U.S. Forest Service to Launch Free i-Tree Inventory Software
New software tool can analyze the advantages of trees on public and private lands and assign a dollar value to the benefits of urban forests.

Landscape architects often prescribe healthy canopy trees to improve the urban landscape. But do you find that clients and local governments shy away from the cost of installing new trees? Are they unwilling to commit to working to protect and care for established trees? The U.S. Forest Service (USFS) is trying to change that by providing tools to quantify the ecosystem services provided by urban trees.

The USFS has developed user-friendly software to assign values to the costs and benefits of specific urban trees and tree assemblages. The software, called i-Tree, is now in beta testing and soon will be made available to the public at no charge. Its capabilities can be adapted to a wide variety of user needs, according to the USFS, from analysis of a single tree to consideration of an entire urban forest.

The two main analytical components of i-Tree are the Urban Forest Effects Model (UFORE) and the Street Tree Resource Analysis Tool for Urban Forest Managers (STRATUM), both developed by the USFS from scientific field research that has been peer-reviewed and published.

Both UFORE and STRATUM calculate the forest's environmental benefits using field data describing species composition, tree density, and tree health. If the data is sufficiently thorough, the model can calculate estimated values for levels of air pollution mitigation, carbon sequestration, and stormwater control. These benefits are then assigned a dollar value.

The data from an existing inventory can be used, or data can be collected by the user with the help of i-Tree utility programs:

• PDA programs improve the use of handheld PDAs to collect field data.
• MCTI (Mobile Community Tree Inventory) helps users conduct tree inventories, using either paper tally sheets or a Personal Digital Assistant (PDA).
• Plot and street segment selection programs help determine where to collect data for sample inventories.
• Storm Damage Assessment Protocol provides a standardized approach to assessing storm damage and determining the time and funds needed to mitigate damage.
• Report writers summarize data and results in the form of reports, graphs, charts, and tables.

The i-Tree software is scheduled for public release on August 1, 2006. Through a public–private partnership with the National Arbor Day Foundation and Davey Tree, the USFS is prepared to disseminate the software free of charge and to offer technical support and training. Interested persons can visit the i-Tree website, http://www.itreetools.org/index.html, for detailed information about the programs. Technical support is also currently available to answer questions; call 877-574-8733, M-F 8:30-12 and 1-4 (EST) or email info@itreetools.org.