iTree canopy for tree stand delineation

[Ben the tree hugger]

Hello everybody, I was wondering if any of you have experience using iTree canopy to conduct a tree survey, if so what your thoughts on the experience are, and if you have any suggestions for using iTree or any other software for large scale tree inventory projects. I need to conduct a "tree stand delineation" over a large area, and would greatly appreciate any input or advice any of you more experienced arborists might have. I'm not certain if I've posted this in the right place (101 vs commercial tree care), this is my first post on this site. Thanks!

 

[emo]

hi marcel, the town of atlantic beach florida used icanopy to do a study of the canopy over about a ten year period to the present. their conclusion seems off to me. i am quite sure that we have lost more than 5% of the canopy over this time span. the wording also seemed to focus on loss from hurricanes, very little emphasis on the human (builders, home owners expanding, new owners tearing down small houses and bungalows and building macmansion.) the emphasis on how inexpensive this methodology is also raised an alarm. supposedly they sampled 100 locations in the city to come to their conclusion. i am not convinced. emo (grandmother, environmental activist)

 

[emo]

p.s. have you read stanley kunitz's poem "the war against the trees"?

 

[emo]

p.s. here is a group of student in massachusetts who are using icanopy: http://crackest.com/cracker/1425564118_541ae66261/fall2012.txt

 

[Ben the tree hugger]

Thanks for the reply Emo, as I understand it the recommended minimum sample size is 500 points, so it makes sense that you're seeing a discrepancy between their results and reality. The free nature of the software is what attracted me to it, but yeah, paradoxically makes me a bit skeptical as well. I guess as with any tool its all in how its used.

 

[emo]

ben, please let me know where you found the information about the recommended minimum sample. i am going to follow up with the city of atlantic beach florida and need the facts to back me up. i have googled to no avail. any help greatly appreciated.

 

[Ben the tree hugger]

I think I saw it in an iTree canopy tutorial video, I'm looking for a link to send you now...

 

[Ben the tree hugger]

So I'm having trouble finding a reference to the number 500 (pretty sure I had seen it in tutorial video of some kind) but I was able to find the following quote in the iTree Canopy technical notes, it states:
"As the number of points increase, the precision of the estimate will increase as the standard error of the estimate will decrease. If too few points are classified, the standard error will be too high to have any real certainty of the estimate."
It goes on to outline how to calculate a confidence interval. Might be worth checking out. It's really not too difficult to survey a bunch more points, and it should impact the accuracy of the results substantially (assuming of course that whoever is using the software is correctly classifying each point). Here's the link to the source material:

https://www.itreetools.org/canopy/resources/iTree_Canopy_Methodology.pdf

Hope that helps. Do you have any more info on the Atlantic Beach study?