Grandwazo
I am aware of a club in Melbourne who had a similar problem. To cut a long story short, they developed detailed vegetation management plans, indicating the variety of different vegetation across the course (original vegetation), detailed tree inventories, commentary on why some introduced tree types should stay and others go, research on locally important (heritage) trees etc etc. There were about three different reports on vegetation prepared, in addition to the Master Plan. The Local Council gave them approval for a number of years to implement the Plan. Without that approval, it was tedious progress, and the beauty that has been since emerged would still be hidden by non-native evergreens.
In Adelaide, our vegetation control is on trees with trunks at 1.5 metres from ground level greater than 2.5 metres in circumference (about 2 feet in diameter). If we are doing 'the right thing' overall, we have been able to get approval to date.