Isolating leads in 80 year old plus dugfirs

[noahoak]

Wondering what anyone has to say about isolating leaders in old dugfirs. Reciently moved to Portland Oregon and the company I am with does a lot of work with dugfirs ( go figure). It is standard practice to isolate the lead in the top of 100ft plus trees if they are showing signs of codominance, but I am wondering if trees of this size and age ( generally 80 years plus) really need to be messed with, and if in fact they start to loose there excurant structure after a while for good reason. Similar to big cypress back east that go decurent after a while. Yes it is all subjective ( tree, target, client specific), but was looking to see if anyone know of any research out there to prove either way that isolating leads (talking about 2 inches) in old trees was good or bad.
cheers

 

[DangerTree]

Wondering what anyone has to say about isolating leaders in old dugfirs. Reciently moved to Portland Oregon and the company I am with does a lot of work with dugfirs ( go figure). It is standard practice to isolate the lead in the top of 100ft plus trees if they are showing signs of codominance, but I am wondering if trees of this size and age ( generally 80 years plus) really need to be messed with, and if in fact they start to loose there excurant structure after a while for good reason. Similar to big cypress back east that go decurent after a while. Yes it is all subjective ( tree, target, client specific), but was looking to see if anyone know of any research out there to prove either way that isolating leads (talking about 2 inches) in old trees was good or bad.
cheers

You mention 2" ( diameter ) leaders that have become co dominant is that correct? If so have they became co dominant from mechanical damage or genetics ? The conifer is strongest as a single dominant leader and presents less sail as such. Many Schoolmarms may have weak unions and can be susceptible to failure. However; location and target, as you put it would have bearing as to any reason for pruning a rogue leader. A 2" cut in a healthy tree done in the fall after sap stops flowing should cause no harm to the tree. If the tree were to be a center piece or heritage I would do the surgery to maintain balance and form just like any other tree. But for random urban trees where failure is not a big threat it would seem to be either more effort than it's worth or a cash grab.