How does the poem "The Human Seasons" by Keats reflect the Romantic period?

While Enlightenment-era writers embraced reason and logic, Keats and his fellow Romantics said "Thanks, but no thanks" and got emotional.
As a meditation on life's stages, "The Human Seasons" fits this sentimental mold. In fact, it doubles down on its Romanticism by incorporating another hallmark of Romantic poems: melancholy. The speaker uses metaphor to move from the youthful lustiness of spring all the way through winter and the "pale misfeature," or death, that it brings man. Few things are more emotion-filled and melancholic than thinking about the day you'll inevitably kick the bucket.
Romantic poems are also known for their love of nature. How important is nature to "The Human Seasons"? Keats's sonnet uses the constantly evolving state of the entire natural world to represent man's progression from young and seemingly invincible to—if he's lucky (and Keats wasn't)—old and thoroughly mortal.
http://academic.brooklyn.cuny.edu/english/melani/cs6/keats.html