Urban Ecology

Definition: Urban ecology is an integrated scientific study of complex, spatially extensive urbanized systems.  The subject includes central and edge cities, suburbs of various ages and densities, and the exurban settlements in which urban lifestyles and economic commitments are dominant compared to those of rural or natural resource management.  Urban ecology shares many features of the antecedent biological science of ecology, but also emphasizes linkages with social and economic sciences, geography and physical sciences.  In application, urban ecology acknowledges the need for sustainability and for social equity in the distribution of environmental vulnerabilities and amenities.

Examples: Urban ecology has a rich foundation.  Wildlife ecologists early on established a productive and ongoing tradition of understanding the plants and animals in urban green spaces, yards, and gardens.  Such studies include genetics and adaptation of urban populations, and their relationships with social and behavioral controls imposed by people.  The energy and material flows in cities were another of the roots of modern urban ecology.  Now recognized as urban metabolism, the understanding of these budgets of urban areas are important for improving management and reducing environmental costs of city living, both for residents and for environments downstream and downwind.  The burgeoning studies of urban environments, entire urban areas or neighborhoods as heterogeneous, dynamic socio-ecosystems have enlivened urban ecology and stimulated the search for urban ecosystem functions and an evaluation of urban ecosystem services.

Figure 1.  Examples of some contrasting components of urban ecosystems which can be the subject of urban ecological research.  Upper left: Urban/rural complex near Kigoma, Tanzania. Upper right: A revitalizing neighborhood in west Baltimore, Maryland.  Lower left: A suburban neighborhood dating from the 1920s west of Cleveland, Ohio, showing the classic park-like lawns.  Lower middle: Stonetown, Zanzibar Island, Tanzania, showing the dense urbanization with narrow streets and courtyard houses.  Lower right: Redevelopment on a brownfield site in Harbor East, Baltimore. 

 

Figure 2.  A diagrammatic conception of the urban ecosystem.  Biological ecology traditionally focused on plants, animals, and microbes and their relationships to one another and to the physical environment, consisting of soils, waters, gasses, and the fluxes of energy, matter, and information in a specified location.  Urban ecology requires explicit attention to the social complex, including economic, power relations, social institutions, and political processes, along with the buildings, infrastructure, and modifications of topography and substrates by human actions and their intentional and unintentional effects.

Why important: Urban ecology as a term has been appropriated by disciplines in the social sciences during the period when mainstream ecological science was focused on apparently pristine or wild lands.  However, the understanding of the nature of ecological science can sometimes be problematic in such applications.  Readers of the broader literature on urban ecology as it has been informed by other disciplines must be aware of outdated ecological concepts and generalizations, and a use of background assumptions that are no longer accepted by mainstream ecology.  These include assumptions of equilibrium in system function, climax in system dynamics, and spatial uniformity in system structure.

For more information:

 ·         Pickett, S.T.A., V.T. Parker, and P.L. Fiedler. 1992. The new paradigm in ecology: implications for conservation biology above the species level. Pages 65-88 in P.L. Fiedler and S.K. Jain, editors. Conservation biology: the theory and practice of nature conservation, preservation, and management. Chapman and Hall, New York. 

·         Pickett, S.T.A., M.L. Cadenasso, J.M. Grove, C.H. Nilon, R.V. Pouyat, W.C. Zipperer, and R. Costanza. 2001. Urban ecological systems: linking terrestrial ecological, physical, and socioeconomic components of metropolitan areas. Annual Review of Ecology and Systematics 32:127-157. 

·         Grimm, N.B., J.M. Grove, S.T.A. Pickett, and C.L. Redman. 2000. Integrated approaches to long-term studies of urban ecological systems. BioScience 50:571-584. 

·         Marzluff, J.M.; Shulenberger, E.; Endlicher, W.; Alberti, M.; Bradley, G.; Ryan, C.; ZumBrunnen, C.; Simon, U. (Eds.) 2008. Urban Ecology: An International Perspective on the Interaction Between Humans and Nature. Springer-Verlag.