Managing Urban Green Areas: The Benefits of Collaborative Governance for Green Spaces

Abstract

Urbanisation has had an impact on people’s livelihoods, and on social infrastructures as well as on the consumption of resources. In the last century, we have witnessed many transformations at the urban scale that in many cases led to the commodification and enclosure of public areas and, especially, green areas. With the turn of the millennium and following the adoption of the UN Agenda 2030, the trend has been partially reverted and cities in Europe are becoming progressively greener, although the phenomenon do not always bring positive societal outcomes and it is not able to re-distribute benefits among community members, promoting unequal access to green areas. Instead, in many cases the so-called green gentrification phenomenon has been identified as a primary societal challenge connected with urban regeneration projects. Building on this, the paper aims to find an answer to the question of whether or not the governance model adopted for urban green areas influences how benefits connected with ecosystem services are perceived by stakeholders and re-distributed at the community level. Based on the gaps highlighted in the theoretical background and direct observation of Biblioteca degli Alberi Milano (BAM), a recently developed urban park in Milan, an analytical framework was developed and tested. The results allow us to identify innovative practices for the management of green areas capable of maximising ecosystem services’ benefits beyond the intervention area. This will support the adaptability, replicability, and scalability of these initiatives while providing effective tools for practitioners and planners when developing a collaborative management model for urban green areas.

1. Introduction

As most of global growth will be urban, the role of cities in the sustainability discourse has drawn increased attention [1,2,3]. In urban areas, social and environmental challenges are becoming even more urgent when considering the constraints on economic and natural resources, and physical spaces that lead to a reduction in the well-being of the population [4,5]. In this context, urban green spaces have an intrinsic importance in making life in cities more sustainable. Green spaces are a mean to provide ecosystem services at the urban level, i.e., those services, goods and benefits gained from the environment that benefit humans [6,7,8]. For this reason, the protection, restoration and creation of new urban green areas has become central in recent urban re-development and re-generation agendas [9,10]. Even more relevant became the inclusion of stakeholders in designing solutions for the sustainability challenges that cities are facing nowadays [8]. In many European cities, large-scale development projects include new green areas as a way to contribute to the livelihood of the neighbourhood while meeting the call for environmental sustainability. However, there is still the need to investigate the implications of these type of interventions, considering both environmental and social effects, and the way in which green areas and related ecosystem services are managed [3].

Furthermore, the question regarding the beneficiaries of the benefits that underpin ecosystem services and their involvement in the management of green areas has received little attention so far. Therefore, these interventions need to be planned and managed in a way that avoid the so-called “green gentrification effect”, leading to the exclusion of the most vulnerable segments of the population and to displacement phenomena [3]. For this reason, it is fundamental to move beyond traditional models of natural resource exploitation and management models promoting multi-stakeholder governance measures based on the values that green areas represent to different stakeholders [8].

This paper, building on previous research, aims to understand the role that management arrangements can have on the access to green areas and on the provision of ecosystem services’ benefits for the community at large [3,6,11], thus answering the question of whether or not collaborative forms of governance enable the redistribution of ecosystem services’ benefits at the urban level and enhance access to green areas. To answer this question, an analytical framework to assess the benefits of collaborative governance models for the management of urban green areas was developed. The framework allows an assessment of the effects and impacts that a management model can have for direct, indirect, and potential users of urban green areas. In particular, the study will focus on how participatory and multi-stakeholder management models maximise ecosystem services’ benefits for the community of users, taking into consideration the actors involved in the governance processes and the capacity of collaboration to re-distribute benefits among citizens.

The objectives for this study are as follows: (i) to understand the role of collaborative governance models in providing access to urban green areas; (ii) to understand whether or not collaborative governance models for the management of urban green areas have a redistributive effect regarding the benefits generated via the ecosystem services provided; (iii) to understand whether or not collaborative governance models enhance community participation in the production and management of urban green areas and underpinned ecosystem services.

The model, described below, has been developed with respect to the case of Biblioteca degli Alberi Milano (BAM) through field observation and interviews with relevant stakeholders. The developed framework allowed us to conduct an analysis of the governance model adopted for the management of the BAM project, being a novelty in the Italian panorama, and understand if and how it enables the maximisation and sharing of benefits among the community of direct, indirect, and potential users. The analytical framework provides recommendations for actors approaching participatory management models for urban green areas in contexts of urban regeneration projects.

The paper Is organised as follows. In the next section, the theoretical background is presented, with a description of the role of urban green areas and the governance approaches that can be adopted to maximise their benefits (Section 2). In Section 3, the analytical framework will be presented with reference to its different components (Section 3). The BAM case will be then introduced, explaining how it contributed to the creation of the analytical framework (Section 4). Before the discussion and conclusions (Section 6), Section 5 will present the main results of the analysis and evaluation conducted.

2. Theoretical Background of the Study

The theoretical background is grounded on two interconnected themes: the conceptualisation and role of urban green areas, Section 2.1, and the governance models of urban green areas, Section 2.2. In the first sub-section, the importance of green areas in urban contexts is investigated, with a particular focus on their classification based on the level of accessibility and the role of ecosystem services that benefit communities. The second sub-section investigates management models—in the forms of collaborative governance and cross-sectoral partnerships—that can be adopted to successfully manage urban green areas, favouring the involvement of key stakeholders and avoiding the risk of gentrification.

The methodological approach adopted for the literature is structured as a four-stage analysis framework [12]. In the first stage, named “Literature search”, the Scopus and Web of Sciences databases are chosen to support the literature search using different combinations of keywords for the two topics. The “Screening process”, the second stage, is devoted to investigating the literature. Regarding the conceptualisation and role of green areas, articles are searched using “urban green space AND ecosystem services”, “green areas AND urban commons”, “urban commons AND ecosystem services”, and “nature-based solutions” as keywords. On the other hand, “urban commons AND management”, “urban green areas AND management models”, “urban green spaces AND management models”, and “collaborative governance” are used as references for the research.

