Thanks Inkydigit for the observation regarding the rock coloring, you're right, but at this point I'm still trying to figure out how to accomplish such things. Dune: just what I need in the area of direction. Power fractals seem such an important part of creating so much in T2 and I'm just starting to explore their properties. The tree distribution is too even, 'clumping' was something I hoping to achieve thru multiple small populations manually overlapped, but clearly that didn't quite measure up. As to a variety of trees, yeah I agree. Also the scale of the trees is a bit 'wrong' in hindsight.
To masonspappy and 4int: kind words indeed. Thank you.