Question
Several surface roots (6 to 8) were cut on our oak tree.  I know this can be harmful for the tree.  What can we do now to hopefully save the tree?  I live in Arkansas.  

Answer
It depends on how big is the tree, the spread of the crown (foliage), the size of the roots, the depth of the cut and how close to the tree trunk the roots were cut. The overall concern is the amount of the root system that was cut. The root system extends out beyond the dripline of the foliage maybe another 1/3 the width if the crown. The key is not cutting more then 20 percent of the root system. If you draw a circle on the ground around the tree where the outermost edge of the foliage extends (dripline) and then cut this circle like a pie where the roots were cut and this area is not more then 20% of the circle them the tree will show little effects from the root cutting. Anything above the 20% you can see die back in the foliage crown.
 The root are in the first 2 feet of the soil so if the cut was not two feet deep then all the roots in the area were not cut.
 The closer you cut to the tree trunk the larger the roots are and the likelihood of a bigger percentage of root have been cut. The larger roots also give the tree an anchor against winds.
 The only thing that can be done is cover the exposed roots and water as you would a newly planted tree. Water the area with the cut roots daily when it does not rain for a couple of months. This will stimulate the growth of new roots in this cut area.
I know this is a long answer but without seeing the tree and the area cut it is hard to give a short answer. If you are still not sure I would recommend that you call the Ark. State Forestry Commission and ask one of their Foresters to come out and take a look at the tree and the cut. They can advice you if they think there will be a problem. You should be able to find the number in your local phone book.