i-Tree is a suite of computer software tools developed through a collaborative publicprivate partnership. These tools are designed to assess and value the urban forest resource, understand forest risk, and develop sustainable forest management plans to improve environmental quality and human health. This report provides details about the underlying methods and calculations of these tools, as well their potential limitations. Also discussed are the history of i-Tree, its future goals, and opportunities to facilitate new science and international collaboration.
This report was revised in 2021 and is available at https://doi.org/10.2737/NRS-GTR-200-2021. Revisions include updates to procedures and values.
The appendixes can be accessed through the links below.
Appendix 1: i-Tree Staff and Collaborators
Appendix 2: i-Tree Links
Appendix 3: Shading Coefficients
Appendix 4: Conversion Factors for Leaf Area to Biomass
Appendix 5: Conversion Factors for Shrub Volume to Biomass
Appendix 6: Invasive Plant Species
Appendix 7: Compensatory Value of Trees
Appendix 8: Average Energy Costs
Appendix 9: Energy Conservation Estimates for Buildings in non-U.S. Countries
Appendix 10: New Biomass Equations
Appendix 11: Wood Density Values
Appendix 12: Volatile Organic Compounds (VOC) Emission Rates
Appendix 13: Equations for Tree Height, Crown Height, and Crown Width
Appendix 14: Partial List of Publications Referencing i-Tree Tools
air pollution removal
Nowak, David J. 2020. Understanding i-Tree: summary of programs and methods. General Technical Report NRS-200. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station. 100 p. plus 14 appendixes . https://doi.org/10.2737/NRS-GTR-200.