ash failure

[the verminator]

Hi all

 

we had this ash failure to sort out today. in the close up picture it looks like wall 4 of codit forming? this would suggest that the tree partly failed a while back and has been waiting to go for a while? no fungal brackets etc visible, just a weak union i think. any thoughts appreciated. thanks, Gary

 

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc6/199751_10151050041068068_127505461_n.jpg

 

http://a1.sphotos.ak.fbcdn.net/hphotos-ak-snc7/486494_10151050038593068_1104585763_n.jpg

 

http://a6.sphotos.ak.fbcdn.net/hphotos-ak-ash4/376811_10151050990203068_2061580315_n.jpg

[Alinicoll]

Looking at the pictures I would say the included fork had already given way a bit and had put on a small amount of callus growth. Not really the same as wall 4 as I understand it but the doesn't `t mean it didn't `t also form a wall 4

[Alinicoll]

It`s probably worth adding that this kind of growth callus is probably also present on the other half of the inclusion too. This could have lead to Mattheck`s `big ears` if the crack had continued to open and close or `little ears` if it had successfully sealed itself. In this case obviously it did not. As you have observed the failure may well have no major decay fungi involved, simply a mechanical weakness.

[the verminator]

Thanks for that reply, roughly how long would it take for that amount of callous to form?

[Alinicoll]

It`s a bit difficult to tell from a photo but that doesn't look that old to me. Perhaps a season or two.

[the verminator]

Ok thanks for that

[Beezy]

I agree with all the above, my five pence worth....

 

We have had a few 'unseasonal' emergency call outs over the last couple of weeks, trees are currently in the fullest amount of leaf during their seasonal cycle, your one looked ivy covered too, adding to the overall weight loading and wind sail effect.

 

Very erratic weather patterns also, very wet, then very warm and dry has also casued a few failures too.

 

Your failure was a historical weak union, that had put on a small amount of woundwood or callous growth, but not enough to develop the elephant ears and bring the union together sufficiently to prevent a mechanical failure.

 

Cheers Beezy

[openspaceman]

It`s probably worth adding that this kind of growth callus is probably also present on the other half of the inclusion too. This could have lead to Mattheck`s `big ears` if the crack had continued to open and close or `little ears` if it had successfully sealed itself. In this case obviously it did not. As you have observed the failure may well have no major decay fungi involved, simply a mechanical weakness.

 

Have a look at this one, the callus looks at least 3 seasons, wood peckers have been having a go so I suspect a summer bat roost.

 

splitoak | Flickr - Photo Sharing!

 

It's a surprising one as the tree is in a wood of self sown oaks, average 50 years old and vigorous, on a steep bank. The lever arm isn't that long, about 10 metres and the split is 5 metres up, so 15 metres overall. I cannot decide if it's the tougher densered whorled growth at the two branch unions below that has prevented the crack from propagating. Because the target occupancy is high I think it will have to go.

 

I'm particularly interested in comparing these fork failures with similar failures at the stool of coppice growth because logically a branch union should be stronger than the union between two copice stems merging at the base, they have little opportunity to grow tension wood to resist a tear out.

[the verminator]

thanks for the info all

 

catweazel, if braced would the oak not heal in time? just curious

[Alinicoll]

Have a look at this one, the callus looks at least 3 seasons, wood peckers have been having a go so I suspect a summer bat roost.

 

splitoak | Flickr - Photo Sharing!

 

It's a surprising one as the tree is in a wood of self sown oaks, average 50 years old and vigorous, on a steep bank. The lever arm isn't that long, about 10 metres and the split is 5 metres up, so 15 metres overall. I cannot decide if it's the tougher densered whorled growth at the two branch unions below that has prevented the crack from propagating. Because the target occupancy is high I think it will have to go.

 

I'm particularly interested in comparing these fork failures with similar failures at the stool of coppice growth because logically a branch union should be stronger than the union between two copice stems merging at the base, they have little opportunity to grow tension wood to resist a tear out.

 

It certainly does look like the whorl has stopped the split. It`s surprising how long things can hang on sometimes. Presumably if the tree was open grown it would have split out all the way a while ago. Interesting photo