Butterflies in the city: a review of urban diurnal Lepidoptera

Human migration to urban centers has resulted in diverse environmental disturbances that affect biodiversity. Although urbanization has been highlighted as one of the main drivers of biodiversity endangerment, this topic is still poorly studied in many countries. In order to establish the status quo of the ecology of butterflies in urban centers, we gathered publications focused on urban butterflies (Lepidoptera). We compiled a total of 173 studies from 37 countries and more than 110 urban areas, including published papers and theses (1956–2015). Most papers (69 %) addressed ecological topics, 14 % were focused on biological conservation, and 17 % corresponded to species lists. In summary, most studies revealed a negative impact of urbanization intensity on butterfly diversity (richness and abundance). In fact, we found studies reporting local extinctions due to urbanization, highlighting the causes related to them. The study of charismatic urban wildlife groups, such as butterflies, is a promising field, as there are still important gaps in our comprehension of the ecological patterns and processes that occur in urban areas. Undoubtedly, understanding the response of butterflies to urbanization will aid in the development of urban biodiversity management, planning, and conservation strategies worldwide, which together with knowledge of other wildlife groups and socioeconomic variables, will lead us to more sustainable, livable, and biodiverse cities.     

An investigation of the composition of the urban riparian soil propagule bank along the River Brent, Greater London, UK, in comparison with previous propagule bank studies in rural areas

Most propagule bank research has been conducted in rural areas and has emphasised agricultural soils, although research on rural riparian propagule banks has expanded rapidly over the last decade. This paper presents observations of the species abundance of plant propagules in urban riparian soils along the River Brent, Greater London, UK. The data are analysed to explore changes in species abundance of the propagule bank with depth (0?C5?cm compared with 5?C10?cm soil layer), with distance from the river (0?C1?m, 1?C2?m, 2?C3?m), and at different locations on the river network. No significant differences were found in propagule abundance with soil depth or distance from the river??s edge, but significantly more species were found in the propagule bank close to the river??s edge. The species composition of the Brent??s propagule bank is then compared with riparian propagule banks from the rural rivers Dove, Frome and Tern, UK. Species richness of the Brent propagule bank samples was generally lower than was found in the three rural rivers and, in total, 21%, 4%, 5% and 4% of observed species were aliens in the Brent, Dove, Frome and Tern soil samples, respectively. When the species present in the Brent??s propagule bank were compared with published data on urban garden soils in another UK city, the latter were found to support a higher number of alien species, suggesting that other propagule sources to urban river systems support lower numbers of alien species in riparian zones than domestic gardens.     

Habitat structure: A fundamental concept and framework for urban soil ecology

Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils.     

Structuring institutional analysis for urban ecosystems: A key to sustainable urban forest management

A decline in urban forest structure and function in the United States jeopardizes the current focus on developing sustainable cities. A number of social dilemmas—for example, free-rider problems—restrict the sustainable production of ecosystem services and the stock of urban trees from which they flow. However, institutions, or the rules, norms, and strategies that affect human decision-making, resolve many such social dilemmas, and thus, institutional analysis is imperative for understanding urban forest management outcomes. Unfortunately, we find that the definition of institutions varies greatly across and within disciplines, and conceptual frameworks in urban forest management and urban ecosystems research often embed institutions as minor variables. Given the significance of institutional analysis to understanding sustainable rural resource management, this paper attempts to bring clarity to defining, conceptually framing, and operationally analyzing institutions in urban settings with a specific focus on sustainable urban forest management. We conclude that urban ecologists and urban forest management researchers could benefit from applying a working definition of institutions that uniquely defines rules, norms, and strategies, by recognizing the nested nature of operational, collective choice, and constitutional institutions, and by applying the Institutional Analysis and Development framework for analysis of urban social-ecological systems (SESs). Such work promises to spur the desired policy-based research agenda of urban forestry and urban ecology and provide cross-disciplinary fertilization of institutional analysis between rural SESs and urban ecosystems.     

