Co-Dominant Loblolly Pine Problem

[Fireaxman]

This is either a very early formed co-dominant loblolly or two closely grown loblollies that grew together and probably tapped each other's roots. I actually suspect the latter, in spite of the title of this thread, because on close examination it appears there is entrained bark all the way to sub-terrain. Both forks were about 95 feet long and two feet DBH. The Southern fork was struck by lightning, fell victim to Southern Pine Bark Beetles (SPBB), died, and was removed last year. The Northern fork still appears quite healthy. The owner of the tree loves it and would like to keep the remaining fork, but is worried about the stability of the tree in a storm. Risk to people is low since it is on the back corner of his property and there are no structures or high use areas within several hundred feet of the tree, but there is an old and treasured white oak within 50 feet of the pine that is at risk if the pine fails.

If I leave it as it is, do you think the rot will stop at the entrained bark and the North fork will again be able to increase diameter in that direction? Or do you think the rot will proceed into the North fork and further weaken the surviving co-dominant? Are there other possibilities?

If I could get a stump grinder in there I would be tempted to try to "Carefully" (is that an oxymoron, using "Carefully" and "Stump Grinder" in the same sentence?) remove the rot down to the entrained bark, but it is certainly too wet to get in there right now. No immediate action needed or planned right now, but ... got any experience with anything like this or suggestions about how to handle it? Do you get a strong feeling the North fork is doomed and needs to be removed, should we "Do Something", or should we just watch it for another year?

 

[ATH]

Even if there were higher risk targets in the area I'd leave that for at least a few more years with on inspection scheduled every other year or so. As it is, the strength hasn't been significantly compromised, but I suspect it will be in the future. It is a race between how quickly new wood is added vs speed of decay.

Don't grind away at it...That accomplishes nothing and risks a lot. If you want to know the depth of decay just use a probe. You could even get a long 1/8" drill bit and drill in through the exposed part to see how deep you go before hitting solid wood if that would make you feel better about it.

Now...Let's assume for a moment that the tree is deemed unstable. How likely is it to fall in the direction of the white oak? What is the likely damage it will cause to the white oak if it hits it? If it might break a few small branches, is that worth the risk of leaving it? That is a question best answered by the owner. You need to give some idea about likelihood and expected extent of damage (or work with another Arborist who can offer that service) and let the owner decide if that is a level of risk they are willing to accept.

 

[Fireaxman]

Thanks! Exactly the advice I was hoping to hear, and I fully agree. Likelihood of hitting the White Oak? The White Oak is immediately East of the pine in question. Assuming the roots are compromised on the South side I would guess the pine would tend to fall away from the compromised root, more toward the Northern quadrants. And, because the pine is about 95 feet tall with clear bole to 50 feet, and the white oak has a severely restricted canopy, there is a good chance the pine canopy and bole would miss the white oak in any event outside of an ENE to ESE fall. Much depends on what quadrant of the next hurricane hits us. It would take a strong West wind to drive the pine into the oak. Unfortunately the pine is the First Tall Tree a hurricane will see after it crosses the Gulf of Mexico and Lake Ponchartrain, the canopy is very exposed to the South and West.

Likely damage to the white oak if it got hit? It would totally decimate the white oak. The white oak is the oldest tree on the property, topped out by Hurricane Katrina, in a severe state of decline, bad case of heart rot, badly crowded and almost shaded out by neighboring pines - alive only as a testament to the determination of some especially hardy and determined individuals to survive. I really am very surprised each Spring when it continues to sprout new leaves. It is a memorial of a perplexing conundrum. A teenager from a neighboring subdivision committed suicide under this tree. So strange. Here is this old oak clinging so hard to life, and there was this young, physically healthy young man throwing his away.

 

[ATH]

Can you cut some of the pine trees that are shade competition for the White oak? You have to be a little careful with that because you don't want to give it too much exposure to extra wind... Might buy it a few more years...which if that is a 10% extension of live and it is a 300 year old tree, that is 30 years! Sounds like it might be beyond that though. Just a thought.

 

[Jason Douglas]

I would leave it too but the visible mycelium and exposed wood characteristics is pointing towards a brown rot decay. Cant tell which one it could be from the pic but there may be some more signs visible to you on site. Usually a matter of how aggresive it is what its decay stategy is.

Conifers tend to be strong in compression and weaker under tension than hardwoods so keep that it mind when assessing wind force and likelyhood of the trees failure mode and direction.