That is actually one of the very few "fresh" ideas I've seen in a very long time. As a long time reader of TFH magazine I keep up with Takashi Amono ( http://www.adaeuro.com/gallery.asp
) for several years. I've seen some great works come from their team but this is a new idea that I think rivals some of theirs. I realize the difference between creating Zen like water themes is a touch different than creating a terrestrial landmark in your fish tank, but hey with his experience why not give it a try?
On another thought for your set up almost being park like, you could get a small piece of glass and bury it in your substrate. Set it so it lightly rises towards the back of the tank. Bury an airline under the substrate to the front of the piece of glass. As the bubbles collect under the glass and move to the back of the tank it will give the appearance of a river flowing quietly under the tree. You may need to add a valve to it to slow it down to get the right effect.