I think zrfraser has made a very good suggestion for this one. I used to have a little pocket tripod, about six inches high. It was very fun for setting up long exposures of Washington D.C. Memorials at night because of the altered perspective on these over photographed subjects and it gave some awesome texture to the pavement leading up to the monuments. I just had to make sure no one kicked my camera while I was doing it!

With a wide angle lens to make the tree really loom up above the pavement this could be a really neat idea. If you do decide to re-shoot please post it so we can see. Good luck!