Urban Ecology - Ecological Systems - page 273

a mature state. This phase of urban ecology ended when social science critics
prompted a move toward more individual behavioral explanations of urban change,
as opposed to community-based models. A similar, but independent shift occurred
in mainstream ecology at about the same time. Even though the academic commu-
nity moved beyond the deterministic, life-cycle approach to cities, urban policy in
the USA continued to assume life-cycle patterns through the 1960s, basing urban
conservation and urban renewal policies on this flawed assumption.
Oddly, during the early twentieth century, while their major ideas were
informing the birth of sociology and being widely applied in urban systems, most
biological ecologists heartily ignored cities and urban systems. European and
Japanese ecologists began to explore ecology in urban contexts after World War
II. The manifest destruction in the cities in which they lived invited their interest as
biologists. What would be the patterns and mechanisms of plant establishment in
derelict sites? How would the newly established biotic communities change over
time? What benefit might they provide the cities in which they occurred? The
questions of the immediate postwar researchers in Europe and Japan were standard
ecological questions, but asked in a novel location. This tradition became linked
with urban planning in Europe and has remained active in that form [ 8 ].
The second wave of urban ecology rose in the 1970s in the USA. Associated
with the birth of environmentalism and its concern with the Earth's exponential
human population growth, the urban ecology of this era tended to assume that
humans were a negative influence on ecosystems, and urban areas provided an
extreme case of the human impact that was beginning to worry scientists and the
public. A key document from this era is the volume by Stearns and Montag [ 9 ]. In it,
the problems of urban areas are outlined, and the nature of potential ecologically
informed solutions is suggested. However, the ecology of the time was rather
coarse-scaled, and assumed equilibrium tendencies of systems, rather than
recognizing fine-scale heterogeneity as a causal feature of systems [ 10 ]. Further-
more, although failure of the old ecological ideas that had informed the Chicago
School was evident, no clear replacement had emerged. Urban ecology in this era
concentrated on investigations of conspicuously green patches in the city. Hence, this
approach can be characterized as ecology in the city [ 3 ]. Parks, cemeteries, gardens,
and abandoned lots exemplify this literature.
Another feature of this second wave of urban ecology was a budgetary, systems
approach. Epitomized by work in Hong Kong [ 11 ], this approach to urban ecology
addressed energy and material budgets of cities, and detailed the human costs of
pollution and crowding. This approach is characterized as a budgetary feature of
ecology of the city. It shares with the early Chicago School an assumption of the
importance of urban “pathologies” in the human population. Industrial ecology and
urban metabolism are branches from this tradition. Both of these schools of thought
analyze the material and energetic inputs, efficiencies, and outputs of urban systems
and their components. Life-cycle analysis of materials is a strategy that aims to
reduce the use of resources and the generation of wastes associated with contem-
porary material use. This era of urban ecology did not persist in the USA as
a comprehensive field.