Differential community and the perception of urban green spaces and their contents in the megacity of Karachi, Pakistan

Urban green spaces (UGS) denote the chief representative of biodiversity and provider of ecosystem services (especially social and cultural) in urban landscapes. Socio-economic circumstances of individuals are significantly derived from their psychometric settings–which ultimately affect their preferences in urban landscapes–more so for multicultural and multifaceted social environments. This paper investigates the coupling of distinct socio-economic (life quality) standards and urban natural spaces (and their content) in the megacity of Karachi, Pakistan. The main research question was how the socio-economic conditions of the differentiated and multicultural community influence their preferences of urban green spaces. It was tested at three systematically selected research sites of distinct structural and functional characteristics but the results and discussion are presented in an integrative form. The study sites were selected using Karachi’s urban-rural gradient to deduce representative samples from different land use and urbanization zones. Public interviews of 340 respondents were conducted with a structured questionnaire. The findings contradict generalizations made in other international studies. Results show that the presumption of tightly coupled social settings and nature space preferences could not be validated empirically for varying types of cities in the world. This is because people perceive their heterogeneous natural and artificial environment differently in different regional settings. The multicultural environment dissembles the choices of people and vice versa. This is true regardless of the sampling strategy for such studies that had been the focus in the past. Community revitalization is deemed necessary for better design, facilities and functions of UGS to foster social wellbeing of residents as well as sustainable urban development.     

Social-ecological innovation: adaptive responses to urban environmental conditions

Novel approaches to natural resource management, particularly those which promote stakeholder participation, have been put forward as fundamental ingredients for establishing resilient, polycentric forms of environmental governance. This is nowhere more pertinent than in the case of the complex adaptive systems associated with urban areas. Decentralisation of urban green space management has been posited as an element thereof which, according to resilience thinking, should contribute to the adaptive capacity of cities and the ecosystem services upon which they rely. Implicit in this move towards increased adaptive capacity is the ability to manage through innovation. Although the importance of innovation towards system adaptability has been acknowledged, little work has thus far been carried out which demonstrates that innovative use of urban green space represents a form of adaptive response to environmental conditions. The current paper reports on research which maps examples of organised social-ecological innovation (OSEI) in an urban study area and evaluates them as adaptive responses to local environmental conditions which may contribute to system resilience. The results present OSEI as a coherent body of responses to local social and environmental deprivation, exhibiting diversity and adaptability according to individual contexts. The study therefore provides evidence for the importance of local stakeholder-led innovation as in the building of adaptive capacity in urban social-ecological systems.     

Ecosystem services assessment of the urban forests of Addis Ababa,Ethiopia

Addis Ababa is a highland city with varied topography and landscape features. The mountains that surround the city are covered with urban forest of different types. These forests are providing various ecosystem services for the urban and peri-urban population of the city. Apart from surface temperature regulating function of the green spaces of Addis Ababa, no quantitative assessment of the carbon sequestration and soil protection ecosystem services provided by the urban forest has been conducted to date. The aim of this study was to assess selected ecosystem services such as carbon storage potential, habitat support and soil erosion protection provided by different categories of urban forest of Addis Ababa. The result showed that carbon density in the study area varied with forest categories viz. 293tons/ha, 142tons/ha and 132tons/ha in the dense, medium and open forest types respectively. The Shannon-Wiener diversity index is3.24 for Junipers dominated forest, 2.98 for mixed forest and 2.76 for Eucalyptus dominated forest. The formation of soil erosion features is significantly different among the Eucalyptus forest, Juniperus forest and Mixed forest where high incidence of soil erosion was recorded in the Eucalyptus forest. Therefore, irrespective of the environmental factors such as slope, aspect and elevation differences, there is an association between Eucalyptus forest cover and high soil erosion features. To ensure sustainable supply of ecosystem services and maintain a balanced urban environment, all green spaces in the city should be ecologically networked and diversified. Therefore, assessment of ecosystem services provided essential information for effective planning of the green space in terms of species composition and interconnectivity.     

