1. Calculating Form, Function and Value of the Urban Forest
i-Tree
Calculating Form, Function and Value of the Urban Forest
Eric Kuehler
Technology Transfer Specialist
USDA Forest Service
Many people and municipalities look at trees simply as beautiful things that are accessories to the landscape. We plant our crapemyrtles and Bradford pears around town and call it good. When budgets are tight, maintenance dollars for these accessories are the first to be cut. While aesthetic beauty has value, relating that value to city managers can be difficult. A new strategy of relating the benefits and value of urban trees to citizens and/or city managers needs to be developed and conveyed. New tools have been developed that uses current research to calculate those environmental services and place a dollar value on those benefits, so that citizens and elected officials can relate.

2. Presentation Objectives
Describe environmental services from trees
Outline available i-Tree tools to calculate those services
Display some of the reporting outputs from the i-Tree products and describe how they can be used
Demonstrate how some of the tools are being used around the Southeast

3. What are Environmental Services?
Energy Conservation
Shade in summer
Wind break in winter
5-20% reduction in home energy use
Reduced ambient temperature
Heat island effect
Environmental services are those services that trees provide to us naturally that improve our quality of life.

4. What are Environmental Services?
Stormwater interception
Captures rain water
Reduced flow rate
Help mitigate stormwater problems

5. What are Environmental Services?
Pollution removal
Particulate matter
Soot
Dust
Gaseous matter
NO2, SO2, O3, CO
Carbon Storage

6. What are Environmental Services?
Aesthetic beauty
Psychological health
Bradford pears and crapemyrtles do provide for emotional, psychological health through their aesthetic beauty, however, that is about all they provide.

7. i-Tree
Suite of public domain urban forest analysis and benefits assessment software
PSW – street tree cost/benefit analysis
NRS – urban ecosystem benefits model
Released to the public in 2006
Quantifies structure, environmental benefits, and monetary value of community trees
Helps communities strengthen
Urban forest management efforts
Advocacy for maintaining its natural resources

8. i-Tree Suite of Software Tools
i-Tree Streets
Street tree cost/benefit analysis model
i-Tree Storms
Pre- / Post-storm debris estimation model
i-Tree Vue
Urban tree canopy / environmental benefits tool
i-Tree Eco
Entire urban forest structure, function, value model
i-Tree Hydro (not yet released)
Stream flow / water quality simulation model
For more information and to download software

9. More specifically, what is i-Tree Eco?
i-Tree Eco = Urban Forest Effects model (UFORE)
Specialized analysis for urban and urbanizing ecosystems
Collection of: 1. standardized field methods & 2. model analysis tools
Method for establishing permanent plots & collecting data in complex urban areas
Combination of research-based mathematical models that quantify urban forest structure, function, and values
i-Tree Eco is the interface for the UFORE model; model is operated by the Forest Service with user data
i-Tree Eco is the interface for the UFORE model. The model with your data is actually run in Syracuse, NY by the Northern Research Station. The UFORE model is a specialized analysis for urban ecosystems that uses standardized field data collection methodologies for establishing plots and collecting data as well as using mathematical models based on current research to analyze and quantify urban forest structure, function, and values.

10. What is i-Tree Eco? Complete or sample inventory methodology
Complete = inventory all trees in a park, campus, etc.
Sample = many 1/10th acre circular plots
Entire ecosystem analysis
Includes all trees
Public & private
All land uses
Native/exotic
Not individual tree management, but we can manage the population (urban forest ecosystem)
“Snapshot” of your urban forest
i-Tree Eco analyzes and quantifies the entire urban ecosystem, not just the publicly-owned trees that can make up less than 5% of the urban forest. It analyzes trees on public and private property, in all land use classifications (i.e. residential, commercial, industrial, forest, etc.). It even analyses native vs non-native species. UFORE is not designed to be an individual tree management program. It can help you manage the entire urban ecosystem. It gives a snapshot of your urban forest.

11. What is i-Tree Eco? UFORE calculates for city & land uses
Structure, e.g.
Tree numbers & cover
Species & size distribution
Function, e.g.
Air pollution removal
Total carbon stored & sequestered
Effect on building energy use
Biogenic emissions
Value based on structure, function
The UFORE model calculates for each land use strata the structure of the urban forest (i.e. the number of trees by species, their size, canopy cover, etc). From that information, it uses mathematical equations to calculate the urban forest’s function such as carbon and pollution removal, energy use, etc. Based on all of that, it estimates a monetary value that the trees collectively provide to the community.

12. Overview & Process How does it work?
Uses field data to calculate structure from a statistical sample
Uses structure data to calculate function
Uses function data to calculate value
Uses value results to draw conclusions and make management recommendations
Everything hinges on the collected field data
How and where do we get these data?

13. To get an accurate picture of your urban forest, you will need to establish random plots around the city. The plots can be randomized within land use categories before or after data collection. Obtain the latitude and longitude for each plot center and group the plots together for field crews. Using fine resolution aerial photography (< 1 ft. resolution), create a plot map for each plot to help field crews find plot center.

14. i-Tree Eco Data Collection
General plot information
Parcel contact info
Reference objects
For relocation (QA/QC)
Land use
% tree/shrub cover
% plantable space
% ground cover
Specific shrub information
Species, HT, surface area

15. i-Tree Eco Data Collection
Tree data
Species
DBH HT
Total height
Base of live crown
Crown width (NS & EW)
% dieback and missing
Crown light exposure
Distance/direction to buildings

16. i-Tree Eco needs 4 inputs
i-Tree users only need to worry about # 1 and 2
Field data
Community-specific data
Study area
Land use strata size
Hourly weather data
Air quality improvement data (mixing height data)
Hourly pollution concentration data
# 3 and 4 provided by the UFORE engine

17. What Results Does i-Tree Eco Provide?
10 charts, 19 tables, and one written report summarizing it all
Species composition (by land use type and total city)
Size class
Condition
Species origin (native or non-native)
Tree density by land use
Importance value of species
Air pollution removal and value
Carbon storage/sequestration
Annual energy savings and avoided carbon
Potential pest impacts (ALB, GM, EAB, & DED)
Ground cover percentages (impervious vs pervious)

19. Why i-Tree Eco? What good is it? Aid planning and management
Improve forest designs
Project future impacts
Assess impact of catastrophic events
Justify programs
Use in conjunction with UTC
So, what can the results be used for? They can help you and the planning department plan for and management the entire urban ecosystem and help with forest design. If you have an over-abundance of ash in your community, the Eco analysis can alert you so that you can develop education materials to targeted land use areas and perhaps provide trees for the residents to plant in their yards for the future.

20. Technology Transfer Specialist
i-Tree Eco
Overview and Process
Questions
Comments
Discussion
Eric Kuehler
Technology Transfer Specialist
USDA Forest Service