Hollows in trees

Treeaddict

Treehouser
Joined
Aug 16, 2021
Messages
2,554
Location
Harford county MD
I looked at a 100’ tall and 80’wide oak which I believe is in the red family. Every union is perfectly formed. Less than 1% of the canopy was dead. I believe this intentional by the tree was because of lack of production. The only defect is a hollow at 15’ off the ground. It’s at least 1’ deep on maybe a 36” trunk. All this from a 3” hole. Maybe from a flush cut which never compartmentalized? It doesn’t alarm me but maybe it should? No major targets. What would you guys/gals think?
 

Attachments

  • 481EC6A7-B767-4178-8001-1C53B175E782.jpeg
    481EC6A7-B767-4178-8001-1C53B175E782.jpeg
    1.4 MB · Views: 10
  • 34F7109E-714F-4829-BCB4-B74E8C19B58D.jpeg
    34F7109E-714F-4829-BCB4-B74E8C19B58D.jpeg
    3.7 MB · Views: 10
It may be a defect but 70% or more hollow the tree is condemnable. 70% or less hollow is not condemnable. No targets I would leave it. But over a house or other high value targets I would tell the owner “it is best to take it down on your time line than natures time line”
 
  • Thread Starter Thread Starter
  • #6
It may be a defect but 70% or more hollow the tree is condemnable. 70% or less hollow is not condemnable. No targets I would leave it. But over a house or other high value targets I would tell the owner “it is best to take it down on your time line than natures time line”
Rajan, is the 70% from a tree risk assessment guideline or an ISA bmp? Curious. Would be good to have a checklist and guideline of sorts.
 
I am not sure where I have heard this “rule” I think Glen Stanoz told me that. It is a great guideline to go by. Also the argument can be made that as a tree goes from a rod to a cylinder as it decays making it stronger, to a point.
 
Most mature trees have holes and hollows, like a pipe they are strong until they become too thin. Also why proper pruning is so important.
 
You don't think it's more likely to rot in the very enclosed space? It wouldn't just be a crotch puddle that goes away soon enough. It would also be nicer for habitat if it didn't flood when it rains. Dunno how much water that collects. Might not even be a concern, but that's a fantastic squirrel or bird hole.
 
If you're looking for a habitat tree, faux-storm damage the snot out of the tree... break it, tear it, flush-cut large wounds, blow it up with explosives, etc.

Trees compartmentalize grow. That's what is happening.

Easy to focus on "defects" around "targets".

This is habitat as a part of the tree and ecosystem, and undergoing a dynamic biological process.



I'd like to know more about the sound-rind thickness, and how it "sounds" (rubber mallet), as well as what is in the potential fall zone.


😃
 
... I have seen some very good results here on old Sugar Maples , either capping with soft metals or draining with PVC
That brings up the question of how best to protect a tree from excessive rot and pest attack if a large surface area chainsaw cut is made. Cap with a soft metal, grafting putty, paint, natural pine pitch?
 
Personally, the best results I have seen is just covering the hole with something you can shrink or move with time. On a fruit tree anyway. Let it keep callousing and closing up. Just observation. A sheet of aluminum and small brads. Kept the larger nesting critters out that make the hole bigger. Tree went from "oh hell no I would not even set foot in it" to "no problem, I'll just climb up there and get it." Apple tree.
 
I met an old timer who sealed the wounds on his apple trees with galvanized sheet metal. Used the matching stub of the branch removed as a template to cut the sheet metal. Perfect fit right up to the bark cambium. The callus completely sealed the cut the first season.

What was going on under the sheet metal I could not see. Of course. But his orchard looked great. All his trees reflected immaculate care.
 
So, what about water in the hole; Good, bad, indifferent?
to my knowledge it doesnt matter. trees are not lumber.

covering/painting (big) cuts has been outdated. best to just not make them. asking if paint will fix a big cut is like asking if an oil change will fix a burned out car :) also drilling/piping cavities to drain out water is not state of the art.
 
I'm not sure that's an accurate comparison. Submerged logs are cold, and virtually oxygen free. Water, in a hole like the above will get absorbed by the wood, and/or evaporate in an oxygen rich environment. I've got a cord of rot around here than wasn't rotten when I split it... Four years ago?
 
No target no risk.
Otherwise healthy, tree is managing by the sounds of it, and from what can be seen in the picture.
Water in cavities is not then problem a lot think it is, it actually can slow down decay.
Hollows that critters can get into are valuable environmental real estate, especially when surrounded with other trees and shrubs for 'connectivity'
Perhaps reduce the tree to a point where it becomes acceptable (subjective I know), enhance hollows and add new ones.
Sean and Stig are on to it.
 
On the pic, the wide grey and smooth area around the hole is the clue of an old limb lost a long time ago. It's the new bark and new wood which the tree grew over the wound. On its sides and over it, there's the darker bark ridge typically generated by the growth in the fork. It can stay as a remnent on the bark's surface a very long time. The hole itself is way too round to be the last bit of the sealed wound and the rougthness of its edge doesn't match with the edge of a callus nor the pattern of the smooth bark around. I'd say that the cavity is or / had been used as an habitat and the criter(s) maintained their access by continuously shewing the "door frame".

The wood pecker often starts first to get some food in the wood, usually a conical hole and if he found the wood suficently weakened by the fungi, he can dig it to carve his nest (he 's not mad, he wouldn't excavate a sound wood). For the tree, the dammage was already in its way no matter an actual cavity or plain punky wood. You find the fungi digesting the wood all around the cavity, sides, top and bottom (excepted where the tree had been able to put a good fence in the living part of its wood). Almost nothing can stop the fungal invaders in the heart wood. Additionaly, they prepare the "ground" for the insects borers or is helped by the some other borers to conquier new territories. The cavity is just optional. Though, it can appear too without the help of the wood peacker when too much dammage is done to the wood. Many other criters apreciate the opportunity to nest.

Also the argument can be made that as a tree goes from a rod to a cylinder as it decays making it stronger, to a point.
No no, a tube is never stronger than a rod with the same diameter. The tube just lacks of all the material inside to make the rod. Like, the rod can be seen as a whole bunch of concentric tubes all welded together. How can just one of these tubes be stronger than the whole?
If they weight the same, yes, as the tube has a bigger diameter for the same quantity of material.
But in the case of the hollowed tree, we are in the first case.
 
Last edited:
  • Thread Starter Thread Starter
  • #24
I appreciate all your feedback!

There was a bees nest in there. A very strange type of bee neither the owner or I have ever seen (she’s a master gardener).

I need to get back up there with a longer probe and maybe my 6’ scope.
 
Back
Top