Social ecological complex adaptive systems: a framework for research on payments for ecosystem services

The environment is both a setting for and a product of human interactions. Understanding the dynamic nature of human-environment interactions is critical for mitigating the impacts of human induced environmental change and understanding how the environment shapes social systems. Current research has focused on the reduced ability of many natural systems to provide ecosystem services and the subsequent impact on human well-being. Furthermore, there has been a proliferation of cases analyzing the impacts of payment programs designed to enhance ecosystem services. However, analyses that link environmental policies through to their ecological results are not common and methods to do so are not thoroughly developed. To better analyze these interactions, a theory or framework is necessary. This article presents a framework of social ecological complex adaptive systems (SECAS). The framework links structuration theory from social science with the theories of complex adaptive systems from ecology to provide an enhanced understanding of the human drivers and responses to environmental change. The framework is presented as a recursive process where social and ecological systems are both the medium for and product of social action and ecological disturbance. A case study of Costa Rica’s ecosystem service payment program is presented as a demonstration of empirical applicability. This framework is proposed as a method to evaluate payments for ecosystem services, conservation policies, urban ecosystems, and for land use change in general.     

Mainstreaming urban ecosystem services: A national survey of municipal foresters

Researchers and advocates are calling for ecosystem services management to advance from theory to implementation. To do so, they argue, requires two things: information on the science and practice ecosystem services management to be more widely developed and distributed, and support for ecosystem services management be incorporated into decision-making. These changes require adding to urban ecology an understanding of the political and information relationships supporting work in this field. To gain insight into these relationships I surveyed the national membership of the Society for Municipal Arborists about their efforts in managing municipal green space to produce ecosystem services. A significant percentage of respondents reported their organizations currently engaged in managing green space assets to produce ecosystem services and predicted such activities would increase over time. Foresters noted they relied on public and informal peer relationships as primary information sources in these efforts and reported little interface with private sector entities, viewing the latter, rather as most likely to constrain their efforts to enhance the production of ecosystem services. While foresters noted that they sought information from public and academic sources, the foresters themselves were less frequently sought out for their expertise. Respondents, however, foresaw becoming engaged in more reciprocal relationships around information exchange. The private sector’s absence in these relationships suggests insufficient legal and regulatory structures necessary to support private engagement in the growing demand for urban ecosystem services. The broad base of local grassroots and public support, however, suggest the emergence of constituencies that could lay the basis for new coalitions to advance green infrastructure and its related ecosystem services into the mainstream of municipal resource management.     

Comparing community garden typologies of Baltimore,Chicago, and New York City (USA) to understand potential implications for socio-ecological services

Urban community gardens offer unique social and ecological benefits in cities. However, given the dynamic nature of cities and the profound effects of variable land uses on green space provisioning for people and wildlife, investigating community gardens from a landscape perspective offers valuable insight into the functions of these spaces in terms of ecosystem services and sustainable development. In this study, we use garden locations provided by stakeholder groups and fine-scale spatial data to compare community gardens across three cities: New York City, NY, Chicago, IL, and Baltimore, MD (USA). In each city, we assess the spatial distribution of gardens and compare the natural vegetation and impervious surface cover within these gardens to the surrounding neighborhood and landscape. We then compared these cities to clarify the role of community gardens in metropolitan development. Our findings demonstrate that gardens cluster in neighborhoods in New York City and Chicago, but they are more spatially distributed across the landscape in Baltimore. The distribution of Baltimore’s community gardens is more likely to be contributing to a greater network of ecosystem services across a broader urban landscape. Moreover, at the garden scale, gardens in NYC and Chicago have more canopy cover and built infrastructure than the more herbaceous gardens in Baltimore. This suggests that our case study cities exhibit different garden typologies, histories, and potential for ecosystem services. This work provides critical insight into the typology in and around community gardens in different cities, which is useful in understanding the potential ecosystem services and planning trajectories of these cities.

