TreeDimensional

bigshea13, don't you folks there get the freeze/thaw thing going on? Or are you speaking of compaction due to use(foot traffic or vehicle). I assume that an air-spade @ 180 psi would need a screw compressor, am I correct?

Gilman has a powerpoint on the benefits of verticle trenching, and it appears to me that if a tree is in an anerobic setting for the roots, the trenching could do nothing BUT good. Coder also went to great lengths to explain that in his part of the world (Georgia), with adequate moisture, you only have to step in the same footprint 3 times before you reach maximum compaction. If I were to adopt this as true, I would have to assume that for the benefit of the trees, I should consider adopting the same policy of prevention for residental trees as I would for tree preservation at a construction site.

In the thread on trees and sewer lines, the process of a tree sending roots into a relatively oxygen deficient enviornment, in the search of water, prompted some additional thought on my part. I remembered that a friend of mine was looking for the tree that caused the sewer line to back up. There was $300,000 worth of damage, and about 75 suspects to look at. In the end they determined that they had found the guilty tree, it was the closest tree adjacent to the trench for the sewer line. I guess that time will tell, but he indicated that when they were grinding the stump, they noticed a more than usual number of grafted roots. Moral of the story, the sewer trench was less compacted (even after 40 years of abuse) than the surrounding soil.

This is the readers digest version, the whole story is better, but this thread has nothing to with genetically identifying the main sewer line instigator, but might be food for thought, OR not.

To answer shea's question: No I haven't used an air-spade, the cost of buying or renting a screw compressor would push the price out of the tree owners comfort zone. Another thing is that if the spade was only for exposing the root flair, would indicate to me that the tree was either planted too deep or some landscape Co. applied too much backfill (grade change). I think there are more productive ways to improve soil structure than blowing dirt all over the neighborhood.