.0 -13.6 -10.6 -0.1

Table 74—Change from avoided heating (kg CO2/tree) for mature evergreen trees.

Table 73—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Table 72—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 71—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.
194 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 78—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.

Table 77—Change from avoided heating (kg CO2

/tree) for mature deciduous trees.

Table 76—Change from avoided cooling (kg CO2/tree) for mature evergreen trees.

Region 04: Mountains, Denver post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 8.4 39.2 106.7 81.9 116.1 96.7 167.5 56.6

Deciduous Near 0.0 2.0 87.3 25.7 39.6 39.1 136.1 11.3

Far 0.0 0.6 48.0 6.7 5.8 13.1 85.0 4.4

Medium Adjacent 4.9 4.6 81.6 33.3 75.3 51.5 135.7 21.9

Deciduous Near 0.0 1.1 46.7 6.0 9.4 12.9 85.4 10.9

Far 0.0 0.3 17.8 0.9 0.0 3.3 44.9 3.0

Small Adjacent 1.6 1.4 27.1 4.1 9.1 9.5 58.0 12.3

Deciduous Near 0.0 0.3 8.1 0.5 0.0 1.5 30.1 3.4

Far 0.0 0.1 2.2 0.0 0.0 0.0 17.1 1.7

N NE E SE S SW W NW

Large Adjacent 7.8 29.3 107.0 71.3 117.9 88.2 172.8 50.5

Evergreen Near 0.0 1.9 80.4 19.7 31.0 33.0 130.9 12.6

Far 0.0 0.5 37.9 4.6 2.4 9.3 73.0 4.0

Medium Adjacent 2.0 2.1 60.3 17.3 35.4 28.1 100.7 16.4

Evergreen Near 0.0 0.8 23.1 2.1 1.9 5.0 54.5 7.8

Far 0.0 0.2 6.7 0.2 0.0 0.8 27.0 2.4

Small Adjacent 1.6 1.1 20.1 3.0 5.7 8.7 50.6 11.4

Evergreen Near 0.0 0.3 5.8 0.3 0.0 1.1 26.4 2.9

Far 0.0 0.1 1.6 0.0 0.0 0.0 15.3 1.7

N NE E SE S SW W NW

Large Adjacent -1.7 -33.0 -144.1 -124.2 -242.1 -153.2 -137.0 -39.9

Deciduous Near 0.0 -1.8 -121.9 -82.3 -166.3 -109.7 -91.6 -3.0

Far 0.0 -0.5 -85.2 -62.3 -82.6 -79.0 -50.3 -0.8

Medium Adjacent -0.8 -6.3 -121.1 -81.6 -191.0 -109.5 -112.6 -10.8

Deciduous Near 0.0 -1.0 -86.3 -53.5 -96.8 -76.5 -63.2 -2.2

Far 0.0 -0.2 -40.1 -34.8 -18.9 -44.1 -31.9 -0.5

Small Adjacent -0.2 -1.1 -59.3 -32.6 -77.1 -53.9 -59.9 -2.5

Deciduous Near 0.0 -0.3 -23.4 -16.2 -10.8 -23.1 -31.0 -0.7

Far 0.0 -0.1 -6.5 -6.2 0.0 -11.6 -10.9 -0.3

N NE E SE S SW W NW

Large Adjacent -1.5 -35.3 -215.3 -226.9 -563.2 -285.8 -243.0 -45.9

Evergreen Near 0.0 -1.5 -153.3 -158.6 -376.4 -228.3 -136.7 -2.8

Far 0.0 -0.4 -88.0 -114.6 -153.8 -157.3 -64.7 -0.7

Medium Adjacent -0.3 -2.1 -139.7 -122.9 -349.5 -175.6 -151.1 -4.7

Evergreen Near 0.0 -0.6 -68.2 -70.2 -103.6 -108.6 -69.9 -1.3

Far 0.0 -0.1 -23.5 -33.0 -3.3 -51.7 -25.7 -0.3

Small Adjacent -0.2 -0.9 -66.4 -55.7 -135.1 -93.7 -88.7 -2.2

Evergreen Near 0.0 -0.2 -22.1 -24.4 -12.7 -39.4 -38.3 -0.5

Far 0.0 -0.1 -6.1 -8.9 0.0 -18.3 -13.3 -0.2

Table 75—Change from avoided cooling (kg CO2/tree) for mature deciduous trees.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 195

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 80—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 79—Change from avoided cooling (kg CO2

/tree) for mature deciduous trees.

Region 05: Southeast, Atlanta post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 10.9 46.8 91.3 84.6 93.8 112.9 195.5 91.2

Deciduous Near 0.0 3.8 75.7 25.6 45.2 55.5 177.9 13.2

Far 0.0 0.5 48.2 6.9 6.5 19.1 124.4 4.6

Medium Adjacent 6.6 18.6 68.1 42.8 69.9 71.5 173.4 50.2

Deciduous Near 0.0 0.9 44.8 6.3 9.6 18.0 119.7 8.4

Far 0.0 0.2 17.9 1.4 0.1 6.1 62.7 1.8

Small Adjacent 0.6 1.2 31.1 6.3 12.9 18.6 91.5 11.2

Deciduous Near 0.0 0.3 10.9 0.9 0.1 4.4 45.1 3.2

Far 0.0 0.0 3.0 0.1 0.0 0.3 19.1 0.8

N NE E SE S SW W NW

Large Adjacent 11.5 50.9 100.5 95.4 111.3 130.1 216.3 100.7

Evergreen Near 0.1 3.9 84.3 31.3 59.7 68.8 200.1 14.2

Far 0.0 0.6 53.3 10.4 9.5 27.2 141.8 5.0

Medium Adjacent 6.9 19.8 77.2 48.9 84.4 82.8 191.5 53.9

Evergreen Near 0.0 0.8 48.8 9.2 13.5 25.5 134.8 8.8

Far 0.0 0.2 19.1 1.5 0.1 8.6 70.6 1.8

Small Adjacent 0.0 0.5 10.7 1.1 2.0 6.1 40.2 5.5

Evergreen Near 0.0 0.1 2.7 0.1 0.0 1.5 19.1 1.4

Far 0.0 0.0 0.6 0.0 0.0 1.1 7.7 0.5

N NE E SE S SW W NW

Large Adjacent -0.2 -7.8 -31.7 -43.6 -86.6 -67.5 -60.3 -20.3

Deciduous Near 0.0 -0.1 -24.6 -36.3 -77.8 -53.0 -43.6 -0.2

Far 0.0 0.0 -13.7 -33.8 -44.3 -46.8 -25.4 0.0

Medium Adjacent -0.1 -3.7 -28.9 -36.6 -82.3 -59.6 -53.3 -15.4

Deciduous Near 0.0 0.0 -17.4 -26.9 -50.6 -43.4 -31.7 -0.1

Far 0.0 0.0 -7.8 -21.2 -11.1 -30.7 -18.0 0.0

Small Adjacent 0.0 -0.1 -17.4 -19.6 -50.2 -36.2 -34.3 -0.6

Deciduous Near 0.0 0.0 -7.4 -13.1 -8.5 -21.4 -18.9 -0.1

Far 0.0 0.0 -2.2 -6.6 0.0 -10.7 -9.4 0.0

N NE E SE S SW W NW

Large Adjacent -0.2 -18.6 -74.9 -113.8 -257.0 -159.4 -134.6 -44.7

Evergreen Near 0.0 -0.1 -57.7 -101.3 -236.7 -135.9 -97.2 -0.2

Far 0.0 0.0 -29.3 -94.7 -137.7 -125.6 -46.2 0.0

Medium Adjacent -0.1 -7.8 -68.8 -96.3 -245.1 -142.2 -120.7 -27.7

Evergreen Near 0.0 0.0 -38.0 -75.6 -148.6 -108.3 -63.6 -0.1

Far 0.0 0.0 -15.6 -54.7 -31.8 -73.7 -28.2 0.0

Small Adjacent 0.0 0.0 -18.8 -22.9 -49.3 -36.7 -38.5 -0.1

Evergreen Near 0.0 0.0 -5.9 -9.9 -0.3 -16.7 -17.8 0.0

Far 0.0 0.0 -1.3 -3.2 0.0 -5.9 -4.6 0.0

Table 81—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Table 82—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.
196 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 86—Change from avoided heating (kg CO2/tree) for mature evergreen trees.

Table 83—Change from avoided cooling (kg CO2

/tree) for mature deciduous trees.

Table 84—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 85—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Region 06: South Central, Dallas-Ft Worth post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 9.1 49.2 126.4 71.9 84.9 88.6 206.6 78.2

Deciduous Near 0.0 3.7 103.1 22.8 43.7 43.0 198.1 15.0

Far 0.0 0.9 69.4 7.4 8.8 16.4 153.0 7.8

Medium Adjacent 5.1 19.6 85.5 34.2 59.7 49.9 170.5 39.4

Deciduous Near 0.0 1.5 58.6 7.7 14.9 15.6 137.1 9.5

Far 0.0 0.3 30.2 1.9 1.3 5.7 83.6 3.7

Small Adjacent 1.0 2.2 40.4 7.9 17.8 19.9 101.9 13.2

Deciduous Near 0.0 0.5 19.7 1.1 1.1 5.0 62.9 5.3

Far 0.0 0.1 6.7 0.2 0.0 1.0 29.8 1.6

N NE E SE S SW W NW

Large Adjacent 9.6 54.1 136.9 81.8 99.0 99.4 223.9 86.0

Evergreen Near 0.2 4.3 114.4 29.0 54.2 50.7 222.1 16.3

Far 0.0 1.0 76.3 10.9 10.9 21.6 171.0 8.4

Medium Adjacent 5.4 20.7 92.3 39.8 70.8 56.9 184.6 42.3

Evergreen Near 0.0 1.6 63.0 9.5 18.4 20.2 150.2 10.1

Far 0.0 0.3 32.5 1.9 1.7 6.7 90.7 3.9

Small Adjacent 4.6 1.1 20.8 18.3 5.6 51.7 91.8 10.3

Evergreen Near 0.0 0.2 6.3 0.6 0.0 4.1 44.9 2.2

Far 0.0 0.1 2.2 0.1 0.0 0.7 20.7 0.7

N NE E SE S SW W NW

Large Adjacent - 0.0 -6.0 -19.7 -29.5 -61.0 -39.2 -37.5 -13.9-

Deciduous Near - 0.0 -0.0 -14.5 -31.8 -77.6 -44.4 -24.4 -0.0

Far - 0.0 -0.0 -7.2 -33.8 -55.1 -45.1 -14.9 -0.0

Medium Adjacent - 0.0 -3.3 -22.1 -27.0 -70.2 -40.0 -44.8 -8.5

Deciduous Near - 0.0 -0.0 -12.6 -26.7 -59.7 -37.0 -26.8 0.0

Far - 0.0 -0.0 -5.2 -22.5 -23.4 -33.8 -14.1 0.0

Small Adjacent - 0.0 -0.0 -16.1 -19.5 -58.4 -33.8 -37.4 -0.0

Deciduous Near - 0.0 -0.0 -8.0 -16.2 -20.5 -28.5 -23.2 -0.0

Far - 0.0 -0.0 -2.2 -9.8 -0.0 -15.8 -11.8 -0.0

N NE E SE S SW W NW

Large Adjacent -0.0 -14.8 -60.1 -92.7 -222.2 -119.6 -113.7 -35.9

Evergreen Near -0.0 -0.0 -46.0 -100.4 -272.6 -136.9 -84.2 -0.0

Far -0.0- -0.0 -23.4 -102.2 -185.8 -140.4 -43.4 -0.0

Medium Adjacent -0.0- -6.3 -63.3 -77.8 -231.9 -113.2 -116.4 -17.6

Evergreen Near -0.0 -0.0 -35.9 -77.7 -192.9 -114.1 -66.0 -0.0

Far -0.0 -0.0 -13.9 -64.1 -70.9 -89.8 -26.5 -0.0

Small Adjacent -0.0 -0.0 -23.7 -32.6 -107.0 -86.6 -76.7 -8.0

Evergreen Near -0.0- -0.0 -8.0 -21.7 -1.1 -49.6 -35.7 -0.0

Far -0.0 -0.0 -1.5 -10.3 0.0 -16.1 -13.6 -0.0

-

-
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 197

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 89—Change from avoided heating (kg CO2

/tree) for mature deciduous trees.

Table 88—Change from avoided cooling (kg CO2/tree) for mature evergreen trees.

Table 87—Change from avoided cooling (kg CO2/tree) for mature deciduous trees.

Table 90—Change from avoided heating (kg CO2/tree) for mature evergreen trees.

Region 07: Pacific NorthWest, Seattle post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 0.3 3.3 5.5 9.6 13.0 10.4 14.0 4.8

Deciduous Near 0.0 0.1 4.6 3.1 9.5 7.5 14.6 0.6

Far 0.0 0.0 2.8 1.3 2.2 3.2 11.2 0.2

Medium Adjacent 0.2 1.3 4.9 5.4 11.3 8.0 13.8 2.8

Deciduous Near 0.0 0.0 2.9 1.2 3.0 3.5 11.6 0.3

Far 0.0 0.0 1.1 0.2 0.0 0.9 6.5 0.1

Small Adjacent 0.0 0.0 2.4 0.9 4.0 3.2 9.2 0.7

Deciduous Near 0.0 0.0 0.7 0.1 0.1 0.5 5.0 0.2

Far 0.0 0.0 0.2 0.0 0.0 0.2 1.9 0.0

N NE E SE S SW W NW

Large Adjacent 0.4 3.7 6.2 10.1 13.7 11.1 14.5 5.1

Evergreen Near 0.0 0.1 5.2 3.3 10.2 7.9 15.3 0.6

Far 0.0 0.0 3.0 1.4 2.6 3.8 12.2 0.2

Medium Adjacent 0.2 1.3 5.2 5.6 11.9 8.4 14.7 3.1

Evergreen Near 0.0 0.0 3.1 1.2 3.1 3.6 12.0 0.3

Far 0.0 0.0 1.1 0.2 0.0 0.9 6.9 0.1

Small Adjacent 0.0 0.0 0.7 0.1 0.5 0.3 3.0 0.4

Evergreen Near 0.0 0.0 0.2 0.0 0.0 0.0 1.1 0.1

Far 0.0 0.0 0.1 0.0 0.0 0.0 0.4 0.0

N NE E SE S SW W NW

Large Adjacent -1.3 -29.8 -60.7 -69.0 -88.9 -65.8 -46.8 -20.9

Deciduous Near -0.0 -2.1 -68.1 -41.4 -82.3 -48.2 -33.8 -1.5

Far -0.0 -0.6 -64.4 -30.5 -49.7 -39.0 -18.8 -0.6

Medium Adjacent -0.6 -13.9 -68.2 -51.6 -88.8 -58.5 -41.8 -12.2

Deciduous Near -0.0 -0.9 -59.7 -29.8 -55.9 -39.3 -24.4 -1.2

Far -0.0 -0.3 -22.1 -16.9 -27.0 -26.4 -12.5 -0.4

Small Adjacent -0.2 -1.7 -44.8 -26.2 -53.6 -32.8 -26.0 -1.8

Deciduous Near -0.0 -0.4 -29.5 -11.3 -21.4 -19.3 -13.3 -0.8

Far -0.0 -0.1 -11.6 -5.4 -4.1 -11.7 -5.8 -0.3

N NE E SE S SW W NW

Large Adjacent -1.3 -42.3 -98.9 -108.3 -175.0 -104.5 -72.9 -30.9

Evergreen Near -0.0 -2.2 -90.3 -80.1 -172.9 -88.7 -50.6 -1.5

Far -0.0 -0.7 -77.7 -66.8 -119.8 -79.0 -26.2 -0.7

Medium Adjacent -0.6 -19.2 -97.5 -89.8 -178.7 -98.8 -67.4 -17.5

Evergreen Near -0.0 -1.0 -74.6 -61.3 -124.2 -75.1 -35.2 -1.3

Far -0.0 -0.3 -54.9 -37.0 -61.0 -51.7 -17.0 -0.4

Small Adjacent -0.0 -0.6 -30.0 -16.0 -53.3 -21.2 -17.5 -1.5

Evergreen Near -0.0 -0.2 -11.1 -6.4 -11.8 -12.0 -8.5 -0.6

Far -0.0 -0.0 -3.2 -2.2 -0.3 -6.8 -4.1 -0.2
198 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 91—Change from avoided cooling (kg CO2/tree) for mature deciduous trees.

