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.     

Hurricane driven changes in vegetation structure and ecosystem services in tropical urban yards: a study case in San Juan,Puerto Rico

Urban forests are valuable spaces for species conservation, protection of local biodiversity and provision of ecosystem services. However, they are also vulnerable to the impact of extreme climate events like hurricanes. Understanding how urban forests are responding to hurricane disturbances is crucial to improve their design, management, and resilience. Here we analyzed pre-and post-hurricane vegetation surveys in 52 residential yards in San Juan to assess urban forest responses after Hurricanes Irma and María impacted Puerto Rico in 2017. We used these surveys to compare vegetation structure and composition (including species-specific mortality and damage rates) and to quantify changes in the ecosystem services provided by these yards. We found that hurricane disturbances significantly altered the structure but not the composition of yard vegetation. We detected a 27% reduction and 31% mortality of standing stems, and a significant reduction in plants health. Yard species composition was dominated by non-native species and this trend did not change with hurricane disturbance. Changes in vegetation structure translated into substantial reductions in ecosystem services. Food provision, an important service provided by a large proportion of yards before the hurricane, reported the highest reduction (41.9%) while carbon storage was the service that changed the least (9%). Our combined results emphasize the key role played by residential yards providing ecosystem services in tropical cities and call for further efforts to manage private and public urban forests in ways that may ensure their resilience to mitigate extreme climate events, provide multiple ecosystem services, and promote long-term urban sustainability.

     

Adaptive governance to promote ecosystem services in urban green spaces

Managing urban green space as part of an ongoing social-ecological transformation poses novel governance issues, particularly in post-industrial settings. Urban green spaces operate as small-scale nodes in larger networks of ecological reserves that provide and maintain key ecosystem services such as pollination, water retention and infiltration, and sustainable food production. In an urban mosaic, a myriad of social and ecological components factor into aggregating and managing land to maintain or increase the flow of ecosystem services associated with green spaces. Vacant lots (a form of urban green space) are being repurposed for multiple functions, such as habitat for biodiversity, including arthropods that provide pollination services to other green areas; to capture urban runoff that eases the burden on ageing wastewater systems and other civic infrastructure; and to reduce urban heat island effects. Because of the uncertainty and complexities of managing for ecosystem services in urban settings, we advocate for a governance approach that is adaptive and iterative in nature—adaptive governance—to address the ever changing social order underlying post-industrial cities and offer the rise of land banks as an example of governance innovation.     

Three categories of urban green areas and the effect of their different management on the communities of ants,spiders and harvestmen

Urban green areas have become an important tool for biodiversity conservation in cities. However, land use and the different management practices applied to these areas determine their effectiveness as biodiversity refuges within cities. In our study, we compare the biodiversity of three bioindicator groups of arthropods (ants, spiders and harvestmen) found in eleven urban green sites in Warsaw (Poland). The studied sites represent three categories of management: botanical gardens, public parks and urban woodlands. Our aim was to determine the effect of the type of management (as urban green categories) on arthropod communities in urban areas.

     

Scientist and non-scientists share a diversity of dimensions in their relations to urban nature

In the current biodiversity crisis, conservation scientists are urgently asked to involve themselves in education and communication initiatives toward non-scientists, who are considered as lacking knowledge to correctly value biodiversity. This is particularly argued in urban areas.In this paper, we showed however with an anthropological survey that urban citizens do express a variety of relations toward surrounding urban nature. Then, in an independent survey, we showed that these ways of being connected with nature were shared by students in conservation sciences. Conservation scientists and non-scientific city dwellers have therefore much more in common than is taken for granted in their relations and perceptions of urban nature, notably concerning emotional, sensorial and memorial relationships. Acknowledging these common features in the scientific community could improve the communication between science and the general public about urban nature, help bridge the gap between science and the society and eventually participate to build a new social contract on nature.     

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.

     

Effects of variations in water quantity and quality in the structure and functions of invertebrates’ community of a Mediterranean urban stream

Urban Ecosystems - Urban streams provide important ecosystem services to cities’ population, from the maintenance of urban biodiversity, temperature, humidity and air quality to improving...     

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.     

