Cities, suburbs, and exurbs are each a kind of human ecosystem. Many of their structural and functional components are designed for human use, convenience, and profit. But many of their features are unintentional. Networks of infrastructure interact in unplanned ways sometimes wasting resources and sometimes resulting in cross contamination of resources and waste flows. Slivers of habitat hug the sometimes oddly shaped boundaries of rights of way or of property parcels. Policies intended for one purpose close opportunities for transformation, or disadvantage groups lacking political power. Designs focusing on one scale may have effects on other spatial scales. Such unanticipated, indirect, and unintentional effects of design, planning, and policy contribute to the novelty of urban ecosystems.
Results/Conclusions
An important lesson of urban ecology is that not all novelty is good. A second lesson is that novelty isn't stationary. That is, each kind of novelty may generate a template, and those templates can change over time as infrastructure wears out, as horticultural plantings mature, die, or are replaced; as regulations are promulgated or changed; or as management changes along with fashion, level of investment, or social identity in particular places. Such templates can appear as legacies with persistent effects on ecological and social processes in urban ecosystems. Baltimore, MD a post-industrial, American city, the urban-influenced "rural" settlements bordering Kruger National Park in South Africa, and Beijing, China provide examples of the unintended and dynamic novelty of urban ecosystems.