     

Vegetation on and around large-scale buildings positively influences native tropical bird abundance and bird species richness

High population growth in the tropics is driving urbanisation, removing diverse natural ecosystems. This is causing native species to suffer while introduced synanthropes flourish. City planners are developing urban greenspace networks, in part trying to address this issue. Architects contribute to these greenspace networks by designing elevated and ground level green spaces on large-scale buildings. However, little evidence is available on whether building green spaces support native fauna. This is true for birds in tropical Singapore that support important ecosystem services and have existence value. Therefore, in this study, we conducted bird surveys and statistical analyses to determine, if and how vegetation on three building green space types (ground gardens, roof gardens and green walls) have a positive impact on native or introduced bird species. We found that elevated greenery (roof gardens and green walls) on large-scale buildings supported a higher richness of birds and abundance of urban native birds than control roofs and walls without vegetation. Ground gardens supported similar levels of native species as roof gardens but also a larger proportion of generalist synanthropes. However, we found no tropical forest habitat specialists across any space type. Therefore, we recommend roof gardens and ground gardens as a potential space for urban natives outside of a less competitive ground-level urban environment. Our study also found certain building design elements (height of elevated space, presence of specific plants) supported different species groups. Therefore, we suggest that these ecological requirements for different species groups are considered when designing a building’s green space.

     

Does demolition improve biodiversity? Linking urban green space and socioeconomic characteristics to avian richness in a shrinking city

Anthropogenic change, specifically urbanization, has lasting impacts on biodiversity and ecosystem services. Past work has linked green space variables and socioeconomic characteristics with biodiversity in urban areas. Shrinking cities present an interesting case for studying biodiversity because many of these places have implemented demolition policies to remove vacant buildings from the landscape, which returns previously urbanized land back into a “natural” state. The objective of this study is to investigate the multifaceted relationship among urban green space, socioeconomic characteristics, demolition activities, and avian species richness in the shrinking city of Buffalo, NY. We first establish a baseline understanding of how social and ecological factors are related to avian species richness through generalized linear models (GLM) and then incorporate a variable characterizing demolition to understand how the process of demolition may be impacting species richness relative to other factors. Second, since our analysis relies on “citizen science” data from eBird, we aim to better understand the factors driving eBird participation in Buffalo through zero-inflated negative binomial (ZINB) regression models to test how social and ecological characteristics and demolition affect checklists submission across the city. Our findings suggested that demolition activities do not increase species richness in Buffalo, indicating these sites may not be returning to a natural state that is usable by birds. We also found that areas that have undergone considerable demolition may be a potential deterrent to eBird participation, and eBird users may create bias by sampling areas with greater green space connectivity, and thus higher richness.     

Singapore as a long-term case study for tropical urban ecosystem services

Ecosystem services have gained rapid interest for understanding urban-environment interactions. However, while the term “ecosystem services” is relatively novel, their principles have influenced urban planning for decades. This study assesses the wealth of urban ecosystem services research conducted in the tropical city state of Singapore, in particular their historical local use and implicit and explicit incorporation into land use planning, and shows how Singapore is exporting their experiences to other cities around the world. Singapore is an important model for urban ecosystem services research, as the nation has experienced rapid urban development and has a 100 % urban population. Singapore also historically utilized ecosystem services in urban decision making long before the concept was popularized. For example, forests were conserved since 1868 for climatic regulation and for the watershed protection services provided to Singapore’s first reservoirs, and green spaces have been conserved for cultural ecosystem services since the 1920s. Urban ecosystem services were formally incorporated into national planning in the 1960s through the “Garden City” urban planning vision. Singapore is now a leading case study for tropical urban climatology and carbon sequestration, exporting its experiences globally through bilateral agreements and the construction of eco-cities in China, and the creation and promotion of a global City Biodiversity Index to assess urban ecosystem service provision in cities across the globe. Consolidating and understanding case study cities such as Singapore is important if we are to understand how to incorporate multiple ecosystem services into large scale planning frameworks, and provides an important tropical example in a research field dominated by western, temperate case studies.     