Copro-necrophagous beetles (Coleoptera: Scarabaeinae) in urban areas: A global review

The world has become an urban world, more than 50 % of the human population live in cities. The effects of urbanization are diverse, complex and wide; ranging from unbalanced biogeochemical cycles in urban areas, to the local extinction of several species in different cities around the globe. However, diverse biological groups live and thrive in cities adapting to the new and sometimes harsh conditions of urban areas. In an effort to compile and assess the current status of knowledge of copro-necrophagous beetles in urban areas, we performed an extensive search for publications regarding Scarabaeinae beetles in urban areas. We found 27 publication that address four general topics: (1) ecological patterns; (2) disease transmission; (3) conservation biology; and (4) species lists. Although in the last fifteen years it has been published extensively about Scarabaeinae as an indicator group in biodiversity studies and in the analysis of ecosystem functions, references to Scarabaeinae in cities are scarce. In a broad sense, the study of copro-necrophagous beetles in urban areas is in an early stage of advance, providing an opportunity for entomologists to explore their response to urbanization, altogether with the role of these insects as host and intermediates of parasitic diseases, but also, with the environmental services provided by them, like the burial and destruction of a great amount of excrements found in urban soil.     

Developing a framework for stormwater management: leveraging ancillary benefits from urban greenspace

Managing stormwater and wastewater has been a priority for cities for millennia, but has become increasingly complicated as urban areas grow and develop. Since the mid-1800s, cites often relied on an integrated system of underground pipes, pumps, and other built infrastructure (termed gray infrastructure) to convey stormwater away from developed areas. Unfortunately, this gray infrastructure is aging and often exceeds its designed capacity. In an effort to alleviate issues related to excess stormwater, many urban areas across the United States are interested in using green infrastructure as a stopgap or supplement to inadequate gray infrastructure. Green infrastructure and other greenspace promote interception and/or infiltration of stormwater by using the natural hydrologic properties of soil and vegetation. Furthermore, there are numerous ancillary benefits, in addition to stormwater benefits, that make the use of greenspace desirable. Collectively, these ecosystem services can benefit multiple aspects of a community by providing benefits in a targeted manner. In this paper, we present a framework for balancing stormwater management against ancillary benefits of urban greenspace. The framework is structured around the Millennium Ecosystem Assessment ecosystem service categories: provisioning, cultural, regulatory, and supporting services. The purpose is to help communities better manage their systems by 1) allowing stakeholders to prioritize and address their needs and concerns within a community, and 2) maximize the ecosystem service benefits received from urban greenspace.

     

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.     

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.     

BIMBY’s first steps: a pilot study on the contribution of residential front-yards in Phoenix and Maastricht to biodiversity,ecosystem services and urban sustainability

Large parts of urban space around the world exist of small-scale plots such as domestic gardens. These small-scale urban spaces carry potential for enhancing biodiversity, sustainability and ecosystem services in and beyond cities. However, domestic gardening and residential garden designs are often guided by aesthetics and ease more than by the aim to create habitat and biological diversity. Yard-management decisions impact socio-ecological systems in various ways, for example through irrigation patterns, fertilization or the use of pesticides or through the choice for exotic species that may become invasive over time. Yard-management decisions can also positively influence the presence of pollinators, improve soil quality or even foster small scale ‘Wildlife Habitats’ that can function as ecological stepping stones to the wider environment. In this paper a pilot assessment is presented of the contribution of residential front-yards in Phoenix (Arizona) and Maastricht (The Netherlands) to biodiversity, ecosystem services and sustainability by applying the BIMBY (Biodiversity in My (Back) Yard) framework.     

Sustainable landscaping programs in the United States and their potential to encourage conservation and support ecosystem services

Sustainable landscaping programs are voluntary initiatives that recommend a set of practices to improve the environmental quality of urban ecosystems by providing landscaping materials, guidelines, and educational resources. Our goal was to examine the recommendations and outcomes of these programs in the United States and their value for encouraging conservation practices in residential ecosystems. We conducted a comprehensive web search and identified 193 sustainable landscaping programs in the United States. Programs aim to increase native species richness, affordably manage stormwater runoff, and offer residents meaningful experiences with nature. Sustainable landscaping programs present many opportunities to engage people with local ecological knowledge and conservation practices, provide accessible spaces for environmental education, cultivate interdisciplinary research collaborations, and advance inclusion in conservation. However, assessments of their ecological value are rare, leaving many questions surrounding the benefits to biodiversity and water quality afforded by participation. Many programs also require investments in landscaping materials and certification fees that might limit participation by some households. Future work should examine how recommended practices influence urban biodiversity, identify and address barriers to participation, and generate social-ecological knowledge that can inform future programs.

