The COVID-19 pandemic has forced us to review our habits, and many citizens have increased their use of urban green spaces. Indeed, not only do green spaces offer nature-based solutions to allow us to socialise in a distanced way, but they have also helped people to keep physically and mentally fit and provided solace in troubled times. But the value of the urban green system extends much further than this. Recent research by David Grohmann and Maria Elena Menconi takes a complex system approach to celebrate the heterogeneity within the functions, spaces, and components that make up urban greenery. They are researchers at the Perugia University in Italy and are experts in urban landscape planning and design.
Providing access to safe and inclusive green and public spaces in cities and communities is vital for human wellbeing – a fact recognised by the UN, which has included access to green spaces in its Sustainable Development Goals for global peace and prosperity.
For example, community gardens allow people to grow food and create a sense of place and community, urban farms provide contact with nature and are an educational resource, and parks and woodlands offer aesthetically pleasing spaces for recreation, socialisation, and contemplation. In addition to these social and cultural benefits, environmental benefits of urban green spaces include helping to regulate our climate by limiting the impact of extreme temperatures and mitigating climate change by storing carbon. Vegetation also helps to reduce pollution, improve air quality, enhance biodiversity, and decrease flood risk by storing excess rainwater.
David Grohmann and Maria Elena Menconi of the University of Perugia in Italy are experts in urban landscape design and urban landscape planning. They regard urban green spaces as unique and dynamic socio-ecological systems which provide citizens with ecosystem services. They argue that, while local government authorities recognise the value of urban green infrastructures, they often fail to fully understand their benefits, not least because these are hard to quantify and evaluate.
Grohmann and Menconi explore the complexity behind this phenomenon in recently published research. They also present a geographical information systems (GIS) based tool to help local government authorities to take a complex systems approach towards the mapping, evaluation and planning of urban green spaces (UGS) and ecosystem services (ES).
Grohmann and Menconi argue that the elements within UGS – from trees and shrubs, to insects, animals and users – change throughout their lifespan and ‘as a consequence, the system also continuously changes and does so at different speeds depending on its constituent variables.’ UGS are therefore heterogeneous, complex systems which comprise a network of diverse but connected dynamic elements that transform under constantly changing conditions, according to non-linear rules.
Challenging simple cause and effect assumptions, Grohmann and Menconi explain: ‘Every action in a green area changes the system’s equilibrium and can activate unpredictable synergies or conflicts with internal or external variables. Therefore, every transformation in a green area also changes the ecosystem services it provides to citizens.’
Grohmann and Menconi argue that urban landscape designers and planners should adopt a complex system thinking approach because the behaviour of UGS cannot be explained by studying their individual parts. They comment: ‘The landscape is, by definition, a complex, multifaceted system with different spatial and temporal layers that are tightly intertwined. A traditional reductionist approach is insufficient to tackle the various goals of sustainability and resilience of urban contexts effectively.’
Complexity and urban greening
Grohmann and Menconi tested the validity of their complex systems theory approach to urban landscape planning and design in research which looked at urban greening and the provision of cultural ecosystem services (CES). The research was based on a review of the literature on the use of complexity science properties to plan, design, and manage the CES provided by UGS. The review took a five-step approach to narrow down the literature to a set of 70 international papers which were analysed descriptively and thematically. Recognised bibliographic software was used to identify the topics and thematic clusters most frequently found together.
The results showed that, while only 8% of papers specifically referred to complex systems, many of the papers considered issues and themes associated with complexity theory. These include relationships with the system’s surroundings (‘interactions’), relationships between elements of the system (‘internal connections’), and interactions between variables which give rise to something new (‘emergence’). In addition they include changes in variables occurring at different rates or in different patterns (‘non-linearity’), how the system responds and adapts to shocks (‘resilience’), and how a collection of elements within the system can change without external intervention (‘self-organisation’).
Literature review findings
Grohmann and Menconi’s analysis shows that, while research has used properties of complex systems to evaluate, analyse and plan CES in UGS, few studies have taken an overall complex systems approach.
The literature also highlights important issues. Grohmann and Menconi find these include the need to study the internal and external relationships within UGS and to evaluate the synergy, conflict and/or complementarity of the different areas of green space in public and private ownership. Studies also point to the value of the active involvement of citizens and users, and the recognition that people differ in their perceptions of CES. In addition, users’ appreciation of the benefits of UGS should not be taken for granted, and urban phenomena have to be observed from different viewpoints.
