twiggs462 ask...

"When it comes to naturally occurring items like this on a property line that are so close - how do you determine what to do?"

Typically when a tree straddles the boundary (part of it in one property and part in another) both property owners have rights associated with it. In general (barring some local governmental requirement or restrictive covenant) you have the right to maintain the tree as you see fit on the part of the tree ON YOUR PROPERTY. As long as such maintenance does not cause the death of the tree (This includes what you might do to the tree roots as well). The fact that the neighbor may have planted them has little to do with this principle.

If you want to remove a tree (that straddles a boundary line) then it would be prudent to get the permission of the adjoining property owner.

You said you wanted to wait until a survey was performed. That is a good idea in my opinion. Once a survey is performed you will know which trees are straddling the boundary and which trees are not.

Good luck.