The third stage, “Analysis of literature under review”, is based on the analysis of the abstract of all the references in order to select and identify the most focused contributions on the topic. In total, 52 papers, with dates ranging from 1970 to 2022, are selected. During the fourth stage, named “Final selection”, from the 52 selected papers, 16 are considered the most relevant ones for the current research as they deal primarily with management arrangements for urban green spaces and with ecosystem service benefits deriving from urban green spaces. The other papers are excluded as they are either out-of-scope (focusing on non-urban areas) or do not deal directly with collaborative governance or other forms of management for urban green areas. Figure 1 below shows the process followed to conduct the literature review.

2.1. Conceptualisation and Role of Urban Green Areas

Green spaces are means to provide ecosystem services at the urban level, i.e., those services and goods that can enhance well-being and thus benefit the surrounding community [6,7,8]. Thanks to the presence of green areas, the comfort of outdoor spaces increases since they significantly contribute to reducing land temperature and consequently the urban heath island effect. Urban green areas and their underpinned ecosystem services have been framed and conceptualised as valuable assets to address sustainability issues at the urban level through nature-based solutions and biophilic planning [5,8]. Furthermore, when green areas are publicly available and managed, they guarantee free access for the community to the benefits generated by ecosystem services, while providing formal and informal aggregation and recreation opportunities [5,8].

For the above reasons, a relevant aspect to consider when looking at urban green areas is the level of accessibility, understood as the ease with which stakeholders can easily and freely access the green areas and their benefits. The level of accessibility depends on two factors: excludability—understood as the capacity to exclude someone from the enjoyment of a given good or resource—and rivalry—the capacity to allow rival uses of the same resource. According to these two characteristics, goods can be divided into four categories: market goods (rival and excludable); club goods (non-rival and excludable); common goods (non-rival and non-excludable); and government goods (rival and non-excludable) [6,11]. Figure 2 synthetises the characteristics of the four categories.

In the literature, urban green areas have been characterised either as urban commons [11,13,14] or as club goods [6,11] depending on the degree of excludability of certain users, and thus their physical characteristics (e.g., presence of boundaries), the rules adopted for their employment (e.g., payment of fees or residency status), and the way they are managed (private management, public management or collaborative governance).

In other words, the level of consumption of ecosystem services that green areas provide and that is not captured by the market produce a distinction between those goods that are characterised as commons and those that, although being publicly available, are subjected to restrictions or fees for their enjoyment [6]. Resulting from this, for example, enclosed parks available only to residents can be regarded as club goods as the resident status gives an exclusive right of use of the green area, whereas public parks can be considered urban commons available for the entire community, given the fact that the absence of enclosures maximises accessibility to the park.

Authors have identified two characteristics that define urban green areas understood as urban commons: their public or community ownership and their free and unconditioned access for all members of the community [6,15,16]. Furthermore, MacKenzie and colleagues [6] identified that in some circumstances urban green areas can be the place where formal or informal recreational activities can take place, thus highlighting the centrality of urban green spaces for the creation and activation of social networks that promotes community engagement in their management.

Interventions such as the creation of new urban green areas, as anticipated, promote the creation and delivery of ecosystem services at the urban scale. Ecosystem services have been defined in the literature as the benefits, in terms of individual or collective well-being, generated through the active or passive use of natural components [5,7,17]. The definition highlights a linkage between ecosystems, understood as set of natural resources, and humans, thus comprising all outcomes that might derive from direct or indirect interactions between humans and ecosystem resources. The evaluation of ecosystem services is generally conducted through “Total Economic Value” (TEV) approaches in order to establish the economic value of the benefits generated [17,18,19,20]. However, the literature still falls short in addressing how those benefits are re-distributed among community members and the impact of the management model adopted in terms of maximising or limiting those benefits, opening up avenues for further research [9,10].

For their intrinsic characteristics, interventions in urban green areas if properly managed can be seen as nature-based solutions (NBSs). NBSs are defined by the European commission as “solutions that are inspired and supported by nature, which are cost-effective, simultaneously provide environmental, social, and economic benefits, and help build resilience” [21]. The potential of NBSs in making a positive impact has been explored in many studies; however, possible trade-offs and negative spill overs of these initiatives from the perspective of surrounding communities also emerge. Therefore, further research is needed to understand the benefits of these initiatives and the level of acceptance of these interventions by the citizens and communities involved [3,8].

2.2. The Governance Models for Urban Green Areas

The issue of management of urban green areas has gained momentum in recent academic discourse. MacKenzie et al. [6], with reference to stakeholder involvement in the governance of urban green areas, identified four different governance structures: governmental (where a single decision-maker is involved); deconcentrated (where decision-making is distributed among different levels of government and public authorities); delegated (where decision-making is delegated to semi-autonomous organisations); and devolved (where decision-making is transferred at the local level). The rise in the complexity and breadth of expertise required to address the challenges related to the management of urban areas has increasingly led governments to develop new forms of collaboration and governance through the involvement of other stakeholders (e.g., private companies, not-for-profits, citizens, etc.) [22,23]. On top of this, in their work, MacKenzie and colleagues [6] recognised the need for multi-level governance supported by public authorities given the fact that stakeholders attribute different values to urban green areas and ecosystem services. This contributed to the proliferation of multi-stakeholder governance models to provide a response to different stakeholder needs and interests.

