Trees and urban greening

Tree thermometer simplifiedWe all know the relief of finding a cool spot under a tree or walking along a shady, tree lined street on a hot day.  Trees are especially vital for our wellbeing in urban areas where there are more hard surfaces, as they provide shade and reduce the impact of radiant heat.  

We’ve created a set of Urban Forest Targets that will see a 20% increase in both tree canopy cover and urban green cover (trees and shrubs) in our urban area by 2045.  This will amount to 100,000 new trees in street verges, waterways and parks. 

The new targets are in response to the community asking for more trees and mapping undertaken in 2016 which showed that canopy cover is uneven across our region’s suburbs and townships.

We’ve already made a great start, by planting over 8000 indigenous trees and 4,000 ornamental street trees across Onkaparinga in 2016-17.

Its official, trees are awesome!

We’ve collected data* on 10 individual trees in Thalassa Park, Aberfoyle Park and in the reserve on New England Drive, Woodcroft to measure the ecosystem services that each tree provides including the amount of oxygen produced, the amount of rainfall intercepted, and the amount of carbon stored.

You’ll be amazed at what we discovered! For instance, a 19 metre high English Oak produces enough oxygen in one year for 150 people to breathe for a day. It also removes over 530 grams of air pollution annually - carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, and fine and coarse particulate matter eg dust, smoke etc.  The amount of shade produced can be calculated from its canopy coverage and then compared to a beach umbrella. Our smaller 19 metre high spotted gum provided the same shade as 52 beach umbrellas.

Tree tag

River redgums are the rockstar Australian trees for reducing stormwater runoff, with greybox a long way second. A 30 metre high redgum was found to intercept 30 cubic metres of water per year. All urban trees in park settings reduce runoff by intercepting a portion of the rain that falls and allowing this water to infiltrate into the soil around their root system. When the volume of runoff is reduced during a storm event, this also reduces the potential for both soil erosion and peak flow levels.

The great news is that these values will continue to increase as the trees grow and increase their canopy coverage.

To turn this data into something meaningful for all ages, we’ve created some cool tree tags - why not go and check them out.

*The data was collected using I-Tree Eco, a tool that was developed by the US Forestry Service and is used internationally to measure and apply a value to urban forests. The tool has been adapted for Australia to include 300 local tree species and uses daily and hourly weather data and hourly pollution metrics.

Creating Pocket Forests

We’re taking underutilised areas in our parks and planting 30 - 40 large growing trees. Our Legacy Tree program aims to get the really big trees like redgums, oaks, maples and Morton Bay figs back into parks where there are less restrictions on their growth.

You can check out Pocket Forests at

  • The corner of Ormiston Rd & Simpson Rd in Morphett Vale
  • The corner of Godfrey St & Antony St in Christie Downs
  • The corner Pembroke Dr & Young St in Reynella
  • Richards Dr at Morphett Vale
  • Corner Pamela St & Byards Rd at Happy Valley

These plantings will help to showcase some diverse species and will create beauty and shade as they grow.

Discover more about our approach to street trees and view the answers to a list of residents frequently asked questions.   

We need your help to reach the targets, as they cover both private and public land. Click on the links below to discover:

 

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