I'm waiting for the completion (it takes ages in France) of a purchase of 4 acres of woodland. It's mainly oak and sweet chestnut but hasn't been touched since the storm of Dec 1999 which blew down literally millions of trees as it swept through the Charante and Dordogne. So - task for 2009 clear all the fallen wood, replace with self seeded oak - lots of those from 2' to 15'. Find/create a big enough clearing for an out apiary as my garden is going to be my queen rearing and nuc nursery this year.
So after all that waffle my answer is I'm growing trees - lots of them
Our sole method of heating is a 15Kw log burner so I need about 8 cubic meters of wood each winter Oak is great but the chestnut spits and sparks no matter how dry it is. We have a lot of Goat Willow round us and that together with masses of Hazel gets the bees off to a good start pollen wise. Our main nectar crop is Sweet Chestnut followed immediately by Acacia. Last season a tremendous flow from the Ivy rounded off a very mediocre season -- Roll on Spring -- 5cm of snow outside as I write!!
PS At the risk of "teaching Granny to suck eggs" any willow twigs stuck 6" into moist ground and kept well watered WILL grow