The first thing I did was to make two duplicate layers in Photoshop. In the top duplicate layer, I moved to the channels palette, selected the green channel, and increased its brightness slightly using Image>Adjust>Curves. I also applied a 4 pixel Gaussian blur to this channel using Filter>Blur>Gaussian Blur. Then I added a glow in the highlights on the green channel by using Filter>Distort>Diffuse Glow with a white background color selected. I then set the blending mode of the layer to multiply.

In the middle layer, I used the Image>Adjust>Channel Mixer to produce a monochrome image (by checking the monochrome box) and using only the information from the green channel (put 0 for red, 100 for green, 0 for blue). I also greatly increased the lightness of the layer using Image>Adjust>Curves, and increased its contrast using Image>Adjust>Brightness/Contrast. I used Filter>Sharpen>Unsharp Mask to sharpen this layer, with a radius of 0.7 pixels, an amount of 500, and a threshold of zero. This will give the image much more definition. Then I set the blending mode of this layer to multiply.

In the bottom layer I boosted the red using Image>Adjust>Curves and also slightly lightened the layer using curves. You can see the result of all this work in Figure 2.

As you can see, Figure 2 is much too green. While the tree trunks have some nice browns, the paler trunks are too green. We will fix this by flattening the image and using a variety of color tools. Using Image>Adjust>Replace Color I selected the lighter tree trunks with the eyedropper, moved the fuzziness slider around until only the tree trunks were selected, and then moved the hue slider to the left to get some brownish color into the tree trunks. The effect is previewed right in the image, so you can see exactly what you are doing. Then, using the channels palette, I selected the green channel and applied a slight diffuse glow. I used Image>Adjust>Hue/Saturation to warm the image by shifting the hue toward the yellow. And I used Replace Color again on the tree trunks to whiten them somewhat. Then I used Image>Adjust>Color Balance to add some magenta to the shadows. This last step adds contrast to the image as well as a little color. You can see the results so far in Figure 3.

Now to get a more painterly feel, I made a duplicate layer, and I applied a Gaussian blur to this layer. Then I used Edit>Transform>Scale to slightly stretch the layer in both dimensions. Then I also applied a slight Diffuse Glow to the lower layer. I applied Unsharp Mask to the lower layer with the maximum amount, a small threshold, and a small radius, to lend a detailed pen and ink feel. I also applied some cyan to the highlights in the lower layer, using Image>Adjust>Color Balance. Then I flattened the image. You can see the results in Figure 4.

Now I want to work a bit on the composition. First I want to apply more emphasis to the diagonal. I did this by selecting the image (Select>All) and using Edit>Transform>Distort to drag down the lower left corner and pull up the upper right corner. I also used Edit>Tranform>Scale to narrow the image somewhat. These operations steepen the diagonal.

Now I wanted to emphasize the twistedness of the tree trunks. I did this by using Filter>Distort>Twirl on the tree trunks. I applied this filter repeatedly to small areas of the image. I also used Filter>Distort>Spherize on portions of the image.

Finally, I did some fine tuning. I used Edit>Transform>Skew to stretch out the top of the image by pulling out both the upper right and left hand corners, and I selected portions of the left hand side of the image with the lasso and used Image>Adjust>Curves to darken those portions somewhat. I also used the Sponge tool in Saturate mode with a medium opacity to paint in a little more saturation to spots in the upper left quadrant of the image. I brightened the image overall a bit using Image>Adjust>Levels. I painted in a few highlights using the Paintbrush tool with a white color, a small brush, and my Wacom tablet. I applied Filter>Brush Strokes>Dark Strokes and then used Filter>Fade to reduce the effect to 10% opacity. This last step added more definition to the image. You can see the final image in Figure 5.

The result of all this work is an image that has the feel of a detailed pen and ink drawing that has been painted in with washes of color over the leaves and ground. The color gives an effect of dappled sunlight, yet the deep shadows retain a sense of mystery. The slope of the ground and the trunks of the trees add a feeling of tension. There is a nice balance of light and dark, with good shadow detail and a glow to the highlights. If you compare this with the original image, you can see that we have completely transformed the image, while retaining much of the original composition.