Table 92—Change from avoided cooling (kg CO2/tree) for mature evergreen trees.

Table 93—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Table 94—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.

Region 08: Gulf Coast/Hawaii, Houston post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 7.5 68.1 117.5 68.7 55.8 72.1 155.6 80.3

Deciduous Near 2.0 13.3 98.1 30.0 37.0 36.8 158.0 22.4

Far 0.0 1.2 63.9 10.7 11.9 19.1 128.2 8.5

Medium Adjacent 6.3 30.8 84.5 35.3 45.0 37.5 127.3 41.1

Deciduous Near 0.0 2.3 54.7 9.9 13.2 15.4 111.6 10.9

Far 0.0 0.5 28.0 2.2 0.7 6.2 74.4 4.3

Small Adjacent 2.0 3.9 40.5 11.6 19.8 16.0 84.4 14.4

Deciduous Near 0.0 0.7 20.8 1.8 1.8 5.2 61.4 6.4

Far 0.0 0.1 8.1 0.2 0.0 1.4 35.7 1.9

N NE E SE S SW W NW

Large Adjacent 8.6 82.5 133.0 86.8 68.9 95.7 172.8 100.2

Evergreen Near 4.1 30.9 118.0 50.5 51.6 64.1 179.9 39.7

Far 0.0 1.7 80.8 16.5 22.0 34.2 156.1 10.7

Medium Adjacent 6.9 46.6 109.1 53.3 62.5 59.3 158.2 57.5

Evergreen Near 0.0 3.8 73.9 18.0 30.7 31.4 146.4 12.9

Far 0.0 0.7 43.3 6.0 7.0 18.1 100.2 6.2

Small Adjacent 7.0 2.5 32.4 31.8 17.8 47.8 92.6 18.1

Evergreen Near 0.0 0.6 14.7 3.8 0.5 17.4 70.0 3.7

Far 0.0 0.1 4.7 0.5 0.0 5.5 41.1 1.2

N NE E SE S SW W NW

Large Adjacent -0.0 -3.6 -9.7 -15.7 -21.1 -17.9 -14.1 -6.2

Deciduous Near -0.0 -1.1 -7.6 -15.5 -28.2 -20.2 -12.7 -2.3

Far -0.0 -0.0 -4.3 -14.5 -21.0 -20.4 -8.5 -0.0

Medium Adjacent -0.0 -2.6 -10.9 -13.4 -25.6 -16.4 -16.5 -3.90

Deciduous Near -0.0 -0.0 -6.1 -11.2 -21.5 -16.4 -14.6 -0.0

Far -0.0 -0.0 -2.4 -9.1 -9.9 -14.6 -9.2 -0.0

Small Adjacent -0.0 -0.0 -7.3 -8.1 -21.5 -16.7 -17.4 -0.0

Deciduous Near -0.0 -0.0 -3.7 -5.7 -10.6 -12.7 -13.1 -0.0

Far -0.0 -0.0 -1.1 -3.9 -0.0 -6.3 -8.6 -0.0

N NE E SE S SW W NW

Large Adjacent -0.0 -10.9 -32.5 -57.7 -76.9 -62.9 -47.2 -18.3

Evergreen Near -0.0 -5.2 -31.7 -58.8 -114.8 -74.8 -50.6 -9.3

Far -0.0 -0.0 -19.0 -55.8 -88.7 -75.3 -34.5 -0.0

Medium Adjacent -0.0 -8.3 -37.0 -50.6 -94.9 -59.1 -55.1 -13.2

Evergreen Near -0.0 -0.0 -25.1 -46.2 -94.1 -65.2 -46.3 - 0.0

Far -0.0 -0.0 -11.1 -40.1 53.6 -61.5 -28.7 -0.0

Small Adjacent -0.0 -0.0 -18.7 -20.8 -68.8 -38.7 -52.8 -7.3

Evergreen Near -0.0 -0.0 -6.8 -15.8 -18.8 -41.5 -34.3 -0.0

Far -0.0 -0.0 -2.1 -9.5 -0.0 -26.0 -16.2 -0.0
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 199

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 98—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.

Table 97—Change from avoided heating (kg CO2/tree) for mature deciduous trees.

Table 96—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 95—Change from avoided cooling (kg CO2

/tree) for mature deciduous trees.

Region 09: California Coast post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 0.3 17.4 27.3 34.0 39.2 36.0 36.5 19.6

Deciduous Near 0.1 1.7 25.9 17.4 35.3 26.9 34.5 3.5

Far 0.0 0.1 17.3 9.7 17.7 19.4 24.6 0.2

Medium Adjacent 0.2 7.9 25.5 23.6 38.1 29.3 33.7 12.0

Deciduous Near 0.0 0.2 17.2 8.2 20.1 17.3 25.8 0.3

Far 0.0 0.0 7.7 3.1 3.9 7.9 12.9 0.0

Small Adjacent 0.0 0.5 16.3 7.9 25.0 15.5 23.1 0.5

Deciduous Near 0.0 -0.0 5.9 2.1 4.0 6.4 10.9 0.1

Far 0.0 0.0 1.8 0.9 0.0 1.6 3.1 0.0

N NE E SE S SW W NW

Large Adjacent 0.3 20.2 30.6 39.9 42.5 40.6 38.4 23.1

Evergreen Near 0.2 6.7 29.1 26.0 40.0 33.5 37.5 9.0

Far 0.0 0.1 20.0 13.2 23.8 23.3 28.7 0.2

Medium Adjacent 0.3 14.8 28.6 32.3 41.9 35.1 38.9 16.1

Evergreen Near 0.0 0.2 22.8 12.7 30.0 22.8 32.5 0.4

Far 0.0 -0.0 12.1 5.8 10.3 13.9 17.9 0.1

Small Adjacent 0.0 0.2 13.4 4.1 19.7 8.1 16.0 0.4

Evergreen Near 0.0 0.0 4.1 1.0 2.4 3.3 5.2 0.1

Far 0.0 0.0 1.3 0.3 0.0 0.9 1.9 0.0

N NE E SE S SW W NW

Large Adjacent -1.8 -34.6 -68.3 -66.6 -75.2 -52.9 -43.8 -21.5

Deciduous Near -0.6 -3.9 -68.3 -51.8 -72.8 -30.9 -46.5 -3.4

Far -0.0 -0.1 -38.7 -46.7 -42.1 -26.0 -38.3 -0.6

Medium Adjacent -1.2 -16.5 -68.8 -53.5 -80.7 -50.3 -51.5 -15.5

Deciduous Near -0.0 -0.2 -40.9 -39.6 -46.5 -28.6 -44.2 -1.3

Far -0.0 -0.0 -14.5 -27.1 -17.7 -19.5 -28.3 -0.2

Small Adjacent -0.3 -1.2 -43.4 -32.0 -54.7 -29.6 -39.6 -5.7

Deciduous Near -0.0 -0.0 -13.2 -18.8 -16.7 -18.4 -26.9 -0.6

Far -0.0 -0.0 -3.6 -8.5 -0.3 -9.2 -15.2 -0.1

N NE E SE S SW W NW

Large Adjacent -1.9 -72.7 -148.8 -162.2 -225.9 -128.9 -79.5 -37.7

Evergreen Near -1.3 -23.9 -161.6 -168.4 -264.0 -113.5 -92.3 -13.8

Far -0.0 -0.2 -94.0 -164.3 -166.3 -96.6 -73.2 -1.0

Medium Adjacent -1.7 -47.8 -165.5 -159.9 -264.4 -134.7 -106.4 -29.1

Evergreen Near -0.0 -0.6 -123.2 -144.3 -211.0 -95.3 -90.8 -2.1

Far -0.0 -0.0 -41.3 -122.8 -94.4 -78.0 -57.6 -0.5

Small Adjacent -0.0 -0.2 -87.4 -70.3 -144.1 -47.0 -58.1 -3.3

Evergreen Near -0.0 -0.0 -23.0 -32.2 -25.2 -25.7 -32.5 -0.6

Far -0.0 -0.0 -5.2 -10.9 -0.0 -14.1 -17.5 -0.1
200 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 102—Change from avoided heating (kg CO2

/tree) for mature evergreen trees.

Table 101—Change from avoided heating (kg CO2

/tree) for mature deciduous trees.

Table 100—Change from avoided cooling (kg CO2/tree) for mature evergreen trees.

Table 99—Change from avoided cooling (kg CO2

/tree) for mature deciduous trees.

Region 10: SouthWest, Fresno post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 10.8 24.2 49.7 24.1 28.1 34.8 86.8 42.0

Deciduous Near 0.0 1.5 40.6 8.5 14.9 13.2 90.5 13.0

Far 0.0 0.3 26.2 2.5 3.1 4.8 74.8 7.8

Medium Adjacent 6.4 10.8 32.2 11.4 19.7 16.0 69.5 25.3

Deciduous Near 0.0 0.6 22.2 2.8 4.0 5.0 65.5 11.2

Far 0.0 0.1 11.9 0.3 0.1 0.8 46.1 3.7

Small Adjacent 1.3 1.0 14.0 2.8 5.4 4.6 47.9 15.5

Deciduous Near 0.0 0.2 7.7 0.2 0.1 0.5 34.9 6.1

Far 0.0 0.1 3.1 0.0 0.0 0.1 22.7 1.4

N NE E SE S SW W NW

Large Adjacent 11.4 26.2 53.6 27.0 32.3 38.7 90.7 45.2

Evergreen Near 0.1 1.6 44.8 9.2 18.5 15.6 97.9 13.7

Far 0.0 0.3 29.9 3.3 4.2 6.6 81.4 8.5

Medium Adjacent 6.7 11.4 34.0 12.5 22.4 17.6 74.9 26.8

Evergreen Near 0.0 0.7 23.8 3.2 5.1 6.2 70.4 11.8

Far 0.0 0.1 12.8 0.4 0.1 0.8 49.5 3.9

Small Adjacent 9.0 0.4 7.7 10.4 1.0 25.6 41.3 13.4

Evergreen Near 0.0 0.1 2.9 0.4 0.0 1.2 27.2 2.4

Far 0.0 0.0 1.0 0.0 0.0 0.0 16.3 0.5

N NE E SE S SW W NW

Large Adjacent -0.2 -6.4 -14.9 -23.1 -31.8 -26.6 -24.8 -8.5

Deciduous Near -0.0 -0.0 -13.3 -15.7 -37.2 -23.5 -19.9 -0.2

Far -0.0 -0.0 -9.9 -12.8 -24.8 -22.3 -9.8 -0.0

Medium Adjacent -0.1 -2.4 -13.2 -16.0 -33.0 -22.2 -22.7 -4.4

Deciduous Near -0.0 -0.0 -9.6 -11.1 -25.7 -19.2 -14.4 -0.0

Far -0.0 -0.0 -5.7 -7.0 -12.6 -14.1 -6.5 -0.0

Small Adjacent -0.0 -0.0 -8.2 -7.0 -24.5 -13.9 -18.7 -0.2

Deciduous Near -0.0 -0.0 -4.2 -4.1 -11.7 -9.4 -9.4 -0.0

Far -0.0 -0.0 -1.5 -2.4 0.0 -5.1 -4.0 -0.0

N NE E SE S SW W NW

Large Adjacent -0.2 -11.0 -33.1 -54.1 -88.8 -63.5 -59.3 -17.6

Evergreen Near -0.0 -0.0 -27.2 -43.1 -108.3 -64.4 -46.2 -0.2

Far -0.0 -0.0 -17.8 -39.0 -73.6 -62.2 -21.8 - 0.0

Medium Adjacent -0.1 -3.7 -29.3 -38.3 -93.6 -55.1 -56.0 -7.8

Evergreen Near -0.0 -0.0 -18.7 -31.5 -74.9 -53.4 -32.6 -0.0

Far -0.0 -0.0 -9.9 -17.9 -31.6 -36.8 -12.9 -0.0

Small Adjacent -0.2 -0.0 -8.7 -13.7 -39.7 -42.1 -40.9 -12.2

Evergreen Near -0.0- -0.0 -2.6 -5.7 -2.4 -21.3 -14.8 -0.0

Far -0.0 -0.0 -0.7 -2.1 -0.0 -7.2 -4.4 -0.0
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 201

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 105—Change from avoided heating (kg CO2

/tree) for mature deciduous trees.

Table 104—Change from avoided cooling (kg CO2

/tree) for mature evergreen trees.

Table 103—Change from avoided cooling (kg CO2/tree) for mature deciduous trees.

pp

Region 11: Desert Southwest, Phoenix post-1980 Vintage

N NE E SE S SW W NW

Large Adjacent 3.0 45.0 107.1 64.6 62.6 73.0 141.4 58.5

Deciduous Near 0.6 9.2 98.0 32.4 50.6 43.6 145.1 13.9

Far 0.0 0.8 72.9 14.0 20.1 24.1 117.4 5.0

Medium Adjacent 3.6 20.2 81.7 34.8 56.2 42.7 118.7 29.5

Deciduous Near 0.0 1.4 63.1 11.4 22.3 21.0 104.4 5.9

Far 0.0 0.4 33.7 4.6 6.9 10.6 68.9 3.1

Small Adjacent 1.4 2.7 44.7 11.4 29.1 18.5 81.1 8.9

Deciduous Near 0.0 0.7 26.3 3.6 7.5 8.6 57.9 4.3

Far 0.0 0.1 10.5 1.1 0.0 3.3 32.9 1.6

N NE E SE S SW W NW

Large Adjacent 3.1 56.8 119.4 85.5 79.7 95.4 158.2 73.5

Evergreen Near 1.3 19.2 116.4 56.3 71.1 68.3 168.4 28.0

Far 0.0 1.0 89.0 23.2 33.6 40.2 139.6 5.8

Medium Adjacent 3.9 30.3 103.7 53.8 75.6 64.0 146.1 43.3

Evergreen Near 0.0 2.5 83.7 21.7 43.5 36.8 134.0 7.2

Far 0.0 0.6 52.8 10.7 13.6 20.0 96.0 3.6

Small Adjacent 1.1 0.9 22.2 7.4 12.6 17.1 59.9 6.1

Evergreen Near 0.0 0.3 8.0 1.4 0.3 5.6 33.9 2.2

Far 0.0 0.1 2.4 0.3 0.0 1.4 18.6 0.9

N NE E SE S SW W NW

Large Adjacent -0.0 -1.6 -5.1 -8.6 -14.4 -9.9 -7.7 -3.1

Deciduous Near -0.0 -0.6 -5.3 -10.8 -25.5 -13.2 -6.9 -1.3

Far -0.0 -0.0 -2.4 -12.8 -21.4 -14.2 -2.9 -0.0

Medium Adjacent -0.0 -1.2 -6.7 -8.7 -20.6 -10.7 -9.7 -2.3

Deciduous Near -0.0 -0.0 -4.9 -10.4 -21.5 -11.9 -7.5 -0.0

Far -0.0 -0.0 -2.2 -10.1 -12.2 -11.2 -3.8 -0.0

Small Adjacent -0.0 -0.0 -6.4 -7.4 -19.9 -10.5 -10.5 -0.0

Deciduous Near -0.0 -0.0 -3.4 -7.2 -12.9 -9.5 -6.3 -0.0

Far -0.0 -0.0 -0.9 -4.9 -0.3 -6.6 -2.6 -0.0

N NE E SE S SW W NW

Large Adjacent -0.0 -4.7 -17.7 -29.3 -54.6 -33.8 -25.2 -9.4

Evergreen Near -0.0 -2.5 -21.1 -41.3 -107.5 -46.6 -27.6 -5.6

Far -0.0 -0.0 -12.0 -49.6 -94.3 -53.1 -13.4 -0.0

Medium Adjacent -0.0 -3.9 -23.3 -32.7 -77.0 -37.1 -32.5 -7.9

Evergreen Near -0.0 -0.0 -18.4 -40.5 -95.5 -43.8 -22.2 -0.0

Far -0.0 -0.0 -7.8 -41.7 -64.7 -44.2 -9.5 -0.0

Small Adjacent -0.0 -0.0 -13.2 -14.3 -52.3 -22.7 -23.1 -0.0

Evergreen Near -0.0 -0.0 -4.6 -11.9 -3.5 -16.3 -10.4 -0.0

Far -0.0 -0.0 -1.1 -5.0 -0.0 -6.1 -3.4 -0.0

Table 106—Change from avoided heating (kg CO2/tree) for mature evergreen trees.
202 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Default Values for Avoided Energy Due to Climate and Shade by

Climate Region for Use in Long Form Analysis.

