The definition is more liberal than the dictionary one of: "the natural world as it exists without human beings or civilization," since people like to "get out into nature," and that area doesn't become "not-nature" whilst they are out in it. However - to most - a city park isn't (really) "nature" - although it can be natural.
It seems that - for many Americans - "nature" is somewhere close(ish) to the idea of "the natural world... without human beings...", but with certain allowances. (Especially since I'd imagine that no one - if they sit down and think about it - can really say that there is any place on earth that does not truly "exist without human beings." Indeed, many things can be considered to be "very natural" and even "nature" that are actually deliberate human (and human civilization) constructions. Indeed, New York City's Central Park is - to many - both a "park" and "nature." And - for a more personal example - the University of Michigan's Saginaw Forest is - to many of its visitors - a natural area (even though it's actually a highly artificial forestry farm that has many direct and indirect human impacts).
Presently, there is a question about whether the City of Ann Arbor should put in an art installation at the recently constructed Cascades on the Huron River.
People's comments from the Facebook story are illuminating in how they perceive this obviously completely artificial, man-made structure:
- "Keep it natural. If I want to see art ill go downtown to the museum."
- "Bad idea. Nature is beautiful art without modification"
- "Lets keep it natural art, plant some really pretty flowers."
- "I don't think that this us a place for it. Keep it in its natural state."
- "Leave it natural"
- "good grief. The "Artists" have more than enough venue in A2, leave Mother Nature's gallery alone."
- "Humans, especially the ones in charge feel a deep seeded need to destroy everything good and beautiful in the world. The only art that should go there are the skulls of the people who first suggested putting art in."
- "Let nature be natural"
- "Idiotic waste of the taxpayer's money! Art does not belong in what should be a Natural Area."
- "How about something architectural?"
- "Isn't the natural setting art enough ?"
- "Ugh. I really don't want to see some cheesy, non-local art awkwardly perched atop some rocks as I go through the cascades. The rocks and plants are already beautiful. This is a really undesirable idea, as most other commenters will surely agree."
So, are the Cascades natural? I'd say that it definitely doesn't match the dictionary definition. However, the reconstructed river channel that was built as a bypass around Argo Dam is definitely more natural than a stormwater canal. And as the plantings in the Cascades grow in and the channel settles into its new configuration, it will continue to become increasingly naturalized.
At what point, though does a naturalized artificial landscape become "nature"? I'd argue that it will never become the nature of the dictionary definition. (And - arguably - it was never that type of nature once the first human being entered the area, thousands of years ago.) Indeed, I'd argue that the objective definition given by the dictionary is completely artificial and conceptual (and also associated with a rather ... problematic ... management and policy history in which native peoples and multi-generational families were evicted from "natural areas" in order to try and reconstruct this definition of "nature"). Indeed, since it is so completely artificial and conceptual, it cannot actually be found anywhere on Earth, and that's why - perhaps - people eschew the purist dictionary definition and instead opt for following the completely subjective definition of, "I know it when I see it."