How we're keeping the trees in Upper Gardens safe
Work is currently underway to upgrade the shared walking and cycle path through Bournemouth’s leafy Upper Gardens. With so much digging and upheaval going on, some might worry that the majestic trees that line the path might get damaged. Nick Colledge, Arboricultural Manager at BCP Council, allays any concerns and explains how the trees aren’t just being protected during the works, but also how new techniques are being employed to ensure they’ll thrive in the future.
BCP Council’s tree stock is its single largest natural asset, its biggest contributor to urban bio-diversity, and its most vital ally in helping to combat climate change.
Conventional construction methods, when undertaken in close proximity to trees, can be extremely damaging. The digging up of the old asphalt and foundations, that is necessary when building something new, may damage root systems and can even lead to trees becoming unstable. What’s more, increases in soil depth over the roots can deprive them of oxygen and water, leading to the decline and possibly even death of a tree.
It is of paramount importance to us that we do all that we can to protect our precious trees while we build a more sustainable, green local transport system.
There are many large, mature trees in Upper Gardens. They work the hardest for us in terms of absorbing pollutants and storing carbon compared with smaller specimens. Despite many of the larger trees being in areas of high traffic flow and near to the proposed cycle and walking path improvements, we are determined to protect them during construction and keep them safe for the future.
The transforming travel team in charge of delivering the sustainable travel improvements in Upper Gardens has consulted closely with the council’s parks arboriculture team, to minimise the impact of construction on our trees.
Following advice, the old path is being excavated using a combination of old-fashioned manual digging and the latest suction excavation equipment, which literally vacuums up the spoil and earth whilst carefully leaving the tree roots intact.
Another useful tool being implemented for the project in Upper Gardens is the use of Cellweb for the construction of the foundations of the paths and roads. This material has a grid-like structure (pictured below) that is placed at the bottom of the excavated path. Stones are placed within the cells and over the top of the material, creating a level yet porous surface that can then be tarmacked over.
This method of construction allows surfacing to be laid very closely to the trees without causing detrimental effects associated with conventional methods. The cells and stones allow water and oxygen to get to the tree roots underneath the path, enabling moisture and nutrients to reach the trees’ root system.
We are proud that by using these methods, the Transforming Cities Fund programme not only provides the infrastructure for future green travel but also retains and preserves our best existing environmental feature; our beautiful trees.