Use values in Tables 107, 108, and 109 for the appropriate climate region to fill in columns B, E, G,

J and M of Table VII of the Long Form analysis. If you are using your own tree distribution, use

table 61 (described in previous section) in place of table 107.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 203

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 107–Default changes in avoided CO2 (tonnes/tree) from shade based on default tree distribution.

 A B C D E F

 1. Mid-Atlantic 2. Northern Tier 3. North Central

Vintage: Pre-1950 Cooling Heating Cooling Heating Cooling Heating

 n Tree Type1 (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree)

 1 Dec-Large 0.0425 -0.0487 0.0573 -0.0609 0.0487 -0.0574

2 Dec-Med. 0.0260 -0.0320 0.0318 -0.0392 0.0263 -0.0353

3 Dec-Small 0.0107 -0.0167 0.0109 -0.0193 0.0080 -0.0161

4 Evr-Large 0.0268 -0.0471 0.0302 -0.0461 0.0246 -0.0394

5 Evr-Med. 0.0168 -0.0315 0.0122 -0.0227 0.0087 -0.0181

6 Evr-Small 0.0036 -0.0095 0.0065 -0.0152 0.0046 -0.0117

Vintage: 1950-80

7 Dec-Large 0.0696 -0.0623 0.0373 -0.0378 0.0352 -0.0515

8 Dec-Med. 0.0425 -0.0409 0.0207 -0.0243 0.0190 -0.0316

9 Dec-Small 0.0176 -0.0213 0.0071 -0.0120 0.0058 -0.0144

10 Evr-Large 0.0439 -0.0603 0.0196 -0.0286 0.0178 -0.0353

11 Evr-Med. 0.0275 -0.0403 0.0079 -0.0141 0.0063 -0.0162

12 Evr-Small 0.0059 -0.0121 0.0042 -0.0094 0.0034 -0.0105

Vintage: Post-80

13 Dec-Large 0.0587 -0.0502 0.0420 -0.0532 0.0527 -0.0607

14 Dec-Med. 0.0358 -0.0329 0.0234 -0.0342 0.0285 -0.0373

15 Dec-Small 0.0148 -0.0171 0.0080 -0.0169 0.0087 -0.0170

16 Evr-Large 0.0370 -0.0485 0.0221 -0.0403 0.0266 -0.0417

17 Evr-Med. 0.0232 -0.0324 0.0089 -0.0198 0.0094 -0.0191

18 Evr-Small 0.0050 -0.0098 0.0048 -0.0133 0.0050 -0.0124

Vintage: Pre-1950 4. Mountains 5. Southeast 6. South Central

19 Dec-Large 0.0390 -0.0353 0.0586 -0.0197 0.0737 -0.0091

20 Dec-Med. 0.0228 -0.0240 0.0361 -0.0136 0.0448 -0.0087

21 Dec-Small 0.0085 -0.0113 0.0151 -0.0080 0.0213 -0.0069

22 Evr-Large 0.0209 -0.0258 0.0378 -0.0237 0.0462 -0.0158

23 Evr-Med. 0.0087 -0.0131 0.0240 -0.0164 0.0285 -0.0125

24 Evr-Small 0.0047 -0.0082 0.0038 -0.0047 0.0093 -0.0071

Vintage: 1950-80

25 Dec-Large 0.0503 -0.0554 0.0785 -0.0224 0.1215 -0.0113

26 Dec-Med. 0.0295 -0.0376 0.0483 -0.0155 0.0738 -0.0107

27 Dec-Small 0.0110 -0.0177 0.0203 -0.0091 0.0351 -0.0085

28 Evr-Large 0.0270 -0.0404 0.0507 -0.0270 0.0761 -0.0197

29 Evr-Med. 0.0112 -0.0205 0.0321 -0.0186 0.0470 -0.0155

30 Evr-Small 0.0060 -0.0129 0.0052 -0.0054 0.0154 -0.0089

Vintage: Post-80

31 Dec-Large 0.0848 -0.0759 0.0993 -0.0264 0.1142 -0.0154

32 Dec-Med. 0.0497 -0.0516 0.0612 -0.0183 0.0694 -0.0147

33 Dec-Small 0.0185 -0.0243 0.0257 -0.0107 0.0330 -0.0116

34 Evr-Large 0.0454 -0.0554 0.0641 -0.0319 0.0716 -0.0268

35 Evr-Med. 0.0189 -0.0281 0.0406 -0.0220 0.0442 -0.0211

36 Evr-Small 0.0102 -0.0177 0.0065 -0.0063 0.0145 -0.0121
204 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 107–Default changes in avoided CO2 (tonnes/tree) from shade based on default tree distribution (contitnued).

G H I J KL

 7.Pacific Northwest 8. Gulf Coast 9.California Coast

Vintage: Pre-1950 Cooling Heating Cooling Heating Cooling Heating

n Tree Type1

 (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree) (t CO2/tree)

1 Dec-Large 0.0029 -0.0451 0.0793 -0.0048 0.0106 -0.0174

2 Dec-Med. 0.0020 -0.0366 0.0482 -0.0043 0.0072 -0.0133

3 Dec-Small 0.0009 -0.0219 0.0254 -0.0035 0.0037 -0.0081

4 Evr-Large 0.0017 -0.0337 0.0588 -0.0108 0.0075 -0.0212

5 Evr-Med. 0.0012 -0.0282 0.0384 -0.0082 0.0053 -0.0181

6 Evr-Small 0.0002 -0.0080 0.0163 -0.0058 0.0015 -0.0078

 Vintage: 1950-80

7 Dec-Large 0.0033 -0.0382 0.1331 -0.0056 0.0111 -0.0155

8 Dec-Med. 0.0023 -0.0310 0.0810 -0.0051 0.0075 -0.0119

9 Dec-Small 0.0011 -0.0185 0.0427 -0.0041 0.0039 -0.0073

10 Evr-Large 0.0020 -0.0286 0.0988 -0.0127 0.0079 -0.0190

11 Evr-Med. 0.0014 -0.0239 0.0644 -0.0096 0.0056 -0.0162

12 Evr-Small 0.0002 -0.0067 0.0273 -0.0069 0.0016 -0.0070

 Vintage: Post-80

13 Dec-Large 0.0074 -0.0340 0.0977 -0.0079 0.0223 -0.0382

14 Dec-Med. 0.0051 -0.0275 0.0594 -0.0072 0.0151 -0.0293

15 Dec-Small 0.0024 -0.0165 0.0313 -0.0058 0.0077 -0.0179

16 Evr-Large 0.0044 -0.0254 0.0726 -0.0180 0.0158 -0.0466

17 Evr-Med. 0.0031 -0.0213 0.0473 -0.0136 0.0112 -0.0397

18 Evr-Small 0.0005 -0.0060 0.0201 -0.0097 0.0032 -0.0172

Vintage: Pre-1950 10. Southwest 11.Desert Southwest

19 Dec-Large 0.0598 -0.0091 0.0561 -0.0019

20 Dec-Med. 0.0374 -0.0062 0.0357 -0.0018

21 Dec-Small 0.0199 -0.0041 0.0194 -0.0015

22 Evr-Large 0.0384 -0.0109 0.0394 -0.0042

23 Evr-Med. 0.0252 -0.0077 0.0269 -0.0032

24 Evr-Small 0.0103 -0.0049 0.0068 -0.0017

 Vintage: 1950-80

25 Dec-Large 0.0758 -0.0149 0.1034 -0.0033

26 Dec-Med. 0.0474 -0.0102 0.0658 -0.0031

27 Dec-Small 0.0252 -0.0067 0.0357 -0.0027

28 Evr-Large 0.0487 -0.0178 0.0726 -0.0073

29 Evr-Med. 0.0320 -0.0126 0.0495 -0.0056

30 Evr-Small 0.0130 -0.0080 0.0126 -0.0029

 Vintage: Post-80

31 Dec-Large 0.0508 -0.0124 0.0897 -0.0045

32 Dec-Med. 0.0318 -0.0085 0.0571 -0.0042

33 Dec-Small 0.0169 -0.0055 0.0309 -0.0037

34 Evr-Large 0.0327 -0.0148 0.0630 -0.0101

35 Evr-Med. 0.0214 -0.0105 0.0430 -0.0078

36 Evr-Small 0.0087 -0.0067 0.0109 -0.0040

1

Dec = deciduous; Evr = evergreen; Med. = medium
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 205

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 108–Default avoided CO2

 savings per tree from windbreaks for mature evergreen trees (t CO2/tree).

A B C D EF

Vintage: Pre-1950 1. Mid-Atlantic 2. Northern Tier 3. North Central 4. Mountains 5. Southeast 6.South Central

n Tree Type1

 1 Evr-Large 0.1931 0.1662 0.1436 0.0538 0.0708 0.0482

 2 Evr-Med. 0.1294 0.1006 0.0869 0.0326 0.0475 0.0323

 3 Evr-Small 0.0206 0.0690 0.0596 0.0223 0.0076 0.0052

Vintage:1950-1980

 4 Evr-Large 0.2320 0.1087 0.1306 0.0748 0.0784 0.0541

 5 Evr-Med. 0.1555 0.0658 0.0791 0.0453 0.0526 0.0362

 6 Evr-Small 0.0248 0.0451 0.0542 0.0310 0.0084 0.0058

Vintage:Post-80

 7 Evr-Large 0.1985 0.1468 0.1425 0.0861 0.0635 0.0927

 8 Evr-Med. 0.1330 0.0889 0.0862 0.0521 0.0426 0.0621

 9 Evr-Small 0.0212 0.0609 0.0591 0.0357 0.0068 0.0099

Vintage: Pre-1950 7. Pacific Northwest 8. Gulf Coast 9. California Coast 10. Southwest 11. Desert Southwest

10 Evr-Large 0.1172 0.0302 0.0376 0.0218 0.0125

11 Evr-Med. 0.0786 0.0214 0.0266 0.0146 0.0088

12 Evr-Small 0.0125 0.0033 0.0041 0.0023 0.0014

Vintage:1950-1980

13 Evr-Large 0.0964 0.0328 0.0338 0.0265 0.0135

14 Evr-Med. 0.0646 0.0232 0.0239 0.0177 0.0096

15 Evr-Small 0.0103 0.0036 0.0037 0.0028 0.0015

Vintage:Post-80

16 Evr-Large 0.0618 0.0450 0.0229 0.0231 0.0173

17 Evr-Med. 0.0414 0.0318 0.0162 0.0155 0.0122

18 Evr-Small 0.0066 0.0049 0.0025 0.0025 0.0019

1

Dec = deciduous; Evr = evergreen; Med. = medium
206 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2

 /tree).

 1. Mid-Atlantic

ABCDEF

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.02132 0.01283 0.01172 0.40755 0.16228 0.06589

2 Dec-Med. 0.00996 0.00599 0.00547 0.19036 0.07580 0.03077

3 Dec-Small 0.00385 0.00232 0.00212 0.07358 0.02930 0.01190

4 Evr-Large 0.02302 0.01385 0.01265 0.44008 0.17523 0.07114

5 Evr-Med. 0.01034 0.00622 0.00568 0.19772 0.07873 0.03196

6 Evr-Small 0.00421 0.00253 0.00231 0.08045 0.03203 0.01301

1950-1980

7 Dec-Large 0.04992 0.03016 0.02818 0.46365 0.18062 0.07159

8 Dec-Med. 0.02332 0.01409 0.01316 0.21656 0.08437 0.03344

9 Dec-Small 0.00901 0.00545 0.00509 0.08371 0.03261 0.01293

10 Evr-Large 0.05390 0.03257 0.03043 0.50066 0.19504 0.07731

11 Evr-Med. 0.02422 0.01463 0.01367 0.22494 0.08763 0.03473

12 Evr-Small 0.00985 0.00595 0.00556 0.09152 0.03565 0.01413

Post-1980

13 Dec-Large 0.03214 0.02422 0.02366 0.41855 0.16740 0.06817

14 Dec-Med. 0.01501 0.01131 0.01105 0.19550 0.07819 0.03184

15 Dec-Small 0.00580 0.00437 0.00427 0.07557 0.03023 0.01231

16 Evr-Large 0.03471 0.02615 0.02555 0.45196 0.18076 0.07361

17 Evr-Med. 0.01559 0.01175 0.01148 0.20306 0.08122 0.03307

18 Evr-Small 0.00634 0.00478 0.00467 0.08262 0.03304 0.01346

 2. Northern Tier

GHI JK L

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.01032 0.00777 0.00724 0.37534 0.13485 0.04010

2 Dec-Med. 0.00516 0.00388 0.00362 0.18757 0.06739 0.02004

3 Dec-Small 0.00180 0.00136 0.00126 0.06553 0.02354 0.00700

4 Evr-Large 0.00921 0.00694 0.00646 0.33505 0.12038 0.03579

5 Evr-Med. 0.00338 0.00254 0.00237 0.12274 0.04410 0.01311

6 Evr-Small 0.00159 0.00119 0.00111 0.05771 0.02073 0.00616

1950-1980

7 Dec-Large 0.01131 0.00871 0.00827 0.21312 0.07815 0.02416

8 Dec-Med. 0.00565 0.00435 0.00413 0.10650 0.03905 0.01207

9 Dec-Small 0.00197 0.00152 0.00144 0.03721 0.01365 0.00422

10 Evr-Large 0.01009 0.00777 0.00738 0.19025 0.06976 0.02157

11 Evr-Med. 0.00370 0.00285 0.00270 0.06970 0.02556 0.00790

12 Evr-Small 0.00174 0.00134 0.00127 0.03277 0.01202 0.00371

Post-1980

13 Dec-Large 0.01514 0.01132 0.01157 0.35775 0.13064 0.03985

14 Dec-Med. 0.00756 0.00566 0.00578 0.17878 0.06529 0.01992

15 Dec-Small 0.00264 0.00198 0.00202 0.06246 0.02281 0.00696

16 Evr-Large 0.01351 0.01011 0.01033 0.31936 0.11662 0.03558

17 Evr-Med. 0.00495 0.00370 0.00378 0.11699 0.04272 0.01303

18 Evr-Small 0.00233 0.00174 0.00178 0.05500 0.02009 0.00613
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 207

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2

 /tree) (continued).

