I made a layered map with a variety of tree sizes! I used Worldpainter and MCedit to craft this landscape. The trees below the canopy are from a tree schematic pack by lentebriesje. I used a schematic of an epic forest someone made a while back for the main stand of huge trees. I used a cleaned up schematic of a mega tree from another map i found a while back for the MEGA trees, which i made by layering multiple trees together.
I also hid a little book in the map where i tried out writing a small dramatic story thing. Enjoy
original main stand: http://www.minecraftworldmap.com/worlds/LYgIM
tree pack (compatible with WorldPainter): http://www.planetminecraft.com/project/native-trees-of-europe-template-repository-1779952/
Unfortunately i don't remember where i found the original mega tree. :/