Urban and agricultural soils: conflicts and trade-offs in the optimization of ecosystem services

On-going human population growth and changing patterns of resource consumption are increasing global demand for ecosystem services, many of which are provided by soils. Some of these ecosystem services are linearly related to the surface area of pervious soil, whereas others show non-linear relationships, making ecosystem service optimization a complex task. As limited land availability creates conflicting demands among various types of land use, a central challenge is how to weigh these conflicting interests and how to achieve the best solutions possible from a perspective of sustainable societal development. These conflicting interests become most apparent in soils that are the most heavily used by humans for specific purposes: urban soils used for green spaces, housing, and other infrastructure and agricultural soils for producing food, fibres and biofuels. We argue that, despite their seemingly divergent uses of land, agricultural and urban soils share common features with regards to interactions between ecosystem services, and that the trade-offs associated with decision-making, while scale- and context-dependent, can be surprisingly similar between the two systems. We propose that the trade-offs within land use types and their soil-related ecosystems services are often disproportional, and quantifying these will enable ecologists and soil scientists to help policy makers optimizing management decisions when confronted with demands for multiple services under limited land availability.     

Experts’ versus laypersons’ perception of urban cultural ecosystem services

Urban cultural ecosystem services are understood differently by experts and laypersons. Yet, unaccounted differences can lead to management problems for urban green spaces, as experts may recommend practices that do not meet the laypersons’ wishes. Qualitative research on the perception of cultural ecosystem services can be one tool to analyze these differences. We use expert and problem-centered interviews to assess differences in cultural ecosystem service perceptions for experts and laypersons in Berlin. Using an innovative approach, we combine inductive qualitative content analysis with a frequency analysis and multidimensional scaling. This explorative study innovatively merges qualitative and quantitative approaches to show new ways of analysis. Our results show that the experts’ perceptions of nature appear to be more practical, management-centered, whereas laypersons appear to prioritize enjoyment of nature. Overall, multidimensional scaling indicates different perceptions and conceptualizations of cultural ecosystem service bundles, emphasizing the diverging understandings. If these different perceptions are not accounted for it could lead to social and political contrast. They should therefore be acknowledged in decision-making and goal formulation for the management of urban green.     

City-wide relationships between green spaces,urban land use and topography

The growing proportion of human populations living in urban areas, and consequent trends of increasing urban expansion and densification fuel a need to understand how urban form and land use affect environmental quality, including the availability of urban green spaces. Here we use Sheffield as a case study of city-wide relationships between urban green space extent, quality (vegetation cover and tree-cover), and gradients in urban form and topography. The total area of buildings and length of the road network are equally strong negative predictors of extent of green space, while the former predictor is a more important negative influence upon green space quality. Elevation positively influences extent of green space but negatively influences tree-cover. In contrast, slope of terrain positively influences green space quality and is the best predictor of tree-cover. Overall housing density is a more important negative predictor of extent of green space and tree-cover than the densities of individual housing types. Nevertheless, the latter are more important influences upon levels of vegetation cover. Threshold effects of densities of different housing types suggest opportunities for optimising green space quality, with implications for housing policy. Variation in ecological quality of green space may partly reflect different historical intensities of industrial activity.     

Approaches to the study of urban ecosystems: The case of Central Arizona—Phoenix

CAP LTER focuses on an arid-land ecosystem profoundly influenced, even defined, by the presence and activities of humans and is one of only two LTER sites that specifically studies the ecology of an urban system. In this large-scale project, biological, physical, and social scientists are working together to study the structure and function of the urban ecosystem, to assess the effects of urban development on surrounding agricultural and desert lands, and to study the relationship and feedbacks between human decisions and ecological processes.Our interdisciplinary investigations into the relationship between land-use decisions and ecological consequences in the rapidly growing urban environment of Phoenix are of broad relevance for the study of social ecological systems and cites in particular. Refinements in our conceptual model of social ecological systems focuses our attention on recognizing the scales and periodicities of ecological and human phenomena, understanding the means and impacts of human control of variability in space and time, and finally an evaluation of the resilience of various aspects of socio-ecological systems especially their vulnerabilities and their potential for adaptive learning.     

