What does tree pruning do to the roots?

[nailer]

`If you prune a tree back to a certain size the roots will die back accordingly.`

 

Is that more or less true?

[Mesterh]

That was the thinking but I think it may have changed a bit.

 

I think it was to help with root damage, insurance, subsidence probs etc.

 

No doubt if you prune back hard then some roots may become redundant and therefore die off but who can say how much and from where etc.

[Mark T]

Not exactly answering your question but this may be of use...

 

http://www.oca-arb.co.uk/pub/june2005.pdf

[john@arbtech]

That was the thinking but I think it may have changed a bit.

 

I think it was to help with root damage, insurance, subsidence probs etc.

 

No doubt if you prune back hard then some roots may become redundant and therefore die off but who can say how much and from where etc.

 

I must agree with mesterh, the roots (to a certain extent) are independant and will still grow, depending on the extent of pruning, as epicormic growth shoots up after pruning?

[nailer]

Thanks guys, that`s helpful. Based on that article the current thinking seems to be that reductions won`t make any difference after the first year of pruning. The tree won`t kill off its own roots because it`ll need them again to start growing faster, and with bigger leaves, and with more stomata. Thus, the transpiration rate / taking-up of water out of the shrinkable clays will soon be no different than if the tree had been left alone. Only option is to fell it. But not to worry because there`s loads of trees.

 

What would you think to this statement:

`Providing the tree reduction is not too drastic, say 25% maximum, if you prune a tree to keep it at a certain size, the roots will generally be kept in check. Imagine a bonsai tree - it does not matter how old the tree is, as long as the tree is kept trimmed to a certain size, the roots will remain in its dish. They will not carry on growing down under the foundations of your house!`

[Peter]

You could always add root pruning to your list of services.

 

Why would a tree root want to grow under the foundations of a house anyway? Can't be much water under there.

[nailer]

I don`t want to get into root pruning! Forget about foundations then, what about a shed or a fence?

[alliaria]

Hi,

As I understand it, the roots are totally dependant on the products of photosynthesis for food, so there may be an initial effect due to lack of food, but this is short lived as the subsequent regrowth has larger leaves and therefore transpiration and photosynthesis rate increases.

[Bundle 2]

"`Providing the tree reduction is not too drastic, say 25% maximum, if you prune a tree to keep it at a certain size, the roots will generally be kept in check."

 

B2- I think you can perhaps say this.Without going over that which has already been stated, or attempting to deconstruct the stages through which both the tree and pruning must have to progress, you just need to know that there will be a balance to which the plant aspires...min waste of energy for max effect so to speak...ie Root to shoot ratio.

Smaller shoot mass = related smaller root mass...

Cheers 4 the link btw

[paradise]

Won't it partly depend on how much stored energy the tree has? I would think if it had a lot of energy reserves it could maintain the roots for a while (with some loss of disposable fine roots) and try to recover its leaf area. If it was low on reserves it would not be able to recover leaf area so quickly and would not be able to support the roots while in recovery, so the roots would likely die back a bit.

Seems reasonable anyway, even if I just made it up