Kveldssanger

Hah! It's literally rammed with information. Absolute wall of text in places, though paragraphed very well into digestible snippets. Few typos I noticed thus far and an incorrect Darwin quote, though as it's all from Davis' own notes it's darn impressive.

16/08/15. Fact #8.5. Building on the above a little, though nonetheless as a tangent, Europe has so few tree species as tree populations could not retreat southwards as the ice sheets encroached into their territory, given the east-west running mountain ranges that are the Alps and Pyrenees, and the area that is now the Mediterranean Sea. Because of these blockading landscapes, tree diversity is rather low within Europe, when compared to the Americas and Asia. The UK's plant diversity is even more impoverished as when the ice sheets last retreated 12,000 years ago, the subsequent rising of sea levels bridged the gap to mainland Europe. Thus, only species that had colonised during the 6,000 years after the ice caps began to retreat are found today - any others that may have potentially once again reached these shores (I suspect sweet chestnut, plane, holm oak, etc, though definitely Norway maple and larch) were barred from doing given the mass of water in the way. Source: Davis, M. (2015) A Dendrologist's Handbook. UK: The Dendrologist. Building on this, I read somewhere that the 'bog oaks' of the Channel area showed that the Channel was once heavily 'treed', and would therefore have facilitated succession into the UK from mainland Europe.

If you do, try and get the TO on side. I do imagine that, especially if you offered to do it, there may not be an issue. This tree is clearly important at least historically, so its retention in a manner as close to it currently exists as possible is crucial, as I doubt there is any desire to rekindle past management practice from what was likely once wood pasture of sorts.

Absolutely look to install some fencing and put some signs up warning people of the presence of an old tree - if the tree currently resides by a path, would fencing extent out to the path on the one side and out further on the other sides (assuming the path isn't moved)?. Be careful with signs however as they can unfortunately attract vandals who think it's 'cool' to proceed to damage the tree. I suppose that depends on demographics.

If the path can be moved, that would be the best thing to do. Trying to undertake any sort of significant works to this tree, which has developed its own internal equilibrium over many years, will likely unsettle it to the point it wouldn't recover desirably. As a lapsed pollard (it appears) there's an issue with future branches failing due to weight and internal cavitation beneath, so perhaps consideration into selective reduction of particular branches may be possible, though if you can eliminate the hazard by simply moving the footpath, I would pursue that instead. If money isn't an issue, consider supporting some of the limbs with cables, props, etc. Take a look at these (PDF) publications courtesy of the ATF: Ancient and other veteran trees: further guidance on management Veteran Trees: A guide to good management Veteran Trees: A guide to risk and responsibility

16/08/15. Fact #8. A step back in time with this one courtesy of the very recently published A Dendrologist's Handbook. During the Carboniferous Period some 345-280m years ago, the continent of Pangaea began to drift northwards from its southern hemisphere origins, and also began to pivot 30 degrees to the west. Giant insects developed, amphibians evolved further and reptiles became more land-based. Plants were reproducing in an alternating manner of asexual and sexual methods across different generations (spores and seed respectively). Equisetum plants (includes Horsetails) became huge, forming Calamites in damp, swampy areas, and forming Cordaites (that had pollen sacs and ovules at branch tips - later forming the first conifers, such as ginkgos, during the Permian Period 280-225m years ago) in drier areas. Clubmosses grew to 30-45m in height. All of this development was fueled by the equatorial climate induced by the drift northwards of Pangaea, particularly at the northern-most end of the super-continent. Coal measures were thus formed very readily from such large plants in what now constitutes Northern Europe (given this segment of Pangaea was first to travel over the equator), once the sea began to engulf the swamps of massive clubmosses, semi-composting them and later compacting them down with silt and clay to form lignite, and eventually forming coal under continued compression events. It took 20m of rotted 'forest' biomass to produce a 1m-thick coal measure, so given many European coal measures are hundreds of metres thick, the length of time required to create such coal measures would have been hugely significant. This also adds significance to our eagerness to burn such stored coal, releasing carbon that has been locked away for hundreds of millions of years in mere decades. The southern area of Pangaea (Africa, Australia) contained smaller plants and thus smaller coal measures, only beginning to lay down larger coal measures (that never amounted to the extent of the earlier coal measures, as the steamy swamps that produced the huge clubmosses and subsequent coal measures no longer existed due to climate change) much later once the southern segment of Pangaea did reach the equator (during the Cretaceous and Tertiary Periods) when plants had evolved to develop roots and reproduce sexually via seed. Evolutionary-speaking, the development of reproduction via seed was critical to the survival of plants long-term, as germination could be delayed until conditions were desirable. Source: Davis, M. (2015) A Dendrologist's Handbook. UK: The Dendrologist.

