[Rueben Berg]

They are all turnovers.

Rule 2.7 helps deal with obstructions within 3 metres of the field, but the thrower must call that violation before the throw.
Also the aim of 2.7 is to deal with moveable objects. If the tree was always in that spot, then 2.7 doesn’t really apply.

If there is a tree over the field, I think it could be reasonable for captains to discuss this before the game and determine how they want to manage that, but I think it would be too late once the game had already started.