Green Infrastructure and Climate Resilience of Urban Neighborhoods: What Can the Citizens Do Together?

Abstract

This study began from the assumption that community self-organization, characterized by independent action without external control, could be a suitable approach to developing green infrastructure and strengthening climate resilience in urban neighborhoods in Serbia. The study employed a mixed methods approach to verify this assumption, combining a technical case study and citizen survey analysis. Technical simulations demonstrated that self-organized community interventions on green infrastructure could contribute to climate resilience, even in neighborhoods with unfavorable conditions. However, the survey uncovered significant social constraints that cannot be resolved within the community, including a perceived lack of internal capacity; belief in the primacy of external actors; moderate cohesion level; lack of community platforms; limited understanding of the interconnections between resilience, climate change, and the role of green infrastructure; limited environmental literacy; and unclear collective action benefits. Based on these findings, the study proposed a multi-level and multi-phase model for improving neighborhood green infrastructure. The model emphasizes participatory citizen collaboration and applies to the current context of Serbian urban neighborhoods.

1. Introduction

Recent years have witnessed the emergence of various initiatives in response to the changing global climate and its impacts on the built environment. These actions encompass parallel efforts to mitigate future negative climate change manifestations and foster climate resilience. To that end, collective intelligence, defined as the capacity of people and their joint action to address complex challenges, has been increasingly recognized as a crucial factor in tackling climate-related problems and achieving sustainable development, as evidenced by studies [1,2,3].

Urban growth, especially in developing countries, often conflicts with sustainable growth [4,5]. Green infrastructure emerges as a critical element of the quality of the urban environment. The importance of green infrastructure is multifaced, as described by [6,7,8]. Significantly, green infrastructure possesses the unique capacity to actively enhance the quality of the living environment, while other sustainability-related measures primarily focus on mitigating environmental damage [9].

Numerous international studies have highlighted the positive role of green infrastructure in mitigating the effects of climate change on different components and aspects of urban areas, including urban built infrastructure [10], socio-economic needs [11], energy consumption, flora and fauna [12], the urban heat island (UHI) [13], ambient temperature, air quality, human health [14], and others. A direct correlation exists between the quality of green infrastructure and climate resilience [15]. Furthermore, the concept of nature-based solutions is applicable across diverse climates and human settlements. Given the inherent connection to human nature, it is reasonable to expect that people may be more receptive to engaging in spatial actions related to nature-based solutions.

Studies [16,17] have shown that addressing various climate change-related challenges should be operationalized on the local urban, i.e., neighborhood scale. The emphasis on the social dimension of neighborhood [18,19,20] underscores the importance of involving citizens in resilience building processes. The authors of studies [21,22,23] agreed that the sustainability of green urban spaces depends on citizens and the level of their engagement with planning, design, construction/installation, use, and management. Social capital is increasingly recognized as a key determinant of climate change adaptation [24].

Engaging citizens in the (re)development of green infrastructure at the neighborhood level requires a strategic approach, customized to local and regional contexts, as shown by [25,26], as a result of which this engagement can manifest in a variety of forms. This study focuses on the Republic of Serbia, where residents have recently experienced significant climate change manifestations and extreme weather events [27], highlighting an urgent need for adaptation strategies. Furthermore, a notable gap exists in Serbia at both national and local levels regarding the development and implementation of practices, policies, and plans for engaging citizens in climate action through green infrastructure improvement. As greenery is insufficiently present in Serbian cities, initiatives to enhance green infrastructure will yield multiple benefits, including a reduction in climate-related risks. Finally, three-phase research conducted between 2006 and 2016 revealed that most Serbian citizens refrained from participating in formal community organizations, with environmental issues consistently ranking among the least prioritized areas of citizen engagement [28]. Although the civil sector in Serbia [29] has grown since 2016, the promotion of citizen engagement in neighborhood planning processes remains inadequate and requires attention. These findings underscore the relevance of Serbia as a case study for this research.

The existing body of literature on green infrastructure in Serbia primarily focuses on regulatory, technical, and ecological aspects, with limited attention given to social dimensions, particularly citizen engagement. References [30,31,32] analyze existing legal frameworks at national and local levels, highlighting the unsatisfactory position of green infrastructure. The application of geospatial methods and tools in green infrastructure planning and design is explored in [31,33]. Different types of green infrastructure are examined in [34,35,36], and [37,38,39] investigate the impact of plant species on local climate resilience and sustainability. According to [40], there is evidence of the positive impact of building-integrated greenery on energy consumption. The landscape ecological principle of green infrastructure connectivity is explored in [32], and [41,42,43] report positive health effects of urban green infrastructure. Finally, only one national study [44] has specifically examined citizen engagement in the context of green infrastructure enhancement. This study, focusing on two case neighborhoods in Belgrade, compared the quality of green infrastructure before and after community spatial interventions, and emphasized the need for revised local regulations and plans.

