Skinnybass (funny username...hope you get to have that changed in a couple years ;)), the last issue of PondBoss mag had a short illustration and article about a creative way of setting tree structure over ice. Basically you have your hole, your tree, a rope, and this weight. You plunge the weight, using rebar, into the pond bottom, set it and the anchored rope will keep the tree in place when the ice melts, and until it settles to the bottom, almost exactly where you placed it. Pretty cool idea. Check it out.
