Altering the soil level or changing the grade around trees can have negative consequences. This oak tree blew over in a recent storm and is an example of damage caused to the roots by raising the grade. When the soil is raised the tree’s absorbent roots are no longer at the surface of the soil where the moisture and nutrients are readily available. This stresses the roots and does not allow them to do their job, resulting in root and trunk decay. When the roots are decayed they do not provide the necessary anchorage and the tree is more likely to fall over. Note the lack of roots in the photo.