Urban river wall habitat and vegetation: observations from the River Thames through central London

Along heavily engineered urban rivers, river walls and embankments represent the most common habitat available to riparian vegetation. This paper presents the first study into river wall vegetation and the influence of wall surface materials on plant diversity. We were concerned with investigating the plant diversity of such wall habitats, assessing relationships between different wall surface materials and plant diversity, and determining whether river wall and embankment habitats along the River Thames through central London could support native riparian species alongside more typical urban wall flora. Fifteen sites along the River Thames through central London were surveyed to describe wall flora and establish relationships between plant diversity and wall materials. Walls were not species rich, but contained a mix of terrestrial and riparian species. Stone walls with surface fractures and heterogeneous wall surfaces were conducive to plant diversity at the local scale, while wall surface heterogeneity was also important at the landscape scale. Some stratification of vegetation was observed based on wall position relative to flow disturbance. The potential exists for walls to act as sites for habitat improvement and reconciliation ecology within urban rivers.     

Toward a pragmatic program for critical urban ecology

Our essay responds to the critique of Dooling et al. (Urban Ecosystems in press, 2007) of our previously published article “Goal attainment in urban ecology research: a bibliometric review 1975-2004 (Young and Wolf, Urban Ecosystems, 9:179–193, 2006). We identify our critics’ concerns as rooted in a project of deconstruction of scientific inquiry and a redefinition of the boundaries separating academic disciplines from each other and science from society. While we identify important differences with our critics, we largely support this critical project, as evidenced by our previously published empirical research. In exploring the relationship between critical and positivist approaches to urban ecology research and how we might work toward an integration of nature and society in thought and action, we defend pragmatic approaches to empirical research as well as disciplinary projects as legitimate and essential elements of urban ecology research. We argue in favor of theoretical and methodological pluralism. Rather than define urban ecology through exclusionary projects that would limit the scope and significance of urban ecology research, we reaffirm our call for diverse sets of actors inside and outside university settings to engage and support each other in order to develop and strengthen analysis and pursuit of sustainability.

Response to Young and Wolf: goal attainment in urban ecology research

Our critique focuses on the poorly defined key concepts, methodological inconsistencies, circular research design, and over-reaching substantive claims made by Young and Wolf. We suggest that Young and Wolf have provided an assessment of the Urban Ecosystems journal, not of urban ecology as a field. We conclude by identifying questions to guide a bibliometric analysis that focuses on a collaborative and interdisciplinary future of urban ecology (how are participating disciplines contributing to urban ecological research and scholarship; what theories and conceptual frameworks are being used, and how are these theories being tested and modified; and what mixed methodologies are being developed to collect data to address complex urban issues that are inherently interdisciplinary). We take seriously Young and Wolf’s call for a “fundamental discussion as to if and how the intentions of the field have been or need to be updated” and argue that such a discussion requires a more inclusive, rigorous, and meaningful identification of the “core” of urban ecology literature than provided.     

Some simple tools for communicating the biophysical condition of urban rivers to support decision making in relation to river restoration

This paper illustrates a set of simple tools that may be used to assess and communicate the biophysical condition of river and riparian habitat in urban catchments. The tools are based upon information collected using the Urban River Survey (URS), a habitat survey designed for application to 500?m stretches of urban river corridor, and comprise (i) a series of aggregate indices, (ii) three classifications relating to the materials, habitat and vegetation characteristics of urban river stretches, which contribute to an overall score, the Stretch Habitat Quality Index (SHQI), and (iii) two environmental gradients which define a URS matrix of engineering:habitat associations. This toolkit may be used to gather and exchange knowledge about urban river habitat quality to a wide range of specialist or non-technical stakeholders and local community members. It may be used to provide information at the catchment and reach scales to support stakeholder discussions and decision making relating to initial site selection for restoration works; to post project appraisal; and to track changes in river character across space and through time. Example applications of the tools are provided using URS surveys undertaken on tributaries of the River Thames within London in comparison with an archive of previous surveys from three other urban river systems. These tools are being validated in London as part of a larger interdisciplinary research project that is testing the suitability of this type of approach in the context of the London Rivers Action Plan, Water Framework Directive, and urban green space regeneration.     