Ecosystem services of urban green spaces in African countries—perspectives and challenges

The concept of ecosystem goods and services is increasingly used to describe how biodiversity and ecosystems are linked to human well-being and that it should be placed at the core of sustainable urban development. Predictions of a tremendous future increase of urbanization in Africa necessitate an investigation into the research on ecosystem goods and services in the urban green infrastructure of Africa. Ecosystem goods and services (ES) are described as the benefits humans derive directly or indirectly from ecosystem functions and are classified as supporting, provisioning, regulating and cultural services. A literature study focusing on journal papers was conducted. Additionally a case study based on two masters studies was further refined. ES studies in African cities are biased towards South Africa and include assessments and economic valuations in which several different methods were used to determine direct consumptive and non-consumptive and indirect use values. Emphasis was placed on the multifunctional nature of ES. The main objectives of these studies were to sensitize policy makers, planners and the general public about the importance of biodiversity and ES. Ecosystem-based adaptation is discussed as the most appropriate approach in terms of applying knowledge about ES and their values in African cities as many residents still rely on ES from natural areas, but the major ecological, economic and political challenges are acknowledged. A case study focusing on domestic gardens (private green spaces) have indicated that the demand and supply of certain ES differ along a socio-economic gradient due to poor service delivery and smaller plots in the poorer areas mainly due to the legacy of separate development of the past. Where provisioning services are mainly outsourced in cities, it was found that plant species useful as food, medicine, etc. were more frequent in the gardens of poorer residents than in those of more affluent areas. The tendency to pay more for residential properties close to public open spaces, as in Europe, could not be statistically proven in the more affluent areas of a South African city, although the property values in proximity of public open spaces in some of the areas studied were lower than further away.     

Local and landscape drivers of arthropod abundance,richness, and trophic composition in urban habitats

Urban green spaces, such as forest fragments, vacant lots, and community gardens, are increasingly highlighted as biodiversity refuges and are of growing interest to conservation. At the same time, the burgeoning urban garden movement partially seeks to ameliorate problems of food security. Arthropods link these two issues (conservation and food security) given their abundance, diversity, and role as providers of ecosystem services like pollination and pest control. Many previous studies of urban arthropods focused on a single taxon (e.g. order or family), and examined either local habitat drivers or effects of landscape characteristics. In contrast, we examined both local and landscape drivers of community patterns, and examined differences in abundance, richness, and trophic structure of arthropod communities in urban forest fragments, vacant lots, and community gardens. We sampled ground-foraging arthropods, collected data on 24 local habitat features (e.g., vegetation, ground cover, concrete), and examined land-cover types within 2 km of 12 study sites in Toledo, Ohio. We found that abundance and richness of urban arthropods differed by habitat type and that richness of ants and spiders, in particular, varied among lots, gardens, and forests. Several local and landscape factors correlated with changes in abundance, richness, and trophic composition of arthropods, and different factors were important for specific arthropod groups. Overwhelmingly, local factors were the predominant (80 % of interactions) driver of arthropods in this urban environment. These results indicate that park managers and gardeners alike may be able to manage forests and gardens to promote biodiversity of desired organisms and potentially improve ecosystem services within the urban landscape.     

A comparative gradient approach as a tool for understanding and managing urban ecosystems

To meet the grand challenges of the urban century??such as climate change, biodiversity loss, and persistent poverty??urban and ecological theory must contribute to integrated frameworks that treat social and ecological dynamics as interdependent. A socio-ecological framework that encapsulates theory from the social and ecological sciences will improve understanding of metropolitan dynamics and generate science for improved, sustainable management of urban ecosystems. To date, most urban ecological research has focused on single cities. A comparative approach that uses gradients within and between cities is a useful tool for building urban ecological theory. We offer five hypotheses that are testable using a comparative, gradient approach: (i) the current size, configuration, and function of larger metropolitan ecosystems predicts the potential trajectory of smaller urban areas; (ii) timing of growth explains the greatest variance in urban ecosystem structure and function; (iii) form and function of urban ecosystems are converging over time; (iv) urban ecosystems become more segregated and fragmented as populations increase; and (v) larger cities are more innovative than smaller cities in managing urban ecosystems.     

