Urban Street Trees and Root Compaction

 Urban Street Trees and Root Compaction 

A review of the GreenBlue Urban ‘Urban Tree Planting’ CPD Seminar. 

We plant trees in busy urban street environments to improve the quality of the air, to absorb noise and filter pollution, keep our atmosphere oxygen rich, offer privacy and shade, and even boost our physical and mental health. The government spends millions planting trees in urban street environments across the country. However, there is a problem. On average 30% of trees will not survive more than 1 year after being planted, according to the Forestry Commision. Not only is this incredibly unsustainable and wasteful, but urban tree planting is usually funded by the public sector, resulting in millions of pounds of our money being wasted on poor tree planting systems (Carbon Gold (2022). Therefore, we must find the origin of this issue. 

In urban street environments, there are many factors which can cause trees to die, including a wide variety of pests and diseases, drought, heat, frost damage, water scarcity, poor maintenance and root compaction. With high volumes of footfall in urban streets, it is logical that root compaction is a key issue. This takes place when the tree roots are suffocated under the soil making it impossible for trees to retain the nutrients they require, hence resulting in stressed plants which are more likely to suffer from secondary problems. Soil compaction is a current issue that many of us take for granted, every piece of land where there is foot fall and infrastructure there is guaranteed to be soil compaction. Planting trees in these environments is possible, however, the current planting system we have limits the trees ability to grow larger root systems, making it hard for the tree to get any bigger above ground (GreenBlue Urban (2015). 

Currently, whether trees are planted as root balls or as bare roots, they undergo similar planting processes. The tree will be planted into a tree pit (sometimes with root director - to divert roots deeper in the soil) and compacted with substrates to support the paving above. This system offers zero root protection from heavy footfall above ground, consequently causing root compaction. However, GreenBlue Urban have formulated RootSpace, a pavement support system which helps trees to florish in busy urban street environments.  

RootSpace is constructed from interlocking recycled plastic crates which are fitted together to form an open lattice structure. It is composed of an aeration deck lid, an upright panel, and an optional infill panel; this provides unlimited access for all roots to grow, free from compaction. Nutrients penetrate the roots helping them grow deeper into the soil, producing a vigorous, sturdy tree. Overall, the installation is both cost and time efficient, and is designed for easy re-excavation which eases the process of maintenance and utilities (GreenBlue Urban (2022). GreenBlue Urban’s RootSpace has the potential to prolong urban street trees life expectancy and health, in harmony with surrounding building infrastructure. Thus far, ‘GreenBlue Urban systems have helped over 450,000 trees thrive around the world’, from great streetscapes to smaller residential zones (GreenBlue Urban (2022).  

To conclude, urban street tree planting will continue to not improve unless the government begins to invest in companies like GreenBlue Urban. If this fails to happen root compaction will continue to be a significant underlying problem for tree health in urban street environments across the globe, resulting in an appalling amount of wasted trees, funds, materials and time.