My last post on Parque Nacional da Tijuca, Rio de Janeiro’s urban rainforest, alluded to some of the social and psychological benefits of “urban wilds,” defined here as islands of native ecosystems in cities. In that case the city didn’t really have an option other than to restore and preserve the forest, given the importance of the watershed and the impracticality of urban expansion into the Massif (and presumably it was assumed that native plants would result in the healthiest forest possible). But in places where the direct practical benefits of preservation are less clear-cut, what is the actual value of carving out these relatively small islands of nature at the expense of preserving much larger tracts beyond urbanized areas? The wellness benefits of generic green spaces—from parks and gardens down to planted medians—are common-sense and have been well-documented. But to what extent should they at least partially exhibit the region’s ecology as it was before urbanization, anything from forest down to desert, though they might be considered less useful or ornamental?
Parque Nacional da Tijuca again, rising dramatically from the center of Rio.
As I explained in my Realities of Nature posts (long and involved, but here’s a summary), if we start from a common understanding that human and environmental health are inextricably linked, can be objectively measured, and are good things to begin with, then we can agree that sharpening the edges between nature and civilization by contracting our physical ecological footprint, creating a “divided canvas” as Roderick Fraser Nash calls it in Wilderness and the American Mind, is justifiable in an ideal world. That would mean, most importantly, densifying our cities into a series of well-defined urban islands surrounded by preserved and restored ecosystems. While we’re still far from that common understanding, and it’s arguable how achievable that ideal world is, among well-informed people with their values in the right place I don’t think it’s reasonably debatable as a goal.
If “island civilization,” as Nash calls this idea of boundaries around cities rather than boundaries around nature, is taken to its extreme, then technically it precludes preserving or restoring natural areas surrounded by urban development. In terms of direct environmental benefits, it’s generally true that a small piece of native nature has more value beyond the city—less exposed to human impacts, contiguous with much more extensive areas of habitat, and permitting increased urban density with lower auto emissions—than isolated within it. I think, though, that Nash would agree that this extreme version of separation would never be desirable let alone realized, at least for large metropolises. As Tijuca illustrates, most urban wilds exist partly if not mainly for practical reasons, but they may also have benefits that are less tangible—for city dwellers but also (indirectly) for the environment in terms of increased awareness and appreciation. The next few posts will look at these more abstract benefits of intermingling city and surrounding nature to some degree through the preservation or restoration of urban wilds—relatively small and accessible—versus a stricter separation between the two that concentrates all natural areas into much larger and more continuous tracts further afield.
I’ve said a lot about the feeling of empowerment that attracts me to edges and islands, particularly pronounced in the case of urban wilds. That’ll become relevant to the discussion a bit later on. But since I’ve never assumed that many others share that impression (though I’m always waiting to learn otherwise) let alone that it would ever drive planning or conservation policy, here I’ll focus on impressions that are likely much more widespread. These ideas will be speculative and broad-brush, given not only the intangibility of the benefits themselves but the fact that defining what is “inside” vs. “outside” the city, and what is “native,” can be complicated. In the latter case, “nativeness” depends on how large of an area, and on what time scale, we’re talking about. But even on an abstract level these thoughts can provide a framework for thinking about what the urban-nature divide actually means.
Twin Peaks, an iconic landform near the geographical center of San Francisco. The ecosystem is threatened by invasive species and foot traffic, but it represents a relatively intact remnant of native California grassland and shrubland.
The first benefit I’ll go into relates to “bioregional identity” or “ecological sense of place”—emotional connection to a certain region based on its native species and ecology. (I’m focusing on the “bio” here because I think talking about the “geo” is less illuminating and less useful—I doubt the positive influences of urban mountain scenery would come as a surprise, and in any case eliminating it isn’t usually an option. It would be interesting to determine how much of Tijuca’s iconic status has to do with its rainforest versus its topography.) There’s been a lot said and written about the concept of bioregionalism and especially the importance of regional and local identity more generally: our physical environments are important in creating a sense of belonging, and that sense of belonging is important to our well-being. The concept of biophilia, explained and popularized by E.O. Wilson’s book of the same name, isn’t explicitly about identity, but its claim that we have an innate, evolved connection to other living things would suggest that other species do have some role in creating a shared sense of place.
As the city’s second-highest point, visible from many neighborhoods, how important is the landscape of Twin Peaks to the city’s identity?
Buena Vista Park is another of San Francisco’s hilltop open spaces. Unlike Twin Peaks, and the majority of the city’s parkland not used for active recreation, it’s been converted to forest. It’s cooler, less windy, and arguably more interesting, but what has it lost as a result? Throughout the city there are controversial plans to return pieces of parkland back to their original open landscapes.
But so far I haven’t come across anything attempting to quantify how strong, prevalent or important that biological sense of place is, particularly with respect to cities. A few years ago I had some correspondence on this topic with U. of Illinois professor Frances Kuo, who studies the psychological and health benefits of urban greenery; she said that “everyone more or less prefers the landscapes in which they grew up, and savanna,” but that “I don’t know if that entails a preference for native plants, so much as for familiar plants.” She also noted that “preference is not necessarily the same thing as psychological benefits. So, for example, people may not like walking in an arboretum in the dead of winter, but they still derive psychological benefits from it, according to measures of cognitive function. So, while we have plenty of research on which landscapes people like, we can’t confidently predict psychological benefits from that research, and unfortunately, at this point we haven’t really conducted research on which landscapes people benefit most from.”
So apparently it’s a tough subject to study, and I would add that trying to distinguish a preference for familiar vs. native plants would probably be complicated by the likelihood that many of us without botanical interests or expertise assume that familiar plants are native. And, again, does “native” refer to just that particular urban region or to a wider area that might encompass multiple ecological conditions? And does it include species that have been there for centuries but were brought by humans? Results would vary a great deal depending on whom you ask, and how you ask the question. And it’s probably even more difficult to determine which concrete conservation measures accrue directly from these attitudes.
But I think it’s reasonable to assume that at least for some of us, and to some extent, an urban ecological sense of place is (or could be) real and important—we’d prefer that our natural surroundings, even specifically urban, not be homogeneous. It would be nice if we had some evidence beyond the anecdotal.
Darren