Turning off Contiguous, I used the Magic Wand tool to select and copy the green tiled moss from the color map. I then pasted it into the according bark texture sheet. With the same settings for the Magic Wand tool I then selected, copied and pasted the cutout bump onto a 50% gray fill in the same file. This image was then saved as a jpeg, sent into CrazyBump for normal map conversion, then back into Photoshop to be cut out and was finally layered over its matching bark normal generated in ZBrush from the sculpt (Fig.18 – 19).
I used the same tools and techniques described above to create the remainder of the trees, along with the supporting natural and vegetal elements in the scene. ZBrush was utilized to bake out some of the normal and displacement maps, as well as Photoshop for alphas colors and specs. As far as material setup goes, I used MIA materials, with tweaked settings to simulate different surface qualities.
Lighting, Render and Composite
For the lighting setup, I used a few directional lights: one key, another for bounce and the last light linked to the objects with translucency and refraction. Additionally, I used an environment sphere for reflections, an ambient for fill diffuse light and a couple of point lights with decay to help simulate glowing surfaces (Fig.20).
Mental ray was used for the final render with Final Gather switched on at production settings at a resolution of 3K.
For the composite I opted not to take out a plethora of render layers with the exception being an ambient occlusion pass.
In Photoshop, I made use of tools such as High Pass, Unsharpen Mask and Lens Correction to add the finishing touches to my final render (Fig.21).

Fig. 21
Conclusion
Thanks for joining me on this tutorial journey, as it is my hope that you have gained something from it!