A balancing act in urban social-ecology: human appreciation,ponds and dragonflies

Green spaces in cities provide cultural ecosystems services (CES) such as nature connection, wildlife interaction and aesthetic appreciation which can improve aspects of human well-being. Recognising these benefits, researchers are now examining the complex relationship between humans and nature in urban social-ecology. Most studies investigate people’s appreciation and valuation of different green space features and their contribution to urban biodiversity. Recommendations arising from such studies are best practices to achieve a balance between landscape aesthetic and ecological objectives, but many knowledge gaps still exist. In a social-ecological project in Greater London, appreciation of ponds and dragonflies in urban green spaces, and the environmental factors determining dragonfly diversity were investigated. We found ponds and their appearance were valued by people as enhancing their green space experience. The preference for wild-looking ponds was moderate. Dragonflies were enjoyed for their colour and high visibility, especially by those who had basic dragonfly knowledge. Species richness of dragonflies was positively associated with habitat heterogeneity in and around a pond. However, people were unable to relate a heterogeneous pond to more dragonfly species. For the first time, some factors that influence the human appreciation-ponds-dragonflies (HPD) relationship in an urban context are revealed. To fully realise the CES potential of ponds and dragonflies in Greater London, a HPD framework is proposed. The framework underpins strategies that foster cultural sustainability for ponds and dragonfly conservation.     

Woody plant species richness,composition and structure in urban sacred sites,Grahamstown, South Africa

Sacred sites are important not only for their traditional, spiritual or religious significance, but may also potentially be valuable for biodiversity conservation in human transformed landscapes. Yet, there has been little consideration of sacred sites in urban areas in this respect. Consequently, to better understand the ecosystem service and conservation value of urban sacred sites, inventories of their floral communities are needed. We examined the richness, composition and structure of the trees and shrubs in 35 urban churchyards and cemeteries in the City of Saints (Grahamstown). The combined area of urban sacred sites (38.7 ha) represented 2.2% of the city area and 13.6% of the public green space area. Species richness of woody plants was high, albeit dominated by non-native species. Levels of similarity among sites were low, indicating the effects of individual management regimens. There was no relationship between age of the site and measured attributes of the vegetation, nor were there any significant differences in vegetation among different religious denominations. However, the basal area and number of woody plants was significantly related to site size. These results indicate the significant heterogeneity of urban sacred sites as green spaces within the urban matrix. The significance of this heterogeneity in providing ecosystem services to users of sacred sites and the broader urban communities requires further investigation.     

Methods for spatial and temporal land use and land cover assessment for urban ecosystems and application in the greater Baltimore-Chesapeake region

Understanding contemporary urban landscapes requires multiple sets of spatially and temporally compatible data that can integrate historical land use patterns and disturbances to land cover. This paper presents three principal methods: (1) core analysis; (2) historic mapping; and (3) gradient analysis, to link spatial and temporal data for urban ecosystems and applies their use in the Baltimore-Chesapeake region. Paleoecological evidence derived from the geochronology of sediment cores provides data on long-term as well as recent changes in vegetative land cover. This information, combined with contemporary vegetation maps, provides a baseline for conducting trend analyses to evaluate urbanization of the landscape. A 200-year historical land use database created from historical maps, census data, and remotely sensed data provides a spatial framework for investigating human impacts on the region. A geographic information system (GIS) integrates core analyses with historic data on land use change to yield a comprehensive land use and land cover framework and rates of change. These data resources establish the regional foundation for investigating the ecological components of an urban ecosystem. Urban-rural gradient analyses and patch analyses are proposed as the most appropriate methods for studying the urban ecosystem as they link ecological and social patterns and processes for varying degrees of urbanization.