Collaborations and different forms of governance offer key opportunities to deliver projects aiming to create, protect and restore urban green areas while strengthening social justice and social inclusion outcomes [24]. In fact, collaborative governance and cross-sectoral collaborations are expected to lead to higher-quality urban NBSs that would otherwise deteriorate or not be created in the first place, based on shared responsibilities between public and private actors that might also enhance the opportunities to access innovative financing forms [24,25,26]. Additionally, collaborative forms of governance characterised by multi-stakeholder decision-making processes are capable of reducing the risk of an unequal distribution of benefits among citizens as they are based on analyses of proximity and opportunities to access green areas and connected ecosystem services [24]. One of the main reasons for this is the increased diversity of stakeholders that comes from effective and well-planned citizen consultations and involvement in the different phases of the design, delivery and management of urban green spaces [24,27,28].

Partnership models for the delivery and management of urban green areas have been seen as a promising solution for space scarcity given their enablement of the needs-oriented design of public space [29]. In this way, urban greening can promote social cohesion and neighbourhood aggregation through the adoption of collaborative processes in the negotiation of common space [29,30,31]. This becomes particularly relevant when addressing urban regeneration projects that also aim to restore biodiversity or to create new green areas that might result in social injustices and unequal access to ecosystem services if stakeholders are not correctly involved [24,32].

In particular, the development of public–private partnerships (PPPs) in the literature is seen as one of the most effective approaches to solve complex challenges and produce public value [33,34]. The combination of public–private resources and competences has proven to be a winning approach to designing and managing products or services more effectively in terms of benefits for the community involved. As a way to enhance social outcomes through public–private partnerships and models of collaborative governance, in many cases, the involvement of not-for-profit organisations has often been seen as a promising solution to inequity and social injustice. The involvement of not-for-profit organisation guarantees a way to include citizens’ needs and interests in policy planning in a regime of subsidiarity with public administrations [35]. Furthermore, it provides enhanced legitimacy to the partnership promoting a way to redistribute resources among stakeholders [36]. Brandsen and Johston [36], for the success of partnerships involving not-for-profit organisations, recognised four characterising factors: mutuality (the definition of mutual goals and objectives in a regime of resource interdependency), membership (interdependency and mutual recognition among actors involved in the partnership); authority (resource allocation to reach social objectives); and identity (shared mission and values among the actors involved in the partnership). By collaborating closely with not-for-profit organisations, it becomes possible to leverage social capital to increase funding and promote sustained community commitment [31]. Models as such, to date, have not been applied to assess the inclusiveness and responsiveness of multi-stakeholder governance models adopted for the management of urban green areas. Exploring this is relevant in connection with stakeholders’ participation and distribution of benefits.

Coordination across public and private sectors is further necessary to finance urban NBSs as interventions aiming to create, protect and restore ecosystem services that might be highly expensive for single actors [8,25]. Funding for urban NBSs can come either from market-based mechanisms (e.g., bonds), through public budgets allocated for public and green areas, or through mixed mechanisms that require cross-sector cooperation and uses of mixed-sources finance [25]. In all cases, evaluating and accounting for the multiple benefits of urban NBSs is necessary although it might be challenging to translate intangible benefits into monetary units, including factors such as quality of life, job creation and other social benefits [25]. Furthermore, what remains challenging, especially when using partial or full public funds, is the assessment of the equity of projects promoting the creation, protection and restoration of urban green areas, understanding who the beneficiaries of the interventions are and their degree of involvement in the process. For this, a model based on payment mean, context and process has been identified for the evaluation of the equitable nature of urban NBS projects [26]. Although this model focused mainly on the creation of ecosystem services rather than on their management, the present article aims to explore the relationship between contextual factors, ecosystem services and management models to better understand how and for whom social outcomes are generated and redistributed over time. The model will be described in the following section.

3. Analytical Framework

The analytical framework adopted for this paper has been developed based on the literature gaps identified in the previous paragraphs coupled with field observation conducted at Biblioteca degli Alberi Milano (BAM), one of the newly developed urban parks in Milan, which is managed through an innovative public–private partnership model that will be described in greater detail below. The analytical framework was developed in response to the lack of tools available to analyse the effects that governance arrangements have on the provision of and access to ecosystem services, and it can be used to support feasibility studies and ex-post evaluations for the current study.

The analysis has focused on how to better understand the role of governance arrangement in the management of urban green spaces and in the descending provision of ecosystem services. So far, no studies have focused on how a given management arrangement might affect the distribution of benefits underpinning ecosystem services at the urban scale. In this sense, moving beyond the feasibility assessment, the present analytical framework was created, based on previous works by MacKenzie et al. [6], Malekpour et al. [9] and Toxopeus et al. [24], to assess the management phase of projects delivering urban green spaces and nature-based solutions looking at the outcomes generated via the governance arrangements in a given context. Thus, the analytical framework aims to better understand how the context, ecosystem services and management models influence each other, how the combination of the three dimensions can lead to the generation of social benefits, and how those benefits are re-distributed at the community level. In particular, the framework helps to understand the capacity of the management model adopted to maximise the benefits generated through the urban green area under analysis and how, through the involvement of different actors, it can expand the benefits beyond the context of intervention.

The framework builds on a combined analysis of the context, the management model and the ecosystem services providing a trans-disciplinary analysis of the effects that governance arrangements might have on the redistribution of benefits generated via urban green area intervention, conceptualised as nature-based solutions. In particular, the analytical framework deals with the role of the management models with reference to two main characteristics: (i) accessibility to green areas, comprising whether or not management models contribute to the classification of urban green areas as urban commons; and (ii) the provision of ecosystem services, comprising whether or not the management model can expand the effects and benefits of ecosystem services beyond the project area. In the context of the present study, the analytical framework was used to assess the benefits of a collaborative governance model—specifically a public–private partnership—for direct, indirect, and potential users of a given urban green area.

