Nadja Kabisch

A quantitative review of urban ecosystem service assessments: concepts, models, and implementation.

Although a number of comprehensive reviews have examined global ecosystem services (ES), few have focused on studies that assess urban ecosystem services (UES). Given that more than half of the world’s population lives in cities, understanding the dualism of the provision of and need for UES is of critical importance. Which UES are the focus of research, and what types of urban land use are examined? Are models or decision support systems used to assess the provision of UES? Are trade-offs considered? Do studies of UES engage stakeholders? To address these questions, we analyzed 217 papers derived from an ISI Web of Knowledge search using a set of standardized criteria. The results indicate that most UES studies have been undertaken in Europe, North America, and China, at city scale. Assessment methods involve bio-physical models, Geographical Information Systems, and valuation, but few study findings have been implemented as land use policy.

Birds and the city: urban biodiversity, land use, and socioeconomics.

We examined bird diversity in relation to land use and socioeconomic indicators in Leipzig, Germany. We used neighborhood diversity (ND) and bivariate correlation to show that the potential to experience biodiversity in a city is associated with population density, household income, unemployment, and urban green space. People living in urban districts with high socioeconomic status experience the highest species richness around their homes, whereas lower social status increases the chance of living in species-poor neighborhoods. High-status districts are located along forests, parks, and rivers that have a high quantity and quality of green space. However, green space in general does not guarantee high bird diversity. We conclude that bird diversity mirrors land use and socioeconomic patterns within the compact European city of Leipzig. Therefore, urban planning should focus on decreasing these patterns and protecting the remaining species-rich green spaces.

Nature-based solutions to climate change mitigation and adaptation in urban areas: perspectives on indicators, knowledge gaps, barriers, and opportunities for action

textabstractNature-based solutions promoting green and blue urban areas have significant potential to decrease the vulnerability and enhance the resilience of cities in light of climatic change. They can thereby help to mitigate climate change-induced impacts and serve as proactive adaptation options for municipalities. We explore the various contexts in which nature-based solutions are relevant for climate mitigation and adaptation in urban areas, identify indicators for assessing the effectiveness of nature-based solutions and related knowledge gaps. In addition, we explore existing barriers and potential opportunities for increasing the scale and effectiveness of nature-based solution implementation. The results were derived from an inter- and transdisciplinary workshop with experts from research, municipalities, policy, and society. As an outcome of the workshop discussions and building on existing evidence, we highlight three main needs for future science and policy agendas when dealing with nature-based solutions: (i) produce stronger evidence on nature-based solutions for climate change adaptation and mitigation and raise awareness by increasing implementation; (ii) adapt for governance challenges in implementing nature-based solutions by using reflexive approaches, which implies bringing together new networks of society, nature-based solution ambassadors, and practitioners; (iii) consider socio-environmental justice and social cohesion when implementing nature-based solutions by using integrated governance approaches that take into account an integrative and transdisciplinary participation of diverse actors. Taking these needs into account, nature-based solutions can serve as climate mitigation and adaptation tools that produce additional cobenefits for societal well-being, thereby serving as strong investment options for sustainable urban planning.

Actors and factors in land-use simulation: The challenge of urban shrinkage

Both modelers and social scientists attempt to find better explanations of complex urban systems. They include development paths, underlying driving forces and their expected impacts. So far, land-use research has predominantly focused on urban growth. However, new challenges have arisen since urban shrinkage entered the research agenda of the social and land-use sciences. Therefore, the focus of this paper is a twofold one: Using the example of urban shrinkage, we first discuss the capacity of existing land-use modeling approaches to integrate new social science knowledge in terms of land-use, demography and governance because social science models are indispensable for accurately explaining the processes behind shrinkage. Second, we discuss the combination of system dynamics (SD), cellular automata (CA) and agent-based model (ABM) approaches to cover the main characteristics, processes and patterns of urban shrinkage. Using Leipzig, Germany, as a case study, we provide the initial results of a joint SD-CA model and an ABM that both operationalize social science knowledge regarding urban shrinkage.

Key insights for the future of urban ecosystem services research

Understanding the dynamics of urban ecosystem services is a necessary requirement for adequate planning, management, and governance of urban green infrastructure. Through the three-year Urban Biodiversity and Ecosystem Services (URBES) research project, we conducted case study and comparative research on urban biodiversity and ecosystem services across seven cities in Europe and the United States. Reviewing > 50 peer-reviewed publications from the project, we present and discuss seven key insights that reflect cumulative findings from the project as well as the state-of-the-art knowledge in urban ecosystem services research. The insights from our review indicate that cross-sectoral, multiscale, interdisciplinary research is beginning to provide a solid scientific foundation for applying the ecosystem services framework in urban areas and land management. Our review offers a foundation for seeking novel, nature-based solutions to emerging urban challenges such as wicked environmental change issues.

Endless urban growth? On the mismatch of population, household and urban land area growth and its effects on the urban debate.

