At what level of continuous ground pressure will roots be dammaged.

[Will Hinchliffe]

A drystone wall sited very close to trees. No digging for foundations but what is the maximum pressure the wall can exert on the soil without damaging larger roots that lead to feeding networks.

 

What I really want is a figure with a refference.

 

The Soil is a deep brown earth woodland soil. It is free draining.

 

Any comments gratefully received.

[slack ma girdle]

Are we talking about lots of roots or just one or two ?

[Will Hinchliffe]

Lots of roots.

[Arborist Sites]

I wouldnt worry, the pressure exerted per square inch will be low and lost within the first 4" depth, also as its consistant pressure and not variabble the roots will naturally adapt there growth accordingly.

[Will Hinchliffe]

Thats what I have said in my report but I would like to put some reference to research that backs this up.

[Arborist Sites]

this will be of use for depths etc but there really is nothing much out there on compaction.

 

http://www.forestry.gov.uk/pdf/fcin078.pdf/$file/fcin078.pdf

[Mark T]

Hi mate,

 

Can't give you an exact reference point but my first point of call would be either the Biddle books or Tree Roots in the Built Environment - mine are tucked away in the loft so can't look for you. I wouldn't be suprised if you don't find anything specific to help you as the answer would likely be as varied as the possible soil type. I'd speculate that the actual effect on the root processes would be negligible. - there you are... about as useful as a chocolate teapot!

 

Interesting question though!

[Will Hinchliffe]

From what I have read its all about the bulk density at which roots can survive or penetrate and this is specific to soil stucture and moisture content.

 

The weight of the wall will increase the bulk density of the soil in the upper layers but with depth the load will have less influence on the bulk density of the soil.

 

The soil depth and quality on the site in question will be sufficient.

 

Cool article Arborist Sites. Cheers.

[Johny Walker]

a d6 can sort the job out ,

[AA Teccie (Paul)]

From what I have read its all about the bulk density at which roots can survive or penetrate and this is specific to soil stucture and moisture content.

 

The weight of the wall will increase the bulk density of the soil in the upper layers but with depth the load will have less influence on the bulk density of the soil.

 

The soil depth and quality on the site in question will be sufficient.

 

Cool article Arborist Sites. Cheers.

 

 

Sounds the basis for an interesting research project (does Mr Percival partake here?)

 

I can't offer any 'pearls of wisdom' I'm afraid (but then that's probably no surprise) but on reading the threadth my thought immediatly lent towards gentle (air-spade?) excavations along the line of the proposed wall to expose roots and use a 'pier and lintel' (nearly spelt that wrong and refered you to a type of 'pulse) construction to 'bridge' the roots. Then it wouldn't matter if there's any increase in soil bulk density BUT thsi is probably to much work and inappropriate for dry stone walling.

 

The othert thing struck me is tree species, i.e. London PLane can (nearly) bash its way through concrete so a bit of compacted soil along a specific line is 'easy peasy!'

 

There, any other highly techncial questions I can('t) help with?

 

'D' hat n corner again Paul!!!