It costs a lot more to establish an urban forest in Perth.
Because the biggest cost associated with getting trees through their first three years is watering. And the minimum watering frequency that will guarantee success in a hot climate with pure, flowable sand is twice a week.
When I was at Brimbank City Council in Melbourne last week they were amazed at this because their contractor, Citywide Services, only waters their trees once a month and still offers them a 100% success guarantee! The difference is their heavy clay soils, a cooler climate and rainfall more evenly spread across the year.
Perth councils (and the state and federal governments) have to accept that establishing extensive canopy here is going to cost more relative to everywhere else* and recognise that with appropriate levels of funding.
* The other side of the coin however is that the potential gains from extensive canopy cover are also greater here than elsewhere.