(Arboricultural-styled) 'Fact of the Day'

[armybloke]

This little snippet would be appropriate for this thread - being as it is a fact. Apologies if I have already missed this post elsewhere.

 

There are roughly 3 trillion trees on Earth — more than seven times the number previously estimated — according to a tally by an international team of scientists. The study also finds that human activity is detrimental to tree abundance worldwide. Around 15 billion trees are cut down each year, the researchers estimate; since the onset of agriculture about 12,000 years ago, the number of trees worldwide has dropped by 46%.

 

“The scale of human impact is astonishing,” says Thomas Crowther, an ecologist now at the Netherlands Institute of Ecology in Wageningen who led the study while at Yale University in New Haven, Connecticut. “Obviously we expected humans would have a prominent role, but I didn’t expect that it would come out as the strongest control on tree density.”

 

Nature doi:10.1038/nature.2015.18287

 

Crowther, T. W. et al. Nature http://dx.doi.org/10.1038/nature14967 (2015).

[Kveldssanger]

Blimey. Great bit of info!

[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.

 

cant get hold of him tonight - will try tomorrow

[Kveldssanger]

No worries. As and when.

[Kveldssanger]

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.

Edited September 9, 2015 by Kveldssanger

[Acer ventura]

09/09/15. Fact #29.

 

 

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.

 

[/i].

 

Hi Kveldssanger

 

Nice idea for a thread. Though I appreciate the Lynne Boddy paper you cite is a great and a useful source, can I just point out your paragraph about ‘Panic-fruiting’ has nothing to do with it.

 

I’m aware the term ‘Panic-fruiting’ seems to have gained common currency on Arbtalk, that Tony Croft has tossed the term around a lot, and he seems to have become colonised by it via Gerrit Keizer. I have major issues with it both as a misleading term, and as a concept. I’ve have not yet seen any peer-reviewed evidence for ‘Panic-fruiting’, and would be grateful if someone could point me in the right direction if there is some.

 

There was a lengthy debate on the UKTC about it in involving Tony, and I’ve included a link to one of my last comments to give you a taster of my misgivings.

 

RE: Panic fruiting of fungi- stuff of nonsense?

 

Sorry to bomb your thread with this, but I’d rather ‘Panic-fruiting’ didn’t end up like a Dr Fox’s Brass Eye ‘fact’ about paedophiles having more genes in common with crabs than they do with you and me. As he memorably reasoned,

 

"Now that is scientific fact—there's no real evidence for it—but it is scientific fact"

 

Cheers

 

Acer ventura

[Kveldssanger]

I greatly appreciate the comment. A reminder for me to be acutely aware of using 'slang' - so to speak - when describing a science.

 

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?).

[Mark J]

Excellent thread. Thanks.

[Eddy_t]

I greatly appreciate the comment. A reminder for me to be acutely aware of using 'slang' - so to speak - when describing a science.

 

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?).

 

 

It's more of a mouthful than 'panic fruiting', but like panic fruiting on trees, it's a reactive fruiting to less favourable conditions where the tree may die, so it tries to continue its genes.

[Kveldssanger]

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.