Kveldssanger

I made a wordpress blog (so I can collate more of my stuff into one central area) - https://arboriculture.wordpress.com/ I will use this to document facts and other bits (such as pictures, and so on), though my facts will all be principally posted here for as long as I do post facts (which should be for a very long time), as will lots of cool snaps I take be posted here. I suppose it just gives stuff a wider audience perhaps, and as I will continually link back to here hopefully, if I do get any traffic, people will then visit here.

Trametes 'overgrows' Armillaria by sheer exclusive rate of mycelial growth (it's a faster grower), though I don't think the author suggests Sparassis crispa 'overgrows' Armillaria, but instead suggests that compounds 'toxic' to Armillaria (secreted by Sparassis crispa) hinder growth of Armillaria. Yes, perhaps the wrong use of the word by the author. Unless a Sparassis' antifungal compounds actually degrade the Armillaria, and the Sparassis then consumes the degraded Armillaria mycelium for its own use. But my understanding was that the Sparassis simply can amass a larger territory when combating Armillaria, by sheer virtue of its more expansive arsenal of antifungal secretions over and above sparassol.

The book says, and I quote: "Cauliflower mushrooms (Sparassis crispa) secrete the antifungal antibiotic sparassol, or orsellinic acid, which is also produced by Armillaria fungi. Mushrooms are naturally immune to their own antifungal secretions and are unaffected by the same secretions from competitors. However, cauliflower mushrooms also secrete other antifungal agents that allow them to parasitize other Armillaria mushrooms. This suggests an antifungal strategy for foresters to consider. In principle, mushrooms like cauliflowers could defend forests against blights by Armillaria; innoculating stumps at the perimeter of an Armillaria blight could limit further spread of this destructuve forest disease." So the answer is.... I don't know. I read it as the fungus parasitises Armillaria, in the sense that the compounds secreted attack Armillaria, making the existence of it alongside Sparassis crispa untenable. The author shows how, when both are grown in the same pertri-dish, the cauliflower fungus will vastly outweigh the honey fungus in terms of capacity of the petri-dish occupied.

27/12/15. Fact #109. Some weeks ago I was asked to write a post on controlling parasitic Armillaria spp. colonisation, and did write up a response with some sourced material. I have however just come across something else, which is very interesting to say the least. Sparassis crispa (the cauliflower fungus) and Armillaria spp. secrete the same antifungal and antibiotic compound (known as sparassol or orsenellic acid). Because fungi are resistant to their own secretions, if both aforementioned species of fungus exist within an area, neither will be affected by the compound. However, Sparassis crispa also secrets other antifungal compounds that can parasitise Armillaria spp. What this means is that foresters may utilise Sparassis crispa - in the form of incoluating stumps with its spores - in regions peripheral to where Armillaria spp. are known to be blighting. This could potentially limit any Armillaria spp. spread, and reduce the financial impacts associated with timber damage upon a to-be-harvested forest. Trametes versicolor may also readily out-compete Armillaria spp, for reasons associated with the rate of mycelial growth (turkey-tail will simply 'over-grow' honey fungus). Source: Stamets, P. (2005) Mycelium Running. China: Ten Speed Press.

27/12/15. Fact #108. We often see parasitic fungi (such as honey fungus) as bad - perhaps because they kill prized ornamental trees, reduce the (financial) productivity of a forest, or make trees more of a hazard to human existence. More intrinsically however, parasitic fungi are good, and in fact are crucial to the healthy existence of an ecosystem. The author of this source asserts that parasitic fungi filter-out weak specimens and, at times, entire weakened ecosystems. This enables for stronger individuals (and groups of plants) to come in and take the place of the (now dead or dying) weaker ones. Without this constant destruction and renewal, and alongside the recycling of all the nutrients and minerals contained within the decaying weakened individuals, ecosystems would cease to function as they must. In artificial environments this concept may not apply as robustly, though even when we are looking at ornamental trees that are struggling, what can we assert as a result of their host role for parasitic fungi? Probably many things, including poor genetic stock of the individual (a nursery / breeding issue), and improper planting of species (an individual of the wrong species planted in the wrong place; thus causing it to be weak), to name two. Source: Stamets, P. (2005) Mycelium Running. China: Ten Speed Press.

Really awesome pictures here! I wonder what their watering regime is like, and if they incorporated stormwater management systems to retain water and irrigate trees throughout the summer via an underground network of pipes. And do those chestnuts have leaf miner or blotch? I am referring to the last picture in the first post.

Almost as good as a turkey roast, eh!

