i-Tree is a collection of software programs for urban forestry that anyone can use. It was designed and developed by the USDA Forest Service to place a value on urban forest ecosystem services such as pollution removal, carbon storage, avoided carbon emissions, and avoided storm water runoff. I-Tree provides baseline data so that the growth of trees can be followed over time, and is used for planning purposes. Reports are based on tree inventories of species, DBH (diameter at breast height) and tree height. I-Tree is peer-reviewed and has a process of ongoing collaboration to improve it.
There are seven different i -Tree applications which can enhance an individuals or organizations understanding of the benefits which trees provide in modern society. Over the course of many years The United States Department of Agriculture - Forest Service has developed and refined these different applications as follows: i - Tree Eco, i - Tree Landscape, i - Tree Hydro, i - Tree Design, i - Tree Canopy, i - Tree Streets, and i - Tree Vue.
I-Tree began in 2002 as survey of a sample of urban forest to simulate taking a tree inventory of an entire urban forest. It then added hand held devices for efficient inventory of street trees. The current version of i-Tree allows for several sources of data to be used, such as National Land Cover Data, Google Maps, and tree inventories. Some versions allow for continuous data on air pollution and meteorology in order to average the results for a more accurate answer.
The current version uses groundwater capture, building energy savings, air pollution benefits, carbon sequestration, homeowner value, and pest detection.
Researchers using i-Tree have examined:
- The benefits of urban trees
- Selecting the best tree planting locations
- Storm damage to urban forests
- Potential bird habitats
- PM2.5 removal and health effect
- Lerman, Susannah; et al. (2014). "Using urban forest assessment tools to model bird habitat potential". Landscape and Urban Planning. 122: 29–40. doi:10.1016/j.landurbplan.2013.10.006.
- McPherson, Greg; et al. (2008). "Los Angeles 1-Million Tree Cover Canopy Assessment" (PDF). United States Department of Agriculture, Forest Service, Pacific Southwest Research Station General Technical Report PSW-GTR-207: 1–64.
- Nowak, David; et al. (1996). "Assessing Urban Forests Effects and Values, New York City's Urban Forest" (PDF). United States Department of Agriculture, Forest Service, Northwest Research Station Resource Bulletin NRS-9: 1–26.
- Nowak, David; et al. (2013). "Modeled PM2.5 removal by trees in ten U.S. cities and associated health effects" (PDF). Environmental Pollution. 178: 395–402. doi:10.1016/j.envpol.2013.03.050.
- Thompson, Benjamin; et al. (2014). "Urban Forests in Florida: Storm Damage Assessment Utility for Estimating Hurricane-Caused Tree Debris." (PDF).