Landscape Architects and Parks and Gardens people in Perth are afraid.
They're afraid that if they don't recommend native trees they'll be considered "environmentally-insensitive".
Well my friends, be afraid no longer!
The jury is in: going all-native is a BAD idea.
In fact, we can now safely say that if you recommend native-only, YOU are not being environmentally-sensitive!
Diversity is king and that means using both natives and exotics in good measure. Until now this has made good sense purely from a pest and disease risk-mitigation perspective. But it's even more imperative now from a climate change perspective. A hotter, drier climate could significantly impact our local flora and if we're soley dependent on it for our urban forest we could end up in a bad way.
Don't be intimidated any more by those who refuse to see this. You are quite right to be using a tree palette which includes exotics. "Native-only" is yesterday's news and those who advocate it are out of touch.