Grohmann and Menconi also note the unpredictability of UGS and the need for planners to constantly monitor systems and find flexible solutions to issues that arise. They recommend a multi-scale and multi-temporal approach to avoid oversimplification and generalisation. In addition, instead of reacting passively to events, planners should actively create and react to feedback loops and use dynamic simulations to monitor the system and identify weaknesses. They conclude: ‘To design and manage cultural services in an urban context, an urban green systems thinker must consider all the core themes of complexity and include them in innovative mathematical frameworks and flexible methods for the study thereof.’
GIS analytical tool
The literature also notes the usefulness of GIS software to study the variables within UGS. In other research, Grohmann and Menconi have developed a GIS-based method to help local government planners to design UGS and provide CES to local communities.
Based on an urban park in Perugia in Italy, the study aimed to requalify the old park, evaluating its relationships with the rest of the urban green system. Citizens who use the park had made various requests to improve the space, and the experts have evaluated these new functions and equipment considering their potential synergies or conflicts with uses and characteristics of the near green areas. To determine supply and demand, the researchers evaluated each request against five criteria: availability – is there provision nearby?; accessibility – is the nearest service reachable safely?; attractiveness – what is the nearest service like?; usability – is the nearest service under-used?; and suitability – is the requested service suitable for the park?.
GIS datasets were acquired for Perugia’s UGS, population and roads. The municipal website provided information about the green areas’ features. Furniture in green areas was observed from Google Images. Field research provided additional information such as the attractiveness of equipment provided and allowed researchers to talk to citizens about such things as the time and duration of visits.
Mapping the datasets over one another at city level revealed that, while Perugia in theory has sufficient green space at an average 34.7 m2 per person, in practice this is not equally available to all and 18% of citizens have no access to any green areas that provide CES. Almost half of the city’s greenery is found along urban roads or near public buildings, with no provision of furniture or equipment. In addition, only 24% of citizens have good access to a green area providing a good level of equipment.
At the level of the case study park, the research showed that 41% of the requested services were already available in other green areas accessible locally, which also had attractive and usable equipment. This result of Grohmann and Menconi reveals that citizens are creatures of habit and have limited knowledge of CES offered by other green spaces within the UGS. This GIS-based method supports citizens in the knowledge of the richness of their city’s green spaces, and supports local administrations in the design of urban green areas while taking into account the complexity of the whole system.
Grohmann and Menconi argue that applying system thinking and GIS-based analysis offers a multi-level approach to planning urban green systems. They argue that their research shows the value of network analysis and the importance of accessibility in the provision of CES. In addition, it highlights the importance of evaluating the relationships between the variables of the system. Last but not least, they argue that their research shows the need for continuous evaluation of site-specific and community-led solutions.
Grohmann and Menconi conclude: ‘Beginning with the demand for CES provisioning in a studied green area, the method offers a transparent and clear process to collect and choose solutions for individual green spaces in a holistic strategy that can also identify aggregate effects and emergent characteristics at city level.’
- Menconi, ME, Sipone, A, Grohmann, D, (2021) Complex systems thinking approach to urban greenery to provide community-tailored solutions and enhance the provision of cultural ecosystem services. Sustainability 13 (21), 1787. doi.org/10.3390/su132111787
- Menconi, ME, Palazzoni, L, Grohmann, D, (2021) Core themes for an urban green systems thinker: a review of complexity management in provisioning cultural ecosystem services. Urban Forestry & Urban Greening, 65, 127355. doi.org/10.1016/j.ufug.2021.127355
David Grohmann and Maria Elena Menconi’s research takes a complex system approach to the planning and design of urban green spaces.
The research has been carried out within the CoSy Project (Cosy Thinking—Enhancing higher education on COmplex SYstems Thinking for sustainable development), co-funded by the Erasmus + Programme of the European Union. Project Number: 2020-1-SE01-KA203-077872
- Ambra Sipone
- Luca Palazzoni
David Grohmann is a researcher and professor of landscape design at the University of Perugia, Italy, where he is the Director of the University Center for Science Museums, and manages a collective gardening project. His main research interests are landscape design, nature-based solutions, green infrastructures and urban horticulture.
Maria Elena Menconi is a researcher and professor of landscape planning and territorial analysis at the University of Perugia. Her main interests regard GIS, spatial planning, and participatory processes in urban green system governance.