Trophies...

1. The highest point is in that small fort where the squad are held after being captured after the heli crash.
2. just google them, few vids or maps about
3. Any small forest will do

Thanks for the help:)

Actually, the singleplayer campaign and online modes have separate trophies for tree cutting.

Easiest way to get the "Manic Lumberjack" trophy in the campaign is, imo, on a map that has weapon emplacements. I got it on the first map, leveling the woods around the village where the convoy of trucks comes, before the artillery barrage destroys them.

The online trophy is "Forest Ranger" and what RoH said, applies to that.