A comparative analysis of national and international research reveals a gap in the Serbian context regarding the recognition of the significance of social components in green infrastructure concepts and projects. National studies often fail to recognize the neighborhood as the optimal urban scale for addressing climate change adaptation. Moreover, they lack a comprehensive understanding of the interdependencies between all constituent components and the external social factors that influence a neighborhood’s resilience. This research gap is further exacerbated by the lack of social innovations for green infrastructure improvement that can be effectively applied across diverse neighborhood contexts.

Overall, there is limited published international evidence on how community engagement with green infrastructure can contribute to neighborhood microclimate regulation. These concepts are typically studied in a fragmented manner. By considering the neighborhood as both a socio–spatial and a technical–spatial entity, this study intends to integrate all relevant components, leading to more practical and meaningful results.

Having considered the above points, this study aims to provide novel insights into the complex interplay between urban neighborhoods, their communities, green infrastructure, and climate resilience. The main objectives of this work are to: (1) explore the optimal form of citizen engagement to enhance urban green infrastructure and thereby contribute to strengthening climate resilience in Serbian urban neighborhoods; and (2) utilize findings to develop a multi-level strategy applicable across various urban contexts.

2. Materials and Methods

Local communities are not sufficiently valued or recognized as legitimate actors in the development of urban neighborhoods in Serbia. In the absence of adequate external support, externally led initiatives, or externally developed engagement plans, bottom-up community organizing emerges as a potentially optimal approach to address green infrastructure and climate resilience.

Integrating citizens’ involvement into institutional or business frameworks requires significant effort, substantial reforms, and considerable time. Given the already observable impacts of climate change in Serbian cities, it is crucial to identify an engagement model that enables immediate action. This model should empower citizens as primary agents of change, allowing them to act independently and efficiently within their neighborhoods to enhance green infrastructure and build climate resilience. Hypothetically, one such model could be self-organization, defined by Boonstra and Boelens as “initiatives for spatial interventions that originate in civil society itself, via autonomous community-based networks of citizens, outside government control” [45] (p. 100).

Self-organization is a fundamental and longstanding form of community action. In urban environments, citizens may self-organize for various reasons, with many initiatives focusing on the improvement of the quality of life, such as community gardening or urban food production. To determine whether self-organization is an effective approach for enhancing green infrastructure and climate resilience in urban neighborhoods in Serbia, it is crucial to objectively assess both the technical and social dimensions of this concept. To this end, this research combines several techniques, primarily case study analysis and survey. The independent application of these techniques allows for the collection of objective individual results, enabling subsequent comparisons and ultimately facilitating the validation or refutation of the initial hypothesis. In any case, the objective conclusions derived from these analyses will serve as a foundation for developing a readily applicable model of citizen engagement for enhancing green infrastructure and strengthening climate resilience in Serbian urban neighborhoods, thereby achieving the primary research goals.

2.1. Case Study Analysis

The case study analysis aimed to investigate the potential for community self-organization to enhance climate resilience in an urban neighborhood characterized both by:

• Significant vulnerabilities and exposure [46] to climate change impacts, and
• Limited possibilities for greening-related spatial interventions.

The assumption was that, if successful greening interventions could be identified and implemented in a challenging neighborhood environment, the principle of self-organization could be effectively applied to other neighborhoods with more favorable spatial, climatic, and environmental conditions, where a wider range of intervention options would be available.

The initial step in selecting a relevant neighborhood sample involved analyzing data on observed and projected climate changes available at the municipal level in the Digital Climate Atlas of Serbia [47]. The analysis focused on temperature growth, recognized as the most certain climate change-related manifestation, both currently and in future projections [27,48]. However, analysis of data from the Atlas for the reference period (1986–2005) and the forecasted periods (2021–2040, 2041–2060, and 2081–2100) indicated a uniform risk of temperature increase across all cities in Serbia, making it impossible to identify a narrow urban area with substantially higher temperature-related climate hazards.

Given the increased vulnerability of densely populated urban areas to climate change effects, the second step in the neighborhood selection process involved examining urban density across Serbian municipalities. Based on an analysis of national statistical data [49,50], the municipality of Vračar, located in the central zone of Belgrade (Figure 1), was identified as the smallest municipality (2.92 km²) with the highest population density in the country (18,975 residents per square kilometer). Moreover, due to its central location within the city and a high proportion of concrete and asphalt surfaces, Vračar is particularly susceptible to the UHI effect, which is characterized by an increased frequency of tropical nights [47,51].

The final step involved selecting a specific neighborhood within the Vračar municipality. Due to the lack of available data on microclimate variations, the analysis could not delve deeper than the municipal level. As a result, the Kalenić neighborhood, located in the central part of Vračar, was selected for this case study (Figure 1). The boundaries of the selected Kalenić neighborhood are set at 400 m distance and they coincide with delimiting roads.

The total area of the selected Kalenić neighborhood is 0.11 km². The built-up area constitutes 39.73% of the total neighborhood area. The proportion of green infrastructure (green areas and tree cover) within the Kalenić neighborhood, at 11.35% of the total area, falls below the European average and the percentage observed in many European cities [52]. The existing green elements, comprising limited ground surfaces covered with grass and scattered trees, are dispersed throughout the neighborhood, further limiting their potential to effectively regulate the microclimate.

