KTSmith

Please excuse me if this is now a gratuitous response, but those prominent little black bumps on the branch in the second image are likely fruiting structures of some sort of xylariaceous fungus. I'd be a fool to name it on the basis of this image, but I'd start with one of the Diatrype. In any event, it likely is a secondary invader, perhaps of already killed tissue. But no, they have no direct relationship to DED. Some in the xylaria family are primary pathogens to some degree and all are good opportunists, though!

That is a good book to be sure. In looking over my copy, much of the information that I use from the text is in the research papers by the authors and their students, and most of the papers are available from their research websites I don't know the state of inter-library loan in the UK, but my local library (two doors down from my home) gets me most anything for a week or two loan, from libraries across the country. Then I can copy what I need, under our "fair use" for scholarship provisions of our copyright law. Sure photocopies or scans are not nearly as rewarding as having the whole book, but if it is otherwise unavailable, well, the information should still be available. But maybe I misunderstand. The above would be of no interest for the book collector, but for the practitioner, it might work. As for reprinting...I expect that Wiley-Interscience would need an updated text, which would be quite a task!

Could it be a sooty mold associated with Cypress aphid? There likely wouldn't be any aphids on the dead parts now, but you might see some at the margins of the killed/living tissues. Or the aphids from early summer may have entirely moved along, leaving the foliage and branchlets with impaired translocation capacity. Then, late summer heat and dry conditions can make evident the earlier infestation, even without the aphids. In that scenario, the sooty mold is more an indicator of the insect than a primary pathogen.

Although famously not an insect expert, I'll hazard to suggest that the pest is one of the Lecanium "soft scales". Usually, predation by native biocontrol agents (lacewings, ladybugs) keeps the numbers down, but you've got a pretty strong infestation going. Chemical treatments are available, but are usually applied earlier in the season when the immature crawlers are up and about. Often the adults (what you have pictured) have laid their eggs and are dead and brown by the time they are noticed. I don't know what is labeled for use in the UK for tree scales, but check at your local supply store. Also, the picture does demonstrate how to dwarf an oak by keeping the root system constrained. Perhaps that was the intention!

Excellent case study, Guy. Shows the importance of good record-keeping and follow-up. I'd also agree that knowing the precise species of Armillaria would help in the fungal ecology story, but for practical tree care is much less important. I know folks use some field characteristics to differentiate Armillaria, but the folks in my shop only believe in genetic sequencing, given variation and integradation of macro characters. Please don't argue with me on that, that's not my fight!

JosephD, tree species will make a big difference. Stumps of decay-resistant walnut, at least the heartwood core, will last significantly longer than non-durable birch. Seasonality of cutting has been shown to affect the vigor of stump or root-system sprouts after felling the mature tree, at least in the US. As to the "why"...the tree, as a total organism, wants to survive. If "wants" is inappropriate language, then the tree's metabolism is programmed to survive. Remove the stem and foliage and the root system or stump will try to rebuild. Of course, some species, including most conifers, don't readily sprout or don't sprout at all in nature. Some species' metabolism invests in setting a store of seed rather than bothering with sprouting. Here in the States, red maple is a prolific sprouter, but the closely related sugar maple sprouts reluctantly, if at all. So it's not just a question of the differentiation of large groups. Sure, helping out the decay fungi with nitrogen should accelerate decay. I'm a bit dismayed at using petrol as herbicide, but perhaps I'm just naïve!

Thanks Guy for posting those references concerning the veteran stage of tree ontogeny. On first reading of the original post, I thought Fredward was asking about physiological/anatomical shifts from seedling--sapling--pole-stage--sawtimber--overmaturity/decadence...Yes, quite right, those terms are from commercial forestry and extractive timber production. I'm not trying to be provocative, just to point out that those stages are generally the province of silviculture rather than tree care or nature conservation. They don't have to be restricted to silviculture and timber production, though. Nursery production also concerns itself with some of the earlier transitional stages. Excellent question from Fredward. I don't know of a single work that sketches ontogeny from beginning to end--or to immortality if that is the case. Silviculture and traditional physiology can contribute to an understanding of some of these transitions, say from a seedling's tap root to a more spreading system (perhaps) as trees grow in size and age. My personal interest has been in the shift from the plant being mostly foliage (by mass) to being mostly wood. Branch shedding in native stands as the canopy closes is definitely an interesting story and the source of one view of proper pruning. I'd be happy to be shown to be wrong about the lack of a single guide covering Fredward's topic!

