Journal of Urban Ecology: Linking and promoting research and practice in the evolving discipline of urban ecology: Figure 1.

Abstract

Human settlements are unique ecosystems consisting of human-made structures and natural elements, including people, which are maintained and transformed by a complex set of interactions within and between ecological and social systems. The sheer number, size, extent, rate of growth, and degree of environmental impacts of current human settlements are unsurpassed in the history of our planet. Today, cities and towns face a multitude of formidable environmental and social challenges including air and water pollution, increasing energy demands, poor waste management, and food shortages, all of which directly impact on human health and well-being (UN-Habitat 2008). There is also growing evidence regarding the influence of urbanization on cultural values and social cohesion (Thiagarajah et al. 2015; van Tran 2015). In addition, the creation and expansion of urban environments have lead to a significant degradation of native habitats resulting in the reduction of local, regional, and global biodiversity (Mcdonald, Kareiva, and Forman 2008; Seto, Guneralp, and Hutyra 2012). New ‘novel ecosystems’ have been created that exhibit unique species compositions and ecosystem processes that may have only nominal resemblance to historic or existing ecosystems (Kowarik 2011; Mascaro et al. 2013). These issues are not restricted to our larger cities of a million residents or more, they are also occurring in less populated, but growing, periurban areas and small villages and towns especially in developing countries (Elmqvist et al. 2013). The effects of ongoing human actions in the form of urbanization and climate change currently threaten the quality of life, and the economic and social stability of human societies around the globe (UN-Habitat 2011). Our planet has advanced into what Haughton and Hunter (1994) refer to as the fifth and most current stage of human–ecosystem relationships in which cities are more economically and environmentally interconnected and their impacts have grown from local … markmc{at}unimelb.edu.au