The different components of the analytical framework are presented in the following sub-paragraphs.

3.1. Description of the Analytical Framework

The analytical framework supports in assessing the current situation with a stakeholder-centred approach, and the effects that a multi-stakeholder management model can have on re-distribution of ecosystem service benefits. In the current context, ecosystem services are analysed only with reference to their quality and characteristics, while no economic evaluation is conducted according to the analytical framework. Figure 3 below presents a schematisation of the analytical framework. The three components of the analytical framework will be described in the following subsections.

From the conduction of the analysis according to the three pillars presented, we can better understand the benefits generated for the direct, indirect and potential beneficiaries of the project. By combining the three analyses, we can study how the context and the management model adopted might influence the diffusion of benefits at the urban level, moving beyond the geographic scope of the project. The combined analysis of the three components allows us to identify the enabling and limiting factors deriving from the management model adopted, how they might influence the generation and re-distribution of benefits, and how they might influence or be influenced by contextual factors.

Through the combined analysis of the three pillars, we can better understand the nature of urban green spaces as either commons or club goods, and the coalition of stakeholders that can support the development of the project and drive it towards the maximisation of benefits for the community. Conducting this combined analysis allows us to answer the question “for whom are the benefits generated?”, introducing a lens of social justice to the analysis of urban green areas in large-scale urban regeneration projects that, up until now, have been scarcely addressed. The output of this analysis can further influence the context by promoting new regulations and policies that aim to redistribute social and ecological benefits where these are not already happening as a way to limit or counteract green gentrification effects.

3.1.1. Context

The context refers to the characteristics of the geographic context where the intervention is located referring to both the natural and built environment as well as their transformation over time, encompassing social, political and geographical conditions [26]. When addressing the issue of context, particular attention shall be given to the policies and regulations acting in the given context in order to understand the factors that have led to the development of the green area. Analysing all these characteristics together allows to understand better the specificities of the area where the intervention is located, its socio-political legacy, and environmental stressors that shape the character of the urban community, as well as the types of NBS that can be implemented and the available funding mechanisms.

Further attention, when addressing the context, shall be given to stakeholders that are present in the given context, the degree of their involvement and the networks present at the local level. Analysing the stakeholder present in the field empowers decision-makers to reach out the most relevant actors in a given community and supports the development of an engagement plan throughout the different project phases.

Developing a joint assessment of the context and the relevant stakeholders allows us to understand the complexity of urban green spaces at the local level and allows us to identify the enabling or limiting factors coming from the context itself and from stakeholders’ interests, needs, and values. In fact, projects, especially multi-stakeholder and cross-sectoral ones, as urban regeneration interventions, might fail due to poor stakeholder understanding and engagement as well as shortcomings in taking into account different stakeholders’ needs and interests [24,26]. Together with a better understanding of the motivation and commitment of different stakeholders, the analysis conducted according to the framework allows us to acquire knowledge about the skills and capabilities of the different actors as well as the capital, especially relational capital, that they bring to the project [31].

3.1.2. Ecosystem Services

According to the definition given above, for the sake of this study we will consider as ecosystem services all those benefits generated for human well-being through the active and passive use of natural resources included in the green space under analysis. For this, it is fundamental to understand the quality and characteristics of the natural resources included in the urban green area as the object of analysis and how they support the generation of effects and impacts on individual or collective well-being. In order to achieve this, ecosystem services will be analysed according to their ability to produce social outcomes, especially in terms of aggregation, cohesion, and quality of life [7].

Addressing the issue of social benefits also allows an understanding of how ecosystem services benefit the relevant community in trying to determine the individual and collective benefits that communities enjoy. In this sense, it is crucial to understand how the context and ecosystem services influence each other, posing the first question regarding equity of how capable they are at responding to the stakeholder interests and needs analysed according to the analytical framework.

3.1.3. Management Model

The third pillar of the analytical framework refers to the management model adopted for the urban green area, distinguishing forms of individual management from forms of collective or hybrid governance. In particular, it is crucial to understanding the reasons behind the choice of whether or not to have collaboration among different stakeholders. In large-scale regeneration projects, we support the trend of public–private partnerships as a means to share resources, and this becomes even more crucial when developing new urban green areas that are costly and hard to manage only with public funding and resources [9,10]. For this reason, this part of the assessment deals mainly with the cases of collaborations that, according to Malekpour and colleagues [9], might originate from necessity (when projects are not viable or feasible if developed by a single actor), innovation (when one or more actors pursue an innovation agenda), or vision (when the promoters have a shared vision of societal outcomes to be achieved).

When addressing the issue of collaboration among different stakeholders, it becomes fundamental to understand who should participate and with what responsibility. In carrying this out, it is fundamental to take into consideration the stakeholders present in the given context and to understand who, among those, have the necessary resources for the success of the projects, can guarantee legitimation to the partnership and have a primary interest in the development and management of the project. By answering these three questions, it is possible to define the collaboration structure throughout the different phases of the project while also understanding who the beneficiaries of the collaboration beyond the parties involved will be. This supports the analysis of the processes behind the collaboration scheme, the appropriate level of collaboration and how they contribute to the generation of well-being benefits underpinning ecosystem services [9].

3.2. Data Collection

Given the three components of the analysis conducted, data collection required a complex and combined effort in order to support the framework presented above. Data collection was conducted in the second half of 2022 while analysing the case of the urban regeneration project of Porta Nuova, where BAM is located. Data collection started with desktop analysis to identify relevant stakeholders and to understand the characteristics of the project that were employed in the first stage.

