AO Unlit Trees

After experimenting with lots of different ways to light the trees, be it basic diffuse maps, vertex-lit or lightmapped - they never seemed to fit in with the surrounding environment. I finally came up with a solution to this problem, I sampled lots of plants from photographs of Arizona to get a sample of greens/reds that are naturally found in a landscape similar in tone to my own.
I then brought each tree model in to Cinema 4D and baked on the lighting to achieve a soft AO finish to each of the models. It seems odd that I am baking the shadows in to the trees, but  for them to sit right in the environment they need to use an unlit shader (which still allows to cast shadows as if it were a normal diffuse tree). Baking the shadow directly on to the texture and using an unlit shader makes for the quickest render pass for the object, which is perfect considering how many are used to fill up the level. 

Here is a selection of screenshots which show the trees casting shadows and having AO and the texture baked on from Cinema 4D.