Why did urban ecology emerge as a frontier in the 25 years prior to the creation of the LTERs in Baltimore and Phoenix in 1997? To understand the challenges facing the LTERs at their inception, we must recover the sense of urgency, expressed from 1970 on, that stimulated ecologists and social scientists to focus on urban problems and the need for an interdisciplinary approach. Diverse experiments in interdisciplinarity at first failed to produce a sustainable research plan or model. The solution posited by the urban LTERs was to evolve a strategy to foster interdisciplinary connections through long-term study of particular places. The new strategy meant focusing more on “subtle” human effects and their importance for understanding ecosystem processes. What did this shift mean for the definition of ecological science?
In going from a “frontier” science to a mainstream or “textbook” science, a key challenge in the 1990s was to figure out what difference it made to place humans at the core of an ecological science that had mostly excluded humans, except as unwelcome disturbers of “natural” systems. The conceptual transformation was to think through what it meant to study the ecology “of” the city, rather than just ecology “in” the city. Articulating these goals raises questions about how we are to understand ecological resilience and sustainability, as well as their links to environmental and social justice. Reassessing these concepts can alter the definition of ecological science. Historically, ecology became a discipline a century ago because scientists entered new environments that stimulated new questions and perspectives. The efforts to answer those questions involved interdisciplinary borrowings. Advances in ecology are often the result of cross-disciplinary interaction and synthesis. The unresolved question is how open modern ecology is to such redefinition and evolution as it encounters new urbanized environments. This question goes beyond the problem of institutional barriers to interdisciplinarity, although these are real constraints. It involves more basic philosophical questions about the meaning, purpose, and social function of ecology.