The impact of soil filling on health and growth of trees


EFLA Engineering and Iceland's forest service have recently completed a study of the effects of deep soil in tree root areas, i.e. the influence of soil depth on the health and growth of trees.

The aim of the study, performed by EFLA Engineering in collaboration with Iceland's forest service, Iceland's Landscape contractors association and the Reykjavik City Division of Environment, was to examine the impact of soil fillings on the health and growth of trees.


The study was conducted in two parts. In the autumn of 2010, a tree was dug up from a noise barrier next to a motorway in Reykjavik city for examination of roots and wood. In autumn 2011 some wood cores were taken from trees in the same area to evaluate the growth of the trees.

Results from this study confirm that the level of oxygen, controlled i.a. by soil depth has a major impact on health and growth of trees.


The authors hope that the results of the study will be a positive contribution to professional development and care of trees in Iceland. The tolerance limits for trees to soil depth is now better known than before and it´s effect on wood growth and health.