In European cities, the rate of population growth has declined significantly, while the number of households has increased. This increase in the number of households is associated with an increase in space for housing. To date, the effects of both a declining population and decreasing household numbers remain unclear. In this paper, we analyse the relationship between population and household number development in 188 European cities from 1990–2000 and 2000–2006 to the growth of urban land area and per capita living space. Our results support a trend toward decreasing population with simultaneously increasing household number. However, we also found cites facing both a declining population and a decreasing household number. Nevertheless, the urban land area of these “double-declining” cities has continued to spread because the increasing per capita living space counteracts a reduction in land consumption. We conclude that neither a decline in population nor in household number “automatically” solve the global problem of land consumption.

Evolving Reurbanisation? Spatio-temporal Dynamics as Exemplified by the East German City of Leipzig:

After a decade of tremendous population loss indicating severe decline, some large east German cities have been displaying signs of reurbanisation since the late 1990s. Using the city of Leipzig as an example, this paper identifies the major characteristics, progress and underlying spatio-temporal dynamics of reurbanisation, and examines whether it is a long-term process of urban living or features only short-term tendencies. Socio-demographic indicators are used to observe the development of inner-city districts. At the spatial scale of municipal districts, time-series data are analysed for the years 1993 to 2005. The paper argues that reurbanisation has occurred primarily in inner-city districts and has progressed considerably since the early 1990s. However, the spatio-temporal distribution of the relevant indicators shows that reurbanisation is far from being a homogeneous process. In light of this, the paper presents a ring of reurbanisation-sensitive municipal districts around the city centre.

Structural Diversity: A Multi-dimensional Approach to Assess Recreational Services in Urban Parks

Urban green spaces provide important recreational services for urban residents. In general, when park visitors enjoy “the green,” they are in actuality appreciating a mix of biotic, abiotic, and man-made park infrastructure elements and qualities. We argue that these three dimensions of structural diversity have an influence on how people use and value urban parks. We present a straightforward approach for assessing urban parks that combines multi-dimensional landscape mapping and questionnaire surveys. We discuss the method as well the results from its application to differently sized parks in Berlin and Salzburg.

The impact of urban regrowth on the built environment

After several decades, an increasing number of European cities have been experiencing population growth after a longer phase of decline. This new growth represents not just a quantitative phenomenon but also has qualitative implications for the urban space and the built environment. A juxtaposition of re- and de-densification, as well as changes in land use, in the form of a small-scale spatial mosaic, can be observed. A crucial factor for estimating the relationship between the built environment and demand for it is population density. Increasing population densities may put pressure on sustaining a certain quality of life and on ecological recovery spaces. In this vein, an indicator concept for re- and de-densification will be applied to the city of Leipzig, one of the most illustrative examples of a regrowing city, in order to shed light on the complex relationship between changing human housing demands and their impact on land use. The concept involves measuring population density. Our study has demonstrated that, although similar density changes can be observed in different periods in different parts of the city, they are dominated by different drivers, leading to the formation of different spatial patterns. The results of our study emphasise that regrowth should be understood as a distinctive process because it is distributed very heterogeneously within the city area, with a variety of spatial effects and impacts. The concept allows us to draw conclusions about processes that mitigate, drive or reinforce regrowth, and therefore contributes to a better understanding of this phenomenon and its implications for land use.

The health benefits of nature-based solutions to urbanization challenges for children and the elderly – A systematic review

ABSTRACT Urban green and blue spaces promote health by offering areas for physical activity, stress relief, and social interaction, which may be considered as cultural ecosystem services. They also provide a number of regulating ecosystem services that can be regarded as nature‐based solutions to mitigate impacts from urbanization‐induced challenges. Urban trees and other vegetation provide cooling through shade and evapotranspiration, which reduce the impact of the urban heat island on hot summer days. Urban vegetation may improve air quality by removing air pollutants. Open areas in cities, such as parks, gardens, playgrounds and cemeteries, are unsealed spaces that also improve infiltration during extreme precipitation events providing water regulating functions. All these services have the potential to improve the health of urban residents, particularly of specific vulnerable groups such as children and the elderly. The aim of this paper is to provide an overview of the current state of evidence on the relationship between the health of children and the elderly and urban green and blue spaces that can account as nature‐based solutions to urbanization‐induced challenges. We discuss potential confounding factors and refer to the different green space metrics used to identify associations to health. From the results, we cannot conclude on a universal protective health effect of urban green and blue spaces for children and the elderly. While the association trend is positive, the results remain inconclusive, context dependent and are partly overridden by socioeconomic confounders. However, the research area is consistently increasing, and we advance important prospects for future research on urban green and blue spaces in the face of global challenges such as urbanization. HighlightsReview shows current evidence on the green‐blue space – health relationship.Focus is on childrens and elderlys health in the urbanization context.Results show a positive trend of association between health and green.But results remain inconclusive and partly overridden by socioeconomic confounders.A universal protective health effect of urban green & blue spaces cannot be concluded.