This is an example of soil compaction in an area adjacent to a home site. Compacted soil is hard, largely impenetrable to tree roots, drains poorly, and hold less water than non-compacted soil.
Figure 2, Photo by Bruce Hagen
This a site where new soil was introduced. The new soil had different physical, chemical and biological properties than the native soil on the site. It was then compacted. This can create unfavorable soil conditions for the trees.
Figure 3, Photo by Bruce Hagen
The soil within the root zones of these young oaks was compacted by heavy equipment during the excavation and soil engineering for the road base under the driveway that was installed nearby.