Trees in city areas are infrastructure assets that contribute environmental gains as well as enhancing the developed landscape.
Benefits include:
- Provide shade and reduces the elevations in temperature caused by the radiant heat of buildings and pavements.
- Absorption of water from intense rain events.
- Reduction in wind speeds.
- Removal of air pollutants.
Soilco has supplied vault and structural soils to support trees planted at the Wollongong City Council Crown St Mall Refurbishment.Two planting systems were designed.
Vault Soil
The works have included planting for approximately 20 Spotted Gum (Corymbia maculata). A suspended slab has been constructed to take the load weight of pavement and traffic.
A trench has been developed underneath to provide a continuous vault for root zone volume. A well-draining medium was designed to minimise water logging after rain events, and to provide the essential nutrients for the long term growth of the trees.
Structural soil
Structural soil is engineered to take the load weight of pavement and traffic in addition to providing root zone volume.
The planting system contains a number of components including drainage for stormwater runoff, structural soil, and a planting soil. The structural soil consists of aggregate and filler soil to provide a lattice of pore spaces allowing root penetration without collapsing under the weight of the pavement.
The planting soil has a high permeability to deal with runoff, and is a custom blend including organics and added fertilisers to meet the nutrient requirements of the trees.
Soilco has worked with the Landscape Architects, Contractors and the certifying Soil Laboratory to manufacture the custom blends meeting the site design requirements. These blends will help ensure that the trees grow in healthy conditions and meet the expectations of their life span.