Sapwood/ Phloem Circulation After Injury

[asker]

Hello,

I'm wondering if xylem and phloem are able to move water and nutrients laterally. Like if there is a very large injury to the lower trunk as in a large section of bark and cambium on the lower trunk was skinned off down to the sapwood. The sapwood would be walled off.

Can the existing healthy phloem and xylem circulation go laterally around the injury to nourish the rest of the tree? I'm thinking it must.

Thank you.

 

[Jason Douglas]

Well... Yes and no. Kind of.
Depends on the ring porosity and the species as well as ray cell amounts I believe. Tissues immediately adjacent to the wound are compartmentalized (hopefully) and the vessels or tracheids will be quickly plugged by tyloses to stop air embolism. That said some flow and tissues are no longer functional and the rest of the intact ones will have to carry the load until new functional wood and phloem can be formed. Larger and deeper the wound can be particularly dreadful to poor compartmentalizing species and young woodies.

That help or is it clear as mud?

 

[asker]

Thanks JD,

Yes that was helpful. Thank you. Pretty much what I have been suspecting.

I'm wondering about the root system. I deal with a lot of car wrecks into trees and small to large sections of trunk are damaged. Trees can have pretty large chunks out of the trunk yet years later still have a full crown so they pretty much must be able to move things around.

I'm also wondering how long it might take, just loosely more or less not species/soil/etc specific, for the roots to die if they were completely cut off without access to the phloem. My guess is until they use up their store of nutrients and depending on how long it takes for decay to take its toll. Duh?

Reasons for wondering include having to determine if the tree should be replaced and some clue as to the long-term effect the accident could have on the tree if it is allowed to remain (preferable with large trees with smaller wounds. There are a lot of variables, I know.

Probably kind of a silly question but I'm trying to clarify it more in my mind.

 

[Jason Douglas]

Look into tree risk assessment...if many roots are severed near the trunk you are potentially looking at a tree that could fail from that area. Big liability potential.

However, many municipalities regularly root prune trees HEAVILY when replacing sidewalk lifts in hopes of it not happening again. Not advocating the pricess but it does happen.

As far as phloem severence, remeber the phloem and cambium is located just below the p

 

[Jason Douglas]

Sorry, issues with typing.

...just below the periderm so complete and total severance of these tissues can lead to mortality of that root and the tissues above.