I finally managed to add the highlights and shadows for the terrain successfully. I wasn't using Pass Through on the Layer Groups, and I had put those layer modes on Normal. The same goes for the blood.

I've also substituted the previous weird-and-odd-looking webs with tree branches that creep in from outside the map.

Here are possibly the final images for day and night tint (with and without grid).

Wilderness [Day][No Grid].jpg Wilderness [Day][Grid].jpg

Wilderness [Night][No Grid].jpg Wilderness [Night][Grid].jpg

Please let me know what you think of them
Thanks.

Website references for textures:
http://texturelib.com (for ground textures)
http://www.dundjinni.com (for trees & creeping branches)
http://texturer.com (for ground textures)