i-Tree consists of several different applications focused on quantifying the benefits of local trees for neighborhoods and communities. Each application has a unique focus, however several calculate the carbon sequestration and/or energy savings benefits of urban trees.
Inputs
Inputs and outputs will vary with individual application, but in general the tools require a user to define a project study area and input data about the general land use and the trees in that area (species, size, health), whether from an existing or new dataset. Understanding the effect of trees on building energy use also requires information about tree locations in relation to adjacent buildings.
Outputs
Outputs vary by application, but generally include reports and graphs of numerical values for the ecosystem services provided by urban trees or forests. These outputs may include benefits such as air quality improvements, carbon sequestration and storage, building energy savings, and storm water interception. The monetary value of these benefits is also reported. Additional outputs may include an evaluation of urban forest structure, management needs, or susceptibility to invasive pest damage.
Restrictions and Limitations
Most of the applications were built for use in the United States; international users may still be able to use them, however they may be subject to modeling limitations and may need to supply their own location and geographic data if not included with the tools (e.g. pollution data).
Release Notes
The original i-Tree suite of tools was launched in 2005 with two urban forest assessment applications. It has since been through many updates and improvements; the 2017 release features a desktop suite and 8 different web applications.