The Anthrome Era

Cities are growing – and so too is the study of urban ecosystems. A hefty new review finds that, after decades of disinterest, ecologists are piling up new insights into how urbanization can influence everything from soil bacteria to bird calls. Now, studies of the “anthrome” – the human-dominated, or anthropogenic biome – are poised to go even deeper into the heart of the city.

More than half of the world’s population now lives in urban areas, and that share is expected to grow to 60% by 2030. As a result, cities and suburbs are now sprawling across a growing swath of the planet. And “as the reality of the urban signature on metropolitan regions, distant hinterlands, and even the entire biosphere has become clearer… more and more ecological effort has been devoted to urban research,” notes a 14-member team in the Journal of Environmental Management. As a result of the rising tide of research, “recent advances in urban ecology have been swift and multifaceted.”

Hundreds of those findings are summed up in the 32-page review of the field’s “decade of progress.” One important finding, it concludes, “is that ecological function still persists” in the anthrome. “This is against the assumptions traditionally made in many disciplines of social science, geography, and economics, but in line with some pioneering work in these disciplines.” Soil bacteria, for instance, continue to function, as do plant and animal communities.

That doesn’t mean urban ecosystems are just like their “natural” counterparts, however. The study notes, for example, that researchers have identified specific “syndromes” that are common in cities. “Urban stream syndrome” describes some common problems in urban waterways, including deeply cut banks, high nutrient levels and degraded fish communities. Researchers have also noticed an “urban wildlife syndrome,” with city animals exhibiting reduced wariness of humans, increased aggression, and changes in hibernation patterns. Then there’s the impact of all that hustle and bustle: Birds, for instance, change their calls to cope with the noise. And, in general, cities have fewer native plant species and more invasive exotics.

To make cities more sustainable, the authors say we’ll need even more understanding of the anthrome. “Ecology has much to learn by measuring the effects of developments as though they were experiments,” they note. And that includes understanding how certain aspects of human communities – such as culture and wealth – interact with things like climate and water supplies. “The increasing population and spatial prominence of urban areas is reason enough to study them,” they conclude. But “an even more compelling argument for understanding how cities work ecologically is the need for information for decision makers involved in regional planning or conservation… Proper management of cities will ensure that they are ecologically, economically, and socially more sustainable places to live in the future.” David Malakoff | October 28, 2010

Source: Pickett, S., Cadenasso, M., Grove, J., Boone, C., Groffman, P., Irwin, E., Kaushal, S., Marshall, V., McGrath, B., & Nilon, C. (2010). Urban ecological systems: Scientific foundations and a decade of progress. Journal of Environmental Management DOI: 10.1016/j.jenvman.2010.08.022

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