In Ireland a tree over ten years cannot be dropped without a permit, I've cut hundreds of tree's now on farms and around my woodland but never got permits, the only problem I've had is the Gardai (cops) stop by when they hear the saw and ask who owns the land or general questions like that. I've seen lots of big trees coming down in my area without permits. There seems to be very little control here on trees, is it the same anywhere else? Does an arborist need a permit if they know more about the tree than the permit giver? I'm thinking that you'll only be asked to show a permit if you look like a nutcase on a rampage, if you look like you know what you're doing they leave you alone..