We all know that trees are beneficial to a neighborhood - they are pretty, they are good for the environment - but how much is a tree actually worth?
David Nowak, head of the U.S. Forest Service's (USFS) Northeastern research unit, hopes to provide an answer. He has spent the last couple of decades analyzing trees in several U.S. cities and is trying to standardize their valuation.
The USFS has developed a platform, called i-Tree, that uses data from sampled areas, maps the trees across a city, calculates a city's "leaf surface area," and derives the economic value of trees, factoring in everything from carbon stored, to ozone, nitrogen, and particulates removed, health impact, effect on building heating/cooling costs, and hydrology.
i-Tree, which is free to use and has a mobile version (for remote data logging), also uses localized weather and pollution data in determining the trees' value based on official sources. As an example, New York has approximately 876,000 trees, which cover 23.1% of the city. The trees provide $11.2 million in annual energy savings, have a carbon sequestration value of $386,000, and a pollution removal value of 836,000.
Nowak's goal in creating the i-Tree platform is twofold: firstly, it allows cities to place trees in budgets along with other quantifiable items. And secondly, "it lets us understand what’s out there, and understand its importance," he said. "We see trees all the time, we just haven’t quantified them."