 3. North Central

ABCDEF

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

19 Dec-Large 0.00704 0.00573 0.00595 0.31565 0.11176 0.04279

20 Dec-Med. 0.00352 0.00286 0.00297 0.15774 0.05585 0.02138

21 Dec-Small 0.00123 0.00100 0.00104 0.05511 0.01951 0.00747

22 Evr-Large 0.00629 0.00511 0.00531 0.28177 0.09977 0.03820

23 Evr-Med. 0.00230 0.00187 0.00195 0.10322 0.03655 0.01399

24 Evr-Small 0.00108 0.00088 0.00091 0.04853 0.01718 0.00658

1950-1980

25 Dec-Large 0.00651 0.00731 0.00710 0.24252 0.08676 0.03392

26 Dec-Med. 0.00325 0.00365 0.00355 0.12119 0.04335 0.01695

27 Dec-Small 0.00114 0.00128 0.00124 0.04234 0.01515 0.00592

28 Evr-Large 0.00581 0.00652 0.00634 0.21649 0.07745 0.03028

29 Evr-Med. 0.00213 0.00239 0.00232 0.07931 0.02837 0.01109

30 Evr-Small 0.00100 0.00112 0.00109 0.03729 0.01334 0.00522

Post-1980

31 Dec-Large 0.02546 0.01238 0.01137 0.31396 0.11185 0.04306

32 Dec-Med. 0.01272 0.00619 0.00568 0.15689 0.05590 0.02152

33 Dec-Small 0.00445 0.00216 0.00198 0.05482 0.01953 0.00752

34 Evr-Large 0.02273 0.01105 0.01015 0.28026 0.09985 0.03844

35 Evr-Med. 0.00833 0.00405 0.00372 0.10267 0.03658 0.01408

36 Evr-Small 0.00391 0.00190 0.00175 0.04827 0.01720 0.00662

4. Mountains

GHI JK L

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

19 Dec-Large 0.02666 0.02370 0.02323 0.13285 0.04432 0.01465

20 Dec-Med. 0.01332 0.01184 0.01161 0.06639 0.02215 0.00732

21 Dec-Small 0.00465 0.00414 0.00406 0.02320 0.00774 0.00256

22 Evr-Large 0.02380 0.02116 0.02073 0.11859 0.03957 0.01308

23 Evr-Med. 0.00872 0.00775 0.00760 0.04345 0.01449 0.00479

24 Evr-Small 0.00410 0.00364 0.00357 0.02043 0.00681 0.00225

1950-1980

25 Dec-Large 0.04631 0.04190 0.04086 0.14432 0.04734 0.01528

26 Dec-Med. 0.02314 0.02094 0.02042 0.07212 0.02366 0.00764

27 Dec-Small 0.00809 0.00732 0.00713 0.02520 0.00827 0.00267

28 Evr-Large 0.04134 0.03741 0.03648 0.12883 0.04226 0.01364

29 Evr-Med. 0.01514 0.01370 0.01336 0.04719 0.01548 0.00500

30 Evr-Small 0.00712 0.00644 0.00628 0.02219 0.00728 0.00235

Post-1980

31 Dec-Large 0.08951 0.08326 0.08267 0.22744 0.07336 0.02297

32 Dec-Med. 0.04473 0.04161 0.04131 0.11366 0.03666 0.01148

33 Dec-Small 0.01563 0.01454 0.01443 0.03971 0.01281 0.00401

34 Evr-Large 0.07990 0.07432 0.07379 0.20303 0.06549 0.02051

35 Evr-Med. 0.02927 0.02723 0.02703 0.07438 0.02399 0.00751

36 Evr-Small 0.01376 0.01280 0.01271 0.03497 0.01128 0.00353
208 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2 /tree) (continued).

 5. Southeast

MNOP QR

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.01624 0.01186 0.01132 0.10813 0.03306 0.01006

2 Dec-Med. 0.00759 0.00554 0.00529 0.05051 0.01544 0.00470

3 Dec-Small 0.00293 0.00214 0.00204 0.01952 0.00597 0.00182

4 Evr-Large 0.01754 0.01281 0.01222 0.11676 0.03570 0.01086

5 Evr-Med. 0.00788 0.00576 0.00549 0.05246 0.01604 0.00488

6 Evr-Small 0.00321 0.00234 0.00223 0.02134 0.00653 0.00199

1950-1980

7 Dec-Large 0.03204 0.02351 0.02229 0.10588 0.03206 0.00965

8 Dec-Med. 0.01496 0.01098 0.01041 0.04945 0.01498 0.00451

9 Dec-Small 0.00578 0.00424 0.00403 0.01912 0.00579 0.00174

10 Evr-Large 0.03459 0.02538 0.02407 0.11433 0.03462 0.01042

11 Evr-Med. 0.01554 0.01140 0.01082 0.05137 0.01555 0.00468

12 Evr-Small 0.00632 0.00464 0.00440 0.02090 0.00633 0.00190

Post-1980

13 Dec-Large 0.02910 0.02606 0.02696 0.12300 0.03684 0.01096

14 Dec-Med. 0.01359 0.01217 0.01259 0.05745 0.01721 0.00512

15 Dec-Small 0.00525 0.00470 0.00487 0.02221 0.00665 0.00198

16 Evr-Large 0.03142 0.02814 0.02911 0.13282 0.03978 0.01183

17 Evr-Med. 0.01412 0.01264 0.01308 0.05967 0.01787 0.00532

18 Evr-Small 0.00574 0.00514 0.00532 0.02428 0.00727 0.00216

 6. South Central

S T U V WX

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.03655 0.02311 0.01946 0.09481 0.03578 0.01390

2 Dec-Med. 0.01707 0.01079 0.00909 0.04428 0.01671 0.00649

3 Dec-Small 0.00660 0.00417 0.00351 0.01712 0.00646 0.00251

4 Evr-Large 0.03947 0.02495 0.02102 0.10238 0.03864 0.01501

5 Evr-Med. 0.01773 0.01121 0.00944 0.04600 0.01736 0.00675

6 Evr-Small 0.00721 0.00456 0.00384 0.01871 0.00706 0.00274

1950-1980

7 Dec-Large 0.08960 0.05524 0.04633 0.10036 0.03753 0.01444

8 Dec-Med. 0.04185 0.02580 0.02164 0.04688 0.01753 0.00674

9 Dec-Small 0.01618 0.00997 0.00837 0.01812 0.00678 0.00261

10 Evr-Large 0.09676 0.05965 0.05003 0.10837 0.04053 0.01559

11 Evr-Med. 0.04347 0.02680 0.02248 0.04869 0.01821 0.00701

12 Evr-Small 0.01769 0.01090 0.00915 0.01981 0.00741 0.00285

Post-1980

13 Dec-Large 0.07210 0.04483 0.03885 0.14970 0.05686 0.02219

14 Dec-Med. 0.03368 0.02094 0.01815 0.06992 0.02656 0.01037

15 Dec-Small 0.01302 0.00809 0.00701 0.02703 0.01027 0.00401

16 Evr-Large 0.07786 0.04841 0.04195 0.16165 0.06140 0.02397

17 Evr-Med. 0.03498 0.02175 0.01885 0.07263 0.02759 0.01077

18 Evr-Small 0.01423 0.00885 0.00767 0.02955 0.01122 0.00438
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 209

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2 /tree) (continued).

 7. Pacific Northwest

M NO PQ R

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

19 Dec-Large 0.00301 0.00269 0.00266 0.12563 0.03872 0.01125

20 Dec-Med. 0.00140 0.00125 0.00124 0.05868 0.01809 0.00525

21 Dec-Small 0.00054 0.00048 0.00048 0.02268 0.00699 0.00203

22 Evr-Large 0.00325 0.00290 0.00288 0.13565 0.04181 0.01215

23 Evr-Med. 0.00146 0.00130 0.00129 0.06095 0.01878 0.00546

24 Evr-Small 0.00059 0.00053 0.00053 0.02480 0.00764 0.00222

1950-1980

25 Dec-Large 0.00496 0.00426 0.00420 0.10531 0.03225 0.00927

26 Dec-Med. 0.00232 0.00199 0.00196 0.04919 0.01506 0.00433

27 Dec-Small 0.00090 0.00077 0.00076 0.01901 0.00582 0.00167

28 Evr-Large 0.00536 0.00460 0.00454 0.11372 0.03482 0.01001

29 Evr-Med. 0.00241 0.00207 0.00204 0.05109 0.01565 0.00450

30 Evr-Small 0.00098 0.00084 0.00083 0.02079 0.00637 0.00183

Post-1980

31 Dec-Large 0.01157 0.01090 0.01135 0.11224 0.03375 0.00942

32 Dec-Med. 0.00540 0.00509 0.00530 0.05243 0.01576 0.00440

33 Dec-Small 0.00209 0.00197 0.00205 0.02027 0.00609 0.00170

34 Evr-Large 0.01249 0.01177 0.01225 0.12120 0.03644 0.01017

35 Evr-Med. 0.00561 0.00529 0.00551 0.05445 0.01637 0.00457

36 Evr-Small 0.00228 0.00215 0.00224 0.02216 0.00666 0.00186

 8. Gulf Coast

S TU V WX

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

19 Dec-Large 0.04988 0.02715 0.02203 0.09046 0.03180 0.01164

20 Dec-Med. 0.02227 0.01212 0.00983 0.04038 0.01419 0.00520

21 Dec-Small 0.00920 0.00501 0.00406 0.01669 0.00587 0.00215

22 Evr-Large 0.06045 0.03290 0.02669 0.10961 0.03853 0.01411

23 Evr-Med. 0.03020 0.01643 0.01333 0.05475 0.01925 0.00705

24 Evr-Small 0.01142 0.00621 0.00504 0.02070 0.00728 0.00266

1950-1980

25 Dec-Large 0.11810 0.06394 0.05084 0.09627 0.03383 0.01233

26 Dec-Med. 0.05271 0.02854 0.02269 0.04297 0.01510 0.00551

27 Dec-Small 0.02179 0.01180 0.00938 0.01776 0.00624 0.00228

28 Evr-Large 0.14311 0.07748 0.06161 0.11665 0.04099 0.01495

29 Evr-Med. 0.07149 0.03871 0.03077 0.05827 0.02048 0.00747

30 Evr-Small 0.02703 0.01463 0.01164 0.02203 0.00774 0.00282

Post-1980

31 Dec-Large 0.09227 0.05016 0.04154 0.12161 0.04222 0.01542

32 Dec-Med. 0.04119 0.02239 0.01854 0.05428 0.01884 0.00688

33 Dec-Small 0.01702 0.00926 0.00766 0.02244 0.00779 0.00285

34 Evr-Large 0.11181 0.06079 0.05033 0.14736 0.05116 0.01869

35 Evr-Med. 0.05585 0.03037 0.02514 0.07361 0.02556 0.00934

36 Evr-Small 0.02112 0.01148 0.00951 0.02783 0.00966 0.00353
210 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2 /tree) (continued).

 9. California Coast

Y Z AA AB AC AD

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.00736 0.01076 0.01218 0.05264 0.01664 0.00565

2 Dec-Med. 0.00329 0.00480 0.00543 0.02350 0.00743 0.00252

3 Dec-Small 0.00136 0.00199 0.00225 0.00971 0.00307 0.00104

4 Evr-Large 0.00892 0.01304 0.01475 0.06379 0.02016 0.00685

5 Evr-Med. 0.00446 0.00652 0.00737 0.03186 0.01007 0.00342

6 Evr-Small 0.00168 0.00246 0.00279 0.01205 0.00381 0.00129

1950-1980

7 Dec-Large 0.00976 0.01623 0.01848 0.04350 0.01360 0.00454

8 Dec-Med. 0.00436 0.00725 0.00825 0.01942 0.00607 0.00202

9 Dec-Small 0.00180 0.00299 0.00341 0.00803 0.00251 0.00084

10 Evr-Large 0.01183 0.01967 0.02239 0.05271 0.01648 0.00550

11 Evr-Med. 0.00591 0.00983 0.01119 0.02633 0.00823 0.00275

12 Evr-Small 0.00223 0.00371 0.00423 0.00996 0.00311 0.00104

Post-1980

13 Dec-Large 0.01683 0.02257 0.02428 0.09693 0.03254 0.01164

14 Dec-Med. 0.00751 0.01007 0.01084 0.04327 0.01452 0.00520

15 Dec-Small 0.00311 0.00416 0.00448 0.01788 0.00600 0.00215

16 Evr-Large 0.02039 0.02735 0.02942 0.11746 0.03943 0.01411

17 Evr-Med. 0.01019 0.01366 0.01470 0.00587 0.00197 0.00070

18 Evr-Small 0.00385 0.00517 0.00556 0.02218 0.00745 0.00266

10. Southwest

AE AF AG AH AI AJ

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

1 Dec-Large 0.04796 0.04117 0.03908 0.06110 0.02003 0.00549

2 Dec-Med. 0.02240 0.01923 0.01826 0.02854 0.00935 0.00257

3 Dec-Small 0.00866 0.00743 0.00706 0.01103 0.00362 0.00099

4 Evr-Large 0.05179 0.04446 0.04220 0.06598 0.02163 0.00593

5 Evr-Med. 0.02327 0.01998 0.01896 0.02964 0.00972 0.00267

6 Evr-Small 0.00947 0.00813 0.00771 0.01206 0.00395 0.00108

1950-1980

7 Dec-Large 0.08926 0.07587 0.07333 0.04967 0.01610 0.00439

8 Dec-Med. 0.04169 0.03544 0.03425 0.02320 0.00752 0.00205

9 Dec-Small 0.01612 0.01370 0.01324 0.00897 0.00291 0.00079

10 Evr-Large 0.09638 0.08193 0.07918 0.05363 0.01738 0.00474

11 Evr-Med. 0.04330 0.03681 0.03558 0.02410 0.00781 0.00213

12 Evr-Small 0.01762 0.01498 0.01447 0.00980 0.00318 0.00087

Post-1980

13 Dec-Large 0.10833 0.08541 0.08172 0.06955 0.02302 0.00649

14 Dec-Med. 0.05060 0.03989 0.03817 0.03249 0.01075 0.00303

15 Dec-Small 0.01956 0.01542 0.01475 0.01256 0.00416 0.00117

16 Evr-Large 0.11698 0.09223 0.08824 0.07510 0.02486 0.00701

17 Evr-Med. 0.05256 0.04144 0.03965 0.03374 0.01117 0.00315

18 Evr-Small 0.02138 0.01686 0.01613 0.01373 0.00454 0.00128
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 211

Appendix F Instructions for Adjusting Tree Distributions to Customize Avoided Carbon Dioxide Emissions

Table 109–Default Climate Effects for Mature trees for 10, 30 and 60% existing cover (t CO2 /tree) (continued).