A case study of urban ecological networks and a sustainable city: Tehran’s metropolitan area

The aim of this study is to propose the application of landscape ecology in planning urban ecological networks to conserve nature in urban landscapes and to develop a sustainable use of urban lands. Compared to the classical planning approach based on socio-economic land suitability, the principles of landscape ecology are helpful simultaneously conserving the ecological processes of landscapes and their steady changes. This approach could help in defining sustainable landscape development, aiming for a balance between both physical and natural systems in urban areas. This research is focused on the ecological networks in Tehran’s metropolitan area as a case study to provide a model for network planning in other urban areas, where urbanization seriously threats the natural environment. In concluding this research, the spatial structure and function of the area are studied and categorized based on the patch-corridor-matrix model. The paper concludes with methods of intervention and suggestions for the structural and functional improvement of urban landscapes towards achieving a more sustainable form of land use planning.     

Interdisciplinary foundations of urban ecology

Researchers have identified urban ecology as a new field integrating social and ecological science. Critics have portrayed the field as under-theorized with negative implications for research and urban environmental planning. Unprecedented urbanization and historical bias against research integrating social and ecological systems are identified as driving this deficit. Researchers have called for new integrative approaches to address this issue. In response, this paper applies ecology’s analytic framework of “patch dynamics”, Kuhn’s concept of “normal science” and Mazoyer and Roudart’s “evolutionary series” to demographic data and historical texts to perform an analysis of interdisciplinary contributions to theory applicable in the field of urban ecology. The subsequent exploration reveals a rich history of interdisciplinary inquiry along the nature/society divide. The paper concludes that these “largely ignored” contributions offer urban ecology the opportunity to claim much broader depth as a field gaining access to precedents and innovations accomplished during the field’s early theoretical development. Drawing upon this history, a framework for ecological urban development is suggested to inform and assist contemporary research in urban ecology and planning.

A conceptual framework for the study of human ecosystems in urban areas

The need for integrated concepts, capable of satisfying natural and social scientists and supporting integrated research, motivates a conceptual framework for understanding the role of humans in ecosystems. The question is how to add humans to the ecological models used to understand urban ecosystems. The ecosystem concept can serve as the basis, but specific social attributes of humans and their institutions must be added. Learning and feedback between the human and natural components of urban ecosystems are key attributes of the integrated model. Parallels with familiar ecological approaches can help in understanding the ecology of urban ecosystems. These include the role of spatial heterogeneity and organizational hierarchies in both the social and natural components of urban ecosystems. Although urban watersheds are commonly highly altered, the watershed approach can serve as a spatial basis for organizing comparative studies of ecosystems exhibiting differing degrees of urbanization. The watershed concept can also spatially organize the hierarchically scaled linkages by which the integrated human ecosystem model can be applied. The study of urban ecosystems is a relatively new field, and the questions suggested by the integrated framework can be used to frame ecosystem research in and associated with urban and metropolitan areas.     

Place-based urban ecology: A century of park planning in Seattle

This research responds to calls from within the field of urban ecology to explicitly incorporate humanities-based research in order to achieve robust interdisciplinarity. Our research provides an example of a place-based urban ecological analysis. We use this framework to analyze over a century of park planning and development within the city of Seattle. We identify four eras of park planning that are linked by a comprehensive 100-year park plan. This case study examines how the political, cultural, and economic aspects of park planning have produced and been influenced by long-term trends and historical contingencies. This research also offers practical insights for effective contemporary urban planning, emphasizing the need for flexible and adaptive long-term plans when confronted with unpredictable events, emerging political arrangements, changing cultural priorities, and shifting fiscal climates.     

Public life in Bangkok's urban spaces

The paper examines public life within Bangkok's urban spaces on the premise that user needs and satisfaction should play an integral component in the design of these spaces. An ecology-culture-behaviour paradigm is introduced to appropriately rationalise the relationship between urban design, ecology and sociology. Bangkok, a canal- and river-based port city, echoes the urban morphological processes of early Southeast Asian coastal settlements, but differs in its social and physical construct because of its lack of exposure to colonial dominance. Only in the latter part of the 19th century, when Western influence was introduced and became stronger, a change in its physical form was manifest, but the city still retained the social construct within its urban spaces and activity nodes (i.e. informal, commercial and religious spaces). Bangkok street users and their corresponding activities within the contemporary urban street space are also examined through field observation and survey to paint an overall picture of the behaviour and attitudes of the street users. The Bangkok experience presents a case of a dynamic city with competition between its traditions and the Western contemporary influences on its urban spaces. Finally, the paper reiterates the significant need to reconsider the intrinsic relationship between ecology, culture and behaviour to better understand the life between structures to create an urban space that satisfies its end users.     

