GETS RID OF TREES?!

My computer is awesome, it could easily run the 1000 battles some mods allow, but there's one tiny problem: If there is a single tree involved, my framerate KILLS ITSELF!!
I really want some better battles, and the larger battle sizes could help that, but it's not practical if I'm in a forest... or a grove... or anywhere near trees. So, if there's some way, or some mod, to get rid of them, please help!