 11. Desert Southwest

Y Z AA AB AC AD

Pre-1950 Cooling Heating

n Tree Type1 10% 30% 60% 10% 30% 60%

19 Dec-Large 0.04703 0.03731 0.03479 0.02565 0.00806 0.00232

20 Dec-Med. 0.02099 0.01665 0.01553 0.01145 0.00360 0.00104

21 Dec-Small 0.00868 0.00688 0.00642 0.00473 0.00149 0.00043

22 Evr-Large 0.05698 0.04521 0.04216 0.03108 0.00976 0.00281

23 Evr-Med. 0.02847 0.02259 0.02106 0.01553 0.00488 0.00140

24 Evr-Small 0.01076 0.00854 0.00796 0.00587 0.00184 0.00053

1950-1980

25 Dec-Large 0.11501 0.09387 0.08894 0.02067 0.00665 0.00198

26 Dec-Med. 0.05134 0.04190 0.03970 0.00923 0.00297 0.00088

27 Dec-Small 0.02122 0.01732 0.01641 0.00381 0.00123 0.00037

28 Evr-Large 0.13937 0.11375 0.10777 0.02505 0.00805 0.00240

29 Evr-Med. 0.06962 0.05682 0.05383 0.01251 0.00402 0.00120

30 Evr-Small 0.02632 0.02148 0.02035 0.00473 0.00152 0.00045

Post-1980

31 Dec-Large 0.11840 0.08722 0.07996 0.04026 0.01362 0.00437

32 Dec-Med. 0.05285 0.03893 0.03569 0.01797 0.00608 0.00195

33 Dec-Small 0.02185 0.01609 0.01475 0.00743 0.00251 0.00081

34 Evr-Large 0.14348 0.10569 0.09690 0.04878 0.01651 0.00529

35 Evr-Med. 0.07167 0.05279 0.04840 0.02437 0.00824 0.00264

36 Evr-Small 0.02710 0.01996 0.01830 0.00921 0.00312 0.00100

1

Dec = deciduous; Evr = evergreen; Med. = medium
212 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix G

Energy Simulation Methods

Avoided carbon dioxide savings are the result of reduced energy demand for building

heating or cooling due to the presence of trees. Reduced residential energy demand

translates into reduced need for energy production, and hence reduced CO2

 emissions from

generation of that energy, whether it be electrical generation for cooling or furnace operation for

heating.

Energy used for cooling is reduced in summer by tree shade. Although use of heating energy

in winter can be increased because of reduced solar gain caused by tree shade, sheltering of

buildings by nearby trees tends to reduce heating energy use. In addition to these localized

Shade and Windbreak Effects, lowered air temperatures and wind speeds from increased

regional tree cover (Climate Effects) produce a net decrease in demand for cooling (reduced

wind speeds by themselves may increase or decrease cooling demand, depending on the

circumstances). In winter, reduced wind speeds decrease heating requirements. To estimate the

net impact of all these effects on energy use, and hence CO2 emissions, a series of computer

simulations were done for 11 climatic regions in the United States (see Appendix C for climate

region information). These account for regional differences in utility, building, site, tree, and

program characteristics. Carbon dioxide emissions avoided due to these energy savings are

calculated using utility-specific emission factors for electricity, and appropriate emissions factors

for natural gas and other heating fuels.

Building Energy Use

Computer simulations. Hour-by-hour cooling (kWh) and heating (kBtu) energy were calculated

with Micropas 4.01 (Enercomp 1992) following methods from Simpson and McPherson (1998).

Primary model inputs are (1) building construction characteristics, (2) hourly weather data for a

typical year, and (3) hourly shading data for each month of the year simulated with Shadow

Pattern Simulator (SPS) (McPherson and others 1985). Simulations are done with and without

tree shade, and with and without wind and air temperature reductions due to trees, and

differences in energy use used to determine tree impacts on energy use. Because weather data

and prototypical buildings represent typical conditions, results are reflective of long-term impacts

for a large building population rather than impacts of extreme events on individual buildings.

Building Prototypes. Prototype buildings representative of construction practices in the 11

selected climate regions (Appendix C) are used as a basis for determining avoided heating and

cooling from energy savings. Three prototypes for pre-1950, 1950-1980, and post-1980 vintages

were used in each region, primarily reflecting differences in building energy efficiency and size

with age of construction. Prototypes are based on a previous study that categorized building

energy efficiency characteristics for climate regions similar to those used here (Ritshcard and

others 1992). Relevant data for each building are recorded in tables 43 and 44, in Appendix E.

Vintage is used here as a surrogate for building energy efficiency that is generally related to age

of construction, differences in insulation levels, heating and cooling equipment efficiency, or

number of glazing panes. Gross floor area was divided equally between floors of two-story

buildings. Buildings were simulated with 0.45-m (1.5-ft) overhangs. Blinds had shade coefficients

of 0.63, and were assumed closed when the air conditioner was operating. Summer thermostat

settings were 25  ̊C (78  ̊F); winter settings were 20  ̊C (68  ̊F) during the day and 16  ̊C (60  ̊F) at

night.

Energy use was scaled up from individual buildings to the entire population using equipment

and base case adjustment factors (Long Form Adjustment Table VI). Equipment adjustment

factors are averages of estimated reductions in energy consumption for alternative cooling

methods (SMUD 1995) compared to central air conditioning, weighted by the occurrence of each

type of equipment in the Climate Region on the basis of data for five U.S. climate zones (DOE/

EIA 1994). It is assumed that all residences are heated. Base case adjustment factors allow

adjustment for operational differences within a population that reduce average consumption per

unit, e.g., some space conditioning units being turned off, thermostat set points being much

higher or lower than normal, and differences between locally observed and simulated energy use.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 213

Appendix G Energy Simulation Methods

Shade Effects

Tree shade cast on building surfaces, especially glazing, is a function of tree species and location

with respect to the structure being shaded. Relevant species parameters are primarily related to

tree dimensions and include crown height and width, height to live bole (bole height), canopy

shape, canopy density (expressed as shade coefficient), growth rate, and leaf-on period, which in

turn vary as a function of tree age and condition (environment). Location parameters include

tree-to-building distance and tree azimuth (direction measured from building to tree). Amount

of shade on a building is affected as well by building characteristics such as size, orientation,

window distribution by azimuth and extent of overhangs. Attenuation of solar radiation by trees

was simulated using the Shadow Pattern Simulator program (SPS), which accounts for tree size,

location, canopy density, and time to calculate shade on building surfaces. A glazing obstruction

factor of 50 percent was used to reduce solar gain on windows by one-half to account for shade

from existing trees, adjacent buildings, and other shading obstructions.

Six tree types (large, medium, and small, both deciduous and evergreen) were simulated for

each prototype. Tree characteristics used in a particular climate region were based on one of three

tree growth zones; additional information on trees can be found in Appendix D. Each tree was

simulated for eight tree azimuths and three tree-to-building distances, for a total of 24 tree

locations for each prototype. Thus a total of 4,752 simulation runs (24 locations x 6 tree types x 3

prototypes x 11 climate regions) were conducted for mature (35-year-old) trees. To evaluate the

effect of tree age on results, simulations were repeated for trees of ages 5, 15, and 25 years,

requiring a grand total of 19,008 (4752 x 4 ages) simulations for shading effects.

Changes in energy use due to shade were calculated as the difference between unshaded and

shaded simulation results. To simplify the analysis without losing information, results are

tabulated by building vintage (3) and tree type (6) only, for a total of 18 values in each climate

region (11). Effects of tree age are incorporated in separate tables of “Tree Age Fractions” detailed

in Appendix H. Effects of tree location (24) are incorporated by calculating an average value

based on the residential tree distribution by azimuth and distance found for Sacramento,

California (tables 46 and 47, in Appendix F). This appendix gives the user the option of using a

tree distribution customized for their site if the Long Form is used (see Chapter 3 and the Tucson

example in Chapter 4).

Evergreen trees have more specialized roles than deciduous trees in terms of their energy

saving potential. Broadleaf evergreens are commonly used as shade trees in warmer climates

(e.g., zones 5-11), where air conditioning savings are relatively more important than increased

heating load that may result from winter shade. However, because this heating penalty can be

substantial even in cooling-dominated regions, placement of evergreens for building shade

(within 18 m) is not allowed to the southeast, south, or southwest of buildings by setting the

default tree distribution to zero at those locations (tables 46, in Appendix F).

Directional distribution of window and wall area can have a major impact on building

shading. For example, for walls oriented toward south, east or west, a short wall with few

windows will be minimally affected by shade compared to a longer wall with many windows.

Neither wall would be greatly affected if oriented toward the north. To avoid a large increase in

the number of simulations necessary to account for these effects, a set of preliminary simulations

was done. These compared energy savings for a single tree opposite south, east and west walls of

a square house with windows distributed equally on all four sides, to a rectangular house with

the same total floor and window area and an asymmetrical window distribution. Length of front,

back, and side walls, window area for each wall, and the relative frequency of each building

orientation (i.e., percent of time front is oriented toward north, south, east, and west) were based

on a sample of 254 homes in Sacramento (Simpson and McPherson 1998). For the rectangular

house, four simulations were done for each tree location so that each wall was shaded. Average

energy use for the rectangular house for the south, east, and west tree was computed by

weighting the results at each orientation by the relative frequency of that particular orientation.

All simulations were also done without the tree to provide a reference for calculating savings.

The result was that for each tree orientation, weighted average energy savings for the

rectangular house were within a few percent of the energy savings found with a single simulation

for the square house. Consequently, all simulations done for this analysis were for a square house

with symmetrical window distribution.
214 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix G Energy Simulation Methods

Windbreaks

In most areas of the country evergreen trees can provide winter heating savings by acting as

windbreaks (deciduous species, leafless in winter, are much less effective). This is especially true

of coniferous species in northern, heating-dominated climate regimes (e.g., Mid-Atlantic,

Northern Tier, North Central and Mountain zones). In this application, trees are best located 1 to

10 tree heights upwind from the structure to be shielded so as to provide minimal shading in

winter. Heisler and others (1979) give a simplified method for determining reduction of winddriven infiltration, based on scale-model wind tunnel studies using scale model evergreen trees

8-m (25-ft) tall and 4 m (14 ft) in diameter. A windbreak consisting of four trees on 5-m (16-ft)

centers 1 tree height upwind of an 11-m x 8-m (35-ft x 25-ft) house reduced air infiltration index

by 30 percent for wind speed (U) of 29 m s-1 (65 mph); increasing density by reducing spacing to

2.5 m (8 ft) approximately doubled the reduction. Mattingly and others (1979) found similar

reductions in infiltration rates (air changes per hour) for a row of trees upwind of a townhouse.

Trees were 8-m (25-ft) tall white pine, with 3 m (10 ft) spacing approximately 1 tree height distant

from the building. Reductions were 42 percent for winds normal to exposed walls, 39 percent for

15 percent incidence angle, and 27 percent for 45 percent, corresponding to a wind speed of 5.6 m

s-1 (12.5 mph) and inside-outside air temperature difference of 18  ̊C (32.5  ̊F).

An equivalent change in infiltration rate (43 percent) is found for a change in wind shielding

class from 2 to 5 (light local shielding to very heavy shielding) calculated as Q = L (A ∆T + BU2)

1/2 at

20  ̊C and 5.6 m s-1 (ASHRAE 1989). Here Q is airflow rate (L/s), L is effective leakage area (cm2),

A is stack coefficient ((L/s)2

(cm)-4( ̊C)-1), ∆T is average indoor-outdoor temperature difference for

the time interval of the calculation, B is a wind coefficient ((L/s)2

(cm)-4(m/s)-2), and U is average

wind speed measured at a local weather station for the time interval of interest (m/s). This

change in wind-shielding classes is consistent with the virtually unobstructed wind before

placement of trees in the experimental studies, but points out that infiltration reductions of that

magnitude are likely to overestimate wind reductions from addition of trees in an area with preexisting tree and building cover. This suggests that a reasonable estimate for the effect of a single

row windbreak positioned properly to block prevailing winter winds is an increase in shielding

factor of from 3 (moderate local shielding) or 4 (heavy shielding) to 5, depending on pre-existing

conditions.

Consequently, savings per tree were computed using Micropas from energy use differences

for each base case residence for changes in wind shielding class from 3 to 5 and 4 to 5,

respectively. Sample calculations of savings per tree from windbreak effects for Sacramento,

Calif., are shown in table 110. Savings for immature trees are reduced in proportion to the ratio of

immature/mature crown diameters. Mean values for savings can be used for all trees, or two

levels of regional defaults can be defined on the basis of predominant existing cover (e.g.,

southwest would use “3-5” data, southeast “4-5”). We chose to conservatively use the reduction

from a change in wind-shielding class of from 4 to 5. Note that savings are computed both with

and without an additional tree providing shade on the west side of the building (table 110),

which indicates that percentage savings are not appreciably affected by the presence of a shading

 wind speed ∆T ( ̊C) Spacing (m) Distance pct

 (m s-1) (tree heights) reduction

Heisler and others 1979 29 0 5 (16 ft) 1 30

2 (7 ft) 1 50

Mattingly and others 1979 5.6 18.5 3 (10 ft) 1 40
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 215

Appendix G Energy Simulation Methods

tree. Savings are reduced by an additional factor of 3 to account for non-normal wind incidence

angles, based on Heisler’s (1991) estimates of relative wind speed reductions as a function of

wind direction. His calculations were for 46-m (150-ft) long windbreaks. We assume that

preferential placement of windbreak trees to block prevailing winter winds approximately

compensates for the smaller horizontal extent used here.

In summary, we estimate that a windbreak of four small, mature trees reduces annual

heating load from 1 to 3 percent depending on Climate Region, equivalent to a change from

shielding class 4 to 5. We assume that two medium or a single large tree (mean diameters of 10 m

(32 ft) and 18 m (60 ft), respectively) provide wind reduction equivalent to four small trees (mean

diameter of 5 m (15 ft)).

Climate

Air temperature. Increases in urban tree cover over neighborhood or larger scales can have a

cooling effect due to transpiration, which reduces summer demand for air conditioning.

Individual trees are unlikely to have a significant effect on air temperature beyond their

immediate vicinity because atmospheric mixing rapidly dilutes cooler air near the tree with air at

ambient temperature (Lowry 1988), but larger groupings of trees can measurably reduce summer

air temperatures. Evaporation is largely driven by net (incoming minus reflected) solar radiation,

so that resulting temperature reductions typically reach a maximum in early to mid-afternoon.

Temperature reductions at other times are approximately proportional to the amplitude of the

diurnal temperature cycle, approaching zero in morning and evening (Huang and others 1987).

In the remainder of this paper, temperature reductions refer to the afternoon maximum.

The basic unit of heating and cooling energy use used here is Unit Energy Density (UED),

which is energy use per unit conditioned floor area (CFA). Reduced cooling energy use from air

temperature modification (∆EcT) is the summed product given as

∆EcT =[∆UEDT

j

 x CFAj x ∆Tj

CC x CC x nj

]. (Eq.9)

where

∆UEDT

j

 is UED temperature coefficient (change in UED per  ̊C),

Tj

CC is canopy air temperature coefficient (change in air temperature/percent change in

canopy cover),

CC is percent canopy cover per tree,

CFAj is conditioned floor area (m2), and

nj is the number of trees associated with vintage j

∆UEDT is the product of change in energy use due to change in air temperature (∆UED/

UED)/∆T) and UED based on building energy use simulations, or (∆UED/UED)/∆TxUED

=∆UED/∆T = ∆UEDT. Reductions of 14 and 17 percent in annual residential air conditioning

Heat load (MBtu) Heat savings (pct) Heat savings/tree (pct)

Shielding class no shade west tree no shade west tree small medium large

2 43.18 43.61 from shielding class 3-5

3 42.33 42.75 5.2 pct 5.2 pct 1.3 pct 2.6 pct 5.2 pct

4 41.37 41.78 from shielding class 4-5

5 40.11 40.51 3.0 pct 3.0 pct 0.8 pct 1.5 pct 3.0 pct

average from shielding classes 3-5 and 4-5

4.1 pct 4.1 pct 1.0 pct 2.1 pct 4.1 pct

Table 110—Summary of effect of wind shielding class on simulated heating energy use for Sacramento.
216 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix G Energy Simulation Methods

energy use (kWh) were simulated for a 1.2  ̊C air temperature reduction (12 and 14 percent  ̊C-1)

for pre-1973 and 1980’s construction, respectively, in Sacramento (Huang and others 1987). Sailor

and others (1992) estimated a 13 percent  ̊C-1 reduction in cooling degree days for Sacramento,

which are closely related to annual kWh consumption. McPherson (1994b) found kWh savings of

5.1 to 7.0 percent  ̊C-1 for various construction types in Chicago. Capacity (kW) savings of 6.4 and

2.0 percent  ̊C-1 were simulated by Huang and others (1987) for 1980’s and pre-1973 homes in

Sacramento, respectively. Results of a similar magnitude (4.9 percent  ̊C-1) were found in Dade

County, Florida, based on measured central air conditioner energy use and outside air

temperature for a sample of approximately 50 properties (Parker 1994). In our simulations,

percentage cooling reductions by climate region tended to be inversely correlated with cooling

energy use, ranging from 5 to 25 percent  ̊C-1, Larger values are associated with regions with small

cooling requirements, smaller values with large cooling requirements.

