Rootcells® improve the establishment of Corylus colurna L. in a compacted car park substrate

Abstract

Trees growing in an urban environment often experience very poor rooting environments that have a detrimental effect on the trees’ longevity and the benefits that the trees can provide. This study compares the condition of trees planted with RootCells® with trees planted without provision of any additional rooting volume, in a car park with a varying level of soil compaction across the site. Twelve Turkish hazels (Corylus colurna L.) were planted in compacted hard-core, half of which were supplied with RootCells® that increased the volume of these planting pits by approximately 34%. After 5 growing seasons, 2 trees had died (one control and one treatment tree) and we measured a selection of growth and health indicators in the remaining 10 trees, to assess the effect of the RootCells®. Mean stem girth at 1.5 m was 15.4% greater for the treatment group, and mean twig density was 18.3% greater for the canopies of the treatment trees. For a range of other tests, the trees growing with the RootCells® performed marginally better than the control group. However, chlorophyll fluorescence readings gave a contrary reading, which indicates that this method may not always be a reliable means of assessing successful tree establishment.