How do I make a script run when you load a savegame?

[chaospearl]

The thing with adding new trees is that I have to account for all situations because I can't predict where a player's savegame might be, or which cells are going to be loaded. I could just tell everyone to make sure they save in an interior location, then purge the cell buffer before going outside whenevr I update the mod. But I personally dislike mods that force you into a complicated update procedure, particularly when it feels like every time I open NMM I see that stupid yellow exclamation point indicating that I need to update AGAIN. I don't want to make people do that when I can script around it with a couple extra lines.