Many paddocks have no living trees in them at all
Establishing trees in these “empty” paddocks is more challenging, but not impossible.
In such an "empty" paddock, it is likely that one will need to use tubestock seedlings to jumpstart revegetation. These seedlings can come from a nursery, or you can also transplant naturally grown seedlings from your own property. Just be sure to equip them with an adequate guard to shelter them from the stock.
With so few trees in this paddock, it is unlikely that any natural regeneration can occur without our help.