Seems like Kveldssanger has already ordered the code for cultivated plants, but in case others are interested, order details are here: International Code of Nomenclature for Cultivated Plants | International Society for Horticultural Science and the bibliographic information is here: INTERNATIONAL CODE OF NOMENCLATURE FOR CULTIVATED PLANTS edited by C.D. Brickell and others. Published by the International Society for Horticultural Science (ISHS) as Scripta Horticulturae Vol. 10, 204 pages, October 2009 [iSSN 1813-9205 - ISBN 978-90-6605-662-6]. Keep in mind that the code of nomenclature is just that, how are names coined, conserved, accepted, rejected, etc. It is not a list of "approved" names as such. As to how to cite cultivars properly, that is in there. If I have a need in an article or presentation to give a formal citation, I just look at back issues or previous presentation and see the editorial preferences for that venue. It can vary!

Thanks Guy, that makes sense to me! In my shop, when we speak of columns, we mean columns of discoloration and decay. I knew that was not what you meant! I don't know much about the tracing, I hear folks refer to it.

Yes, that is a lot of bracket. Maybe more important than the shear mass or volume of fruiting body is the degree of arc or circumferential extent around the base of the tree. I accept the original description that the crown looks OK, but the sapwood is dead and decaying inward from the points of attachment of the brackets. Or that's my bet!

Thanks Guy for emphasizing the structure which is present, rather than what is "missing". I'm with you there. What are the two columns to which you refer?

Can anyone point me to a comparison of this new book with the 1996 "Body Language of Trees: A Handbook for Failure Analysis (Research for Amenity Trees)"? Yes, if you get a chance to see Prof. Mattheck at a workshop or conference, do so...especially if you can be with him in a small group setting, with wood samples or better yet--living trees!

The effects of the sugar/molasses/corn syrup and related amendments are on the soil microflora, of course. With molasses, you are usually adding a small of sulfur which in small amounts can be helpful, especially for bacteria, less so for fungi. Although trees use sugar in various forms all of the time, they don't assimilate or take it up from the soil. So that makes comparisons on effects difficult in that it is tricky to evaluate the relevant soil microbe communities (nitrogen fixers, de-nitrifiers, potential mycorrhizal partners, etc.) Sure some folks have great results. Hard to see that it could be damaging short of really massive dumping and messing with the osmotic potential. Not likely, but some folks figure "if a little is good, then more must be better!"

As touched on above, the International Code of Botanical Nomenclature (ICBN) determines the rules for the valid publication of a species name for plant and fungi. The ICBN is revised at the Botanical Congresses that are held every five years. The particular "current" version of the ICBN is referred to by the city at which the Congress was held. The current version is the Melbourne Code which superseded the earlier Vienna code. http://www.iapt-taxon.org/index_layer.php?page=s_ICBN However, the ICBN determines the process for valid naming but does not dictate what is or is not the correct name, with a very few exceptions. For example, when I was more involved in formal taxonomy of fungi, a description or "diagnosis" of the fungus was required to be in Latin. More recent versions of the ICBN have dispensed with that. The "correct" name is the earliest valid publication consistent with the taxonomic concept of the user. The Congress can dispense an exception to that "earliest" requirement if doing so would reduce confusion. That last bit of taxonomic concept requires some scholarship, but is open for those willing to bear the burden. As for the other elements of what makes for a valid publication of a "new" name, I could go on but I've probably lost everybody by now. The key point for this thread, perhaps, is that No central authority rules on the name to use. Scholars present arguments and validly (we hope) publish names that fit with current concepts of what makes a critter related to another critter. Those concepts are in flux due to the input of molecular genetics. It is up to the users of those names, primarily other academics, to see what makes useful sense through time. Many of the "new" genera of wood decay fungi were erected from the 1880s-1930s, and only now has the generational shift caused them to be commonly used and be part of the assumptive world. So, unless I am willing to wade into the academic fray with my own scholarship, I'll choose an authority for a group which could be a textbook or institution and use the names they use.

Thanks for the info on fire in your community landscapes. I have active research projects on compartmentalization in rural / wild forests...I will need to extend that to housing estates! Actually, I'm sure we have those sorts of fires in the US as well. People do what they do!

The good discussion prompts a novice's question, Do you folks see much fire injury in your work? I know fires both accidental and intentional do occur. In my first look at the picture, I thought immediately of basal mechanical injury from some machine, but sure, fire fits.

Over here in New England, I'd reckon that to be the first nubbin of a Ganoderma.

Thanks for the additional detail. I reckon your interest is not so much historical but predictive to help guide current or near-future treatments. That poses some challenges in that most big/old tree injections that I've worked on from the wound response perspective did not involve the currently available injection technology or chemical formulations. So it's hard to make "apples to apples" comparisons!

