Root Protection Area questions

[treeseer]

As far as I am aware there is no clear guidance regarding varying RPA for different species.

 

How about UNclear guidance in the BS??

 

There is clear guidance on needed variance for species and condition in ANSI A300; sorreee...

[Treecreeper1961]

Another question I have about RPAs:

 

Bundle planting.

If you come across a tree that appears to have been a bundle planting (multi stemmed, no clear unions above ground or with 2 inches of soil removed, stems tightly appressed against each other but gaps strongly suggesting bundle) how do you assess that in terms of working out an RPA?

 

a)Measure around base of all stems as if a multi stemmed tree or

 

b)Measure stems individually.

 

c)Use of own judgement as to the required rooting volume.

 

Thing is there is massive potential area differences between a and b.

There is no guidance on this in the document or on whether trees close to each other should have accumulative rpas or share each others space.

 

Could really do with some advice on this:confused1:

[Treecreeper1961]

Seems like the accepted solution is to add up the cross sectional area of all the stems and then use the 12x multiplier as per single stemmed trees.

 

That is not really what I was expecting but I guess it makes sense.

 

Any comments???????

[monkeybusiness]

Paul, it depends on the demands. Mainly I had in mind the biological/hydraulic demands, hence the caveat and caution. 9% max. live crown off is a common spec, and I have written 4% too. Reduction is more often targeted to improve symmetry/balance/alignment with structural roots than overall. Crown cleaning is typically done in advance as well.

 

Treeseer - I agree with your take on this, but surely 9% and 4% are way too specific and therefore a little pointless. How can that be measured accurately?