25/12/15. Fact #107. The response of a tree - in terms of cambial growth - to insect defoliation will vary greatly, with some variables including insect species, tree species, tree vigour, and defoliating extent. For example, one single defoliation event upon a gymnosperm may kill it, though defoliation of a similar extent upon an angiosperm or deciduous gymnosperm will likely not lead to death. This is because they can rapidly replace foliage lost (and they do this every year as the seasons change, by default). However, two severe defoliation events within a single year may well kill angiosperms and deciduous gymnosperms, as may a single extensive defoliation event not necessarily kill a coniferous gymnosperm - different species of Pinus will vary in their ability to withstand huge losses in foliage, for instance. Defoliator species will also play a role in the effects of defoliation upon cambial growth. Some insects only gradually remove foliage whereas others do so rapidly, and some insects may only feast upon the latest year's worth of growth and others older growth. There really are a huge amount of variables. To give an example, we can look at Choristoneura fumiferana (eastern spruce budworm) and see how it will consume only the newest year's foliage. This consumption strategy leads to cambial growth remaining largely unimpacted at the base of the tree during the first year of defoliation, whilst the cambial growth in the crown is greatly impacted. This reduction is cambial growth is principally down to the reduction in supply of carbohydrates, though other drivers also exist (such as a drop in the supply of hormonal growth regulators). In fact, insect defoliation effects will typically manifest within the crown first-and-foremost (perhaps for obvious reasons). At times, there may be a lag period of a few years before the radial growth in the lower trunk is negatively impacted by insect defoliation The timing of defoliation also determines how cambial growth will be affected. In early summer, before shoots have fully extended, defoliation is more likely to kill gymnosperms, though by mid summer (once shoots have fully extended from the buds) defoliation is less impactful. In Pinus echinata, for example, early summer defoliation lead to a drop in radial growth during the current growing season and a subsequent recovery of radial growth within the following growing season, whilst late summer defoliation lead instead to a reduction in cambial growth in the following year (growth in the same season was not impacted). This is because most of the radial increment had already been laid down by late summer. Source: Kozlowski, T. (1971) Growth and Development of Trees - Volume II: Cambial Growth, Root Growth, and Reproductive Growth. USA: Academic Press.

Hah! There are plenty. Got my eyes on a few books from Summerfield - Rethinking Ancient Woodlands being one of them. In time...

When people buy you tree books as presents you know you talk about trees too much.

Just checked the sloe gin - it's ready. Have a good one all.

I shall be horifically festive and post a fact tomorrow, so for all of you here who are relying on me posting a fact so to not have your Christmas ruined, fret not.

24/12/15. Fact #106. Xylem conductivity is not constant. Conductivity will vary depending upon leaf water potential, and the associated effects of cavitation in the water column that is being (principally) pulled through the xylem. In fresh xylem of the current growth year, the transition between a fully-functioning xylem and a highly embolised one is very short - only small changes in water potential may mark the difference between the two. If left un-checked, any such embolism at an undesirable water potential may lead to "runaway embolism" (as in, the xylem rapidly becomes wholly lacking in function). Because "runaway embolism" is not to be desired, plants will invest heavily into producing cavitation-resistant xylem tissue. Varying significantly between species and individuals however (photosynthetic rates, genetics, environment, etc), the quality of the xylem from an embolism-resistant perspective depends upon the amount of carbon invested in producing effective walls and membranes for the xylem conduits. Increased resistance to cavitation also means the xylem vessels have reduced hydraulic conductivity (they cannot transport as much water per hour). Because of the above (demanding) factors associated with producing robust xylems, many plants will lurk at the threshold of what is 'safe' - as in, hydraulic conductivity will be at a level very close to the 'tipping point' that would induce cavitation, so to maintain maximum efficiency. Therefore, stomatal regulation of minimum leaf water potential is crucial to maintaining this fragile hydraulic 'optimum' of the xylem. Source: Franks, P. & Brodribb, T. (2005) Stomatal control and water transport in the xylem. In Holbrook, N. & Zwieniecki, M. (eds.) Vascular Transport in Plants. USA: Elsevier.

23/12/15. Fact #105. These last few days have been a little tumultuous, so pardon the lack of posts. A short and snappy fact here, though nonetheless awesome. A Ganoderma applanatum sporophore of a large size can release up to 30,000,000,000 (30 billion) spores per day, or 5,000,000,000,000 (five trillion) per year (from late spring to early autumn). It is suggested that such a profuse outpouring of spores into the atmosphere is necessary for the continuation of the species (as the odds of a spore germinating on a suitable substrate are low). Source: Stamets, P. (2005) Mycelium Running. China: Ten Speed Press.

I am still pulling thorns out of my hand from getting to those brackets, so will probably not go back to grab a sample unless I have a brushcutter with me. If it's this or Ridigidoporous the consueqneces are largely similar in terms of potential risk (of course, one is suspected white rot and the other a brown rot), though will seek to obtain a slice to check it when the tree works are done. I just read JFL's little document on the fungus, and he states similarly to your suggestions. I will go speak to the guy and suggest to get the ash reduced at the very least. Else, a monolith would retain the habitat value in part. Thanks.

Cheers, David. Would you suggest significant reduction work here, or even monolith the ash? It's certainly well into maturity. I am concerned that the brackets are on the compression side of the lean, and there's a very significant load upon the region. If it fell, it's go plum over the footpath. This one isn't for the LA I work for, but I know the people who own the tree and I need to inform them.

