Andrew, It is easy to see how a the tape draping over a branch, not hanging free, or tangled can lead to tape measurement errors. Typically a PVC pole is used to reach the very top of the tree and it could potentially not be exactly line up even with the top sprig, and lead to errors. These can be corrected with better technique and careful checking when doing tape drops. From the ground some types of errors are commonly discussed, rangefinder error, clinometer error, etc. One problem that can not be overcome in ground based measures is if the top sprig is not visible from the ground. This may be the case if the forest is tightly packed. The top of the tree may be broad or the tops nested in the center and not actually visible from the ground. It is in these cases that the climb and tape drop has a serious advantage over ground based measures. In some cases no matter how good your technique, you just can't see the top from the ground. The two methods can and should be used in conjunction with each other for exceptional trees, but one can not practically or completely replace the other.
Ed "Oh, I call myself a scientist. I wear a white coat and probe a monkey every now and then, but if I put monetary gain ahead of preserving nature...I couldn't live with myself." - Professor Hubert Farnsworth --~--~---------~--~----~------------~-------~--~----~ Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -~----------~----~----~----~------~----~------~--~---
