Evolution and future of urban ecological science:ecology in,of,and for the city

The contrast between ecology in cities and ecology of cities has emphasized the increasing scope of urban ecosystem research.Ecology in focuses on terrestrial and aquatic patches within cities,suburbs,and exurbs as analogs of non-urban habitats.Urban fabric outside analog patches is considered to be inhospi-table matrix.Ecology of the city differs from ecology in by treating entire urban mosaics as social-ecolog-ical systems.Ecology of urban ecosystems incorporates biological,social,and built components.Originally posed as a metaphor to visualize disciplinary evolution,this paper suggests that the contrast has conceptual,empirical,and methodological contents.That is,the contrast constitutes a disciplinary or“local”paradigm shift.The paradigm change between ecology in and ecology of represents increased complexity,moving from focus on biotic communities to holistic social-ecological systems.A third paradigm,ecology for the city,has emerged due to concern for urban sustainability.While ecology for includes the knowledge generated by both ecology in and ecology of,it considers researchers as a part of the system,and acknowledges that they may help envision and advance the social goals of urban sustainability.Using urban heterogeneity as a key urban feature,the three paradigms are shown to contrast in five important ways:disciplinary focus,the relevant theory of spatial heterogeneity,the technology for representing spatial structure,the resulting classification of urban mosaics,and the nature of application to sustainability.Ecology for the city encourages ecologists to engage with other specialists and urban dwellers to shape a more sustainable urban future.

Global urbanization as a shifting context for applying ecological science toward the sustainable city

There is an abundance of conceptual frameworks relevant to sustainability in urban systems.However,to advance urban ecological science and its application to sustainable urban transformations,key existing frameworks must be synthesized.This paper is a conceptual synthesis cast in essay form in order to encompass a broad range of relevant ideas.It starts from the premise that the familiar models of metropolitan and megalopolitan urban structure,of industrially driven urban development,and of the contrasts between urban and non-urban lands are manifestly inadequate representations of evolving global reality.Such inadequacy is illustrated with examples from the United States and from China.Both the form and the interactions involved in contemporary urbanization and urban change suggest the need for a new integrated framework synthesizing two existing yet still evolving concepts:(1)The urban megaregion framework accommodates the spatial extent,interdigitation of contrasting land uses,and the linked spatial relations between nominally urban and nominally rural areas.(2)The new concept of the continuum of urbanity emphasizes the shifts in livelihood and lifestyle driven by regional and global teleconnections and their joint effects on local environments and landscapes.Together these frameworks suggest a common conceptual structure for addressing urban areas of different ages,sizes,forms,and dynamics in both urbanizing and urbanized areas in developing and developed countries and regions.The synthesis of frameworks points to empirical research needs,and has the potential to better match sustainability plans and actions with the diverse urban forms and dynamics now appearing around the world.

Democratization of ecosystem services--a radical approach for assessing nature's benefits in the face of urbanization

Objectives:(1)To evaluate how ecosystem services may be utilized to either reinforce or fracture the planning and development practices that emerged from segregation and eco-nomic exclusion;(2)To survey the current state of ecosystem service assessments and synthesize a growing number of recommendations from the literature for renovating ecosys-tem service analyses.Methods:Utilizing current maps of ecosystem service distribution in Bushbuckridge Local Municipality,South Africa,we considered how a democratized process of assessing ecosys-tem services will produce a more nuanced representation of diverse values in society and capture heterogeneity in ecosystem structure and function.Results:We propose interventions for assessing ecosystem services that are inclusive of a broad range of stakeholders'values and result in actual quantification of social and ecological processes.We demonstrate how to operationalize a pluralistic framework for ecosystem service assessments.Conclusion:A democratized approach to ecosystem service assessments is a reimagined path to rescuing a poorly implemented concept and designing and managing future social-ecological systems that benefit people and support ecosystem integrity.It is the responsi-bility of scientists who do ecosystem services research to embrace more complex,pluralistic frameworks so that sound and inclusive scientific information is utilized in decision-making.

Does the ecological concept of disturbance have utility in urban social-ecological-technological systems?

The ecological concept of disturbance has scarcely been applied in urban systems except in the erroneous but commonplace assumption that urbanization itself is a disturbance and cities are therefore perennially disturbed systems.We evaluate the usefulness of the concept in urban ecology by exploring how a recent conceptual framework for disturbance(Peters et al.2011,Ecosphere,2,art 81)applies to these social-ecological-technological systems(SETS).Case studies,especially from the Long-Term Ecological Research sites of Baltimore and Phoenix,are presented to show the applicability of the framework for disturbances to different elements of these systems at different scales.We find that the framework is easily adapted to urban SETS and that incorporating social and technological drivers and responders can contribute additional insights to disturbance research beyond urban systems.

Integrating structure and function:mapping the hierarchical spatial heterogeneity of urban landscapes

Background:Cities are social-ecological systems characterized by remarkably high spatial and temporal heterogeneity,which are closely related to myriad urban problems.However,the tools to map and quantify this heterogeneity are lacking.We here developed a new three-level classification scheme,by considering ecosystem types(level 1),urban function zones(level 2),and land cover elements(level 3),to map and quantify the hierarchical spatial heterogeneity of urban landscapes.Methods:We applied the scheme using an object-based approach for classification using very high spatial resolution imagery and a vector layer of building location and characteristics.We used a top-down classification procedure by conducting the classification in the order of ecosystem types,function zones,and land cover elements.The classification of the lower level was based on the results of the higher level.We used an objectbased methodology to carry out the three-level classification.Results:We found that the urban ecosystem type accounted for 45.3%of the land within the Shenzhen city administrative boundary.Within the urban ecosystem type,residential and industrial zones were the main zones,accounting for 38.4%and 33.8%,respectively.Tree canopy was the dominant element in Shenzhen city,accounting for 55.6%over all ecosystem types,which includes agricultural and forest.However,in the urban ecosystem type,the proportion of tree canopy was only 22.6%because most trees were distributed in the forest ecosystem type.The proportion of trees was 23.2% in industrial zones,2.2%higher than that in residential zones.That information“hidden”in the usual statistical summaries scaled to the entire administrative unit of Shenzhen has great potential for improving urban management.Conclusions:This paper has taken the theoretical understanding of urban spatial heterogeneity and used it to generate a classification scheme that exploits remotely sensed imagery,infrastructural data available at a municipal level,and object-based spatial analysis.For effective planning and management,the hierarchical levels of landscape classification(level 1),the analysis of use and cover by urban zones(level 2),and the fundamental elements of land cover(level 3),each exposes different respects relevant to city plans and management.