Identification: black staining butt rot in a black oak

Discussion in 'Fungi, Lichens and Slime Molds' started by lord andrew barham, Jun 21, 2009.

  1. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    On East 7th just up from Commercial Drive, one of the boulevard trees was felled recently. I took the trouble to examine the stump and the chunks trunk which had been bucked up into firewood sized logs (which I can't help but feel is a waste of a potentially valuable resource, since we are no longer allowed to burn wood in Vancouver).

    The stump was clear with no evidence of infection that I could see: the wood was even coloured, of that reddish brown characteristic of black oak, and firm and hard. A cyclist who alighted nearby, upon my questioning him (He lived in the house adjacent to the felled oak.) informed me that the city had cut it down because there was evidence of a fungal infection on the outside of the trunk. I examined all the logs as best I could, but the only fungal evidence I could find was the usual lichens found growing on many of our mature boulevard trees.

    I didn't have time to continue my examination of the tree's remains. However, I returned the following day and made a more detailed examination of the cut up trunk. I observed on most of the cross-sections, black staining. The black staining was in the heart wood, although I did see small (less than 1 cm) circles of black staining just beneath the cambium. The other stains were fairly large, irregularly shaped, but inconsistent. By this I mean that the pattern of staining on one end of a log was different from the pattern on the other end. Sometimes the patches of stained wood were closer to the edge, other times, in or close to the centre.

    I scratched some material off from one of the stains. It was dry and granular/powdery, with a textured like burnt sawdust. It had no detectable aroma (though proximity to Commercial Drive, with all the cars and lorries roaring by constantly, exuding exhaust fumes might have masked any fragrance that I might otherwise have been able to detect). Underneath where I scratched, the colour was lighter, suggesting that the staining might only be surface deep. I wondered if it might be an artifact of the felling process caused by an overheating chainsaw.

    A couple of days later, I returned with a mallet and chisel and chopped out a couple of samples. (If there is anyone out there in the ether who can analyse these, would be happy to pass them over.) The first sample I removed from the place where I had scratched at the surface with my fingernail. The staining, contrary to previous experience, did penetrate deeper into the wood (deeper than the cuts I made), but the wood from the removed sample seemed to be firm and otherwise healthy.

    The second sample I cut out from a different section. This sample was wet and somewhat spongy, a much stronger indication of a butt rot. However, most butt rots, in the absence of external injury to the stem, originate in infected roots. (Recollect that I saw no evidence of injury or infection on the outside of the logs.) The only black-staining agent that seems to be able to penetrate healthy, uninjured stems, so far as I have been able to find out, is Phytophthora ramorum, a water mould that has so far been found only either in Europe or California (with one report from Oregon). It also causes lesions in the stem which ooze black, tarry exudates – however, this occurs when the infection is in or has penetrated the cambium. None of the other potential candidates seems to adequately fit the symptoms I've so far observed. These include the Armillaria species complex (formerly Armillaria mellea), Ceratocystic fagcearum (restricted to the Eastern United States and Texas), Innonotu dryophilus, and Laietiporus sulphureus. All of these are capable of infecting the butt or stems without infecting roots first, but only if there is an injury large enough or deep enough to penetrate to the heartwood. Additionally, the black staining in red oaks (Black Oak is now classified within this group instead of, as formerly within its own group.) evinces a radiating pattern as the infectious agent spreads through the rays of the wood. The black staining on the specimens observed was patchy, but uniformly dense and coloured in the patches.

    Any suggestions as to what agent is responsible for the unusual staining would be appreciated.

    A cou
     
  2. C.Wick

    C.Wick Active Member

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    Welcome to UBC....
    Do you by any chance have photos to help us first? I'm a horrible one for trying to understand all the 'black staining here but not here, small spots and big spots' (i'm a horrible interpreter sometimes, forgive me). It's also 4:30 am and I really should be asleep.
    Also, is this oak the Quercus ellipsoidalis?
    An interesting find... http://www.inspection.gc.ca/english/plaveg/pestrava/cerfag/tech/cerfage.shtml
    refers to Ceratocystis fagacearum in Canada?
     
  3. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    Black Oak usually means Quercus velutina, but it may refer here to California Black Oak Quercus kelloggii. Neither is native to Vancouver, but both can be grown there successfully.
     
  4. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    I thnk it's Quercus velutina – the eastern species rather than a California species. This is based on the assumption that all the Black Oaks on East 7th between Commercial and Victoria are the same species including the one that was felled. I base this on the shape and colour of the leaves of the remaining trees.
     
  5. Frog

    Frog Contributor Forums Moderator 10 Years

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  6. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    than ks – will contact them and have a look at the table
     
  7. fish dr

    fish dr Active Member

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    Knowing Vancouver as I do, my first suspicion would be that the tree was in front of the yard of someone influential who wanted it gone. But your mention of the heartwood stains complicates that simpler assumption.

    If it is a saprophyte instead of a pathogen of only live trees, you could send me a few chips, I could try to grow it on agar, inoculate grains and spawn them to hardwood chips (I hope cherry would work). It could take a few months, but once it had used up the substrate it could be apt to fruit. It sounds like a lot of trouble, it's not. I am standardly doing all this daily growing edible woodloving mushrooms.

    Additionally, you could send chips to the Pacific Forestry Centre in Victoria or UBC. I remember hearing one of the two (?!!) was able to do DNA testing for as little as $8 a sample. They would have to be interested of course.

    Perhaps easier, and likely quicker would be to call Van Parks and Rec and speak to the city arborist. They would know why they think they cut the tree down.

    I admire your diligent curiosity.
     
    Last edited: Jun 21, 2009
  8. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    I would be happy to send you the samples, or, if you're in Vancouver, bring them to you. They are currently sitting in a jar. If you need fresh samples, I'm sure I could chop some new ones out.

    I had thought of calling the city – but figured it would tax my patience. I don't do telephoning very well at the best of times, and do the modern multiple menu being put on hold and transferred around even less well.

    ps – I did actually talk to the bloke who lived in the house beside where the tree once was, and he was even more annoyed and cynical about it's being cut down than I was.
     
    Last edited by a moderator: Nov 24, 2009
  9. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    Have looked at the BC govt website, and like every other website I've so far looked at, can't find anything that adequately matches what I've observed.
     
  10. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    I reply to C. Wick, the fact sheet cited at the following address http://www.inspection.gc.ca/english/plaveg/pestrava/cerfag/tech/cerfage.shtml#tphp
    is one that i have already read. Although it is a Canadian Govt web publication, I couldn't find any reference to the organism Ceratocystis fageocereum being found in Canada. They do list all the American states where it has been observed however, and obviously, because of the close proximity to the border of some of them, there are grounds for concern that it might get into this country. I reread the article just to be sure I hadn't missed something, and I must say that the pattern of staining shown does look quite similar to the staining seen on at least one log. If this is the case, then it may well represent not only the first known instance of C. fag found in Canada, but also it's spread to the West. Certainly important considerations.

    Of interest to Fish Dr, it gives detailed instructions for the cultivation of the fungus from infected wood chips, as well as morphological information to enable its identification.
     
  11. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    These days, you should be able to drop them an e-mail, surely?
     
  12. lord andrew barham

    lord andrew barham Member VCBF Cherry Scout Maple Society

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    I suppose – if one knows who to email. I don't even know which Dept. is responsible for maintaining our boulevard trees.
     
  13. fish dr

    fish dr Active Member

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    Google search: Vancouver and "city arborist":

    Paul Montpellier, Vancouver's city arborist.

    Vancouver Park Board (the Street Trees Division and City Arborist)

    Good luck.
     

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