impressive start. I'm not sure such detailed leaves is the way to go with your scene, but i'm especially bad at trees with detailed leaves, so that could just be me
Generally in forests there is no grass
That depends on the slope of the ground (and wind exposure). Forest near here have almost no grass in their "horizontal ground", with only a few plants growing through dead leaves carpet, but plenty of (sometimes quite hairy) grass is found at the roots in the more "hill side" part, when going down to the river.
If not grass, "foam" (unlikely to be the right word. I mean
) can be very common, especially in conjunction with some trees such as Oaks. and they may have "hairy" look that can be looking much like grass sometimes. Anyway,
you are defining the look of the forest here. Grass/foam ground will give it a more "good/welcoming/fairy" forest while dead leaves and mushroom give a more "witch-wood" feeling, etc. I.e. Lothorien is not Fangorn woods, nor the Old Forest.
