Nature poetry down through the ages, from the Greeks and early oriental poets, up through the pastoral (shepherd) poetry of the Romantics, to modern-day paeans to Nature, treated Nature as unspoiled, largely unspoiled, a personified force that opposed or ameliorated the grittiness of man’s intrusion. The skylark sang uninhibited, the woods were undisturbed, the sea washed unto the cobblestone beach without Man’s intrusion; in fact, Mankind was invited by the nature poets to return to Nature as a soothing force that could heal the bruises of civilization: “I love time out with Nature, a brief release from care/ For Nature she is generous her gifts with all she share/ We drink of her clear spring waters and we breathe in her life sustaining air” (Francis Duggan, “I Love Time Out With Nature”).
But, while Williams does deal with Nature, it is inhabited, even tamed, by Man, not pristine Nature. Williams’ real contributions are stylistic, and distinctly American in voice; in fact, America was the prime example of the conquest of Nature—agriculture, industrialization, railroads, etc. Consider these contrasting lines about birds:
From Williams’ “Pastoral”: (they) hop ingenuously/ about the pavement/ quarreling/ with sharp voices/ over those things/ that interest them.” And from Shelley: “Hail to thee, blithe spirit,/ Bird thou never wert…”
His epic multi-volume poem Paterson speaks of the civilized city, for example – “city streets, vacant lots, workers and their tools, a sheet of paper rolling along in the wind, pieces of broken glass behind a hospital, the number five on a speeding fire engine,” etc., even though it is surrounded by mountains, waterfalls, etc. Nature, represented by flowers and trees, is “an active presence in his poems, and it is celebrated without ever being idealized; it is puddles rather than lakes, sparrows rather than nightingales, weeds rather than roses.” The city of Paterson is emblematic of how industry exploits Nature, the opposite message from the nature poets.
So, given his very real contribution to poetic form, and to capturing an “American” voice, it would be short-sighted to place him in the “Nature Poet” category, unless you stretched the word “Nature” to include “human nature” or “civilized landscape nature.”