I believe the core of all art exists in Nature and if one has the eye to recognize it they have the potential to make great images. Whether it is the slope of a hill, the shape of a flower, or an animal poised for action, nature is full of artistic compositions. Capturing the artistic qualities on film is the challenge of the nature photographer. We do not see nature with our eyes, but with our understandings and our heart. Since art is so subjective, this could be a very personal question with as many answers as there are nature photographers.
Strong composition is important to artistic interpretation.
But good composition is more than placement, perhaps more importantly it is the conscious decision by the photographer as to what to include and exclude from the viewfinder. Before releasing the shutter, explore all corners of your viewfinder and ask yourself if there is any extraneous or distracting information inside. Then simplify, simplify and simplify some more. To ere on the side of simplification is probably best, because as in nature, nature photographers produce the greatest results with the simplest means. Science will never be able to reduce the value of a sunset to arithmetic.