Ok, I noticed that it's not the grass as earlier speculated because I just stood in the middle of some flaming torches with those little shrubs around and noticed no performance degredation at all. I'm going to agree with you in that it's the fact that it's trying to draw everything at once and I need to turn down the adaptive distance, that way when I get out of the forest and into a wide open world it's not trying to draw stuff 5 miles away.
Edit: Just tested, it is the fact that the hills in that area are one solid object and not seperate ones. I turned the view distance down so low that the pieces of the forest road barely loaded before I got to them, so I know that the road is seperate meshes, and 4 or 5 of those can be left out in the distance without affecting the ones around you. However when I went outside the entire area loaded as one huge object and thus the lag started, view distance reduction just made objects in the distance disappear, but the ground stayed and so did the lag. At least now we know what is causing the problem.