Maximum temperature deficit for each percent increase in canopy cover (canopy coefficient

of air temperature, ∆Tj

CC) was estimated to range from 0.05 to 0.20  ̊C/percentage increase in tree

cover. These temperature deficits are based on reported reductions of maximum midday air

temperature ranging from 0.04 to 0.20  ̊C per percent increase in canopy cover, where temperature

reductions reflect the aggregate effect of all the trees in the local area (Huang and others 1987;

Taha and others 1991; Sailor and others 1992; Myrup and McGinn 1993; Wilkin and Jo 1993). For

Sacramento, Huang and others (1987) simulated a 1.2  ̊C decrease for a 10 percent city-wide

canopy cover increase. Sailor and others (1992) estimated a decrease of 0.36  ̊C/10 percent cover

increase on the basis of regression analysis of measurements at 15 residential locations scattered

throughout Sacramento. Cover was determined for  ̃40 ha areas surrounding each measurement

location; substantial scatter was observed in the data. Taha and others (1991) consistently found

midday air temperature reductions of  ̃1  ̊C/10 percent cover difference for an orchard compared

to a dry field in Davis, California; reductions occasionally reached 2.4  ̊C/10 percent cover

difference. In the present analysis, values of ∆Tj

CC is dependent on climate region (table 44).

Regions with dry climates were assigned larger values, while humid regions assigned smaller

values. The value 0.05  ̊C/percentage increase in tree cover was used for climate regions with

ratios of LEH/CDD>1.0, 0.10  ̊C/percentage increase in tree cover for 1.0≥LEH/CDD≥0.1, and

0.20  ̊C/percentage increase in tree cover for LEH/CDD<0.1 (table 31).

Changes in cooling UED temperature coefficients (∆UEDT

j

) were estimated based on

simulations for each vintage and climate region for 0.05, 1.0 and 2.0  ̊C peak air temperature

reductions. Weather files are modified by scaling peak air temperature reductions diurnally using

the expression (T-Tmin)/(Tmax- Tmin), where T is the actual hourly air temperature, and Tmax and Tmin

are the hourly maximum and minimum temperature for that day. Peak air temperature reduction

is further scaled annually by the expression (K-Kmin)/(Kmax-Kmin), where K is the total global solar

radiation for a given day, and Kmax and Kmin are the maximum and minimum values of K for the

year. As a result, peak temperature reductions occur only at the hour of maximum temperature

on the day with maximum solar radiation. Effects on heating were not considered because most

plants are dormant and not actively transpiring during the heating season.

Canopy cover per tree (CC) is estimated assuming an effective lot size (actual lot size plus a

portion of adjacent streets and other rights-of-way) of 1858 m2

 (20,000 ft2) and crown projection

areas given in table 111. Mature canopy cover per tree is the product of effective lot area and

crown projections areas, expressed as a percentage in table 112.

Tree growth zone

 north central south

Dec Large 108 172 252

Dec Med 54 80 112

Dec Small 19 31 46

Evr Large 96 186 305

Evr Med 35 84 152

Evr Small 17 34 58

Table 111—Mature tree canopy crown projection area (m2).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 217

Appendix G Energy Simulation Methods

Wind speed. Trees not only reduce wind speed in their immediate vicinity (one to five tree

heights) as discussed in the section on windbreaks, but the aggregate effect of a number of trees

scattered throughout a neighborhood is to reduce overall wind speed for the entire planted area.

This reduction in wind speed can have a number of effects on building heat gain (Huang and

others 1990). Convective heat gain may increase for sunlit surfaces, increasing cooling load in

summer and reducing heating load in winter; shaded surfaces may experience just the opposite

effects. In addition, infiltration of outside air is reduced, which reduces demand for both heating

and cooling. Effectiveness of natural ventilation for cooling will be diminished.

Energy impacts from wind speed reduction (∆EcU) is the summed product

∆EcU =[∆UEDj

U x CFAj

 x ∆Uj

CC x CC x nj

]. (Eq.10)

where

∆UEDU

j

 is UED wind coefficient (UED change per percent change in wind speed),

∆Uj

CC is canopy wind speed coefficient (percent change in wind speed per percent change in

canopy cover),

CC is percent canopy cover per tree,

CFAj conditioned floor area, and

nj

 is the number of trees associated with vintage j, and

∆EcU is the change in simulated energy use from estimated wind speed reductions.

Canopy cover per tree (CC) estimates are the same as in the previous section on air

temperature. Fractional change in wind speed (∆U/U) for each percent increase in canopy cover

(wind speed coefficient ∆UCC) is estimated as

∆UCC=(TC+BC)/(24+1.1x(TC+BC))-BC/(24+1.1xBC)1 (Eq.11)

where TC and BC are percent tree canopy and building cover, respectively (Heisler 1990).

Results apply to aggregate effects of trees and buildings in the local area. Reductions range from

3 to 8 percent for a 10 percent increase in canopy cover, depending upon antecedent canopy and

building cover (fig. 33).

∆UEDU is the product of change in energy use due to change in wind speed (∆UED/UED)/

(∆U/U), and UED based on building energy use simulations, or (∆UED/UED)/(∆U/U)(UED =

∆UED/(∆U/U) = ∆UEDU. Values for ∆UEDU for heating and cooling in typical pre-1973 and

1980’s houses in Sacramento are given by Huang and others (1990) using wind reductions from

Heisler (1990). Their base case was no trees and  ̃25 percent ground coverage due to buildings.

Wind speed reductions were simulated for 10, 20 and 30 percent canopy cover increases

(equivalent to 1, 2 and 3 trees/property). Resulting ∆UEDU’s were approximately -0.03 kWh/

m2/percent change in wind speed for cooling and 1.0 MJ/m2/percent change in wind speed for

heating.

Tree growth zone

 north central south

Dec Large 5.8 9.3 13.6

Dec Med 2.9 4.3 6.1

Dec Small 1.0 1.7 2.5

Evr Large 5.2 10.0 16.4

Evr Med 1.9 4.5 8.2

Evr Small 0.9 1.8 3.1

Table 112—Mature canopy cover per tree (pct).
218 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix G Energy Simulation Methods

20%

30%

40%

50%

60%

70%

80%

0% 10% 20% 30% 40% 50%

Building cover: 10% 20% 30%

Percent of unobstructed wind speed

Tree canopy cover

For the current analysis, ∆UEDU’s were estimated for each vintage and climate region for

wind reductions of 47, 37 and 29 percent, which correspond to tree + building cover of

approximately 30, 50, and 80 percent, respectively. Results are tabulated for use in the avoided

CO2 analysis, where an interpolation scheme is used to evaluate energy-related CO2 changes

based on tabulated values at 10, 30, and 60 percent canopy cover. These values of canopy cover

were used to minimize interpolation errors due to the non-linearity of the wind response to

increasing canopy cover (fig. 33). Changes in energy use were calculated based on existing cover

percentages for each region given in table 11.

Figure 33—Decrease in wind speed from increase in canopy and

building cover (from Heisler 1990).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 219

Appendix H

Instructions for Adjusting Tree Age/Survival Tables

Tree Survival Rates

Survival rates of trees in urban environments are highly variable. Factors that influence

survival include the quality of nursery stock, type of species planted and their suitability to

local growing conditions, planting methods, and tree care practices. Participation in tree planting

by local residents has been shown to increase satisfaction and promote stewardship and longterm survival rates (Sommer and others 1994). Survival rates for street tree plantings 4 years after

planting in three Wisconsin cities ranged from 62 to 77 percent (Miller and Miller 1991). Similar

rates were reported for street trees planted in Boston (67-77 percent 2 to 3 years after planting)

and Oakland (66 percent after 2 years) (Foster and Blain 1978; Nowak and others 1990). A survey

of street trees in Urbana, Ill., found that 59 percent of the trees survived after 50 years (1932-1982)

(Dawson and Khawaja 1985).

Residential yard trees may have higher survival rates than street trees because they are

subject to less damage from deicing salts and other pollutants, autos, dogs, and vandalism, but

few data are available to confirm this hypothesis. A survey of trees provided to customers

through the Sacramento Shade program found that 23 percent of the trees were either dead,

missing, or had not been planted after 5 years (Hildebrandt and others 1996). A 30-year survival

rate of 58 percent was selected as the most likely future scenario for trees already planted.

Improved stewardship by program participants was estimated to increase long-term survivability

to 70 percent.

These guidelines provide three survival rates (low, moderate, and high) based on the

literature cited above. The default survival rates assume that mortality rates are greatest during

the first 5 years of establishment, and relatively constant thereafter (Richards 1979; Miller and

Miller 1991). You can create your own table of survival rates by entering the percentage of trees

expected to be alive at each 5-year time period.

Percent of mature benefits as a function of tree age (e.g. size) are tabulated here for each

region and process. These tables show how CO2

 uptake and release are distributed through time

as a percentage of mature tree values.

Tree Age/Survival Tables

Tables 113-121 quantify the fractional reduction in mature tree CO2 savings and emissions with

age in 5-year increments, including effects of tree mortality. These values are used to “backcalculate” CO2

 reductions and releases in Worksheet 2 to reflect changes in tree size and numbers

over a 40-year time span. A moderate survival rate is recommended unless project-specific

information indicates otherwise. A Table is provided for each Tree Growth Zone. These tree age/

survival fractions are entered directly into Worksheet 2. Provision is made in this appendix to

adjust both tree age and survival effects to customize tree age/survival fractions. You have the

option of using pre-calculated combinations of tree age and survival from tables 113-121, or

calculating your own values using tables 122-124. Differences in tree age and survival effects at

any given age were similar for all tree sizes and types; hence, tabulated tree age/survival

fractions were averaged over tree size and type.

Tree age/survival tables based on the default tree distribution can be used in all but the most

extreme cases, e.g. all trees oriented to the south or west, which can result in underestimation

(west) or overestimation (east) by up to 10 percent overall, and as much as 30 percent when trees

are small.

Custom Tree Age/Survival Tables Based on User-Supplied Tree Survival

Rates

You can combine tree survival data with data on tree age effects to develop your own tree age/

survival table. If this option is selected, cumulative survival data are entered in table 122a, and

then multiplied by the Regional Default Tree Age Table for your climate region (table 123a - k) to

derive a customized Tree Age-Survival Table (table 124). Cumulative survival fractions used to

develop tables 113-121 (table 122b) are included for reference.
220 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix H Instructions for Adjusting Tree Age/Survival Tables

Table 113—Combined tree age/survival table, North Growth Zone, moderate (default) survival rate.

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.04 0.17 0.29 0.39 0.47 0.50 0.53 0.54

2 Shade Heating 0.11 0.24 0.36 0.43 0.50 0.51 0.53 0.53

3 Climate C oolingand H eating 0.01 0.07 0.15 0.24 0.32 0.39 0.45 0.49

4 Sequestration 0.05 0.18 0.34 0.44 0.47 0.46 0.43 0.40

5 Decomposition 0.0008 0.0004 0.0010 0.0020 0.0033 0.0046 0.0060 0.0075

6 Maintenance 0.07 0.18 0.28 0.36 0.42 0.45 0.48 0.49

7 Production/Program 0.75 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.05 0.20 0.34 0.47 0.59 0.65 0.70 0.75

2 Shade Heating 0.12 0.28 0.42 0.53 0.62 0.66 0.70 0.73

3 Climate C oolingand H eating 0.02 0.08 0.18 0.29 0.40 0.50 0.59 0.67

4 Sequestration 0.05 0.21 0.40 0.53 0.58 0.59 0.57 0.54

5 Decomposition 0.0005 0.0003 0.0007 0.0014 0.0022 0.0031 0.0040 0.0050

6 Maintenance 0.08 0.21 0.33 0.44 0.52 0.58 0.64 0.67

7 Production/Program 0.85 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.04 0.14 0.23 0.30 0.35 0.36 0.35 0.33

2 Shade Heating 0.10 0.20 0.29 0.34 0.37 0.37 0.35 0.33

3 Climate C oolingand H eating 0.01 0.06 0.12 0.19 0.24 0.28 0.30 0.30

4 Sequestration 0.04 0.15 0.27 0.34 0.35 0.33 0.29 0.24

5 Decomposition 0.0011 0.0005 0.0014 0.0027 0.0043 0.0061 0.0080 0.0100

6 Maintenance 0.06 0.15 0.23 0.28 0.31 0.32 0.32 0.30

7 Production/Program 0.65 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 114—Combined tree age/survival table, North Growth Zone, high survival rate.

Table 115—Combined tree age/survival table, North Growth Zone, low survival rate.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 221

Appendix H Instructions for Adjusting Tree Age/Survival Tables

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.07 0.21 0.33 0.42 0.49 0.51 0.53 0.53

2 Shade Heating 0.19 0.31 0.42 0.47 0.51 0.52 0.53 0.52

3 Climate C oolingand H eating 0.02 0.08 0.18 0.28 0.36 0.42 0.47 0.49

4 Sequestration 0.08 0.28 0.48 0.58 0.58 0.51 0.44 0.35

5 Decomposition 0.0006 0.0005 0.0013 0.0025 0.0038 0.0052 0.0064 0.0075

6 Maintenance 0.09 0.22 0.33 0.41 0.46 0.49 0.50 0.49

7 Production/Program 0.75 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.07 0.24 0.40 0.51 0.62 0.66 0.70 0.74

2 Shade Heating 0.22 0.36 0.50 0.58 0.64 0.67 0.70 0.72

3 Climate C oolingand H eating 0.02 0.10 0.21 0.34 0.45 0.54 0.62 0.67

4 Sequestration 0.09 0.33 0.57 0.71 0.72 0.66 0.58 0.48

5 Decomposition 0.0003 0.0003 0.0009 0.0017 0.0026 0.0035 0.0043 0.0050

6 Maintenance 0.10 0.26 0.39 0.50 0.58 0.62 0.66 0.67

7 Production/Program 0.85 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.06 0.17 0.27 0.33 0.37 0.36 0.35 0.33

2 Shade Heating 0.17 0.26 0.34 0.37 0.39 0.37 0.35 0.32

3 Climate C oolingand H eating 0.01 0.07 0.15 0.22 0.27 0.30 0.31 0.30

4 Sequestration 0.07 0.24 0.39 0.45 0.43 0.37 0.29 0.22

5 Decomposition 0.0008 0.0006 0.0017 0.0033 0.0051 0.0069 0.0085 0.0100

6 Maintenance 0.08 0.19 0.27 0.32 0.35 0.35 0.33 0.30

7 Production/Program 0.65 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 116—Combined tree age/survival table, Central Growth Zone, moderate (default) survival rate.

Table 117—Combined tree age/survival table, Central Growth Zone, high survival rate.

