Rotten sycamore

[Morton]

Hi and hopefully someone can help advise me.  I have looked at a large sycamore today with a number of cavities from previous wounds.  The wood is growing really well to heal up the holes but water is getting in and most of the heartwood is rotten.  I could push my metal probe through to the sapwood on the other side of the tree.  There were around three cavities that had black rotten wood inside and the lowest was also oozing a brown sludge along with water that is collecting.  I'm reading though my books but struggling to know whether this tree is likely to be safe.  The main trunk is rotten inside but the growth as you can see around the cavities is really good.  The canopy is nice and tight with very little dead wood and overall looks healthy.

Any advice here would be much appreciated.

  

 

[DanVC]

Whats the target/usage area in the vicinity of the tree?  This would be my first thought. Can the risk can be mitigated by moving the target. Can the tree be pruned to reduce the risk of faliure?  You also need to know the size of the decay cavities to get a better idea of what you're dealing with

[Morton]

The cavity openings are around 30 x 30 cm.  The rotten heartwood goes all the way through the tree to where the second stem starts, around 5ocm deep.  Two main stems start at around 1.3 metres from ground.  Pruning is probably the way forward as target areas are gardens and minor road.

[Morton]

My concern is the lack of good heartwood will make the tree structurally unsafe even though the sapwood and canopy suggest good health elsewhere.  Many old trees rot on the inside and are even hollow but I have little experience with sycamore.

 

[skyhuck]

My first thought would be "is it a nice tree" "does it enhance the area" or would it be better felled and replaced?

 

Its not posable to give sound advice from that pic, IMO.

 

How far in does the decay go? Are the various cavities close together? 

[Anno]

Don't forget Matthecks equation of relative ratio and the tensile strength of a tube.

[fagus]

Is the tree in full leaf and otherwise healthy. Identify the hazards/target and estimate what the outcome would be if it, or bits of it,  fell. If the danger is low e.g it just falls into a field the more credence to letting a tree survive; different adjacent a busy commute road.

The branch structure links directly to the roots, i,e. a rotten branch will link now, or later, to a rotten root. In many old trees the heart wood drops away and the cavity dries out and the tree lives on; stronger wood trees like Oak last longer.

[Gary Prentice]

7 hours ago, fagus said:

Is the tree in full leaf and otherwise healthy. Identify the hazards/target and estimate what the outcome would be if it, or bits of it,  fell. If the danger is low e.g it just falls into a field the more credence to letting a tree survive; different adjacent a busy commute road.

The branch structure links directly to the roots, i,e. a rotten branch will link now, or later, to a rotten root. In many old trees the heart wood drops away and the cavity dries out and the tree lives on; stronger wood trees like Oak last longer.

But if the moisture content in the cavity is high, or the cavity is full of water, the conditions inhibit fungal colonisation due to the anaerobic conditions - every cloud has a silver lining.

[Gary Prentice]

12 hours ago, Morton said:

Hi and hopefully someone can help advise me.  I have looked at a large sycamore today with a number of cavities from previous wounds.  The wood is growing really well to heal up the holes but water is getting in and most of the heartwood is rotten.  I could push my metal probe through to the sapwood on the other side of the tree.  There were around three cavities that had black rotten wood inside and the lowest was also oozing a brown sludge along with water that is collecting.  I'm reading though my books but struggling to know whether this tree is likely to be safe.  The main trunk is rotten inside but the growth as you can see around the cavities is really good.  The canopy is nice and tight with very little dead wood and overall looks healthy.

Any advice here would be much appreciated.

  

 

•  

Being pedantic, trees don't 'heal' wounds and no tree is 'safe'.

 

At this wound there's certainly evidence of adaption to the change in stresses. I'd be starting off with Matthecks T/r ratio (bearing in mind the issues involved in that), looking at the canopy size/ exposure, changes in the surroundings/tree position/clients  tolerance/aversion to risk etc

 

If the remaining stem wall is within limits and there's no indications of buckling/kinking, don't worry about it. Do you think that the tree is producing new wood at a quicker rate than the internal wood is losing strength?  Signs of vitality? A good canopy only says that there is good hydraulic function (which is in the outer circumference of the stem and being added to/replaced annually, it's not always a good indicator of structural strength.

 

If you're struggling to reach a conclusion that you're confident with, try to get someone more experienced to look at it with you, if nothing else you'll learn something (everyday's a school day) and there's nothing wrong with saying "I don't know", I say it regularly

 

Good luck.

 

[fagus]

Yep, water cavities work.

Gary, good explanation;  better than mine.