I'm in S Wales. I'm very lucky that when the mines closed the tips were reclaimed and some of them have grown over with scrub and young forest and around here those young woodlands stretch the length of the valley, with no really clear ownership so I don't feel too guilty about taking the occasional stave - the woods are primarily oak, hazel, beech, silver birch, ash and thorn trees. I've also had a chat with local farmers and found tree surgeons really helpful too. Have you checked out Arbtalk, Woodlots, or, the the forestry commission web-sites?