The Urban Forest Strategy Forum: Urban Heat or Cool Green was held at the Pride Centre on 19th March 2024. It was hosted by PECAN with the Eco Centre with the participation by the City of Port Phillip.
An overview was provided by Dr Greg Moore from Melbourne University who provided invaluable insights to the importance of canopy cover in mitigating hot spots. He strongly supported aiming for a 30% canopy cover overall. He also however pointed out that the movement of air during heat waves from the west to the east was causing eastern parts of the Melbourne to heat up disproportionately at night.
Jen Witheridge, leading the City of Port Phillip’s Urban Forest Strategy (UFS) team, addressed issues for the CoPP in achieving 30% tree coverage across the city, and the challenge of greening public land, including heritage expectations and competition for space both under and above the ground, which can make it difficult to plant new trees. She also addressed increasing canopy cover on private land through mechanisms such as the Green Factor Tool, which offers guidelines for developers and builders, and which the Council hopes to adopt shortly. Jen spoke of the importance of planning to plant not just trees, but the right trees in the right place.
Gio Fitzpatrick, our local naturalist spoke on biodiversity expanding into the issue of co-evolved dependencies between insects, birds and trees requiring the planting of regional flora species rather than ‘non-native natives’ (e.g. flowering gums from WA).
With many parks in Melbourne being classified as ‘green deserts,’ we are losing bird species reliant on locally diverse insect life fostered by local flora.
These ‘green deserts’ have in turn provided an ideal habitat for the rapidly expanding Noisy Mynah which is well adapted to open grasslands and is finding a plentiful supply of food from a lerp infection of our many Eucalyptus (lerps are structures of crystalized honeydew produced by psyllid bugs). The Mynahs aggressive habits are driving away both migratory birds and many local bird species.
So what is the answer? A multi-pronged attack is needed:
- Increase our planting of regionally specific trees, shrubs and grasses of all kinds.
- Include a wider variety of tree genus to include more wattles and boxes: Yellow Box, Black Box and Black wood – currently we have about 5 Yellow Box trees across Port Phillip.
- Increase smaller trees and shrubs such as sweet Bursaria which could replace Crepe Myrtle in our streets.
- Provide protective habitats in reserves with more shrub zone species such as Saltbush and Acacia Paradoxa.
PECAN also proposes that the CoPP review all current projects where enhanced biodiversity could make material immediate changes:
The Green Line – Corridors such as these will increase the habitat for native bird life. The CoPP has already provided a small budget for some sections however additional funding and an finalized approved plan is needed to realize the vision of it as a bio-diversity corridor, connecting to the Yalukit Willam Nature Reserve and the Rippon Lea Estate.
Gio Fitzpatrick identified this railway corridor as an environmental area of significance already supporting habitat and wildlife diversity.
The Gas Works site – Work on the rehabilitation of this recreational area has been agreed and a plan endorsed by Council. Vegetation selection must however be compliant with the principles outlined to ensure it is both lerp resistant and insect supportive.
Before finalizing and implementing the work on the Gas Works site, plant selection needs to be reviewed through this lens.
Brighton Road central medians – In 2023 the CEO offered to support the review of these medians for additional canopy cover in this designated Hot Spot. This would see a plan approved by Vic Roads in 2019 progressed. This Plan was proposed to reestablish the WW1 Avenue of Honour extending it in 3 sections from Carlisle Street to Glen Huntly Road.
Section 1 from Carlisle Street to Chapel Street has remnant Plane trees which could be planted out with large Blackwood, Yellow Box or Blackbox Eucalypts and Wattles.
A direction is needed to immediately review any new park and street trees plantings in order to reverse these trends. Readily available plant lists include: https://www.victorianflora.com/VictorianFlora/Trees
Since alternative planting stock needs to be sourced, this part of the process should happen without delay.
Planting lists such as these should be readily available to residents with information on where such plants can be sourced locally:
https://westgatebiodiversity.org.au/
– Helen Halliday OAM
– Photos: Danny Fog