As a second step, an online survey was developed and administered to 100 selected stakeholders representing COIMA’s and Fondazione Riccardo Catella’s employees, current and former members of Municipal and Regional public administration bodies, and corporations and not-for-profit organisations with a statutory seat in Porta Nuova or in its proximity, as well as local residents. The online survey was aimed at understanding, according to the value and opinions of different stakeholders, the impacts resulting from the Porta Nuova regeneration project and the creation of BAM for the district, for the neighbouring areas and for the entire city of Milan.

Following the administration of the online survey in June and July 2022, a set of individual and group interviews with the most relevant stakeholders were conducted in September 2022. For the conduction of the interview, semi-structured protocols were adopted, and a set of pre-defined questions were developed in accordance with the results of the survey. Based on the answers received, follow-up questions were formulated in a way that allowed us to further explore the topics introduced by the interviewees.

4. Case Study: Biblioteca Degli Alberi Milano (BAM), Milan, Italy

In line with the research objectives, a particularly relevant case of green area development and management in a metropolitan context was identified. The selected case study, on one hand, supported the development of the analytical framework presented above, while, on the other hand, it offered the possibility to test the logical model adopted and to assess its effectiveness in analysing the impact that hybrid governance models have in terms of providing access to green areas and ecosystem services as a way to maximise benefits for the community beyond the project area.

Biblioteca degli Alberi Milano (BAM) is a recently developed public park located in the semi-central area of Porta Nuova in Milan and it represents a unique case of public–private partnership for the management of an urban park in Italy. Biblioteca degli Alberi Milano was developed between 2016 and 2018 as part of the urban regeneration project that fully re-developed the former “scalo Varesine”, a railway yard located between the neighbourhoods Isola and Brera, close to the railway station “Milano Porta Garibaldi”. BAM is the biggest non-enclosed park in Milan with a surface of approximately 90.000 sqm that is fully accessible and fully walkable, acting as a hinge between the newly developed areas and the historical neighbourhoods. Figure 4 below provides the location of BAM park in Milan, a map of the park and an aerial picture of the area.

The park was designed by the Dutch architecture firm Inside Outside|Petra Blaise and developed by COIMA in accordance with a planning agreement with the municipality of Milan. Thanks to its innovative design and the variety of plants, BAM represents an example of a contemporary garden where green areas, irregular paths, flower fields and forests interact with each other and with the thousands of daily visitors. Figure 5 shows some of the characteristics of the different areas of the BAM park.

The development of BAM required extensive work in terms of remediation in order to clean the former railway yard that had been in a state of abandonment for over 30 years. The park connects the newly created Piazza Gae Aulenti, beneath the UniCredit Tower, with via de Castiglia and, through it, with the Isola neighbourhood. To allow the regular circulation of trains to and from Garibaldi station, the ground level of the square was raised, allowing car and train mobility under the park. This resulted in a sloped park with a soft incline to bridge the height difference between the two ground levels of via de Castiglia and Piazza Gae Aulenti.

BAM was opened to the public in 2018 and since 2019 it has been managed through a 10-year partnership between the Municipality of Milan, COIMA, and Fondazione Riccardo Catella that oversees the daily operations and takes care of the cultural activities and events of the park. The opening of the cultural program was marked by the “Back to the City Concert” held on the 18th of September 2019, a free concert where the Philharmonic Orchestra of “Teatro della Scala” played for the first time in its history in a public garden. Since then, BAM activated a palimpsest of cultural, recreational, fitness, and educational activities that attract over 20.000 visitors yearly.

From an economic perspective, BAM represents an in-between club and common space. Being a non-enclosed park, it presents the characteristics of non-rivalry and non-excludability, typical of commons, and thus, in theory, allows everyone to enter its precinct and to make use of it, although its location and the presence of the cultural programme might, at the moment, preclude access to the green areas due to events or due to the distance between the park and non-residents thus being more similar to a club good where only participants of certain events can make use of the park, or a portion of it. Bearing these characteristics in mind, the following section aims to present the result of the study conducted on BAM in accordance with the analytical framework presented above.

BAM is a very interesting case study because it has unique and cutting-edge features in terms of the way it has been conceived and managed so far. At the same time, however, it does not shy away from addressing the traditional challenges of an intervention such as this. In particular, the public–private partnership must be able to provide citizens with a proposal that brings diffuse tangible and intangible benefits, avoiding the risk of falling into a “green gentrification” phenomenon.

5. Findings

The study started from the analysis of the context of intervention, the stakeholders, their needs, interests, and values. This allowed us to have some considerations about the degree of involvement of the different stakeholders throughout the phases of the project. Furthermore, thanks to the survey and interviews it was possible to better understand their perceptions of the effects of the project as a way to study whether or not there was a redistribute effect in the implementation and execution of a regeneration project where a new urban green area was developed. Thanks to this, an analysis regarding the ecosystem services was conducted and a management model was determined conducted in accordance with the effects the former have on the stakeholder, adopting a lens of social inclusion.

The study shows that context plays a crucial role in the perception of the effects of a project and the benefits that derive from the creation of new urban green areas. In fact, benefits related to quality of life are felt strongly by stakeholders that are closer to the green area and they become less and less intense the further the stakeholders are from the intervention area. This entails that in the case of BAM, park ecosystem service benefits are felt strongly at the local level, representing a hybrid club–commons nature [9,11]. In fact, when addressing the issue only from an ecosystem service perspective, the benefits derived from the creation of the BAM park seem to make it more of a club good, where membership is given according to one’s proximity to the park, despite it having the characteristics of a common good by design.