Spatial data for the Kalenić neighborhood were initially extracted using QGIS 3.34 Prizren software and subsequently integrated into the ENVI-met for Science V5.7.1 software for microclimate simulations. To enhance model accuracy and facilitate vector representation, building geometries were imported into QGIS 3.34 Prizren. Building characteristics were meticulously verified through on-site observations and Google Earth Pro imagery and corrected where necessary. Key attributes included roof shape (flat or sloping), building height, number of floors, and roof/facades material types. To align with ENVI-met material definitions, the following materials were assigned: 0200C5—Concrete: cast dense, for flat roofs; 0200R1—Roofing: tile, for pitched roofs; and 0200MI—Default wall: moderate insulation, for walls. Vector tree models were incorporated into the model based on data derived from Google Satellite and Google Earth Pro imagery. Additionally, digital elevation model (DEM) data were obtained from the NASA server using the SRTM downloader 3.2.3 plugin. Spatial data and maps were processed using the Coordinate Reference System EPSG: 32634—WGS 84/UTM zone 34N.

Following model preparation in QGIS, the layer containing objects was transferred to the ENVI-met environment using the dedicated QGIS plug-in. Simulation parameters were then defined as follows:

• Initial Soil Conditions. Upper layer (0–20 cm): Temperature 20 °C, humidity 65%; Middle layer (20–50 cm): Temperature 20 °C, humidity 70%; Deep layer (50–200 cm): Temperature 19 °C, humidity 75%; Bedrock layer (below 200 cm): Temperature 18 °C, humidity 75%;
• Building Indoor Temperature: 22 °C; and
• Initial Building Temperature: 22 °C.

The initial simulation (scenario 1) analyzed the thermal environment of the Kalenić neighborhood, with its existing green infrastructure. To focus on peak temperature conditions, the simulation was conducted for 16 July 2024, which was identified as the day with the highest total (day and night) heat load during the summer of 2024, based on meteorological data [53].

Given the limited availability of ground space within the Kalenić neighborhood, building envelopes were identified as the primary target for community-led green infrastructure interventions. To that end, the second simulation scenario (scenario 2), conducted for the same date, aimed to determine the temperature conditions with the implementation of extensive green roof systems (lightweight cassette type, not requiring municipal permits) on available flat roofs. The total area covered by green roofs in scenario 2 amounted to 15.84% of the total neighborhood area, representing 39.88% of the total building footprint.

Following an analysis of the simulation results, specific zones within the neighborhood were identified where the application of green roofs resulted in limited temperature reduction. Suitable building facades within these identified zones were selected for the hypothetical installation of direct green walls with climbing plants, utilizing systems that do not require municipal permits. The total surface area covered by green walls amounted to 28.20% of the total façade surface within the neighborhood. The third simulation scenario (scenario 3), therefore, analyzed the ambient temperature in the Kalenić neighborhood with the combined application of both green roofs and green walls, which collectively covered 58.44% of the total neighborhood area. The results of this analysis, demonstrating the improvements in temperature conditions within the Kalenić neighborhood, as obtained using the ENVI-met for Science V5.7.1 software (Figure 2), are presented in Section 3 of this article.

2.2. Survey

Data and statistics on citizens’ engagement in Serbia are currently limited. To assess citizen perceptions and engagement in shaping their neighborhoods, a survey was conducted among citizens of various Serbian cities. This survey was part of the broader research within the Erasmus+ project “Urban Planning for Social Resilience in Urban Neighborhoods—Transformative Change through Civic Engagement” (UPRUN) [54]. A standardized questionnaire was developed by the UPRUN team, coordinated by project participants from Frederick University, Cyprus, and Kaunas University of Technology, Lithuania. The UPRUN survey aimed to assess citizen participation and explore resilience and sustainability aspects within urban neighborhoods across Europe. Survey findings will inform the development of hybrid educational modules that equip learners with the knowledge and skills to enhance urban neighborhood resilience through planning, collective action, innovation, and education.

The developed structured questionnaire was reviewed and approved by the Research Ethics Commission of Kaunas University of Technology before dissemination (approval document N^o M6-2024-10, dated 28 May 2024). It comprised 39 questions, grouped into eight assessment categories. By type, the questions were designed as both single and multiple-choice, i.e., as open and closed questions. A 5-point Likert scale was used for most closed questions, with exceptions for questions requiring specific values. The estimated survey completion time was 15–20 min. The target was to collect at least 65 completed questionnaires from each participating institution within the UPRUN project.

A Serbian-language questionnaire was distributed via Google Form link in July 2024 to 130 individuals, and 94 complete and anonymous responses were received. This number represents 144.6% of the initially established UPRUN goal.

