Statically effective root plate radius

[daltontrees]

This is a bit of an anoraky question.

 

Recetly while reading up on root decaying fungi, I came across a reference in Fungal Strategies of Wood Decay in Trees "Where fruit bodies appear, the stem radius should be determined, and the statically effective root-plate radius should be deduced from this...".

 

Well two/three questions really. Is the term "Statically effective root plate radius" a recognised one, does anyone use it and is there a precise definition anywhere? The supplementary question is then how to determine it as a function of the stem radius. A wee formula like RPA?

 

If anyone can tell me or point me in the right direction I would be pleased to hear.

[Gary Prentice]

Think it stems from matthecks work, a calculation using radius to calculate the root or soil depth necessary to prevent soil shear

[daltontrees]

Think it stems from matthecks work, a calculation using radius to calculate the root or soil depth necessary to prevent soil shear

 

Spot on, I went straight to 'Body Language...", opened the book randomly at page 188 and there it was. Not a formula or a calculation but reference to a plotted curve whereby the stem radius can be related to the rootplate radius e.g. 10cm = 130cm, 20cm = 230cm, 40cm = 300cm, 60cm = 360cm.

 

Anyone actually use this?

[AA Teccie (Paul)]

Hi Jules...and as you well know I'm no anorak...well, okay H&S wise maybe.

 

I have heard this referenced before, albeit a long time ago, when one of the street works contractors got wise to it and used it as mitigation for root damage / severance within the RPA...when we saw it. Their argument was it's not within the critical rooting zone as far as tree stability is concerned and hence our grievance was overstated / exaggerated in terms of any damage within the RPA could destabilise the tree.

 

Other than that very limited reference I cannot offer nothing more I'm afraid (every little helps I hope )

 

Regards, and have a good weekend.

Paul

[sloth]

Spot on, I went straight to 'Body Language...", opened the book randomly at page 188 and there it was. Not a formula or a calculation but reference to a plotted curve whereby the stem radius can be related to the rootplate radius e.g. 10cm = 130cm, 20cm = 230cm, 40cm = 300cm, 60cm = 360cm.

 

Anyone actually use this?

 

I have once a couple of years ago to assist me in assessing the stability of a silver maple which had been deeply trenched around.

To be honest it was buggered anyway, and used only to help illustrate this point to those responsible.

I couldn't at the time see how to use it to great effect if only say 2 opposite or right angled sides had been trenched, like is seen on roadside verges etc - another arboricultural area for further research!

 

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[daltontrees]

Ta Paul and Kevin. So SERPR is not going to pass into common usage in the industry any time soon. The context of my initial look at it was Meripilus, and all bets are off there since detect healthy looking roots right across the SERPR and then find out the next day when teh whole tree blows over and the root plate is sticking its bum in the air that said healthy looking roots are hollow on the underside.

 

Anyway, I will hang up the anorak on this subject (unless anyone wants to go on). It is interesting just to note that for the 60cm radius the SERPR of 360cm is 6 times the stem radius. This size of tree is close to the 1.25m diameter maximum for RPA calculations, where the RPA radius would be 1500cm, which is 25 times the radius. 4 times the SERPR. There we go, 4 times the radius needed for support is needed for nutrition.