High value landscape tree with basal rot

[fancyman]

Hello arborists.

I've got a tree here that I want advice on. This tree is sitting on a dry stone circular pedestal that is approx. 16ft diameter. My assumption is that when the house was built, the site was regraded and this tree left in place with the dry stack wall to hold its grade. I don't have any problem with the re-grade or the pedestal. It looks really cool and it is big enough to hold the tree's roots.

Here's the problem: the tree has a large basal wound (probably incurred during construction operations) on the north side which has rotted a significant portion (approx 35%) of the tree's basal flare.

I climbed it and inspected the canopy, did some end weight reduction on the house side of the tree.

The tree appears quite vigorous. It is in good health except for this basal rot.

My first instinct was to remove the tree, the house presents a consistent occupied target and there is definite risk involved in leaving it. However, the tree is irreplaceable, it is a mature black oak on a raised pedestal, it doesn't really get more awesome than this.

What do you guys (and gals) think about guying the tree and securing the guy lines with dead men? I have done canopy cabling jobs, but I've never guyed a tree to the ground (unless it was for directional falling).

What would you do with this tree? Anybody that has done guying for risk abatement please weigh in on this.

See pictures for more info.

 

[Del_]

It looks very compromised.

 

[Jason Douglas]

Like to see more if possible.

What's the orientation regarding the tree, house, and wind exposure?

Any fruiting bodies found?

 

[WmTreeCo.]

The tree IS replaceable. It would be selfish of the homeowners to try keep it if its unsafe. The costs of trying to make it safer can be put towards replanting a young, healthy, safer tree for the future.

 

[fancyman]

Like to see more if possible.

What's the orientation regarding the tree, house, and wind exposure?

Any fruiting bodies found?

The house is on the south side of the tree. If you look at the picture of the canopy, the large branch sticking out on the right is pointing away from the house. The the tree's risk radius to the house is 180 deg. Wind exposure is limited from a Norther, but exposed to a south wind. A norther would blow the tree towards the house.

No fruiting bodies found.

I will see if I can get the client to send me a picture of the tree where one can see the pedestal it's on.

 

[ATH]

Did you probe into the base at all? How deep does that decay go?

 

[Jed1124]

There’s too many factors that go into this to make a judgment from a few pictures.
Clients risk tolerance, prevailing winds, exact percentage of decay, climate in the trees location, amount of investment the client would like to make into the tree, they all play a part.
I would start by excavating the soil around the tree to see what is going on around the flare and possibly some tomography or at the very least resistograph work.
Everything is speculation at this point aside from the outward appearance.

 

[Jed1124]

The tree IS replaceable. It would be selfish of the homeowners to try keep it if its unsafe. The costs of trying to make it safer can be put towards replanting a young, healthy, safer tree for the future.

You can make that judgment from those pictures?

 

[fancyman]

Did you probe into the base at all? How deep does that decay go?

I did probe into it, the decay goes fairly deep, I would say approximately 45% depth.

 

[fancyman]

There’s too many factors that go into this to make a judgment from a few pictures.
Clients risk tolerance, prevailing winds, exact percentage of decay, climate in the trees location, amount of investment the client would like to make into the tree, they all play a part.
I would start by excavating the soil around the tree to see what is going on around the flare and possibly some tomography or at the very least resistograph work.
Everything is speculation at this point aside from the outward appearance.

During the root flare excavation I found the sound roots to be in good shape, no signs of girdling or anything. The flare itself is excellent (except obviously for the part that is decayed). I don't own a resistograph or any tomography equipment, I think it's safe to say the base of the tree is pretty well decayed on the side the wound is on and the unaffected roots are in good shape.

 

[fancyman]

The tree IS replaceable. It would be selfish of the homeowners to try keep it if its unsafe. The costs of trying to make it safer can be put towards replanting a young, healthy, safer tree for the future.

Yes, I could remove the tree and plant a different tree. By not replaceable I mean that the new tree would never achieve what this tree does in the lifetime of the client and the client does not have the resources to transplant a mature tree at the site.

 

[WmTreeCo.]

You can make that judgment from those pictures?

Of course not. I was responding to the "What would you do with this tree?" part. He was looking for opinions, I gave him a simple one based on the info provided in the original post.
I've seen a lot of homeowners pump money into trees that aren't worth it. It can also be a liability nightmare for the client and any arborist whos had anything to do with the tree when the lawyers find out the tree was considered unsafe.
With all that said, if theres a way to save the tree, go for it!

 

[WmTreeCo.]

Yes, I could remove the tree and plant a different tree. By not replaceable I mean that the new tree would never achieve what this tree does in the lifetime of the client and the client does not have the resources to transplant a mature tree at the site.

If the risk can be mitigated, sounds like thats the route to take. If it cant be made safe, THEN its selfish of them to put a need for a mature tree on their front lawn over the safety of others.

Good luck, hope you can save it.