Efforts were made to ensure a diverse sample by targeting responders from various neighborhoods, cities, age groups, and professional backgrounds. The gender distribution of responders was 45.7% male and 54.3% female. Regarding education, 14.9% of responders had completed secondary education, 6.4% had completed vocational training, 14.9% held a bachelor’s degree, 45.7% held a master’s degree, and 18.1% held a PhD degree.

For this study, the following 12 items from the survey were analyzed:

• Level of community cohesion;
• Frequency of community meetings;
• Availability of physical meeting spaces within the neighborhood;
• Opportunities for citizen participation in neighborhood planning activities;
• Actual participation in neighborhood planning activities;
• Perceived responsiveness to citizen suggestions regarding neighborhood planning;
• Perception of neighborhood resilience;
• Definitions of a resilient neighborhood;
• Proposed actions to enhance neighborhood resilience;
• Accessibility of neighborhood green spaces;
• Neighborhood environmental quality; and
• Involvement in sustainable practices within the neighborhood.

While the UPRUN project employed statistical methods such as one-way analysis of variance and multiple regression analysis, utilizing software including IBM SPSS Statistics 23 and Microsoft Excel 365, this research prioritized understanding citizen preferences, opinions, and knowledge regarding the 12 listed survey items, rather than generating formal statistical data. Therefore, the analysis did not involve sophisticated statistical techniques. Instead, it focused on identifying key percentage trends within the survey responses to inform the development of a suitable model of citizen engagement aimed at enhancing green infrastructure and strengthening climate resilience, as presented in Section 3.

3. Results

3.1. Technical–Spatial Potential

To investigate the technical potential for community self-organization to enhance green infrastructure and improve climate resilience in the Kalenić neighborhood, simulations were conducted using the ENVI-met for Science V5.7.1 software. The primary objective of these simulations was to assess the impact of proposed green infrastructure interventions on summer ambient temperatures. Simulation results indicated the following:

The implementation of extensive green roof systems (scenario 2) had a moderate cooling effect on the ambient temperature at the pedestrian level (1.5 m above terrain). The maximum potential temperature difference observed between scenario 1 (without applied greening measures) and scenario 2 (with green roofs) occurred at 21:00 h, reaching 0.55 °C (Figure 3). Although the green roofs applied on multi-residential buildings covered a significant surface area, the moderate impact on heat mitigation can be attributed to the large vertical distance between the roofs and ground level. Other studies [46,55,56] have reported similar findings.

The implementation of green wall systems with climbing plants demonstrated a more pronounced cooling effect compared to the implementation of extensive green roofs. The maximum potential temperature difference between scenario 2 (green roofs) and scenario 3 (green roofs and green walls) was 1.02 °C at pedestrian level, occurring at 21:00 h (Figure 4). As expected, the areas with the most significant temperature reductions coincided with the locations of the green walls. Nevertheless, the most effective heat mitigation strategy involved the combined application of both green roofs and green walls. The largest temperature difference observed between scenario 3 (green roofs and green walls) and scenario 1 (no interventions) was 1.16 °C at pedestrian level, occurring at 21:00 h (Figure 5).

Based on the results of conducted simulations, it can be concluded that, despite the limited spectrum of possible greening interventions, community self-organization can contribute to improving microclimatic conditions and strengthening climate resilience even in unfavorable circumstances such as those identified in the Kalenić neighborhood (including limited free space, high density, scarce ground greenery, predominance of impervious surfaces, and high heat load). The positive impact of green roofs on reducing ambient heat load has been corroborated by another study conducted in a neighboring area [36]. However, in neighborhoods with taller multi-residential buildings, the application of green walls should be prioritized over green roofs due to their greater cooling potential.

3.2. Socio–Spatial Potential

The UPRUN survey findings reveal two contrasting trends. Although self-organization could effectively respond to the current lack of community involvement in formal neighborhood planning schemes, there exist several social barriers that hinder its implementation.

The survey showed that 83% of citizens in Serbia do not participate in neighborhood space planning activities, and 77% of responders rated their opportunities for participation as less than good. Only 18% of citizens reported that their suggestions are being considered in neighborhood space planning. These findings highlight a significant disconnect between citizens and formal planning processes. This lack of citizen engagement underscores the need for alternative approaches, such as community self-organization, which can facilitate timely action in the face of the urgent need to address climate change.

However, other important findings from the UPRUN survey were the citizens’ perceptions regarding collective action, neighborhood microclimate conditions, and green infrastructure and its role in enhancing climate resilience. Only 24.5% of surveyed citizens recognize their neighborhood as being resilient (Figure 6). Furthermore, responders identified the organization of community events and public authority support for citizens’ participation in planning and design as important measures to improve neighborhood resilience (

Table 1. Responders’ preferences regarding key actions for improving neighborhood resilience (multiple choice question).

