3DM Blender add on on all objects here.
The tree is just a Blender sapling generated tree. The hexagonal shaped leaves are not masked, rather just white shader applied.
The clumps of snow on the tree are from the create snow add on.
The fallen log also has clumps, that I am not fond of yet, but I see that this clumping could be used as moss or a deviation from just a plain bark system.
The fence has a simple application of snow adhering to the top edges, which I quite like.