NOTE: Follow this ONLY if you don't like the branches and/or groundcover/grass, but want to keep the bark and shrubs.
Some comparisons (watch them sliding and in full resolution):
SFO only bark, shrubs and part of branches:
This works for v1.0.7 of the mod.
-Install "Skyrim Skyrim Flora Overhaul" then also install "Gloomy Snowy Pines" addon. Don't install "Thinner Grass", since we're going to remove the grass.
REMOVING (partially) BRANCHES:
From your Skyrim Data/textures/architecture/whiterun folder:
From your Skyrim Data/textures/landscape/trees folder:
From your Skyrim Data/textures/landscape folder:
-REMOVE the "grass" folder.
PS: Every time you'll update the mod via NMM, you'll need to re-do this procedure!