Percentage of Responses	List of Measures Offered to Improve Neighborhood Resilience
66%	Willingness of Community Members to Engage in Neighborhood Space Planning and Design
54.3%	Organization of Events Within the Local Community
53.2%	Willingness of Public Authorities to Embrace Citizen Participation in Neighborhood Planning and Design
29.8%	Emergence/Involvement of a Leader who Would Unite the Community
29.8%	Creation of Suitable Places for Meetings and Interaction
16%	Involvement of an External Organization that Would Genuinely Represent Community Interests
1.1%	Other

). This outcome suggests that successful citizens’ green infrastructure initiatives could involve a multifaceted approach, combining various forms of engagement. To that end, the primary role of public authorities should be to facilitate and inspire citizens’ actions.

The willingness of community members to engage in collective action was identified as a leading factor in improving neighborhood resilience (Table 1). Furthermore, 68.1% of responders perceive community cohesion within their neighborhood as moderate (Figure 7). 45.7% of responders never attend neighborhood community meetings, and 63.8% lack access to dedicated meeting spaces. These findings present both a challenge to successful self-organization and an opportunity to foster community togetherness and strengthen place attachment through personal involvement in joint actions that improve the neighborhood environment.

While 69.1% of responders recognize that achieving common goals in neighborhood planning, design, construction, and maintenance is crucial for a resilient neighborhood, a significantly smaller percentage (27.7%) associate resilience with the ability to cope with natural disasters and climate change. Similarly, only 26.6% of citizens perceive a resilient neighborhood as prioritizing environmental sustainability and social well-being, integrating green spaces and sustainable design to address climate change challenges (

Table 2. Responders’ perception of the ‘resilient neighborhood’ concept (multiple choice question).

Percentage of Responses	List of Offered Definitions
69.1%	A Resilient Neighborhood is a Community of Residents that Has and Can Achieve Common Goals in Terms of Neighborhood Space Planning, Design, Construction and Maintenance
39.4%	A Resilient Neighborhood Prioritizes Citizen Engagement and Collaboration with Municipal Authorities, with Citizen Demands Driving the Development of Safety, Social Infrastructure, Mobility, and Resource Affordability
39.4%	A Resilient Neighborhood Fosters a Sense of Belonging and Community Cohesion Through Deliberate Planning and the Creation of Vital Social Spaces, such as Community Gardens, Spaces with Benches, or Children’s Playgrounds
27.7%	A Resilient Neighborhood Refers to the Ability to Successfully Cope with Natural Disasters and Climate Change
26.6%	A Resilient Neighborhood Prioritizes Environmental Sustainability and Social Well-Being, Integrating Green Spaces and Sustainable Design to Address Climate Change Challenges
23.4%	A Resilient Neighborhood is Related to the Security (Regarding Criminal Incidents)
23.4%	A Resilient Neighborhood Refers to the Resistance to Social Conflicts
19.1%	A Resilient Neighborhood Refers to the Ability to Successfully Cope with Demographic Changes
2.1%	Other

). This discrepancy highlights a disconnect between the recognized need for community unity and the understanding of the specific goals that unite the community toward sustainability and resilience. Therefore, effectively communicating the importance of green infrastructure and its role in enhancing neighborhood resilience is crucial for community organizing.

Regarding the accessibility of existing green neighborhood spaces, 33% of responders rated them as very accessible, 31.9% as accessible, 9.6% as neutral, 5.3% as somewhat inaccessible, and 20.2% as very inaccessible. These results should in all cases be understood as a guideline for shaping the type of green infrastructure-related action. Concerning neighborhood environmental quality, only 3.2% of responders rated it as excellent. For 25.5% of citizens, environmental quality is good; 37.2% rated it as fair, 27.7% as poor, and 6.4% as very poor. This leads to the conclusion that awareness-raising efforts should emphasize the interconnectedness between green infrastructure and climate resilience, while simultaneously reflecting on improving overall environmental quality.

Finally, the survey revealed that the majority (70.2%) of responders are interested in engaging in sustainable practices, although currently they are not. Only 5.3% of responders are currently actively involved, and 18.1% are somewhat involved in sustainable practices. Therefore, the survey demonstrates a strong individual willingness to engage in neighborhood actions, while togetherness needs to be built.

An analysis of the UPRUN survey results, combined with a technical–spatial case study, reveals both the potential and the challenges of applying the concept of self-organization to enhance green infrastructure and climate resilience in Serbian urban neighborhoods. Notably, the survey findings suggest that both notions of self-organization—the potential to move from a dialectical interpretation to an interpretation based on multiplicity and pluralism, and the potential to understand systems relationally, as outlined by [45]—are missing.

In conclusion, an applicable model to improve neighborhood green infrastructure and strengthen the climate resilience of Serbian urban neighborhoods certainly should promote community self-organization. As an added value, fostering community self-organization can significantly contribute to building social resilience. However, targeted external support in those segments where identified barriers (

Table 3. Potentials and barriers for community self-organization to enhance green infrastructure and climate resilience of urban neighborhoods in Serbia.

