curious ash damage

[Jack.P]

On this subject.i was looking at a few mountain ash /Rowan the other day which looked to have very similar issues like the early signs of the ash dieback .just interested  to know does it spread to just the native ash? 

I often find ash saplings in peoples garden which they want gone so got a growing collection in pots .not planting them out for a while though 

Edited June 17, 2020 by Jack.P
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[Tilio-acerion]

19 hours ago, Gary Prentice said:

What about 'Betty', discovered a few years ago 

 

Jokes aside, the media coverage read 'tolerant' or something like. A quick search this morning just shows that there doesn't seem to be that much up to date information available. 

 

Around 2014 I read that something like 90% of Denmark's trees were infected. It would be interesting to see what their situation is now. Do you think that if highly tolerant trees interbreed there may be some likelihood that in time a properly immune genotype (is that the term?) would occur? 

I far as I am aware, even with tree 149 ('Betty") in the Nornex trials, it wasn't considered 'resistant' to ADB, just that it appeared to have a very high tolerance; as it was growing within a heavily infected stand which was full of badly affected trees yet she was classified as having a very low damage score.

 

What Allan Downie of the project stated is:

 

"I believe that we have generated the fundamentals required to select and potentially to breed trees with enhanced tolerance to the disease. What I mean by this is not ‘resistance’ in the sense that these trees will eliminate the pathogen. Instead, what we probably have found are genetic markers and metabolite profiles that are associated with enabling ash trees to live with, and suppress growth of (rather than kill) the pathogen. One of the advantages of such ‘tolerance’ or ‘low susceptibility’ is that it has a much better chance of being sustained over long periods of time than is the typical gene-for-gene resistance that is used in annual crops and which can so easily be broken by small genetic changes in the pathogen."

 

In 2014 I visited a site in Lithuania (which along with Poland) is where ADB is first thought to have become established in Europe circa 1991. There were big prime specimen ash growing which had endured the disease for nearly 25 years** and had been considered as highly tolerant, yet had just started to decline and were also infected with secondary Armillaria infections. The lesson was that, even trees which at fist appear highly tolerant can succumb to ADB overtime. Bear in mind that they are suffering repeated infection pressure annually and add in all the other compounding factors which contribute towards their overall health / ADB disease susceptibility.

**We are way, way off this point yet in the UK so I treat all the news stories of "resistant" trees being found, with a very healthy dose of sceptisim?

 

As for the future of ash, then maintaining these trees which are highly tolerant and affording them every opportunity to successfullly naturally regenerate is going to be what is key! It'll be pointless having highly tolerant ash saplings that are getting hammered by deer.

Edited June 18, 2020 by Tilio-acerion

[Tilio-acerion]

11 hours ago, Tregroes said:

Thanks for the information. Is there any method of control, or a way to contain the spread? This is a plantation (small) of similarly aged trees. I can't find anything useful online, mostly a lot of taxonomic abstracts. I can't find information on the life cycle, or even whether the adults fly or not. If the adult climbs the tree, and I knew when, I could try sticky bands as for fruit trees. A method of control for the emerald borer I've seen is for soil drenching with pesticide that the tree roots take up, but it was a US site and we don't have access to the chemicals they have there --or I don't.
Anyway, I take it this is a late tree now and should be removed. Is that right? Any other info or links you can suggest?

Yes they fly. This is useful (https://www.forestresearch.gov.uk/documents/6467/FCBU008.pdf) and confirms my understanding of bark-beetles within the UK context, eg they’re very much a secondary issue generally. So on this basis I’m not sure why you’d wish to attempt controlling them, And importantly they’re a native species and part of the ecosystem. 

 

Edited June 17, 2020 by Tilio-acerion

[daltontrees]

On 17/06/2020 at 18:05, Jack.P said:

On this subject.i was looking at a few mountain ash /Rowan the other day which looked to have very similar issues like the early signs of the ash dieback .just interested  to know does it spread to just the native ash? 

I often find ash saplings in peoples garden which they want gone so got a growing collection in pots .not planting them out for a while though 

Mountain Ash/Rowan is not an Ash and cannot be affected by ADB. ADB affects several species of Fraxinus, none immune so far but some with useful tolerance.

[Tregroes]

22 hours ago, Tilio-acerion said:

Yes they fly. This is useful (https://www.forestresearch.gov.uk/documents/6467/FCBU008.pdf) and confirms my understanding of bark-beetles within the UK context, eg they’re very much a secondary issue generally. So on this basis I’m not sure why you’d wish to attempt controlling them, And importantly they’re a native species and part of the ecosystem. 

 

Thanks very much for this, Everything one ever wanted to know about the things. Almost; the sections of bark missing from the tree, is that by birds hunting the grubs? I couldn't see anything about that in the document.

 

[Tregroes]

Thanks to everyone for the feedback, including all the bits about ADB as I had many of the same questions

[slack ma girdle]

young ash tree, about 10 years old, a proud survivor of the die back, in full leaf last year and formed buds. Buds began flushing this year but halted, perhaps because of the drought here in Wales and the Southwest or for some other reason. A few days ago found this damage, which is mostly around the branching areas but not exclusively. I've looked at emerald ash borer info, which was my first thought, but they talk about "serpentine channels" under the bark made by the larvae and I don't see any of those. Wondered if the damage caused by a bird looking for grubs, but which grubs? The stems and twigs on the tree are still flexible. There is insect brash below but actually I think that's wasps taking advantage of the bare wood. I didn't see it initially. Any ideas?

Squirrel

[Tilio-acerion]

16 hours ago, Tregroes said:

Thanks very much for this, Everything one ever wanted to know about the things. Almost; the sections of bark missing from the tree, is that by birds hunting the grubs? I couldn't see anything about that in the document.

As the bark necrosis caused by the beetle larvae appears recent - indicated by the surrounding bark appearing to be live and unaffected - these localised patches of missing bark certainly look like a bird has been seeking the larvae out.

 

P.16-18 Natural enemies ?

 

 

This is what can happen with a mini-population explosion (of beetles) and subsequent avian feeding frenzy on the increased food source.
 

Edited June 19, 2020 by Tilio-acerion

[Gary Prentice]

On 17/06/2020 at 15:22, Gary Prentice said:

Do you think that if highly tolerant trees interbreed there may be some likelihood that in time a properly immune genotype (is that the term?) would occur? 

Coincidentally this popped on another forum;

'I have received this request from Dr Jo Clark of the Future Trees Trust, for
help identifying ash trees that may be tolerant to ash dieback for inclusion
in a nationwide study aimed at producing tolerant ash seed.

Dr Clark is the lead researcher at the Living Ash Project, a Defra-funded
project collecting together ash trees that appear to be tolerant for further
testing and, in the long term, to produce a breeding population and a seed
source for tolerant ash. She is interested in receiving reports of ash trees
that appear to be tolerant, for inclusion in the project. At this stage she
is only asking for reports from expert practitioners who are skilled in
identifying ash and ash dieback (i.e. not the general public), to ensure a
high quality of reports. 

 

The Living Ash Project is identifying, securing and testing trees that
appear tolerant to ash dieback.  We are keen to work with industry to secure
additional trees.  Leaving tolerant trees, or trees that shows significant
signs of healed lesions, can help natural selection ensure ash is around for
many years to come.  Additionally, we can capitalize on this and bring
forward material for reforestation more quickly if we bring tolerant trees
together in a breeding population that can be monitored and improved over
time.'

'Basic site details: we are interested in trees, particularly in woodlands,
where there is plenty of evidence of high ash dieback around.  Single
isolated trees are not of interest at present, due to possibilities if
disease escape.'

 

Seems like a plan.