Table 118—Combined tree age/survival table, Central Growth Zone, low survival rate.
222 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix H Instructions for Adjusting Tree Age/Survival Tables

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.09 0.24 0.37 0.44 0.50 0.52 0.53 0.53

2 Shade Heating 0.37 0.45 0.51 0.52 0.52 0.52 0.53 0.52

3 Climate C oolingand H eating 0.02 0.09 0.20 0.30 0.38 0.44 0.47 0.49

4 Sequestration 0.07 0.30 0.51 0.60 0.57 0.48 0.38 0.28

5 Decomposition 0.0005 0.0005 0.0014 0.0027 0.0041 0.0054 0.0066 0.0075

6 Maintenance 0.10 0.23 0.35 0.43 0.48 0.50 0.50 0.49

7 Production/Program 0.75 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.11 0.28 0.44 0.53 0.62 0.66 0.70 0.73

2 Shade Heating 0.42 0.52 0.60 0.63 0.65 0.68 0.70 0.72

3 Climate C oolingand H eating 0.02 0.11 0.23 0.36 0.47 0.56 0.63 0.68

4 Sequestration 0.08 0.34 0.61 0.73 0.72 0.62 0.50 0.39

5 Decomposition 0.0003 0.0003 0.0009 0.0018 0.0028 0.0036 0.0044 0.0050

6 Maintenance 0.11 0.27 0.41 0.52 0.59 0.64 0.67 0.68

7 Production/Program 0.85 0.00 0.00 0.00 0.00 0.00 0.00 0.00

A BCDEFGH

Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.08 0.20 0.30 0.35 0.37 0.37 0.35 0.33

2 Shade Heating 0.32 0.38 0.42 0.41 0.39 0.37 0.35 0.32

3 Climate C oolingand H eating 0.02 0.08 0.16 0.23 0.28 0.31 0.31 0.30

4 Sequestration 0.06 0.25 0.42 0.47 0.43 0.34 0.25 0.17

5 Decomposition 0.0007 0.0007 0.0019 0.0036 0.0055 0.0073 0.0088 0.0100

6 Maintenance 0.08 0.20 0.28 0.34 0.36 0.35 0.33 0.30

7 Production/Program 0.65 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 119—Combined tree age/survival table, South Growth Zone, moderate (default) survival rate.

Table 120—Combined tree age/survival table, South Growth Zone, high survival rate.

Table 121—Combined tree age/survival table, South Growth Zone, low survival rate.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 223

Appendix H Instructions for Adjusting Tree Age/Survival Tables

pp

Tree Age Intervals

a. User-supplied Survival

for tree sizes: 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

Deciduous-Large

Deciduous-Medium

Deciduous-Small

Evergreen-Large

Evergreen-Medium

Evergreen-Small

b

.

Default Survival 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

Moderate 0.75 0.71 0.68 0.64 0.60 0.56 0.53 0.49

High 0.85 0.83 0.80 0.78 0.75 0.72 0.70 0.67

Low 0.65 0.60 0.55 0.50 0.45 0.40 0.35 0.30

Table 122—Default and User-supplied Cumulative Tree Survival Fractions.

 1. Mid-Atlantic A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.06 0.27 0.48 0.65 0.82 0.91 1.00 1.09

2 Shade Heating 0.10 0.32 0.53 0.68 0.84 0.92 1.00 1.08

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 2. Northern Tier A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.05 0.24 0.42 0.60 0.78 0.89 1.00 1.11

2 Shade Heating 0.15 0.33 0.51 0.67 0.82 0.91 1.00 1.09

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 3. North Central A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.04 0.23 0.42 0.60 0.79 0.90 1.00 1.10

2 Shade Heating 0.11 0.31 0.52 0.67 0.82 0.91 1.00 1.09

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 123—Tree Age data for all Climate Regions. Can be used with table 122 to complete optional table 124. Tree age effects

on avoided energy (rows 1-3) differ between Climate Zones, while remaining effects (rows 4-7) are the same for Climate

Zones in the same Tree Growth Region.
224 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix H Instructions for Adjusting Tree Age/Survival Tables

 4. Mountains A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.08 0.26 0.43 0.61 0.78 0.89 1.00 1.11

2 Shade Heating 0.17 0.37 0.56 0.70 0.83 0.92 1.00 1.08

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 5. Southeast A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.07 0.26 0.45 0.62 0.80 0.90 1.00 1.10

2 Shade Heating 0.32 0.49 0.66 0.76 0.87 0.94 1.00 1.06

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 6. South Central A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.08 0.27 0.46 0.64 0.81 0.91 1.00 1.09

2 Shade Heating 0.43 0.58 0.72 0.81 0.90 0.95 1.00 1.05

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 7. Pacific Northwest A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.11 0.33 0.55 0.70 0.84 0.92 1.00 1.08

2 Shade Heating 0.18 0.39 0.60 0.72 0.84 0.92 1.00 1.08

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 123—(continued).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 225

Appendix H Instructions for Adjusting Tree Age/Survival Tables

 8. Gulf Coast/Hawaii A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.12 0.32 0.53 0.68 0.83 0.91 1.00 1.09

2 Shade Heating 0.41 0.56 0.71 0.78 0.86 0.93 1.00 1.07

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 9. California Coast A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.05 0.25 0.46 0.64 0.82 0.91 1.00 1.09

2 Shade Heating 0.29 0.47 0.66 0.77 0.89 0.94 1.00 1.06

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 10. Southwest A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.13 0.33 0.54 0.68 0.83 0.91 1.00 1.09

2 Shade Heating 0.24 0.43 0.63 0.73 0.84 0.92 1.00 1.08

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

 11. Desert Southwest A BCDEFGH

Years After Planting

Age only back-calculation 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling 0.14 0.35 0.57 0.70 0.84 0.92 1.00 1.08

2 Shade Heating 0.59 0.70 0.80 0.84 0.87 0.93 1.00 1.07

3 Climate C oolingand H eating 0.02 0.13 0.29 0.47 0.63 0.78 0.90 1.00

4 Sequestration 0.10 0.42 0.76 0.94 0.95 0.86 0.72 0.58

5 Decomposition 0.01 0.07 0.19 0.36 0.55 0.73 0.88 1.00

6 Maintenance 0.13 0.33 0.52 0.67 0.79 0.88 0.95 1.00

7 Production/Program 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Table 123—(continued).
226 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix H Instructions for Adjusting Tree Age/Survival Tables

Table 124—User-derived Tree Age-Survival Table. Multiply values from Tree Survival table 122 (Moderate, High, Low, or

User-supplied) by corresponding values in a Regional Default (table 123) or this User-supplied Tree Age Table (table 124).

A BCDEFGH

Age only back-calculation Years After Planting

1-5 6-10 11-15 16-20 21-25 26-30 31-35 36-40

1 Shade Cooling

2 Shade Heating

3 Climate C oolingand H eating 

4 Sequestration

5 Decomposition

6 Maintenance

7 Production/Program
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 227

Glossary

AFUE (Annual Fuel Utilization Efficiency): A measure of space heating equipment efficiency

defined as the fraction of energy output/energy input.

Air Temperature Adjustment: Change in air temperature associated with change in tree canopy

cover (oC per 1 percent change in tree canopy cover).

Carbon: A nonmetallic element (symbol C) found in all organic substances and in some inorganic

substances such as coal and natural gas. The atomic weight of C is 12, and CO2 is 44. To convert

emissions reported as mass or weight of C to mass of CO2, multiply mass or weight of C by 44/12.

Carbon Dioxide: A heavy, odorless, incombustible gas (symbol CO2

) taken from the atmosphere

in the photosynthesis of plants and returned to it by the respiration of both plants and animals.

The molecular weight of CO2 is 44. To convert mass or weight of CO2 to mass or weight of C,

multiply CO2 by 12/44.

Carbon Sinks: Carbon reservoirs and conditions that take in and store more carbon (carbon

sequestration) than they release. Carbon sinks can serve to partially offset greenhouse gas

emissions. Forests and oceans are common carbon sinks.

Central Air Conditioning (CAC): A machine that cools and dehumidifies the air in a building

with a refrigeration unit driven by electricity. A centrally located fan is used to circulate the cool

air through ducts leading to the various rooms.

Climate: The average weather (usually taken over a 30-year time period) for a particular region

and time period. Climate is not the same as weather, but rather, it is the average pattern of

weather for a particular region. Weather describes the short-term state of the atmosphere.

Climatic elements include precipitation, temperature, humidity, sunshine, wind velocity,

phenomena such as fog, frost, and hail storms, and other measures of the weather.

Climate Change (also referred to as ‘global climate change’): The term ‘climate change’ is

sometimes used to refer to all forms of climatic inconsistency, but because the earth’s climate is

never static, the term is more properly used to imply a significant change from one climatic

condition to another. In some cases, ‘climate change’ has been used synonymously with the term,

“global warming”; scientists however, tend to use the term in the wider sense to also include

natural changes in the climate.

Climate Effects: Impact on residential space heating and cooling (kg CO2

/tree/year) from trees

located greater than approximately 15 m (50 ft) from a building (Far trees) due to associated

reductions in wind speeds and summer air temperatures.

Conditioned Floor Area (CFA): Floor area of building that is mechanically cooled/heated.

Decomposition: Annual rate at which CO2 is released to the atmosphere through decay of dead

wood (kg CO2

/tree).

Electricity: Metered electric power supplied by a central utility company to a residence via

underground or aboveground power lines. The heat equivalent for electricity that comes into the

homes is 3.412 kBtu per kWh, but this is a derived form of energy and does not represent the

amount of energy needed to generate the electricity and transmit it to the building. Generation

and transmission requires about 11.26 kBtu per kWh (3.3 times 3.412).

Appendix I
228 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix I Glossary

Emission Factor: A rate of CO2 output resulting from the consumption of electricity, natural gas

or any other fuel source.

Emissions related to trees See tree-related emissions.

Evaporative Cooler (“swamp coolers”): An air conditioner that uses evaporation from a centrally

located pad; no refrigeration unit is involved.

Evapotranspiration (ET): The combined evaporation from the soil surface and transpiration

from plants. Transpiration is the evaporation of water from internal surfaces of living plant

organs and its subsequent diffusion into the atmosphere. Evaporation is the physical process by

which liquid water is converted to vapor.

Far Trees: Trees located greater than 15-m (50-ft) from buildings so as to influence building

energy use through their aggregate effect on air temperature and wind speed at the neighborhood

scale.

Foliation Period: Average period when a tree is in leaf.

Fossil Fuels: A general term for combustible geologic deposits of carbon in reduced (organic)

form and of biological origin, including coal, oil, natural gas, oil shales, and tar sands. A major

concern is that they emit carbon dioxide into the atmosphere when burnt, thus significantly

contributing to the enhanced greenhouse effect.

Fuel Oil (heating): A liquid petroleum product less volatile than gasoline, used as an energy

source.

Global Warming: An increase in the near surface temperature of the Earth. Global warming has

occurred in the distant past as a result of natural influences, but the term is most often used to

refer to the warming predicted to occur as a result of increased emissions of greenhouse gases

from commercial or industrial resources.

Greenhouse Effect: The effect produced as greenhouse gases allow incoming solar radiation to

pass through the earth’s atmosphere, but prevent most of the outgoing infra-red radiation from

the surface and lower atmosphere from escaping into outer space.

Greenhouse Gas: Any gas that absorbs infra-red radiation in the atmosphere. Greenhouse gases

include water vapor, carbon dioxide, methane, nitrous oxide, halogenated fluorocarbons, ozone,

perfluorinated carbons, and hydroflourocarbons.

Heat Pump: A year-round heating and air-conditioning system in which refrigeration equipment

supplies both heating and cooling through ducts leading to individual rooms. A heat pump

generally consists of a compressor, both indoor and outdoor coils, and a thermostat.

HSPF (Heating Seasonal Performance Factor): A measure of the efficiency of space heating

equipment defined as the fraction of energy output/energy input.

HVAC equipment: Heating, ventilating, and air conditioning equipment.

Irradiance: Radiant energy from the sun that is incident on a surface per unit of surface area.

kBtu: A unit of work or energy, measured as 1,000 British thermal units. One kBtu is equivalent

to 0.293 kWh.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 229

Appendix I Glossary

kWh (Kilowatt-hour): A unit of work or energy, measured as one kilowatt (1,000 watts) of

power expended for one hour. One kWh is equivalent to 3.412 kBtu.

Mature Tree Size: The approximate tree size 40 years after planting.

MBtu: A unit of work or energy, measured as 1,000,000 British thermal units. One MBtu is

equivalent to 0.293 MWh.

Metric Tonne: A measure of weight (abbreviate “t”) equal to 1,000,000 grams (1,000 kilograms)

or 2,205 pounds.

MJ: A unit of work or energy, measured as 1,000,000 Joules.

Mulch: A protective covering (as of leaves, bark or rock) spread out on the ground to reduce

evaporation, control weeds, or improve the soil.

Municipal Forester: A person who manages public street and/or park trees (municipal forestry

programs) for the benefit of the community.

MWh (Megawatt-hour): A unit of work or energy, measured as one Megawatt (1,000,000 watts)

of power expended for one hour. One MWh is equivalent to 3.412 MBtu.

Natural Gas Fuel (NG): Hydrocarbon gas (mostly methane) supplied as an energy source to

individual buildings by pipelines from a central utility company. Natural gas does not refer to

liquefied petroleum gas or to privately owned gas wells operated by a building owner.

Natural sinks: In reference to greenhouse gases, refers to any natural process which in which

these gases are absorbed from the atmosphere.

Near Trees: Trees located within approximately 15-m (50-ft) of a building so as to directly

influence irradiance and air flow on the building envelope.

Other Heating: Heating by an energy source other than natural gas, electricity, or fuel oil. This

includes wood heat, liquefied natural gas (LNG), space heaters.

Peak Cooling Demand: The single greatest amount of electricity required at any one time

during the course of a year to meet space cooling requirements.

Program Tree: A tree planted within the site area as a result of the shade tree program.

Room Air Conditioner (Room AC): Air conditioning unit that typically fits into the window or

wall and is designed to cool only one room.

SEER (Seasonal Energy Efficiency Ratio): Ratio of cooling output to power consumption;

kBtuh output/kWh input as a fraction. It is the Btu of cooling output during its normal annual

usage divided by the total electric energy input in watt-hours during the same period.

Sequestration: Annual net rate that a tree removes CO2

 from the atmosphere through the

processes of photosynthesis and respiration (kg CO2

/tree/year).

Shade Effects: Impact on residential space heating and cooling (kg CO2

/tree/year) from trees located

within approximately 15 m (50 ft) of a building (Near Trees) so as to directly shade the building.
230 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix I Glossary

Shade Tree Program: An organization that engages in activities such as tree planting and

stewardship with the express intent of achieving net atmospheric CO2 reductions.

Short Ton: A measure of weight equal to 2,000 pounds or 0.9072 metric tonnes.

Space Conditioning: Mechanical heating and cooling of air inside buildings.

Ton: See metric tonne and short ton.

Tree and Building Cover: Percentage of total site area covered by tree canopy and buildings.

Tree Maintenance emissions: Emissions from municipal forestry programs involved primarily

in tree care activities. Examples of CO2

 releases associated with tree maintenance include fuel

consumption by chain saws, chippers, trucks, autos, and other vehicles and equipment used for

pruning, removals, inspection, planting and pest/disease treatment.

Tree Production emissions: Emissions from tree-growing operations including nurseries and

tree farms. Examples of CO2

 releases associated with tree production include consumption of

electricity and natural gas for office heating/cooling/lighting, fuel consumption by vehicle and

maintenance equipment, and electrical consumption for water pumping, greenhouse heating/

cooling/lighting, and refrigeration.

Tree Program Administration emissions: Emissions from non-profit organizations involved in

tree planting and stewardship. Examples of CO2 releases associated with tree program

administration include office electricity (lighting, office equipment, cooling) and natural gas

(heating) consumption, and fuel consumption by delivery or inspection vehicles.

Tree-Related emissions: Carbon dioxide releases that result from activities involved with

growing, planting, and caring for program trees.