In order to counteract the green gentrification phenomenon, leveraging the innovation power of the PPP, the parties involved had an opportunity to experiment with a new way of managing the space through the creation of a cultural and recreational programme, developed yearly by Fondazione Riccardo Catella and approved by the Municipality of Milan. Since 2019, over 1100 free-of-charge events have been organised accounting for about 130,000 participants from Porta Nuova and neighbouring districts as well as more peripherical neighbourhoods as reported by many of the interviewees. The cultural and recreation programme aimed to attract citizens, organisations, and institutions from other neighbourhoods, which were in many cases peripherical ones. According to stakeholders, this made BAM a destination in Milan, making the park a place for interaction and exchange between people from different socio-cultural backgrounds.

The presence of the cultural and recreational palimpsest acts as a catalyst for community engagement to replicate the co-creation approach used during the development phase and replicate it in the activation and management phases. A focal point of the cultural and recreational programme is the conjunction between nature, culture and sustainable development, that, according to the majority of the interviewees, acted as an enabling factor for the acquisition of knowledge and skills by the participants. At the same time the provision of events and recreational activities is seen as a means to maximise the outreach of benefits connected with the ecosystem services of BAM beyond its geographical boundaries.

When adopting a stakeholder perspective for the assessment of ecosystem services and a management model, it is possible to understand the perception of different effects of different members of a community. A particular feature detected through the application of the analytical framework above is the capacity of urban green areas to act as an attractor for people from different backgrounds and residing in more remote areas of the city. This is identified as a factor capable of creating positive effects in terms of social inclusion and cohesion, according to results of the survey conducted. However, according to the survey and interviews, daily users and residents still perceive the ecosystem service benefits in a different way, thus showing that the cohesion and inclusion effect is more dependent on the management models rather than on the provision of ecosystem services. In fact, environmental and well-being effects are perceived to be stronger by stakeholders that are closer to Porta Nuova district compared to actors coming from peripherical neighbourhoods, whereas cultural, social, and educational effects arising from the events programme are regarded in the same way across the city districts. This could result from the fact that those who perceives the benefits underpinning the ecosystem services are primarily located in proximity to the park, whereas the users that come from further away do not feel the same level of benefits. This could be a limitation of the project, indicating that it has not been able, so far, to fully distribute benefits among different members of the community.

In the following sections, the results of the study in terms of the three pillars of the analytical framework will be presented in detail.

5.1. Context

As mentioned above, BAM is located in the north-western part of Milan city centre in the former area of scalo Varesine, a railway yard dismissed at the end of the 60s that represented, for a long time, a void in the city’s tissue. BAM in this sense “reknitted” together the historical neighbourhoods of Isola and Brera, allowing the walking time from one to another to be halved. In fact, the creation of the park, thanks to its design, doubled the number of walkable paths in the areas, adding 12 km worth of walking paths.

Due to its location, the urban regeneration project has received the attention of many stakeholders that have been engaged throughout the project. From both the survey and the interviews conducted, it emerged that both internal and external stakeholders were interested in creating a connection between the neighbourhood and developing new green areas that could serve as places for aggregation. This shows that, overall, the values at stake were similar among stakeholders before the implementation of the project, and that they were mainly connected with individual and collective well-being, the promotion of social cohesion, protection, and the promotion of biodiversity, as well as with increasing the safety of the area. In a similar way, the survey conducted in 2022 shows that the involved stakeholders perceived the strongest effects of the project to be in the environmental, social, and quality of life dimensions connected to the development of the BAM park thus, confirming an alignment with their interests before the intervention.

Despite the similarity in the values and interests of the stakeholders involved, clashes between the developer and the residents in the neighbourhood Isola were reported during all interviews. Among the main reasons of disagreement was the destruction of the former “Stecca degli Artigiani”, a craftmanship hub close to the precinct of the future BAM park and the closure of a public green area in Isola to host the new development. Both represented part of the historical and cultural heritage of the area. To overcome stakeholder opposition, a series of community engagement events were organised as reported during the interview process. In fact, the masterplan for the development of the lot “Porta Nuova Isola” changed more than once over time to meet the demands coming from the local community. This resulted in the development of a co-creation model that led to the creation of a non-enclosed park that could be accessed day and night by the residents of neighbouring areas and not just by the new residents in Porta Nuova.

The development of the park represents a developer obligation, being designed to compensate for the cost of stronger public infrastructure and service use resulting from private development. Its management model, in the form of a public–private partnership, is new compared to that of traditional in-kind contributions (see Section 5.3). The co-creation model and the presence of a municipal regulation that allowed the development of public infrastructure and green areas instead of its corresponding planning fees to be dealt to the municipality acted in this case as enabling factors of the promotion of a collaborative governance model capable of taking into account a multiplicity of interests and needs coming from different segments of the citizenship. In this sense, in the partnership, the Municipality of Milan and, partly, Fondazione Riccardo Catella represent general interests and assure stakeholders of the commons status and accessible nature of BAM.

5.2. Ecosystem Services

Based on the study conducted, the development of the BAM park with its characteristics had the primary effect of transforming a former brownfield into an urban green area with over 500 trees and other 135,000 plants and flowers covering an area of 90,000 sqm. The rich botanical collection present in BAM enhanced biodiversity in an urban garden via the creation of different habitats for a variety of autochthonous arboreal species, amounting to 100, resulting in a “botanical library”. Although this richness in botanical species was not accounted for in stakeholders’ values, the creation of a green field was among the top priorities of the involved actors who recognised, before the execution of the Porta Nuova regeneration project, its value in terms of the well-being benefits of having a new urban park in an area that was for long time neglected and abandoned.

