We say “Give a Tree” that’s fine as a name; but in reality we will be planting indigenous plants which may be trees, bushes, shrubs, grasses, ground cover.. Whatever is appropriate at the time of that planting area’s regeneration needs. The bush is a community of plants and to regenerate our bush we need to plant the community of plants which will provide habitats for even our smallest indigenous animals/birds/butterflies that is relevant to the specific restoration area. That is working toward reestablishing the indigenous biodiversity of the area.
In the Australian bush, plant space is a competition, between plants, our endeavour will be to “regenerate our bush” will require that we remove non-indigenous plants: trees, bushes, grasses etc. Some of the larger plants may over-time have become habitats for native animals and birds etc, so these non-indigenous plants will need to be managed (protected/controlled to provide a continuing habitat until the native plantings grow sufficiently to safely remove the non-indigenous.)