A procedural terrain. Cirrus clouds made with FrankB's file; bushes made with lightning's file; grass made with Klas's file; and, the Joshua Tree made with ...sorry, don't remember where this came from.
I'm not doing this one over again; but, if I would, I'd elevate the Cirrus clouds much higher; soften the strata color; and, tweak the vegetation a bit.
Well, after you unplanned tweaks, I'd say this is perfect. ;D
I like the clouds. Looks like you're using some sort of masking. There's something about this that cries out for a velvety look...or is it just me looking at too many skin shaders?