I really like the wood and root placement, very interested in the color, the texture, and I love the dark green and brown coloring. I've never attempted to make fake wood or replicate anything, and I think it'll be fun. Left this out: Yes, as a template for my build. lol ANOTHER thing I left out: I really like the first picture because it has LOTS of foliage in the background and some grass in the front, though I might not use grasses.I don't get your question. Use the pictures as a template and go from there?
First thing I'd do is identify what it is you like about the pictures. The grasses? Wood placement? Mosses? Colors? Is it the texture of the bark on the tree? Find out what it is you want to replicate exactly and then research ways to duplicate it.
My artistic skills on a scale of 1-10, -100! I suck at art. But i'd give it a try. I like the smooth feel of the first pic with lots of creaves and stuff, I think it'd be really hard to replicate it.That would be fun. I know that you can mold a lot of stuff out of various foams, or you can hunt down some driftwood that has that same look to it. If you do foams you have the chance to either make something great or end up with something you're not happy with (depending on your artistic abilities. I know anything I'd make/paint up would probably end up looking like a turd...)
Some of the more viney looking roots have been made using rope as the base material.