Energy Conservation Improving After Removing Trees?

VT-EAB · Post by **VT-EAB** » Thu Jul 16, 2009 11:38 am

After loading the project for a select municipality and running the program, I was given a total summary of conservation benefits of $702,XXX. After removing close to 500 street trees from the inventory, I was given a conservation benefit of $770,XXX. This is an increase of $68,XXX by removing these street trees. Is this possible due to the empirical models that are being used in the program or is there something I am doing wrong in the process?

Any and all information would be greatly appreciated on this matter.

Thank you much and take care.

Post by **azelaya** » Mon Jul 20, 2009 7:45 pm

We have been discussing possible reasons that could produce this outcome. It may be possible that the statistical estimation of the model may be impacted by the removal of trees from the data set as segments and the extrapolation of the remaining trees may affect the results.

In short, we would be very interested in taking a look at your data set to see if we can better identify what is happening in this particular case. Also, please verify that this is part of a larger scale project to show the impacts of removing ash trees to model EAB related tree loss. If so, has this consistently happened with the results of other towns in Virginia?

Thanks,
Al

VT-EAB · Post by **VT-EAB** » Tue Jul 21, 2009 7:13 pm

azelaya wrote:We have been discussing possible reasons that could produce this outcome. It may be possible that the statistical estimation of the model may be impacted by the removal of trees from the data set as segments and the extrapolation of the remaining trees may affect the results.

In short, we would be very interested in taking a look at your data set to see if we can better identify what is happening in this particular case. Also, please verify that this is part of a larger scale project to show the impacts of removing ash trees to model EAB related tree loss. If so, has this consistently happened with the results of other towns in Virginia?

Thanks,
Al

Al,

After reading my previous post, I need to revise some information to make it more accurate (but still in the same concept). This was a sample inventory (10%) and was conducted in Winchester, VA. After sampling and running the program, it was found that there were 655 (+\- 367) native ash trees in the municipality (which means we inventoried around 40 ash trees). This analysis, through STRATUM, gave us an estimate of total annuual benefits of $702,XXX. After we removed the 40 trees from the inventory, the roughly 500 ash trees from the population extrapolation, we received an total annual benefit of $770,XXX. All other municipalities that we have run through STRATUM are showing a decrease in total trees and total annual benefits. This has been the only one that is giving us trouble. I will speak with my advisor and try to e-mail you our project and other such files related to this inventory. And yes this is part of a larger scale project to model the loss from EAB colonization.

I look forward to having this matter worked out soon. Please let me know if there is any other information that you require.

Thanks again i-Tree team!

Post by **azelaya** » Tue Jul 21, 2009 8:04 pm

Thanks for the update. Yes, it is still perplexing and it would be interesting to see this data set.

Best regards,
Al

VT-EAB · Post by **VT-EAB** » Thu Jul 23, 2009 3:00 pm

azelaya wrote:Thanks for the update. Yes, it is still perplexing and it would be interesting to see this data set.

Best regards,
Al

Al,

What is the best format/file type to send to you and which files would you like to see?

Post by **dellings** » Tue Sep 08, 2009 9:16 am

I'm would like to go into detail about this issue, but the short answer is that you need to upgrade to i-Tree Streets in order to receive the most accurate benefit information for your inventory. The issue you describe is an issue with STRATUM that was corrected in i-Tree Streets.

Regards,

David Ellingsworth
i-Tree Developer