Given its extension, BAM provides about 22 sqm/habitant of green areas compared to the average of 18 sqm/habitant in the city of Milan. This is particularly important as the development of BAM transformed a former brownfield into a green space capable of capturing CO₂, reducing land temperature and reducing the urban heath island effect perceived by many of the stakeholders involved in the current study. In fact, the reduction in the urban heath island effect is considered to be among the enabling factors that contributed to an increase in the quality of life of residents and daily users of the park. This shows the ability of the newly developed park to address the needs and interests expressed by stakeholders and discussed in the previous paragraph (Section 5.1).

5.3. Management Model

As previously mentioned, one of the major elements of the distinctiveness of the initiative is the public–private partnership agreement for the management of the BAM park signed in 2019 by the Municipality of Milan, COIMA and Fondazione Riccardo Catella. Through the partnership, the municipality conceded the park for a duration of 10 years to Fondazione Riccardo Catella, which oversees its ordinary management and the provision of cultural and recreational events as we have seen above. The partnership developed for the management of the BAM park in accordance with categories identified by Malekpour et al. can be defined as an agreement grounded both on necessity and innovation [9]. In fact, while BAM was being developed, public debate on how to manage urban public and green areas in times of budget constraints was ongoing in many European cities [37,38,39,40]. Thus, a partnership with a private entity looked like a promising solution to sharing maintenance costs between parties. In light of this, COIMA, as expressed many times during the interview phase, was pursuing an innovation agenda and was willing to develop a new governance model for green areas that would leverage the characteristics of the park to maximise benefits for the community. Based on these two drivers, the parties developed the collaboration agreement that is still ongoing.

Building on the work by Brandsen and Johnson [36], the collaboration was built on a long-term commitment between the parties and the inclusion of shared objectives in the partnership agreement, which, according to interviewees, allowed a guarantee of the temporal stability and sustainability of the action. As reported during the interview process, each year the parties renew their objectives and include them in the event programme. Furthermore, knowledge of the urban territory and interaction with the local community led to the development of an integrated project capable of drawing in new financial and non-financial resources for the future development of the park, as reported by the interviewees.

The BAM project further activated a process of contamination of competences between public and private actors that is capable of enhancing the benefits related to ecosystem services. From data collection, it emerged that private expertise and resources have been crucial for the implementation of the project to be on schedule. Beyond tangible resources, the project triggered a process of intersection in terms of skills and sensitivity between public and private actors. As an example, although it was not part of the initial project, Fondazione Riccardo Catella pursued the goal of developing a park that would enhance biodiversity, as discussed above.

Additionally, among the enabling factors of the partnership model, mutual trust between the parties can be accounted for [41]. In fact, according to the interviewees, the success of the management model lies in the continuous dialogue between the parties and the willingness to find a middle ground to advance community interests and needs. In the collaboration arrangement, one of the key points was a willingness to create a strong foundation of trust on both sides. In particular, COIMA and Fondazione Riccardo Catella have been reliable and solid partners for the municipality. For COIMA, the municipality has played a relevant role in representing the needs of the city and its residents. This resulted in a transparent management model that allowed the park to remain an urban common, a place open and accessible to different members of the population.

Moreover, the partnership agreement for the management of the BAM park was capable of activating a network of citizens and organisations that contributed in different ways to the success of the initiative. Through agreements with other not-for-profit organisation in the entire city of Milan, BAM was capable of multiplying the events and projects implemented yearly and of extending the effects generated beyond its borders. For example, the management of the park is currently supported by volunteers who make contributions to both the maintenance of the park and the activities carried out in it. At the same time, the new networks and activities attracted more daily users to the park, protecting its commons-like nature from possible instances of excludability due to enclosures and commodification, which were felt to be a main threat by the local community.

Overall, as reported by the stakeholders interviewed for this study, the management model developed for BAM is a first step towards a pluralistic and multi-actor governance structure that enables a continuous dialogue between public administration and private entities. The enhanced transparency has also enhanced the dialogue with the public and with local communities as a way to constantly assess their interests, and has included different needs in the management models used, although the community at large is still neither involved in the management model and in decision-making processes nor is it directly involved through representative organisations.

Finally, from the survey and interviews it has been possible to draw a picture of the characteristics and mindset that private and public actors should have to successfully develop such an initiative. The private sector should be a solid and reliable actor as well as being open to dialogue with the public and the citizenship for real integration with the territory and for the generation of intentional and additional impact. Public administration, from this perspective, should adopt a proactive approach aimed at collaboration with different actors. Citizens expect that the management of public spaces cannot be made sustainable by the municipal system alone; thus, finding partners who support urban development can be a win–win solution.

6. Discussion and Conclusions

As we have seen from the analysis conducted, the definition of a framework of the design and management of an urban green urban area allows the identification of innovative practices and the support of the adaptability, replicability, and scalability of these initiatives. The analytical framework presented in this paper can be an effective tool for practitioners and planners when developing a collaborative management model for urban green areas. The framework developed for this study has allowed us to conduct an evaluation of the potential of collaborative governance models for the management of urban green spaces. In fact, the findings showed the benefits of a public–private partnership created for the purpose of managing of an urban park (BAM). In particular, collaborative management models can be a valuable means with which to extend the benefits connected with ecosystem services beyond the intervention boundaries, attracting a diverse group of stakeholders that might benefit directly or indirectly from the green space. The analytical framework, taking into account the management phase of green spaces, promote an assessment model based on processes activated for the maximisation of benefits, and might provide guidelines on how to engage stakeholders following the execution of a project. This enables us to also understand also stakeholders perceive the level of benefits differently.