Urban Forestry Program: For this report urban forestry programs are involved in tree planting

and stewardship activities with the express intent of achieving net atmospheric CO2

 reductions

(same as shade tree program).

Vintage: Buildings of similar age, construction type, floor area, and energy efficiency

characteristics (e.g., insulation, heating and air conditioning equipment, etc.)
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 231

Appendix J

Acronyms and Abbreviations

AC air conditioner

AFB Air Force Base

Btu British thermal units

Btuh British thermal units x hours

CC percent canopy cover per tree

CCD Cooling Degree Days (oF day, base 65 oF)

cf cubic feet

CFA conditioned floor area

dbh tree trunk diameter at breast height

D-M Davis-Monthan Air Force Base

DW dry weights

ET evapotranspiration

GAG greenhouse accumulated gases

GHG greenhouse gas

HDD Heating Degree Days (oF day, base 65 oF)

KT available sunshine (fraction)

LEH Latent Enthalpy Hours (Btuh/lb of dry air)

LPG liquefied petroleum gas

LNG liquefied natural gas

MJ 1 million Joules

Mt million metric tonnes

NCDC National Climatic Data Center

SI International System of units

SPS Shadow Pattern Simulator

STF Sacramento Tree Foundation

t metric ton

TEP Tucson Electric Power

U wind speed

UED Unit Energy Density

WND annual average wind speed (miles/hr).
232 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix K

List of Figures

Chapter 1 Urban Forests and Climate Change

Figure 1. Forests in and around cities are sites where CO2 can be stored.

Figure 2. As agricultural and forest land is converted to urban land uses, GHG emissions

increase. These photos show urban development in Sacramento between

approximately 1970 (a) and 1980 (b).

Figure 3. Growth rate and life span influence CO2 sequestration. In this example, the total

amount of CO2 sequestered over 60 years by the slower growing maple (3,225 kg) is

greater than the amount sequestered by the faster growing but shorter-lived poplar

(2,460 kg). Growth curves and biomass equations used to derive these estimates are

based on data from urban trees (Frelich, 1992; Pillsbury and Thompson, 1995).

Figure 4. A Bradford pear similar to the one found to store approximately 306 kg (676 lb) of

CO2

 in aboveground biomass with the authors in Davis, Calif.

Figure 5. Simulated total annual heating and cooling savings due to shade from one 7.6-m (25-

ft) tall tree and ET cooling and wind reduction effects assumed to be associated with

a 5 percent increase in local tree cover (McPherson and Rowntree, 1993).

Figure 6. Projected CO2

 reductions and releases from Sacramento Shade Program’s planting

of 188,800 trees during 1991-95.

Figure 7. Tree planting and stewardship programs provide opportunities for local residents

to work together to build better communities.

Chapter 2 Program Design and Implementation

Figure 8. Direct participation in tree planting fosters increased satisfaction and a healthier

urban forest.

Figure 9. The local media can be a real asset when you need to inform the public about your

program.

Figure 10. Locate trees to shade west and east windows (from Sand, 1993).

Figure 11. Tree south of home before and after pruning (from Sand, 1993).

Figure 12. Mid-winter shadows from a well-located windbreak and shade trees do not block

solar radiation on the south-facing wall (from Sand, 1993).

Figure 13. Conifers guide wind over the building (from Sand, 1993).

Figure 14. (a, b) Know where power lines and other utility lines are before planting. (c) Under

power lines use only small-growing trees (“Low Zone”), and avoid planting

directly above underground utilities. Larger trees may be planted where space

permits (“Medium” and “Tall” zones) (from ISA, 1992).

Figure 15. Prepare a broad planting area and top it off with mulch and a berm to hold water

(from Sand, 1993).

Chapter 3 General Information about These Guidelines for Calculating CO2 Reductions from

Urban Forestry Programs

Figure 16. Flow diagram.

Figure 17. Climate Regions for the United States (Repeated as figure 24 in Appendix C).

Figure 18. Tree growth zones for the United States correspond with mean number of freezefree days per year (North = < 180, Central = 180-240, South = > 240) (Repeated as

figure 25 in Appendix D).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 233

Appendix K List of Figures and Tables

Figure 19. Growth curves for large evergreen and deciduous trees by Tree Growth Zone. Dec

= deciduous; Evr = evergreen.

Figure 20. Deciduous trees of the Northern Growth Zone.

Chapter 4 Illustrative Examples

Figure 21. Projected CO2

 savings (+) and releases (-) for each 5-year period in Boulder City.

Figure 22. Palo Verde study site at Davis-Monthan Air Force Base, Tucson, AZ (circles indicate

projected tree coverage in 40 years).

Figure 23. Projected CO2

 savings (+) and releases (-) for each 5-year period in Tucson.

Appendix C. Regional Climate Information

Figure 24. Climate regions for the United States (Repeated as figure 17 in Chapter 3).

Appendix D. Tree Information

Figure 25. Tree growth zones for the United States correspond with mean number of freezefree days per year (North = < 180, Central = 180-240, South = > 240) (Repeated as

figure 18 in Chapter 3).

Figure 26. USDA plant hardiness zones (USDA 1990).

Figure 27. Predicted dbh curves for the “typical” large deciduous tree in each Tree Growth

Zone. These curves were calibrated using predicted sizes based on measured ash

(Fraxinus spp.) and plane (Platanus acerifolia) trees in Minneapolis, central New

Jersey, and the Sacramento area (mean values shown). In developing the growth

curves, we assumed that trees were 2 years old when planted.

Figure 28. Predicted height curves for the “typical” large deciduous tree in each Tree Growth Zone.

Figure 29. Growth curves for deciduous trees.

Figure 30. Growth curves for evergreen trees.

Figure 31. The accuracy and precision of predictions from eight biomass equations are

compared with actual measured biomass from 32 urban trees representing six

species.

Figure 32. This comparison shows predicted biomass obtained from eight equations when

applied to growth of the same typical tree.

Appendix G. Energy Simulation Methods

Figure 33. Decrease in wind speed from increase in canopy and building cover (from Heisler 1990).

List of Tables

Chapter 1 Urban Forests and Climate Change

Table 1. Data from a 9 year old open-growing Bradford pear tree (Pyrus calleryana ‘Bradford’)

in Davis, CA. (from Xiao, 1998).

Chapter 2 Program Design and Implementation

Chapter 3 General Information about These Guidelines for Calculating CO2

 Reductions from

Urban Forestry Programs

Table 2. Check list of essential data.

Table 3. Regional default values.

Table 4. Default distribution for deciduous trees by size, distance and direction from building.
234 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix K List of Figures and Tables

Table 5. Default distribution for evergreen trees by size, distance and direction from building.

Table 6. Default distribution of trees among vintages can be applied to deciduous and

evergreen plantings and is based on data from the Sacramento Shade program.

Table 7. Tree survival fractions list the percentage of trees planted that are assumed to be alive

at each 5-year period.

Table 8. Combined Tree Age/Survival Fractions for the North Tree Growth Zone, moderate

survival rate.

Chapter 4 Illustrative Examples

Table I. Background information, Boulder City case study.

Table II. Site and building data, Boulder City case study.

Table 9. Climate data for Las Vegas and selected reference cities.

Table 10. Conversion factors (reproduced in Appendices A, B).

Table 11. Default values for short form by region and growth zone (reproduced in Appendices A, B).

Table 12. Distribution of Sacramento Shade trees. This distribution can be applied to

deciduous and evergreen plantings (reproduced in Appendices A , B).

Table 13. Percentage distribution of Far trees for the Boulder City example. This distribution

applies to both deciduous and evergreen plantings.

Table 14. Number of deciduous Far trees for the Boulder City example.

Table III. Tree data, Boulder City case study.

Table IV. Planting and stewardship costs, Boulder City case study.

Table V. Look-Up Table (Short Form), Desert southwest region, Boulder City case study.

Table VIII. Worksheet 1 (Short Form), Boulder City case study.

Table IX. Worksheet 2, Boulder City case study.

Table I. Background information, Tucson case study.

Table II. Site and building data, Tucson case study.

Table 15. Climate data for Tucson and selected reference cities.

Table 16. Tree numbers by species and type.

Table III. Tree data, Tucson case study.

Table IV. Planting and stewardship costs, Tucson case study.

Table VI. Long Form Adjustment Table, Desert southwest region, Tucson case study.

Table VII. Look-Up Table (Long Form), Tucson case study.

Table VIII. Worksheet 1 (Long Form), Tucson case study.

Table IX. Worksheet 2, Tucson case study.

Tables 17-28. Calculation of mean avoided cooling/heating energy (based on tables 49-60,

Appendix F.).

Table 29. Sum of mean change in cooling and heating (t CO2

/tree) for mature trees, Tucson

case study (Based on table 61, Appendix F.).

Table 30. Cooling and heating vintage factors (reproduced from table 62, Appendix F).
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 235

Appendix K List of Figures and Tables

Appendix A. Short Form Data Input Forms and Look-up Tables

Table I. Background information, blank form.

Table II. Site and building data, blank form.

Table 10. Conversion factors (reproduced in Chapter 4 and Appendix B).

Table 11. Default values for short form by region and growth zone (reproduced in Chapter

4 and Appendix B).

Table 12. Distribution of Sacramento Shade Trees. This distribution can be applied to

deciduous and evergreen plantings. (reproduced in Chapter 4 and Appendix B).

Table III. Tree data, blank form.

Table IV. Planting and stewardship costs, blank form.

Table V. Look-Up table (Short Form), 1. Mid-Atlantic region.

Table V. Look-Up table (Short Form), 2. Northern Tier region.

Table V. Look-Up table (Short Form), 3. North Central region.

Table V. Look-Up table (Short Form), 4. Mountains region.

Table V. Look-Up table (Short Form), 5. Southeast region.

Table V. Look-Up table (Short Form), 6. South Central region.

Table V. Look-Up table (Short Form), 7. Pacific Northwest region.

Table V. Look-Up table (Short Form), 8. Gulf Coast/Hawaii region.

Table V. Look-Up table (Short Form), 9. California Coast region.

Table V. Look-Up table (Short Form), 10. Southwest region.

Table V. Look-Up table (Short Form), 11. Desert southwest region.

Table VIII. Worksheet 1 (Short Form), blank form.

Table IX. Worksheet 2, blank form.

Appendix B. Long Form Data Input Forms and Look-up Tables

Table I. Background information, blank form.

Table II. Site and building data, blank form.

Table 10. Conversion Factors (reproduced in Chapter 4 and Appendix A).

Table 11. Default values for short form by region and growth zone (reproduced in Chapter

4 and Appendix A).

Table 12. Distribution of Sacramento Shade trees. This distribution can be applied to

deciduous and evergreen plantings.

Table III. Tree data, black form.

Table IV. Planting and stewardship costs, black form.

Table VI. Long Form Adjustment Table, 1. Mid-Atlantic region.

Table VI. Long Form Adjustment Table, 2. Northern Tier region.

Table VI. Long Form Adjustment Table, 3. North Central region.

Table VI. Long Form Adjustment Table, 4. Mountain region.
236 USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999.

Appendix K List of Figures and Tables

Table VI. Long Form Adjustment Table, 5. Southeast region.

Table VI. Long Form Adjustment Table, 6. South Central region.

Table VI. Long Form Adjustment Table, 7. Pacific Northwest region.

Table VI. Long Form Adjustment Table, 9. California Coast region.

Table VI. Long Form Adjustment Table, 8. Gulf Coast/Hawaii region.

Table VI. Long Form Adjustment Table, 10. Southwest region.

Table VI. Long Form Adjustment Table, 11. Desert southwest region.

Table VII. Look-Up Table (Long Form).

Table VIII. Worksheet 1 (Long Form).

Table IX. Worksheet 2, blank form.

Appendix C. Regional Climate Information

Table 31. Climate data for 11 reference cities (Andersson and others 1986).

Table 32. Climate data for 125 U.S. cities with populations greater than 250,000.

Appendix D. Tree Information

Table 33. Tree Growth Zones by Climate Region.

Table 34. Tree Selection List.

Table 35. Coefficients used in growth curve equations.

Table 36. Eight species, a total of 32 trees with known dry weights (DW), were used to

evaluate the accuracy of eight biomass equations.

Table 37. Attributes of biomass equations for deciduous tree species used to predict carbon

dioxide storage (n/a = data not available or variable not used in equation).

Table 38. Attributes of biomass equations for evergreen tree species used to predict carbon

dioxide storage (n/a = data not available).

Table 39. Tree dimensions and CO2

 sequestration values when trees are sequestering CO2 at

their maximum rate.

Table 40. Survey results of annual CO2

 release by tree-related activities.

Appendix E. Information on CO2

 Emission Factors, Building Characteristics, and Energy

Performance

Table 41. Electric emissions factors (EEF) by state.

Table 42. CO2

 emission factors (EF) for other fuels.

Table 43. Building data by climate region.

Table 44. Other building data by climate region.

Table 45. Total tree and building cover percentages (from McPherson and others 1993, USDA

Forest Service 1997).

Appendix F. Instructions for Adjusting Tree Distributions to Customize Avoided Carbon

Dioxide Emissions

Table 46. Default deciduous tree distribution by size, distance and direction from building.

Table 47. Default evergreen tree distribution by size, distance and direction from building.
USDA Forest Service Gen.Tech.Rep. PSW-GTR-171. 1999. 237

Appendix K List of Figures and Tables

Table 48. Distribution of trees planted by Sacramento Shade by size and building vintage.

This distribution can be applied to deciduous and evergreen plantings.

Tables 49-60. Calculation of mean avoided cooling/heating energy.

Table 61. Sum of mean change in cooling and heating (t CO2

/tree) for mature trees.

Table 62. Cooling and heating vintage factors.

Tables 63-106. Change from avoided cooling/heating (kg CO2/tree) for mature deciduous/

evergreen trees.

Table 107. Default changes in avoided CO2

 (tonnes/tree) from shade based on default tree

distribution.

Table 108. Default avoided CO2 savings per tree from windbreaks for mature trees (t CO2/tree).

Table 109. Default Climate Effects for Mature trees for 10, 30 and 60% cover (t CO2 /tree).

Appendix G. Energy Simulation Methods

Table 110. Summary of effect of wind shielding class on simulated heating energy use for

Sacramento.

Table 111. Mature tree canopy crown projection area (m2

).

Table 112. Mature canopy cover per tree (pct).

Appendix H. Instructions for Adjusting Tree Age/Survival Tables

Table 113. Combined tree age/survival table, North Growth zone, moderate (default) survival

rate.

Table 114. Combined tree age/survival table, North Growth zone, high survival rate.

Table 115. Combined tree age/survival table, North Growth zone, low survival rate.

Table 116. Combined tree age/survival table, Central Growth zone, moderate (default)

survival rate.

Table 117. Combined tree age/survival table, Central Growth zone, high survival rate.

Table 118. Combined tree age/survival table, Central Growth zone, low survival rate.

Table 119. Combined tree age/survival table, South Growth zone, moderate (default) survival

rate.

Table 120. Combined tree age/survival table, South Growth zone, high survival rate.

Table 121. Combined tree age/survival table, South Growth zone, low survival rate.

Table 122. Default and User-supplied Cumulative Tree Survival Fractions.

Table 123. Tree Age data for all Climate Regions—Can be used with table 122 to complete

optional table 124. Tree age effects on avoided energy (rows 1-3) differ between

Climate Zones, while remaining effects (rows 4-7) are the same for Climate Zones

in the same Tree Growth Region.

Table 124. User-derived Tree Age-Survival Table. Multiply values from Tree Survival table

122 (Moderate, High, Low, or User-supplied) by corresponding values in a

Regional Default (table 123) or this User-supplied Tree Age Table (table 124).