There has been a real resurgence in interest in the US in tree injection of systemic chemical treatments for pest and disease control. The Tree Care Industry Association (TCIA) of the US hosted a series of "Tree Injection Summits" across the country over the last year. Those sessions gave treatment developers and vendors a chance to interact with the community of arborists engaged in injection, or considering injection as a treatment tool. I was on all of the presentation programs to speak about my concerns about the response of trees to injection injury. All of that being said, no one spoke of differences in large trees vs. small trees or old trees vs. young trees. We did speak of big differences with respect to tree vigor and amounts of available sapwood and the importance to inject under environmental conditions that favored good uptake and distribution of chemical treatments. So I am somewhat cool towards systemic injection, but they can have a place as a legitimate treatment. Injection tools probably should not be the first tool out of the toolbox, though! TCI Injection summit recap 2013.pdf

Keep in mind that the brackets are simply reproductive structures. Even species of Ganoderma, which can produce perennial brackets, aren't bound to do so! Brackets are shed while the fungal thallus is happy working away on the cell walls within. Also, Ganoderma can grow in culture and dead wood, excised from the tree. The infection may be well-compartmentalized, but that is not the explanation for the dead or shed brackets!

Of course, both illustrations are static 2-D representations of 4-D processes. My quibble with the lower image from Prof. Mattheck is not the image but the labeling. The "bifurcated" stem wood is only bifurcated after adding a heavy mechanical stress. It is not at all bifurcated in the happy, healthy tree. The "branch tail" is the stemwood with the direct connecting flowpath into the branch. Calling it a branch tail is fine, I know what is meant, it's just stemwood. Perhaps we (including me) are trying to put to fine a point on these useful, but limited, cartoons.

Pretty classic Kretzschmaria deusta. I know, that name still seems unfamiliar. I learned it first as Hypoxylon deustum, then Ustulina deusta. But in following the rules of the nomenclatural code, it does indeed fall into Kretzschmaria, which was published as a valid genus in 1849, although deusta wasn't recognized as that being in that genus until 1970. Oh well, more than you wanted to know!

Ha, Ha, I thought I replied to above an hour ago, but I must have mashed it up. I don't see where the problem is. Consider a healthy stem and branch system, no cankers, burls, scars, etc. Topologically, the vascular cambium is a single, continuous layer of cells covering branch, stem, (and roots...). Regulated by hormones in a manner not completely understood, the VC of the branch begins division earlier in the growing season than the VC of the stem. The orientation and differentiation of the daughter xylem cells is a function both of the orientation of the VC and of the cascades/pulses of those hormones. The annual ring of the branch completes formation followed by the annual ring of the stem. But throughout this process, the VC remains a single, continuous surface always to the outside of the derivative daughter cells. OK, perhaps this will help: Visualize the lower surface of the angle formed by the stem and branch. Some portion of the VC surface will produce branch xylem early in the growing season and stem xylem later in the growing season. There is no "branch VC" getting covered by stem xylem. It's one, continuous surface. So does that make sense?

Duncan Slater and I had an extended, collegial, and useful discussion on his contention that the principal difference between co-dominant forks and branches was one of relative size of the members, what is sometimes referred to as aspect ratio. I respectfully submit that is nonsense. My point of view was published some time back in Arboricultural Journal and is also linked here: Letter to the Editor [response to "Towards a new model of branch attachment" by D. Slater and C. Harbinson]. I think that was presented and discussed in Arbtalk at that time. Does that argument still need to be made? If so, I'd pull up my notes from the earlier exchange, but a fresh thread might be in order. Or perhaps the British point of view has this all sorted out and there is no need for discussion. This is all pretty "old news" to me, and perhaps to the rest of the community as well! The Shigo 1985 branch attachment paper is attached. Shigo Branches 1985.pdf

So is there a question on the table? The most recently posted images to this thread simply show branch stubs or what an American lumberman would call "pin knots". Normal branches in every way. They died (due to shading, probably) and were "shed" in the sense of the breaking of symplast connections, yet remained attached. Successive years of vascular cambium growth of the stem encased them. The encasing wood is appressed to the branch stub but not confluent with it. The branches are, as always, only attached at the base. Or have I missed the point entirely or is there no point of discussion on the table. If so, a fresh thread might be in order. This thread had been asking for Shigo's 1985 attachment paper. It's readily available from any good library or interlibrary loan, but I'd be happy to send it along. Perhaps I already have! This thread, like me, is a bit long in the tooth.