In this step, the center was lightened and the trees were darkened using the Darken/Lighten Center filter in Nik Color Efex Pro 3.0. The effect is subtle, being careful to not go too far in any given step.
NOTE: The Nik Color Efex Pro 3.0 filters are pretty incredible, especially with the control points that allow one to place the effect in a precise area. Keep in mind though, that most of these techniques can be done in Photoshop without this software.
10). Graduated Neutral Density
Again, using the Nik Color Efex Pro 3.0 filters, a Graduated Neutral Density is applied to the overall image to brighten the image a bit. Some of the tree trunks are masked out (see red square above on that layer) to retain the darkness and also create definition in the trunks.
This layer is then reduced to 84% opacity and the left side of the image with the tree trunks is masked out so that the darker tones will not be effected. I wanted the tree trunks to remain dark (see the above image for comparison).
12). Selective Color (White) Adjustment
With the Selective Color Adjustment Layer Mask, the black is reduced to lighten the areas that contain white, mainly in the yellow areas, as well as the highlights in the entire image.
Because this effected the darker side on the left as well, a mask is created to block this effect on that side.
14). Dodge & Burn
Two new Dodge & Burn Layers are created to bring out the lights and darks as well as detail. This step can also make things look sharper by creating contrast and definition. If interested, visit this tutorial by Russell Brown to see exactly how these layers are created and their creative power: Soft Light Dodging and Burning. The two layers below have been isolated so that you can see where the dodging and burning is being applied.
14). Final Touches
Don't ask me why but I found one limb distracting so it was removed using the cloning tool. A black border was applied around the entire image using the Stroke tool under "Edit".