# The Naked Scientists Forum

### Author Topic: Uprooting a tree  (Read 15112 times)

#### Science Dolt

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##### Uprooting a tree
« on: 02/06/2003 20:50:32 »
My basic question is this:
How much force, in pounds would it take to uproot a tree?

My extended question is this:
What is the correlation of increase of force to the size of the tree?

My situation is this:
For instance, if I know an object weights X pounds, and my backhoe can lift that object, how would I calculate what it would take to move/uproot that tree with that backhoe?

#### NakedScientist

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##### Re: Uprooting a tree
« Reply #1 on: 02/06/2003 21:42:28 »
I think that this (interesting and unique) question is very difficult to answer for the simple reason that trees are all different.

Beech trees, for instance, tend to develop widely-spreading superficial root systems, which oaks often establish a deeper root ball. I don't think you can answer this one simply, but I'll look into it. What do the physics lot say ?

TNS

#### nilmot

• The Riddler
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##### Re: Uprooting a tree
« Reply #2 on: 02/06/2003 22:07:12 »
This doesn't answer your question Science Dolt. Sorry, I'm not a physic person.

I think you are right TNS different types of trees matters.

I was doing the gardening about a year ago (can't be bothered now, Angel do them) and I was weeding and different weed have differernt root system like you said. But sure takes a lot of force to pull them out of soil even if it's just one single dandelion, so I guess it will take a huge amount of force.

I think trees are the same, they adapt for their own surroundings.

Tom

#### Quantumcat

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##### Re: Uprooting a tree
« Reply #3 on: 03/06/2003 06:47:10 »
The mass of the tree does not matter nearly as much as the type of root system. It makes more sense to say the force required per kind of tree, age of tree, and the growing conditions (assuming they are constant).

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#### Science Dolt

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##### Re: Uprooting a tree
« Reply #4 on: 03/06/2003 15:46:53 »
OK, let's say the following are true facts:

1) The tree is old, an oak.

2) It has a root system which is fairly shallow (some roots are at the surface, some 24 in/60cm, maybe as far as 36 in/90cm, but nothing further I could see). The earth around it is packed relatively tightly

3) The circumference of the tree at the base is 10 feet/3 meters

4) The backhoe front loader has a breakaway capacity of 3800 pounds and can lift 1800 pounds

Assuming all constants on the part of the tree, what amount of force can the front loader produce? And would it be enough to push over or uproot the oak? And what kind of force am I using (footpounds?)

Thanks again for the replies!

#### Exodus

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##### Re: Uprooting a tree
« Reply #5 on: 03/06/2003 16:34:30 »
Why chop down such a beautiful old tree? :o(

If it has to be done, wouldn't it be wiser to chop it down then place chemicals on the stump in order to kill off the rooting system?

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#### Science Dolt

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##### Re: Uprooting a tree
« Reply #6 on: 03/06/2003 19:30:51 »
Unfortunately, Mr. Oak is very disease and bug ridden. I was hoping to uproot him and, with the hole that was left behind, transplant from another section of the yard.

The chemicals may work, but I hesitate to use anything even tauted as environmentally safe. I would rather try and physically remove it, making room for a new generation.

Also, I would like to figure out this whole force equation, since my physics knowledge is very limited.

Can anyone with physics knowledge point me in the right direction to try ands figure out necessary force?

Thanks again!

#### chris

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##### Re: Uprooting a tree
« Reply #7 on: 03/06/2003 20:41:27 »
When I used to pull out trees with a tractor at someone's garden (she had an old orchard with elder trees invading) we used to put a long steel hauser round the tree, reverse right up to it and then have a run at it - full revs, high enough gear to get a pretty good pace before the line bit.

Inevitably it took up to 10 goes (with a pretty heavy agricultural tractor) to pull fairly small trees (trunk less than a foot across) out of the ground.

I don't think you'll pull your oak out very easily. The weight of the earth in the root ball alone is greater than the lifting capacity of your machine. You'll need a more powerful piece of kit.

The other approach is to climb up the tree, tie a cable around the trunk at the top, and then pull the tree over, using it as its own lever - the force of gravity will help you to prise out the roots. You'll need a heavy machine though !

Chris

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#### Quantumcat

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##### Re: Uprooting a tree
« Reply #8 on: 04/06/2003 01:30:02 »
Unless it's dead, why kill it????? Oaks take a very long time to grow, you should leave it and try to cure it, maybe placing bug traps on it and going to a nursery to find something to cure it of its disease. If it's dead I guess there's no hope for it but to take it out ... I'm against killing it if it's not already dead

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#### cuso4

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##### Re: Uprooting a tree
« Reply #9 on: 04/06/2003 11:38:10 »
quote:
Originally posted by Science Dolt
.......
Can anyone with physics knowledge point me in the right direction to try ands figure out necessary force?

Thanks again!

I think Dickie might be the man to help you. He's the physics expert here.

Angel

#### nilmot

• The Riddler
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##### Re: Uprooting a tree
« Reply #10 on: 04/06/2003 12:34:41 »
Where is Dickie? He hasn't post any replies for ages.

Tom

#### Quantumcat

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##### Re: Uprooting a tree
« Reply #11 on: 04/06/2003 13:16:06 »
The DickieNappers took him! :-o

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##### Re: Uprooting a tree
« Reply #12 on: 12/06/2003 23:27:10 »
We had a huge, old oak in our yard until recently. It was the best tree. My step-mother is into God-awful crafts. She has these little stuffed children playing hide and seek.(sorry, UK. I don't know the UK term for "stuffed" as in a doll / bear...I know the translation is WAY off.) They are around the tree and oh, so, cute. I made the comment that the little bastards were sucking the life from the tree. Well, they were. She attached the dolls to the tree with brass staples. Brass is an alloy containing copper. Copper will kill a tree very quickly. But those dolls sure are cute!...Mr. Dolt, wanna buy some dolls?
Just thought I'd share that.

#### The Naked Scientists Forum

##### Re: Uprooting a tree
« Reply #12 on: 12/06/2003 23:27:10 »