Forest scenes are harder to shoot than most types of landscape. The surroundings are more cluttered, drastically limiting one's options for composition. There tends to be a lot of contrast as well; usually enough to overwhelm a recording medium (like film or a CMOS/CCD). Every now and then, things come together wonderfully and the result is the cycle of life in picture form.
The setting sun shows hints of a star pattern in front of a tree's silhouette. Point sources of light show this type of diffraction effect caused by light bending around the iris in the lens, which gets more and more pronounced as you close down the aperture. Night photos tend to show this same effect.