{"id":608,"date":"2012-08-14T15:14:52","date_gmt":"2012-08-14T19:14:52","guid":{"rendered":"http:\/\/www.thenatureofcities.com\/?p=608"},"modified":"2015-10-02T16:08:52","modified_gmt":"2015-10-02T20:08:52","slug":"discovering-urban-biodiversity","status":"publish","type":"post","link":"https:\/\/www.thenatureofcities.com\/TNOC\/2012\/08\/14\/discovering-urban-biodiversity\/","title":{"rendered":"Discovering Urban Biodiversity"},"content":{"rendered":"

The world is losing its biological diversity \u2013 or biodiversity \u2013 at an alarming rate. The primary force driving this is habitat degradation<\/a>.\u00a0When the places where animals, plants, fungi, and the myriad other organisms live are converted to other uses, conditions change and the prior residents often move on or die. The two major causes of this habitat degradation, or the extreme of wholesale habitat loss, are agriculture and urbanization. And it is certainly true that converting forests or wetlands to corn fields or apartment buildings changes the land cover, vegetation, soils, hydrology, and other environmental factors in drastic ways. We all expect that many of the kinds of organisms found in those \u201cnatural\u201d environments will be missing from the \u201cmanmade\u201d environments. And it stands to reason that, as more of the world is converted to \u201cmanmade\u201d habitats, the space left for wild organisms diminishes and many are lost from the earth. [I\u2019m using quotation marks around the words \u201cnatural\u201d and \u201cmanmade\u201d since these are rather gross oversimplifications of the range of human impacts \u2013 but that\u2019s a topic for another day.]\n

While this narrative is true in the broad sense \u2013 there is abundant evidence of biodiversity loss resulting from human modification of the environment \u2013 it is too simple. It\u2019s not just a case of cities (or farms, but this a blog about cities) replacing other kinds of ecosystems\u00a0\u2013 there are some important nuances to this process. Many elements of nature \u2013 the rocks, soils, sunlight and water, but also many organisms \u2013 persist even as a city grows up around them. The kinds of species and their abundances will change after urbanization, but some wild life will remain from the previous community. Urban environments also encourage other kinds of organisms by providing habitats that were not present before. And urban environments are sometimes recolonized by species that were originally lost.<\/p>\n

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Pigeons in midtown Manhattan, New York City. Photo by David Maddox.<\/figcaption><\/figure>\n

The biodiversity among us<\/strong><\/p>\n

When I mention urban biodiversity to my students for the first time, a common reaction is \u201cAre you talking about rats and pigeons?\u201d While rats and pigeons are certainly a part of the system, I think this reaction is shaped by thinking about the largest mobile (and therefore most conspicuous) organisms in the most heavily built-up portions of city. When I press these students, they realize that urban biodiversity also includes the small stuff (like plants in the sidewalk cracks, insects feeding on those plants, and microbes on the surfaces of \u2026 well, everything). They also realize that lots of parts of the city aren\u2019t so heavily built-up \u2013 the parks and greenways, the low-density neighborhoods, or the outskirts of the city\u00a0\u2013 and that these places are often greener (i.e<\/em>., have more vegetation) and busier, biologically speaking.<\/p>\n

When you consider this whole range \u2013 the variety of kinds of organisms and kinds of places in the urban matrix \u2013 it\u2019s not hard to image that urban biodiversity can be quite rich.<\/p>\n

But we can do more than imagine \u2013 increasingly we know. We have data. To list some examples from New York City, where I work:<\/p>\n