     

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.     

Sustainable urban greening strategies for compact cities in developing and developed economies

Urban greening contributes notably to quality of life and ecosystem services in cities. Compact cities in developing and developed countries are commonly beset by greenspace deficit. Based on literature review supplemented by field studies in different cities, a sustainable urban greening strategy is proposed. Urban renewal and new developments without a greening vision could miss the opportunities to bring relief. The public and private sectors can join hands to insert plantable spaces into the urban fabric. Urban greenspaces (UGS) with good connectivity forming a green network to permeate the city constitute the hallmarks of a naturalistic design. Preservation and creation of natural areas with rich biodiversity offer a new dimension to UGS design. Greening benefits could be expressed in economic terms to complement conventional ecological-environmental emphasis. Outstanding trees could receive high-order conservation efforts, and trees in construction sites warrant enhanced protection. Tree transplanting demands an overhaul in concepts and skills. Improving roadside tree planting and maintenance offers a cost-effective way to upgrade the townscape. Ameliorating widespread soil limitations could remove a major hindrance to tree growth. Innovative ideas of development right transfer, street pedestrianization, river and canal revitalization, green roofs and green walls could mobilize hitherto underused plantable resources. Lacking appropriate institutional setup and scientific capability pose intractable bottlenecks. Innovative public policies and greening technologies are needed for sustained improvements. Amalgamating natural and social sciences in a multidisciplinary approach and reinforcing the link between science and public policies could overhaul greening.     

Renaissance of a rural artifact in a city with a million people: biodiversity responses to an agro-forestry restoration in a large urban traditional fruit orchard

The rural landscapes surrounding large cities are rapidly becoming incorporated into the urban environment. The most conspicuous changes involve green spaces, such as former agro-forestry systems like fruit orchards. In this paper, we assess the influence on biodiversity of restoring a large urban traditional fruit orchard as reflected by six selected taxa: plants, lichens, butterflies, beetles, orthopteroids and birds. The study was performed in Prague, which is the capital city of the Czech Republic and has more than a million inhabitants. We studied the effect of orchard renewal in 45 patches (15 for birds and 30 for other taxa). The majority of taxa responded positively to the restoration. The restoration had a significant positive effect on the species richness of lichens, butterflies and beetles. All taxa showed significantly altered species compositions, and the number of red-listed species increased. Orchards have a high potential for multi-functional use. Orchards are productive agro-forestry systems and host numerous possible human activities. Therefore, orchard restoration also has a social aspect. Moreover, our research in this artificial ecosystem revealed that its restoration increased the biodiversity and conservation potential of the associated areas.

     

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.     

Assembling the pieces: a framework for the integration of multi-functional ecological main structure in the emerging urban region of Bogotá, Colombia

Bogotá, the capital of the Republic of Colombia, is a tropical highland city located 2,650 m above sea level. It is the 25th largest city in the world and, among large cities, is also one of the highest. In common with other cities in Latin America, a large part of its urban growth during recent centuries has been unplanned and informal. The introduction of green spaces into urban planning in Bogotá began in the mid-20th century, but was first included in official legislation during the 1990s through the concept of Ecological Main Structure (EMS). Initially developed by Dutch scholars, EMS was brought to Colombia via biological conservation practitioners as a means of enhancing biological connectivity in rural and natural landscapes, extended in this case to urban landscapes as a top-level planning instrument. EMS originally included a variety of components, from protected areas and biological conservation tools to environmental urban elements - the emphasis being on biodiversity conservation, without sufficient recognition of specific urban structures and functions. This process led to conceptual disciplinary-based divergence and conflicting political interpretations. The current emergence of EMS as a planning tool for urban regions represents an opportunity for integration, although the risk of divergent interpretations remains, as no integrative conceptual framework has yet been developed. In this paper we review the concepts underlying EMS that have been incorporated within urban and regional planning, especially those of ecological networks and green infrastructure, and also diagnose conceptual and institutional barriers to its current integration, challenges and opportunities which are set in the context of an emerging urban region. We propose a trans-disciplinary framework for multi-level integration of EMS, along a gradient from wild environments to built structures that incorporates emerging concepts such as urban biodiversity, ecosystem services and design in the urban landscape, with the aim of contributing to the creation of an urban landscape that is resilient to environmental change and suitable for human well-being and adaptation.