can be cut into the wood first then cut an image with the remainder as a border. Then again the same technique can be achieved with a bit of cut and paste in Photoshop. But simply using a material background as the cut adds some very nice texture.
That's the problem with grass, especially long grass. It intersects too much to be defined. I imagine forests would have the same problem with the amount of leaves. Maybe a nice winter shot of barren branchs, not a lot though.