A little side-fact that I just came across whilst reading. Thought it best to share for its sheer obscurity. 15/08/15. Fact #7.5. When the Ancient Woodland Inventory (of the UK) was being compiled, it was initially done with tracing paper and coloured pens, only later shifting to digital (during the late 1990s, when GIS became readily available). Very quickly it was noticed that errors had crept into the data (for obvious reasons), so these were corrected, though more interestingly the change in true magnetic north from when the sites were mapped by hand to when they were transferred to digital had meant that many of the plotted woodlands did not overlay as precisely as necessary. Only when GIS further advanced (in 2003), allowing for precision mapping that accommodated the change in magnetic north, did the boundaries properly align on the digital version overlaying a recent aerial photo. Source: Goldberg, E. (2015) The UK's Ancient Woodland Inventory and Its Use. In Kirby, K. & Watkins, C. (eds.) Europe's Changing Woods and Forests: From Wildwood to Managed Landscapes. UK: CABI.

The good old Yggdrasil, eh!

Had a walk today and found these: A fine example of I. hispidus on ash: A tiny F. hepatica on oak, rather oddly positioned on the stem from a tiny wound: Some desiccated F. hepatica, I believe: A slightly larger L. sulphureus on an oak just close by: And some fine standing oak deadwood - plenty of larval galleries, ants, etc: David - would you consider the reason behind the L. sulphureus I shared yesterday being so large and 'textbook' be due to the host being dead, and thus the fungus can readily allocate resources to fruiting without having to worry about any sort of combat with other fungi (given host-specialism in heart rots) / the tree's active life processes?

Ah sweet - cheers for that. If anyone has anything to add to anything I say, or even has an update on newer information (some of my books are 10-20 years old and thus there may be some more recent developments) then do say. If there's any desire for a particular type of fact, again let me know.

15/08/15. Fact #7. The traditional view of mycelial fungi is that the development cycle can be split into two stages: vegetative and reproductive. The former relates to the mycelial spread within the host and the latter the production of sexual or asexual structures that produce spores. However, a more contemporary approach to discerning the development cycle of fungi reveals four distinct stages: arrival, establishment, exploitation, and exit. Such development stages are considered to be triggered by the changing conditions of the substrate (such as drying, cell degradation, etc), as in meeting the changing conditions the fungus must adapt its own behaviour (dubbed 'functional modes') to successfully persist within the host. Curiously, a fungus can compartmentalise itself so that, at different stages of decay within the same host, it adopts a different functional mode. Each mode is briefly described below: (1) Arrival: two known mechanisms exist: arrival as propagules (airborne and seemingly only favourable when localised conditions are optimised at the arrival surface - good supply of nutrients, a good microclimate, and a lack of competitors), or arrival as migratory mycelium (contact of an infected host to a non-infected host, such as with H. annosum and A. mellea). (2) Establishment & exploitation: three principal concepts of this mode are understood: the fungus must successfully gain access to the host and begin to command available resources; the fungus must begin to successfully convert potential energy resources into actual energy sources, and; the fungus must successfully 'wall-off' an area to resist against competitors or the host tree itself, or in turn have a rapid exit strategy (panic fruiting on the wound surface or within the inside of the hollow(ing) host, for example). (3) Exit: in the rawest sense, exit can be achieved either through the formation of reproductive structures or by the outgrowth of mycelium (relating back to the arrival strategies). The efficacy and extent of the exit mode is dictated by two factors: the extent to which resources are re-allocated from the mycelial biomass within the wood structure to the biomass of external structures, and; the effect of the environment on the form these exit structures adopt. At a slight tangent, the r-K continuum further dictates exit strategy, with r-strategists (Deuteromycotina, Zygomycotina) taking a more rapid, economical stance to reproduction (not developing massive or durable exit structures), whilst K-strategists (Ascomycotina, Basidiomycotina) limit commitment of non-reproductive biomass, though also possess greater ability to develop exit structures that persist and are thus durable and do so at more 'fixed' stages. Within the continuum, certain species do however hold the ability to possess more than one mode of exit (such as with F. hepatica and L. sulphureus having the ability to develop either as a basidiospore on primary fruiting structures and as a conidiospore on auxiliary structures). Source: Rayner, A. & Boddy, L. (1988) Chapter 5: Development Cycles. In Fungal Decomposition of Wood: Its Biology and Ecology. UK: John Wiley & Sons. I learned a lot with this one!

Thanks for the correction! Indeed that chicken of the woods is very intriguing. Never seen such a bulky one before.

Got a ton of snaps today. Wonderful day topped off by the best chicken of the woods I have ever seen. Absolute cracker. Hope you all share my absurd levels of enthusiasm on these ones! The birth of F. hepatica inside an old oak in a car park of all places (had been watching the tree for a good month expecting something, and here is the reward) - shows a good 4th wall in the CODIT model: Some cracking fresh F. hepatica with the fallen bracket from last year below, guarded by a bunch of furious ants that I might have accidentally stamped on clearing a few nettles!: The best example of L. sulphureus I have ever come across on an oak log (someone give this thing a medal): A follow-up of my first G. resinaceum snaps 10 days later: Many D. quercina (some desiccated) on a similar oak log near to the L. sulphureus: A partially-uprooted A. pseudoplatanus that has developed into a sabre tree with a little harping too:

14/08/15. Fact #6. Severing roots out of purpose is hardly ever something that an arborist would find desirable, though it nonetheless occurs rather commonly where construction takes place and also where abatement of nuisance is practiced for terrestrial encroachment of a tree. Current research indicates that the severance of roots is, by-and-large, highly variable. In one instance, root severance may have very little adverse impact on tree stability, though in other cases may weaken a tree by over 20%. Roots that 'guy' a tree (exist uphill of the trunk) or reside on the outer (tension) side of a lean are ultimately far more crucial to the tree than the majority of the remaining root crown. Severing roots may not therefore simply be a case of "no more than 25% of the root crown can be lost", as context is key. If a guying / tension root is severed, the impact upon stability will be far more significant than if a compression root (or even multiple roots) is lost. Statistically (from a survey done on willow oak), when assessing strength loss due to buttress root severance at the base of the trunk, a loss of 50% of the buttress roots will reduce the mechanical required force to move the tree one degree by a third (33%). However, due to the oscillating nature of winds, such a loss in root mass will result in a much higher decline in strength, particularly for larger trees with more wind sail (or where root decay is evident). Interestingly, such a loss can at times be achieved simply by severing a single guying / tension root, which suggests that trenching may be of particularly significant adverse impact to trees in more exposed sites. Additionally, research indicates that severing roots closer than at a radius three-times the trunk diameter is not recommended, as tree stability declines significantly once this threshold is surpassed. Source: Smiley, E. (2009) Root pruning and stability of willow oak. In Watson, G., Costello, L., Scharenbroch, B., & Gilman, E. (eds.) The Landscape Below Ground III. USA: International Society of Arboriculture.

Is there anything putting you off doing it with Tree Life?

For those who are looking to read more about armybloke's comment about acacias and their ant-exciting chemical secretions (as well as the effect of browsing on spinescence), attached are some references. Symbiotic ants as an alternative defense against giraffe herbivory (1992).pdf Relaxation of an induced defense after exclusion of herbivores (1998).pdf Effects of simulated shoot and leaf herbivory on vegetative growth (2001).pdf Effects of natural and simulated herbivory on spine lengths of Acacia (2003).pdf

Fly agaric is unmistakeable. Beautiful thing. Amethyst deceiver is rather distinct too, given its colouration. Not so refined on my boletes and such, though I'll be out trawling woodlands and some more rural areas around south east Essex soon looking for anything that isn't common earthball.

Glad you like the thread, Paul. It's always great to learn - as I come across fungi I'll post them here. My mother said she spotted what sounds like P. squamosus on a dead oak, so I'm going out Saturday to get some photos (I guess it's good family members are being my eyes where I am not able to be, for fungi!). Great time to use my bird-watchers binoculars too, as it's high up in the crown. Will get some snaps of that.

I'm going to go for (they're all, I believe, from the order Agaricales, so that narrows it down): Bottom left: Amanita muscaria. Resident of pinewoods (pine and birch too). Top right: Suillus sp. (or Boletus sp.) - as it's pretty massive and looking at the pores I'm going to go for the latter genus. Top left: Laccaria amethystina , given the colouration. Looks a little faded, however.

I swear I read it in the AA fungi booklet. Definitely a 'proper' publication. I was going to suggest that perhaps it wasn't that rare given I have see it three times now, though that could have just been dumb luck. Perhaps not, it seems. Nice pun. I'll have to go through my fungi book by Roger Phillips and see if I can find that one on the ash stump.

Interesting! Thanks. That's very innovative.

I'm posting this one early as it's so bleedin' awesome (and I might be busy tomorrow)! 13/08/15. Fact #5. The relationship between plants and mycorrhizae is a complex one. Perhaps one of the more intriguing forms of the relationship is when plants utilise their mycorrhizal networks to communicate (or eavesdrop) with one another. Certain plants, such as the tomato, are able to identify when a 'connected neighbour' has come under attack from a pest or pathogen and subsequently begin preparing for a similar attack themselves. In one study, the tomato plant anticipated attack of a pathogen fungus by elevating levels of resistance to such pathogen fungal attack, simply through the mycorrhizal network shared between the infected host and healthy one. Bean plants have also showed similar behaviour to tomatoes. A study that looked into aphid attack on bean plants identified that healthy neighbours of infected specimens connected by the same mycorrhizal network began to synthesise and emit volatiles that repelled aphids and attracted their parasitoids - even before a single aphid had come into contact with the healthy specimens! As mycorrhizal networks may span large distances, sometimes much greater than distances feasibly covered by airborne signals, the potential benefits for such communication may be significant. Furthermore, such research likely acts as a proxy indicator for trees and their communication methods via mycorrhizal networks (which are perhaps even more complex). Research is however lacking, though I'm sure there's a PhD thesis just waiting to be undertaken for this exact topic. Source: Karban, R. (2015) Plant Sensing & Communication. USA: University of Chicago Press.

Haha that one is definitely true.

Ugh... I do detest fungi foragers, too. Yes you may be able to eat some of them, but that doesn't give you the right to purge an area of fungal diversity!

Cheers! Apparently it's rare in England as a fungal species and it shouldn't be removed unless for scientific purposes.