Pretty keen on a positive ID on those first images of what I think is Perenniporia fraxinea, as such a diagnosis will condemn the tree to a serious reduction I would expect.

Front cover of the 2016 Stihl calendar, there.

Hahah I know what you mean on that one. Hey, it's good for fungal diversity!

20/12/15. Fact #104. Drawing attention back to fact 2 about branch failures in wind storms, I am following up with root failures in wind storms. Interestingly, though perhaps expectedly, similar wind speeds are required to initiate windthrow as a result of the failure of roots, during a survey on 113 trees following Hurricane Fran in 1996 (74 of whcih were windthrown). When wind speeds exceed 50-60mp/h, roots even with only minor defects have a significantly higher chance of failing. Where defects are more severe, it will require a lower wind speed to induce failure, or even perhaps gravity in itself will induce the failure. The study did also highlight that where high winds follow heavy periods of rainfall, the risk of windthrow increases. Risk increases yet further if the tree has a full foliage crown and the soil drains poorly in the locality to the tree's rooting environment. Source: Smiley, E., Martin, T., & Fraedrich, B. (1998) Tree root failures. In. Neely, D. & Watson, G. (eds.) The Landscape Below Ground II. USA: International Society of Arboriculture.

...if only the upcoming post would be that poetic! So I went out today to survey a single ash tree for my Lvl 4 course, and as always had an eye out for any fungi. I know the area quite well, so I wasn't passing by any new territory, though it appears I had been only half paying attention before now as the sheer amount of fungal activity I saw was incredible. I hardly walked by any mature trees (must have been 15 at most). So I start walking down a narrow bridlepath that runs to the side of a field on the way to the ash tree and noted that, because of the blackthorn having lost its leaves for the winter, I could inspect the butts of all the mature ash trees that lined the bridleway. Lo and behold... Some (what I intially thought was Ganoderma but I doubt that because of no brown spores) suspected Perenniporia fraxinea at the base of a large ash tree (because of the white spores). The sporophores are on the pathway-side of the ash, and the ash has a very marked lean in the same direction. I had to, after putting my bag down, barge my way through some unforgiving blackthorn for close-up shots, and snagged an expensive hoodie countless times. I'm sure Blue Inc. will have another sale soon enough...! Having quite literally only just picked my stuff back up, my attention is turned towards a three-stemmed ash tree. Through the very dense blackthorn and hawthorn I notice a silhouette of what could only be Inonotus hispidus, though it was surprising how low down it was - perhaps only 30-50cm up from the base. FInally I get down to the ash I want to inspect, that is (from noticing earlier in the autumn) riddled with Inonotus hispidus throughout and has, thankfully, been pruned in the last 2-3 years. Its seriously exposed setting and the fact two informal pathways run beneath it makes it somewhat of a hazard. I hope the ash is on a cycle of maintenance. Many cavities also exist on the trunk and principal limbs (what is left of them!). But I also spot this little duo of Ganoderma or Perenniporia fraxinea sporophores at the base, whilst scrambling around to count the number of fallen Inonotus hispidus sporophores. And so I do my survey on the tree, and depart. However, instead of walking away back from where I came from, I decided to look at the other mature ash very close by that had also been pruned or monolithed (the tree not pruned here is an oak). And I saw these beauties! On the first monolith, what I suspect is Perenniporia fraxinea (the thing was bleedin' massive - that folder is A3 size!) and some Daldinia concentrica to go alongside. And on another but more ivy-clad monolith, some... Desiccated Polyporous squamosus: Suspected Perenniporia fraxinea: And then to top it all off, on the way back I spotted these three Inotous hispidus sporophores in the lower crown of an ash. On the bottom one we can observe a sprout emanating from just above the sporophore. Plenty more pictures, but these are the good ones. Enjoy. And give me a heads up if I have mucked up the ID of any of the fungi in any pictures!

Root:shoot ratios. There will be a lag time of varying degrees, though reduction of the crown will impact upon root growth / death. And vice versa, of course.

You're right, Mick. Pollards are lovely and, when done right and by skilled arborists with a knowledge of working pollards, they really do have a character that is unrivalled. The comment further up about people removing the nuckle concerns me. Yes, there is decay within the area, though the build-up of carbohydrates local to that knuckle keeps the tree vigorous following pruning. Remove the knuckle; remove a dense abundance of sugars. Only where there is serious risk of the knuckle failing should it be removed. When we look at old wood pasture, we see how a pollard would be thinned of poles on a routine basis (perhaps every year or two) - not always fully stripped. Below, animals would be grazed - be it sheep, pigs, goats, deer, or otherwise. There is a rich history in pollarding, and it deserves a place on our streets for that reason alone.

A woodland is anything where canopy cover is above 10%, so many pastures are known as wood pastures for this reason. Old medieval hunting parks (and some modern parks) can also be classified as woodland, in places.