How does i-Tree Eco estimate total population of trees?

[KANG1943]

Using the sample plot-based method, how does i-Tree estimate the total population of trees in a city?
On the introduction page of i-Tree Eco, it says "For plot-based sample projects, total population estimates and standard error of estimates are calculated based on sampling protocols." But how? I haven't found the answer from "Nowak, D.J., 2020. Understanding i-Tree: summary of programs and methods." and other documents.
Thanks for your time and help

[Jason.Henning]

Hi,
i-Tree Eco is using standard stratified random sampling statistics. Basically, it is calculating the average number of trees per unit area on your measured plots then multiplying that by that total project area you entered in the Project & Strata Area table. If you want a summary of the actual statistics you can find them here, https://www.itreetools.org/documents/63 ... riance.pdf but they are the same as what you would find in any statistical sampling text book or internet overview for "simple random sampling with stratification".
-Jason