The engineering of consent: A state-of-the-art review

This study systematically analyzes Engineering of Consent (EOC)-focused scholarly papers published between 1947 and 2018 using content analysis and text mining. It aims to shed light on the progress of EOC research and related disciplines as well as the methodologies, data collection methods, major perspectives, and most frequent words used within these writings. Additionally, this study considers publications by region and the affiliations of first authors. The results show that only a small number of EOC-focused papers have been published since 1947; this area of public relations research has suffered from a lack of scholarly attention despite its relevance to various disciplines, and this is a situation that we hope improves. Recent trends have shown some reasons for optimism. We found that at least one EOC-focused paper has been published annually in most years since 2000 (the exceptions are 2001, 2006, 2010, 2011, and 2015). Our research shows that scholars in the fields of public relations, media studies, and political science published more papers on EOC than scholars in other fields. Research articles usually utilize qualitative research methodologies. Interviews stand out as the most widely used data collection method. Our analysis of publications by region and first-author affiliation shows that the majority of EOC papers were written by faculty and students working or studying in the United States. Seven perspectives frequently discussed by scholars and the most frequently used words within EOC papers are highlighted in a follow-up qualitative review.     

Fengshui theory in urban landscape planning

The spatial configuration of urban landscapes results from cumulative interactions between human activities and the physical environment. Traditional philosophies and cultural legacies have had important influences on urban development and planning in East Asia. In Seoul, traditional land use practices based on ‘Fengshui’ have significantly contributed to human-mediated patterns of landscape changes, in addition to the role of the socio-economic background (development) and other human activities. The concept of Fengshui was originally founded upon people’s empirical cognition of natural landscape patterns. Recently, however, advanced economic development, westernization and urbanization have been rapidly altering the old traditions of the holistic landscape systems through changing urban planning practices. Since the type, scale, frequency, distribution and spreading pattern of environmental and human disturbances have been changed, a new paradigm for urban landscape planning is necessary to maintain the ecological and cultural integrity of landscapes in Korea. In this paper, we discuss recent concepts and methods of landscape ecology and urban planning from the viewpoint of Fengshui, the traditional land use patterns in Seoul, whose application has so far been restricted only to traditional land evaluation. We conclude that, to maintain the sustainability of the urban landscape, it is necessary to develop a new urban planning framework for the region that is based on the integration between landscape ecology principles with the traditional concepts of Fengshui.     

Socio-economic variables as indicators of pond conservation value in an urban landscape

Despite their designation as nationally important habitats in the UK, ponds are among the least well studied of urban habitats. Ponds, as well as existing in a physical landscape, are part of human socio-economic landscapes, especially those in towns and cities. Socio-economic, ecological and land cover data were collected from thirty seven ponds in the urban area of Halton, northwest England over a 3?year period. Significant variation was observed in the CCI Scores for ponds in different Output Area Classifications. Within postcode districts there was a significantly negative correlation between increasing house prices and decreasing BMWP scores. This research offers insights into the impact of urban development on pond ecology, and suggests the potential impacts of future developments and how these may be ameliorated. The research contributes towards the understanding of freshwater systems in the urban context and the relationship between the human and natural elements of urban green and blue spaces.     