Analysing the case of BAM through the analytical framework developed allowed us to identify a set of factors to be taken into consideration when looking at urban green space projects as well as interventions. Stakeholders’ attitudes and interests may act as both enablers and limitations when dealing with large-scale urban interventions and for this reason it is crucial to include their preferences into the decision processes from the early stages. Furthermore, the findings presented above show how the development of a cross-sector management model in the form of a PPP is useful in partially counteracting “green gentrification” phenomena via the redistribution of benefits among community members as highlighted in the literature [6,9,30]. However, as the study has shown, social outcomes still seem to be more dependent on the activities promoted in BAM rather than on access to ecosystem services. This is particularly true when assessing the capacity of urban green spaces to act as attractors and as enablers of community cohesion.

Another aspect of the main results of the study is the fact that a cross-sector management model, such as the one adopted in the case of BAM, supports the understanding of its urban commons status as one that promotes the maximum level of accessibility via a reduction in the park’s excludability, through provisions of activities for all and not just for residents, and enhancing rivalry in use [15,16,29]. This can be read as another factor that enhances the fair and equitable distribution of benefits at the community level [6,24,26,32]. Together with characteristics of non-excludability and rivalry, commons generally entail forms of self-management or participatory governance in identifying the rules of engagement for the use and protection of natural resources as a way of enhancing access to ecosystem services while maximising benefits for the entire community of users. At the current stage of research, it has not been possible to assess stakeholders’ networks and coalitions and how they might influence the management of urban green spaces, the redistribution of benefits and the classification of the park as an urban common. Further research in this regard is needed and will characterise future applications of the analytical framework.

The results presented in this paper contribute to the current academic discourse regarding urban green spaces, nature-based solutions, and ecosystem services, providing a framework to understand benefits through an evolutionary perspective. Benefits created via projects such as this should not only be evaluated according to their monetary value, but also with reference to how the governance arrangement can lead to a redistribution of this value at the community level. The findings presented in this study provide a hint about the kind of mechanisms to be put in place to promote fair access to benefits generated via ecosystem services, expanding the results of previously conducted studies in the field [6,9,25,26]. In particular, the results show that a cross-sector management model can lead to innovative financing mechanisms for green space projects as addressed by Toxopeus and Polzin [25]. If similar governance models are adopted in the operation phase of an intervention, i.e., after its delivery, they can contribute to the promotion of social interactions and the generation of societal outcomes that partly counteract the gentrification phenomena generally connected with urban regeneration projects. Such results are felt more strongly in cases in which not-for-profit entities are involved, showing how the presence of third-sector entities can enhance trust among parties and transparency with the public, as highlighted in previous research [36,41]. Moreover, building on the work of Malekpour and colleagues [9], the study shows the role that innovation agendas can play in enhancing benefits related to ecosystem services through the sharing of costs and the maximisation of access. The results presented, in this sense, are promising in that they show new models with which to finance and manage public services to generate societal outcomes. Further investigation is needed to assess how benefits are re-distributed through cross-sector management models such as the one analysed in this paper.

The analytical framework, developed thanks to the research, presented in this paper can provide guidance on how to plan urban green areas in contexts of urban regeneration and how to take into account a stakeholder perspective in the assessment of their outcomes. In particular, the framework enables planners and practitioners to understand the role of context and the role of management models in the perception of ecosystem service benefits and the redistribution of benefits at the territorial level. In this sense, it allows us to answer questions regarding the beneficiaries of interventions as a way of promoting the redistribution of benefits and inclusion. Despite this initial application, the framework needs to be further developed and tested in other cases in order for it to become a tool for planners and practitioners. In this sense, further applications of the analytical framework will allow us to identify and assess other enabling and limiting factors to be taken into consideration when planning and managing an intervention aimed at providing urban green spaces.

Attention to the negative effects and spill overs of these kind of initiatives remain central in pursuit of reducing or overcoming phenomena such as green gentrification in urban regeneration contexts. In particular, the approach used took into consideration the ability of the management model to engage not-for-profit organisations and to redistribute benefits at the urban level. So far, the results of the study explain that thanks to a participatory management model and a cultural programme, the green areas concerned have the capacity to attract users from different backgrounds, although only few of them reside in neighbouring areas. Further investigations into the capacity of the management model to counteract green gentrification is still needed, as a form of research on the type and degree of ecosystem service benefits perceived by different categories of users. What emerges as a positive effect of the management model discussed is the involvement of not-for-profit organisations in the management of the park to conduct on-going analyses of stakeholder needs, interests and values.

The study presented in this paper and its output are promising in providing recommendations on how to develop innovative and multi-stakeholder management models for urban green areas, especially when they are developed as part of urban regeneration projects. The findings included in this research and the assessment model developed can be particularly relevant for the conduction of future research in this domain, providing a multidisciplinary approach to the questions related to the management of urban green spaces. In particular, new perspectives of research can delve deeper into the connections between the provision of ecosystem services and their redistribution among community members through collaborative governance models.

The case study adopted, Biblioteca degli Alberi Milano, is a unique and cutting-edge one in the Italian panorama and recommendations can be drawn for applications in other contexts when analysis is carried out in accordance with the framework provided. The peculiarity of the case study and its novelty do not allow a generalisation of the conclusions at this stage and leave the door open for further investigations into the evaluation of ecosystem services in a context such as the present one as well as an evaluation of re-distribution capacity of the management model using a lens of social justice and equity. Despite these limitations, the study achieved its objective in showing how a collaborative governance model, in the form of a PPP, protects the commons nature of urban green areas in contexts of urban regeneration preventing enclosures and allowing for a multiplicity of uses of the green areas and their natural resources to be experienced by a multiplicity of stakeholders.