Some ideas on falling trees with one person and a crosscut saw. Normally falling trees with a crosscut saw requires two sawyers, one on each end of the saw. Here is some ideas to eliminate one of the sawyers using something to hold the saw into the cut and maybe pull the saw back and prevent the saw from sagging down on the free end.
The traditional name for this springy saw partner is a Rubber Man. Rubber man — Any kind of a rigging used by fallers and buckers working alone to haul the saw back and keep it from sagging. An inner tube, bungee/shock cord or a bent sapling sometimes will do.