Peeking into the past to plan the future: Assessing bird species richness in a neotropical city

Urbanization has been considered as a major threat to biodiversity, making its ecology of increasing interest. Many urban ecology studies have been developed in a short time-scale, measuring real-time patterns. However, long-term studies are imperative to understand the responses of some species to the urbanization process. In this study, we aimed to assess the information provided by a recent one-year citywide bird survey when compared to a published ‘historical’ bird list of a neotropical city (Xalapa, Mexico) that compiles information of the past three decades, mainly from urban greenspaces. Specifically, we contrasted species richness values and assessed differences in species composition between both lists. We recorded 51 species in the one-year citywide survey, representing ~15 % of those reported in the historical list. Nonetheless, the upper-bound confidence interval of the citywide survey richness prediction represented ~66 %. Most of the species recorded in the one-year citywide survey are insectivores and granivores, a pattern that agrees with previous findings that underline the importance of insectivores as part of urban bird communities in the Neotropics. Although we used robust methods to compare our one-year citywide bird list and the historical list for the city of Xalapa, we acknowledge the limitations of comparing them. However, our results shed some light on the kind and type of information that one-year citywide surveys can provide and the importance of long-term studies for comprehending the processes involved in biodiversity changes within urban areas over time. Undoubtedly, establishing long-term citywide surveys sampling birds and other biodiversity groups will allow us to better understand the response of biodiversity to urbanization over time.     

The influence of land use type and municipal context on urban tree species diversity

Recent research has focused on the ways urban forest patterns vary in relation to level of urbanization and socioeconomic characteristics, with most studies limited to one urban land use type or multiple non-differentiate land uses. Additionally, the majority of studies examining urban forest patterns focus on canopy cover extent, with less attention given to patterns of species diversity. This study explores how tree species diversity varies across different urban land uses and municipal boundaries to better understand the role of land use types in shaping urban forest patterns. The goal is addressed through an exploration of plot-level tree data in the urban municipalities of Peel Region located in the Greater Toronto Area (Ontario, Canada). Species composition and standard diversity metrics are calculated for eight land use types and four municipalities. Our results show that differences in diversity metrics and species composition are greater between urban land uses than municipalities. Moreover, Peel’s urban forest has relatively high alpha diversity but many species are present on only one land use type. The results suggest that different causal processes are associated with each land use type, and that urban forest managers should adopt land use-specific strategies to meet species composition goals within the urban forest.     

Restoring complex vegetation in urban settings: The case of tidal freshwater marshes

Tidal freshwater marshes have diverse plant communities that vary spatially and temporally due to hydrology, animal activity, and other factors. Development of urban centers along rivers of the U.S. Atlantic coast has reduced the historic extent and quality of these and other coastal wetlands. Because the vegetation of these wetlands is more complex than that of salt and brackish marshes (where restoration of vegetation typical of natural systems has sometimes been successful), restoration of tidal freshwater marsh vegetation is likely to be more difficult, particularly in urban areas. Watershed urbanization alters hydrology, sediment load, propagule availability and composition, nutrient status, and other variables that together create an environment different from that of wetlands in less developed areas, possibly precluding restoration of typical marsh vegetation. Tidal freshwater wetlands were historically extensive along the Anacostia River in Washington, DC, but most of these were lost due to filling, dredging, or hydrologic alteration. Over the last decade, the U.S. Army Corps of Engineers has implemented projects designed to restore tidal freshwater wetlands along the Anacostia, which involved increasing elevation with dredged river sediment and planting native vegetation. To illustrate some of the mechanisms affecting vegetation development in restored tidal freshwater marshes in urban areas, I present a case study on one of these wetlands, Kingman Marsh, that also includes research at another restored wetland and two natural reference sites. Studies by my research groups indicate that the restored wetlands undergo essentially a planting-modified process of primary succession. Low densities of seeds are initially present in the substrate, and prolific seed dispersal into the restored sites results in high initial plant diversity comprised of plantings and ruderal (i.e. weedy) natives and exotics. Seed banks develop rapidly at the restored sites, probably due to colonization and early reproduction by ruderal species. Hydrology and disturbance by non-native animals (including resident Canada goose) are important variables controlling establishment of vegetation in these systems. Recent literature and the case study indicate that the environmental conditions of urban settings impose constraints in restored wetlands that result in plant communities more like those of urban natural wetlands than those of wetlands in less urbanized watersheds. This suggests that rather than design wetland restoration projects with the goal of creating pristine wetland vegetation, restorationists must identify, accept, and if possible capitalize on the ecological constraints of the urban environment in setting achievable and desirable restoration goals.