How is nature presented in "To Autumn" by John Keats?

In the poem, nature is presented as mankind's benefactor. The entire poem describes one of the four seasons that routinely visit the human experience: autumn. 

In the first stanza, autumn is pregnant with "mellow fruitfulness." The harvests in early autumn promise a delightful gastronomic experience. The "moss'd cottage-trees" are bent with the heavy weight of luscious apples. Autumn conspires with the "maturing sun" to bring to perfect ripeness the fruits of the season. In this stanza, autumn is unequivocally described as mankind's benefactor.

The same theme continues in the second stanza. Autumn is personified as an illustrious worker, one who threshes the field, gleans the fruits of nature, and works the cider press. In this stanza, nature is both provider and producer.

In the last stanza, autumn is said to have its own song, distinct from that of other seasons. Indeed, autumn reveals its beauty through its unique panoramic vitality. In the fall, the "wailful choir" of small gnats is heard next to the bleating of "full-grown lambs," the singing of hedge-crickets, the whistling of red robins, and the twittering of gathering swallows. In the poem, nature is presented as mankind's benefactor, one who impresses itself on each of our five senses.