In another thread, I mentioned that you could the "party at x,y" trigger with an item, let's say an axe
. With this approach, the party could stay in front of some trees, and if the item is used (use/examine event), the party will chop the trees down... However, I am still not sure if you can let that only happen in a certain level. As an alternative, you could put the trees in a region of very high x/y coordinates of a very big (the biggest) level, so that the coords are only present in this special level.