Urban Ecological Systems: Linking Terrestrial Ecological, Physical, and Socioeconomic Components of Metropolitan Areas

Abstract

Ecological studies of terrestrial urban systems have been approached along several kinds of contrasts: ecology in as opposed to ecology of cities; biogeochemical compared to organismal perspectives, land use planning versus biological, and disciplinary versus interdisciplinary. In order to point out how urban ecological studies are poised for significant integration, we review key aspects of these disparate literatures. We emphasize an open definition of urban systems that accounts for the exchanges of material and influence between cities and surrounding landscapes. Research on ecology in urban systems highlights the nature of the physical environment, including urban climate, hydrology, and soils. Biotic research has studied flora, fauna, and vegetation, including trophic effects of wildlife and pets. Unexpected interactions among soil chemistry, leaf litter quality, and exotic invertebrates exemplify the novel kinds of interactions that can occur in urban systems. Vegetation and faunal responses suggest that the configuration of spatial heterogeneity is especially important in urban systems. This insight parallels the concern in the literature on the ecological dimensions of land use planning. The contrasting approach of ecology of cities has used a strategy of biogeochemical budgets, ecological footprints, and summaries of citywide species richness. Contemporary ecosystem approaches have begun to integrate organismal, * The U.S. Government has the right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper.

Plant food resources exploited by Blue-and-Yellow Macaws (Ara ararauna, Linnaeus 1758) at an urban area in Central Brazil

“…On the other hand, native trees tend to be common in suburban areas in residence backyards and vacant lots (Pickett et al, 2001). Parrots often fed on exotic food plants during famine periods (Forshaw, 1989;Pitter and Christiansen, 1995).…”

“…The vegetation surrounding the urban area includes a mosaic of pasturelands with cerrado remnant trees, cerrado remnants, and seasonal forest in which Blue-and-Yellow Macaws are apparently common (Ragusa-Netto, 2006). The urban vegetation itself is variable, a typical feature of urban areas due to land use and social context (Pickett et al, 2001). In this respect, exotic plant species are often present in central areas, mainly in gardens and squares, whereas native tree species are common in suburban areas in vacant lots and backyards of residences.…”

Indicators of Land Insecurity for Urban Farms: Institutional Affiliation, Investment, and Location

“…At each "branch" of the tree, a decision based on binomial (0,1) regression modeling is made, creating a hierarchical structure that maximizes the reduction in impurity. When the criteria are not met (0) the regression tree branches to the readers left, and when the condition is met (1), to the right. Ability to pay for irrigation, a proxy of economic support, was the most important factor in this analysis followed by school affiliation and the economic opportunity index "high" category.…”

“…Urban populations account for 80% of the population in the United States, and they continue to increase at a steady pace [1,2]. At the same time, participation in urban farming and gardening has risen by 34% in the United States between 2007 and 2011.…”

Studying the patterns of alien and native floras of some habitats in Srinagar city, Kashmir, India

“…But urban areas are characterised by relatively intense stress levels associated with pollution by sewage, nutrients, toxic chemicals, heat and biological pathogens (including invasive species) (Pickett et al 2001). With ever increasing urbanisation, natural areas are becoming increasingly fragmented Saunders et al 1991;Hobbs and Yates 2003), creating ever more urban/wildland interfaces.…”