(Arboricultural-styled) 'Fact of the Day'

[Kveldssanger]

Just a heads up that I won't be doing a fact today.

[Stubby]

Just a heads up that I won't be doing a fact today.

 

I'm gonna give it a miss also

[Kveldssanger]

Absolutely gutted

[daltontrees]

09/09/15. Fact #29.

 

Sporophores (fungal fruiting bodies) are "the tip of the ice berg" when it comes to the overall wood decomposition process. Quite obviously, the presence of a fruiting body means fungal mycelium is present within the tree, though the number of fruiting bodies should not significantly facilitate with the estimation of the extent to which fungal mycelium may have progressed within the wood. Similarly, the lack of a fruiting body doesn't mean decay is not present.

 

Before sporophores can be formed, the mycelium must have access to "sufficient" resources required for sporophore formation. Further to this, and as established in a prior fact on fungal strategies / life processes, the 'strategy' a fungi adopts (be it ruderal or otherwise) also dictates how rapidly sporophores may be produced. To illustrate this, a tree may be host to two fungal species: A and B. A colonised before B, though B produced sporophores before A due to its 'strategy' being more ruderal and / or because it requires less energy to generate sporophores.

 

Further, certain fungal species don't even need to produce distinct fruiting bodies to propagate. Vegetative spread and asexual sporulation within the vascular system or from internal mycelium (then relying on insects to carry spores - Dutch elm disease?), are two ways in which a sporophore need not occur.

 

It is also important to recognise that sporophore presence does not mean the fungi is 'fit'. Panic-fruiting may be the reason for sporophore formation, in response to undesirable internal conditions (good compartmentalisation and / or lack of food source). A 'bail-out!' approach, so to speak.

 

Source: Boddy, L. (2001) Fungal community ecology and wood decomposition processes in angiosperms: from standing tree to complete decay of coarse woody debris. Ecological Bulletins. 49 (1). p43-56.

 

Note on source - you can pick a copy up (it's a book) for quite good value on Amazon. Got mine for a few quid. The full title is: Ecological Bulletins 49 - Ecology of woody debris in boreal forests.

 

Here's a pico-factoid ona slow-fact day for anyone like me that didn't know what 'ruderal' means. 'The word ruderal comes from the Latin rudus rubble.' (Wikipedia - 5 minutes ago). Ruderal species are the first to colonise disturbed land. It seems to have a slightly wider ecological meaning such as "ability to thrive where there is disturbance through partial or total destruction of plant biomass" (Grime, Hodgson & Hunt, 1988).

[Acer ventura]

 

I paraphrased, and I shall instead quote directly.

 

"Fruit bodies should not be taken as a sign of active / fit mycelium as they may in fact be produced as a response to unfavourable conditions (abiotic or biotic)."

 

How one now defines "response to unfavourable conditions" is open to slight interpretation, perhaps. One could potentially define it as a sort of 'panic-fruiting' (admittedly it is a poor piece of terminology, and perhaps something along the lines of 'strategic fruiting in light of problematic site conditions' would be more appropriate, no?).

 

Hi Kveldssanger

 

So, a fruit body could be produced under favourable conditions for the fungal colony, or unfavourable conditions for the colony. There’s no current way of telling the condition of the fungal colony from the fruit body because there are so many unknown exogenous and endogenous factors that can affect its production. It’s not unlike being given an apple and then claiming to be able to form a detailed opinion about the tree it came from. Worse still, ‘panic-fruiting’ seems to be an increasingly common term to not only draw conclusions about the condition of the fungal colony, but to extrapolate from that as to the structural condition of the tree.

 

With current knowledge, I think the only thing a fruiting body tells us is the fungal colony has reached the bark where it is fruiting from, and there will be some decay. It doesn’t tell us how much decay, and it doesn’t tell about the structural integrity of the tree, or the likelihood of it failing.

 

Cheers

 

Acer ventura

[daltontrees]

Of course. I suppose panic-fruiting is a decent term when explaining to laymen who may not grasp the entire exit strategy fungal species adopt when conditions are less than desirable, though I do admit that for us professionals there's a need to perhaps look beyond using such slang.

 

I agree. The term 'panic-fruiting', while I don't much like it myself, is fine in the right context. But it's not much more anthrpopmorphic than the concenpt of fungi having strategies, which they don't. They perhaps have 'modes' of colonisation, but they don't plan it out. The Oxford companion to animal behaviour (1987), albeit referreing to animals rather than fungi, advised that "one is well advised to study the behaviour rather than attempting to get at any underlying emotion".

 

The lack of a better term that is as acccessible to the casually interested person suggests 'panic fruiting' will continue in use, and if it opens up lines of enquiry the budding (or should that be fruiting?) mycologist will be rewarded endlessly by discovering more and more complexities of fungi that we don't yet fully understand.

[daltontrees]

the only thing a fruiting body tells us is the fungal colony has reached the bark where it is fruiting from

 

Not even that. Some fungi fruit on bare wood.

 

I expect anyone knowing why panic fruiting is not an entirely appropriate term will also know not to draw any conclusion from it. As such, I see harmless currency in the use of the term.

[Paul Cleaver]

Shall do that today, cheers.

 

Let me know what your friend says, too. I'll ask someone I know at the FC direct.

 

My friend says Natural Englands funds have dropped considerably over recent years - 5 yrs ago there would probably have funded the venture but not now.

 

As for available land, apart from the bodies already mentioned, some local authorities may have some land available.

[Kveldssanger]

My friend says Natural Englands funds have dropped considerably over recent years - 5 yrs ago there would probably have funded the venture but not now.

 

As for available land, apart from the bodies already mentioned, some local authorities may have some land available.

 

I spoke to Mark Iley and he has put me in touch with someone who was involved with a project of collecting local black poplar cuttings, though he isn't aware of any large-scale project of collecting genotypes country-wide and planting them together.

[Kveldssanger]

Hi Kveldssanger

 

So, a fruit body could be produced under favourable conditions for the fungal colony, or unfavourable conditions for the colony. There’s no current way of telling the condition of the fungal colony from the fruit body because there are so many unknown exogenous and endogenous factors that can affect its production. It’s not unlike being given an apple and then claiming to be able to form a detailed opinion about the tree it came from. Worse still, ‘panic-fruiting’ seems to be an increasingly common term to not only draw conclusions about the condition of the fungal colony, but to extrapolate from that as to the structural condition of the tree.

 

With current knowledge, I think the only thing a fruiting body tells us is the fungal colony has reached the bark where it is fruiting from, and there will be some decay. It doesn’t tell us how much decay, and it doesn’t tell about the structural integrity of the tree, or the likelihood of it failing.

 

Cheers

 

Acer ventura

 

Great point you make and the comparison to with the apple rings true.

 

If one were to see a lot of fruiting bodies one of two scenarios (off the top of my head) can be expected to have lead to the situation:

 

1. the mycelium has developed so well that not only has it reached to, or near to, the boundary on multiple sides of the tree in multiple places, but it has a significant amount of excess energy it can utilise for sporophore creation as well - all whilst continuing its ascent / descent and radial spread within the tree.

 

or...

 

2. the mycelium is using all the energy it feasibly can utilise for sporophore creation, as the progression within the tree has reached a stand-still (due to effective compartmentalisation of the fourth wall or because of other mycelial networks that have established within the wood), thereby inducing a response from the mycelium to begin 'exiting' the tree and colonisation is, long-term, untenable.