Significance of Crown Measurements

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Chrum5555
Posts: 4
Joined: Fri Jul 03, 2020 10:25 am

Significance of Crown Measurements

Post by Chrum5555 » Wed Jul 08, 2020 3:28 pm

Hello,

I am currently inputting an existing tree inventory into the iTree software, and am debating about adding the information for the crown.

I was just wondering, will be data be significantly different if I only use DBH, height and species, versus using DBH, height, species, and the crown measurements (crown widths, % reduction, etc.). I have an inventory of around 10,000 trees total.

Thanks,
Charlotte
Jason.Henning
i-Tree Team
Posts: 220
Joined: Fri Dec 21, 2012 7:45 am

Re: Significance of Crown Measurements

Post by Jason.Henning » Thu Jul 09, 2020 8:44 am

Hi Charlotte,
This can be difficult to answer and varies depending on your tree population. If your trees are similar to the ones used to create the models that estimate crown parameters based on dbh then there will be little impact on average. However, for any single tree the differences may be large. Additionally, if your tree population includes something likely heavily trimmed street trees or a bunch of trees with broken tops due storm damage the crown sizes will likely be overestimated. Please check out this document from the i-Tree website that describes which variables impact which i-Tree Eco results and default values used when field measurements are not provided, https://www.itreetools.org/documents/26 ... _10_21.pdf.
Depending on your project goals it might be worth your time to run a quick test with some of your trees. Create two projects, one that uses all the crown measurements and another that does not. You can even just create test data if you don't have real tree measurements. Compare the results and see if the differences are acceptable for your project goals.
Thanks,
Jason
A member of the i-Tree Team
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