Avoid soil compaction, only use hand tools to remove the last ten inches of fill. Soil compaction is by far the most common way construction damage can harm and kill trees. Tree roots need crumbly, well-aerated soil to grow and to obtain oxygen, water and nutrients. Lacking good soil aeration, roots suffocate and tree health declines. Leaf wilt, early fall coloration, branch die back, overall decline and tree death are symptoms of soil compaction.
Most soil compaction is caused by construction equipment.
One pass by a heavy tractor or truck is all it takes. Compaction can also be caused by stockpiled building materials and excessive foot traffic. By controlling equipment traffic patterns, soil compaction can be prevented. Reroute traffic away from trees, put up protective fences and signs, mulch the equipment routes with several inches of wood chips and locate materials storage areas well away from the dripline of the trees you want to save. Compaction can be partially alleviated by drilling a series of two inch diameter holes to a depth of 12 to 18 inches.