This is the usual thing, started on something I wanted to make, but ended up nowhere near... :)
Used dandelos`grass tutorial for tecturing & Mr.Lamposts`bushes objects.
Been trying to populate more plant life towards the lower end, but not seeming to work...will get back to it.
(http://i264.photobucket.com/albums/ii183/silentgod47/Paiclose.jpg)
I have good results using a distribution shader plugged into the objects blend by input. Both the altitude and slopes can easily be constrained using this. The fuzziness input allows even more control. Use zero for the low altitude fuzziness at the water height. This makes a hard edge. Maybe about 1/4 of the highest altitude for the high fuzziness would be a good start for making adjustment to the high fuzziness value.
Add a little more displacement to the grass (maybe use dandelO's Planetary Grass Shader?) and turn off Ray Trace Everything. Instead, turn on Ray Trace Objects.
The right tree seems to me a bit inadequate...maybe without it ???
Although a wonderful and detailed work
I can't make out what the foreground surface is meant to be - regularly dimpled rock?
Thanks for comments, will have it again soon, I hope.
Hard drive died, still trying to fix it :(