Yeah, there's a reason we had such a hard time getting through hedge rows in ww2.
Green wood is really strong and any tree that has a tap root will be hard to get out. The trick is to tie your rope or chain high so you get the leverage. If you have 4wd put it in low range, with a 2wd just lock it in first. You have to go slow so your tires don't lose traction. I see a lot of people try to just gun it and jerk things down, but if you do that your tires won't have a chance to bite and they'll just spin and tear a hole in the ground.
The other option is to use a slack rope, get 50+ foot run going and see how fast you can go to give it a good jerk.