Potentials

Barriers

Technical–Spatial Potential Limited Inclusion in Formal Planning Schemes, Coupled with Awareness of this Exclusion Among Citizens Recognition of the Concept of Resilience Understanding that the Willingness of People to Engage in Community Action is a Fundamental Prerequisite to Achieving Neighborhood Resilience Understanding that a Resilient Neighborhood is a Community of Residents that Has and Can Achieve Common Goals in Terms of Planning, Design, Construction, and Maintenance of the Neighborhood Space

Perceived Lack of Internal Capacity to Achieve Neighborhood Resilience Belief in the Primacy of External Actors Moderate Perceived Level of Community Cohesion Lack of Community Meetings, and the Absence of Dedicated Meeting Spaces Lack of Understanding Regarding the Interconnectedness Between Resilience and Climate Change Lack of Understanding Regarding the Environmental Components, Including Green Spaces, in Enhancing Neighborhood Climate Resilience Gap in Understanding the Need for Collective Action to Achieve Sustainable and Resilient Neighborhoods

) need to be addressed will be vital for successful outcomes.

3.3. The Model—From Collaborative Participation to Self-Organization

The findings indicate that community actions to enhance green infrastructure and strengthen the climate resilience of Serbian urban neighborhoods currently rely on external initiative and support. External actors can come from diverse sectors, including the science community, academia, civic society organizations, funding bodies, business sector, and public governance. However, to significantly enhance the impact of greening actions, it is crucial to develop systemic plans from the national to the local level, beyond simply identifying project stakeholders and optimizing their collaboration with communities. International research literature [21] and European legislation [57,58] have widely acknowledged the need for a multi-level approach. Similarly, the need to strategically address green infrastructure at both national and local levels was recognized in an external national survey among planning professionals conducted in 2020 [59].

No national or local framework currently addresses the community’s dependence on external actors for green infrastructure development. A lack of knowledge and awareness regarding the interconnections between green infrastructure, climate resilience, and sustainability significantly hinders independent community action. Elaboration of green infrastructure development at the neighborhood level and the role of the community is missing in existing policy documents, such as the Draft of the Spatial Plan of the Republic of Serbia 2021–2035. In fact, this Plan is the first national document in which green infrastructure was mentioned as a specific objective in the context of climate change adaptation [60], indicating that the concept is relatively new in Serbia. The Plan acknowledges the neglected development of green infrastructure and advises providing space for its formation as a measure of adaptation of urban centers/settlements to climate change. A similar goal was, later, again established by the National Program of Adaptation to Climate Change for the Period 2023–2030 [27]. Separately, both documents recognize the need to promote social cohesion in multi-residential urban zones, i.e., to apply measures for residential space improvement by introducing an adequate social component. However, these documents only tangentially address the subject of this research.

At the national level, therefore, it is necessary to identify climate resilience as a high priority, to determine the neighborhood as an optimal spatial scale to deal with resilience, and to assign to neighborhood communities the role of principal contributors. Achieving these goals will necessitate revision of existing and introduction of new spatial, social, and climate policies, clear assignment of roles and responsibilities, and appointment of appropriate decision-makers. At regional and local levels, specific action plans that operationalize the national program need to be developed and put into force. By gradually implementing and iterating these action plans, the barriers identified in this study (Table 3) can be overcome, enabling citizens to independently manage green infrastructure in their neighborhoods in the future.

The key goal of programs and plans should be to empower citizens by informing, educating, and building togetherness among them. When this goal is compared against types of civic action, it becomes apparent that collaborative participation currently represents the most suitable model for engaging citizens in green infrastructure initiatives and enhancing climate resilience within Serbian urban neighborhoods. Preferably, the process of engaging the citizens in green infrastructure-related collaborative action would consist of three phases, comprising campaign, events, and spatial intervention (

Table 4. Key characteristics of the proposed model for collaborative citizen participation in enhancing green infrastructure and strengthening climate resilience in urban neighborhoods in Serbia.

Characteristic/ Phase	Campaign	Events	Spatial Intervention
Administrative/ Spatial Level	National and City	Neighborhood	Neighborhood
Aims	Develop a Culture of Climate Resilience Through Urban Green Infrastructure Improvement	Develop Green Infrastructure Project Implement a Collaborative Participation Approach Increase Community Cohesion	Implement Green Infrastructure Project Strengthen Climate Resilience Generate Positive Examples Strengthen Place Attachment
Objectives	Raise Citizen Awareness Build Individual and Collective Responsibility Educate Citizens Establish Communication with Citizens Encourage/Motivate Participation in Community action	Maintain Multidirectional Communication, and High Levels of Acceptance and Influence [61] Address Citizens’ Needs for Specific Knowledge and Skills Involve Stakeholders Secure Financing Develop Maintenance Plan	Address Citizens’ Needs for Specific Knowledge and Skills Provide Social Benefits of Intervention Establish Community Ownership Confirm Maintenance Plan

).

