Assuming one wave , well on 160mtrs it would roughtly be over 400' long
and
you
would need heavy cables for wires and two towers or phone poles.
There is no way to set up a diapole with trees, it will snap on a windy
day.
=========================
A wire antenna between 2 trees can be very reliable provided there are no
branches in the immediate vicinity of the wire and that connection to 1 tree
is via a pulley with freely suspended counterweight ,such that when it is
windy and parts of trees move the wire remains straight. A really simple
arrangement.

Frank GM0CSZ / KN6WH