On Mon, 19 Jul 2004 15:59:29 GMT, wrote:

On 19 Jul 2004 08:01:02 -0700, (Frank)
wrote:

Is this caused by the roots taking moisture out of the soil?

Yes.
But the tree is also providing shade, thereby reducing the amount of
evapration directly from the soil, so the likely net effect is zero.

Check this link for a discussion of the issue from a decidedly
tree-friendly engineer:
http://users.rcn.com/bobw.enteract/UKSubsidence2.2.html

Since you are watering the soil to avoid too much drying out under the
foundation, you probably do not have to worry about this.

Keith Babberney
ISA Certified Arborist
For more info about the International Society of Arboriculture, please visit http://www.isa-arbor.com/home.asp.
For consumer info about tree care, visit http://www.treesaregood.com/