National and local campaigns should prioritize the dissemination of relevant educational and promotional materials, user-friendly ICT tools, and green infrastructure catalogs, through a diverse range of media channels to effectively engage and inform the public. Campaigns should be cyclical, with regular data collection and analysis of outcomes and impacts. The higher the level of educational attainment among citizens, the more likely is their familiarity with green infrastructure [62] and participation in spatial interventions [63]. To effectively motivate citizen engagement, campaigns should emphasize the empowerment and autonomy that come with participating in green infrastructure-related initiatives. This approach would not only demonstrate democratic local governance but also fulfill the resilience precondition identified by over half of the surveyed citizens.

In the second phase of model application (the events phase) the focus should be placed on the neighborhood scale. The aim is to address the insufficient community cohesion and togetherness identified in the UPRUN survey, by jointly developing a design project tailored to the specific conditions of a chosen urban neighborhood. During this phase, local authorities act as initiators, organizing community meetings, workshops, training, thematic conversations, consultations, tours, and other types of events that aim to extend knowledge transfer from Phase 1, facilitate community organizing, and identify community volunteers for the subsequent spatial intervention. Organizing citizens’ meetings with external experts and volunteers possessing in-depth knowledge [64,65] can significantly contribute to the development of optimal spatial solutions for green infrastructure improvement at the neighborhood level. Additionally, involving ‘social facilitators’, especially in the initial stages of project development, can foster cooperation between citizens and other stakeholders, as demonstrated in [66]. These facilitators can play a vital role in assessing residents’ knowledge, perceptions, and opinions, bridging gaps between different stakeholders’ goals and perspectives, and collecting and disseminating relevant information to all parties involved.

The participants in the spatial intervention (Phase 3) should be members of the neighborhood community themselves. High levels of collective engagement foster a sense of responsibility for the neighborhood and strengthen place attachment. These positive outcomes will facilitate the long-term maintenance and ongoing enhancement of the green infrastructure. Furthermore, this phase can address the lack of common meeting spaces identified as a deficiency in the UPRUN survey. By creating new gathering spaces within the neighborhood, green infrastructure projects can enhance social interaction and reinforce togetherness. The role of public authorities should be to monitor, support, and facilitate these citizen-led initiatives, including assisting with the necessary permits for spatial interventions. Supporting citizens to independently engage in green infrastructure projects within neighborhoods has the potential to significantly improve the outcomes observed in the UPRUN survey.

4. Discussion

The proposed model for improving green infrastructure in urban neighborhoods in Serbia through collaborative citizen participation was developed based on the findings of technical and social analyses presented in Section 3.1 and Section 3.2. The model’s structure and characteristics are designed to leverage identified potentials, while simultaneously addressing the critical points outlined in Table 3. The ultimate goal of model implementation is to empower citizens to independently maintain and continuously improve green infrastructure within their neighborhoods, aligning with their own needs and climate resilience priorities. Although achieving this goal may take time, research by [67] suggests that the acceptance of green infrastructure is not dependent on the time factor as much as on positive experience with green infrastructure. Therefore, citizen collaborative participation in green infrastructure projects must deliver not only climate or environmental but also social benefits.

Implementing green infrastructure projects and effectively engaging citizens in their development represents a complex undertaking. To that end, this research identified several challenges that may arise during the implementation of the proposed model of citizens’ collaborative participation to improve green infrastructure and strengthen the climate resilience of urban neighborhoods in Serbia, including:

• Securing funds and managing costs effectively;
• Organizing and coordinating community participation;
• Addressing micro socio–cultural specificities and community heterogeneities;
• Achieving social equity and justice;
• Managing uncertainties related to community response [68] and acceptance [61];
• Developing and implementing maintenance plans;
• Ensuring long-term sustainability and success of the action [21]; and others.

Each listed challenge presents an opportunity to inform future research and policy development. However, there is a fundamental challenge that precedes all others, and that is the understanding of the meaning of ‘engagement’ as a concept. For a large part, this challenge may arise because of the terminology used. Reference [61] highlights that the excessive use of the term ’community engagement’ has led to a lack of clarity and consistency in its definition and application, covering many different aspects of interaction and cooperation with the community. Therefore, the matter of terminology needs to be approached with the utmost attention, particularly during campaign implementation.

The terms ‘climate resilience’, ‘green infrastructure’, and ‘urban neighborhood’ are not yet fully established within the national context. However, the identified problem is not unique to Serbia. For example, [69] reported that a survey conducted in Toronto, Canada, and Philadelphia, PA, USA, found that most responders were unfamiliar with the term ’green infrastructure’ and had limited knowledge of green infrastructure initiatives in their cities. Although mentioned in research publications, it was only in 2023 that the term ‘green infrastructure’ became officially recognized by the latest amendments of the Serbian Law on Planning and Construction [70], but its further elaboration is missing.

Moreover, the use of the term ‘neighborhood’, translated to the Serbian language as “susedstvo”, is not common. In addition, the lack of understanding of the socio–spatial scale and the neighborhood boundaries from the citizens’ side was confirmed by the UPRUN survey. The answers obtained indicated that some citizens perceive the territory of a neighborhood as too large, while others reduce it to even one entrance within a multi-residential building. Instead of “susedstvo”, the terms “blok”, “komšiluk”, and “mesna zajednica” are used more commonly in Serbia, but each of these terms holds a different meaning.

The term “komšiluk” represents either a group of people living nearby, or a rather small distance from a residential unit to specified spatial contents. What separates the notion of “komšiluk” from ‘neighborhood’ (Srp. “susedstvo”) is a lack of deeper comprehension of the spatial (physical) component.

“Blok” is a predominantly multi-residential urban spatial whole of regular geometric shape, bordered by public traffic surfaces, and with an inner mix of streets, pedestrian paths, and public open and green surfaces [70]. A critical deficiency in the term “blok” within the context of this research is the insufficient consideration of its socio–cultural component. As a result, “blok” and “komšiluk” are often used as two complementary terms, such as in the phrase “komšiluk iz bloka”.

“Mesna zajednica” is a concept used in the former Yugoslavia from the 1960s until about three decades ago to primarily define universal decision-making-related engagement of citizens living in a certain, defined territory—a part of a town/city or a village. The notion of “mesna zajednica” is complex [71], but most closely resembles the concept of ‘neighborhood community’ widely used in international literature. For that reason, “mesna zajednica” was also known as ‘extended family’, whose main function was taking care of people and the development of humane socialist relations [72]. The societal transition, marked by the abandonment of socialist self-governance, the introduction of the democracy model, and the privatization of residential flats, surprisingly marginalized citizens from local decision-making processes. Accordingly, the functional concept of “mesna zajednica” was abandoned, although it still exists in legal and administrative terms [71]. Today, the term ‘residential community’ (Srp. “stambena zajednica”) is predominantly used to regulate living space-based rights and obligations of urban citizens, although its spatial boundaries are much smaller than those of “mesna zajednica”.

Like in other European countries [73], the population in Serbia is aging [74]. In the context of this research, however, this fact could be used to the advantage of community togetherness and joint engagement, since older or middle-aged Serbian citizens still remember the concepts used in the past, including the functioning of “mesna zajednica”. Older and middle-aged citizens could be strategically engaged as active [75] leaders in the initial transition towards old–new terminology and implementing community-led green infrastructure projects. However, to cultivate a lasting culture of climate resilience, ensure the long-term success of green infrastructure projects, and allow a transitioning towards self-organized green infrastructure management, it is essential to prioritize the education of younger generations. This necessitates the development and implementation of comprehensive programs at the national level to provide relevant knowledge and skills and raise awareness among children and young people, as exemplified by [64].

5. Conclusions

This study found that, even in unfavorable spatial, environmental, and microclimate conditions, self-organized neighborhood communities technically can make a notable contribution to climate resilience. However, the research also revealed that social barriers exist, due to which the concept of community self-organization is unlikely to be currently applied in cities in Serbia. Key identified obstacles include a perceived lack of internal capacity; belief in the primacy of external actors; moderate cohesion level; lack of community platforms; limited understanding of the interconnections between resilience, climate change, and the role of green infrastructure; limited environmental literacy; and unclear collective action benefits. As a result, this work has developed a pioneering model of citizens’ collaborative participation to improve green infrastructure and strengthen the climate resilience of urban neighborhoods in Serbia. The model incorporates three distinct levels—national, city, and neighborhood—and encompasses three key types of action: campaigns, events, and spatial interventions.

The findings of this study have the potential to impact both research and practical applications across multiple fields, including policy development, urban planning, climate change adaptation, and community engagement. Firstly, the results of the technical test can directly inform the development of green infrastructure improvement initiatives within the Kalenić neighborhood. Secondly, the Kalenić case study can serve as a valuable example for identifying other neighborhoods, in Serbia and internationally, that should be prioritized for climate action. Moreover, the Kalenić case study demonstrates how climate-related benefits can be predetermined, and how the type and scope of green infrastructure can be effectively calibrated during the planning phase.

Some findings of the national-level survey, such as a general lack of citizen inclusion in formal planning schemes and limited opportunities for public participation, should serve as an impetus for policymakers to revise regulations and launch top-down initiatives aimed at reversing these social trends.

The research methodology employed, grounded in socio–spatial–technical integration, offers a valuable framework that is applicable in other national contexts. By adapting input parameters to specific national and local conditions, researchers can effectively utilize this approach in diverse settings. Furthermore, survey findings can be valuable for comparative analysis across national contexts.

Given its comprehensive definition, the model for collaborative citizen engagement proposed by this work can serve as a valuable foundation for policymakers to develop national programs and local action plans for climate change adaptation and to emphasize the central role of citizens in the adaptation process. Until policymakers and decision-makers fully implement the necessary actions, researchers can play a crucial intermediary role. To that end, future research directions should encompass a deeper analysis of possible strategies for achieving the model’s stated aims and objectives. Optimal outcomes will be achieved through collaborative efforts between authorities and researchers. Ideally, this collaborative approach will facilitate the iterative refinement of the proposed model through its actual implementation in multiple case studies of urban neighborhoods.