Building the Green Infrastructure of Belgrade: the Importance of Community Greening

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Article Building the Green Infrastructure of Belgrade: The Importance of Community Greening

Ivan Simi´c*, Aleksandra Stupar and Vladan Djoki´c

Department of Urban Planning, Faculty of Architecture, University of Belgrade, Bulevar kralja Aleksandra 73/2, 11000 Belgrade, Serbia; [email protected] (A.S.); [email protected] (V.D.) * Correspondence: [email protected]; Tel.: +381-638-648-188

Received: 21 February 2017; Accepted: 16 June 2017; Published: 5 July 2017

Abstract: Due to its important role in increasing human well-being and providing space for ecosystem services, green infrastructure has gradually become an integral part of urban development strategies. Focusing on the activities of community greening, the article considers this approach toward the application of urban green infrastructure as a part of a broader strategy related to the resilience of cities. The neighborhood/district level will be emphasized and the analysis will be conducted in two areas of the Serbian capital Belgrade—Block 45 in New Belgrade and the Savamala neighborhood in the historical city core. Representing two different epochs of Belgrade’s development, they are characterized by different typologies, while the characteristics of community greening also differ in several aspects, including purpose, model of organization, and involved stakeholders/participants. The green space of the identiﬁed typical morphological units has been cultivated and maintained in two different ways—institutional (provided by the public company) and non-institutional (community greening)—and their impact on the quality of the local GI will be compared. The analysis intends to provide data on the level of biodiversity, multi-functionality, and maintenance of green spaces which will show the effect of both applied approaches. Particular attention will be given to the tensions and challenges of the local context: the adoption of plans and regulations that are in accordance with contemporary trends, as well as the drawbacks in their implementation. Furthermore, the possibilities of community greening will be elaborated, as future steps for achieving the formal green infrastructure (hereinafter GI) standards at the neighborhood/district scale.

Keywords: green infrastructure; community greening; urban planning and design; resilience; sustainability; Belgrade; local community

1. Introduction The new discourses of ecology have influenced a shift of planning paradigms, incorporating new knowledge and imperatives [1–3]. Consequently, the ecosystem approach to planning emphasizes the importance of human well-being in the context of an integrated socio-ecological system. This approach is based on several principles—multi-scalability, hierarchical structure of ecosystems, a relationship between elements and processes, connectivity, and spatial continuity [4]—while its built and social elements can be considered as the specific types of physical and biological components [4,5]. Being a part of this discourse, the term green infrastructure appears in recent studies as an important element of new planning/design strategies targeting sustainable development and resilience [6–8], as well as climate change adaptation [9]. Supporting a set of ecological and cultural functions [5,10], it also represents a contribution to the general well-being of people [11–13]. Benedict and McMahon [6] define GI as an interconnected network of green spaces which conserves values and functions of a natural ecosystem, providing associated benefits for human population. Considering GI as an ecological framework needed for environmental, social, and economic sustainability, they

Sustainability 2017, 9, 1183; doi:10.3390/su9071183 www.mdpi.com/journal/sustainability Sustainability 2017, 9, 1183 2 of 16 claim that this planning approach to open spaces differs from conventional ones because it integrates conservation values and anticipated actions with land development, growth management and the building of infrastructure. Green infrastructure provides environmental services in urban areas, which is a prerequisite for ensuring biodiversity, social, and territorial cohesion, sustainable development, and overall human well-being [12,13]. By implementing GI, it is possible to achieve a high level of accessibility, connectivity and attractiveness of its elements in predominantly residential, working or recreational areas. Consequently, the necessary multi-scale approach, targeting metropolitan (regional/city) level, districts/neighbourhoods, and individual sites [5], involves the assessment and planning of spatial configurations composed of landscape patterns and ecological processes. Simultaneously, the analysis of their interaction indicates key points for physical linkages—both existing and possible ones [14]. The significance of green infrastructure has become recognized and gradually introduced by numerous cities as formal (top-down) and informal (bottom-up) initiatives. For example, Berlin and Malmö have crafted a special regulation and standardization of the network of green and open spaces, using the top-down planning approach [15,16]. The experiences of Berlin and Malmö were adopted by Seattle, which established an innovative standard of regulation and preservation of biotopes (2006, extended in 2009). Developing a system of evaluation and standardization called the Seattle Green Factor (SGF), the city emphasized the importance of promoting attractive and environmentally friendly functional areas, as well as its elements (e.g., green roofs and walls, permeable paving, cultivation of food, etc.) [17]. At the same time, there is a growing volume of research focused on the bottom-up strategies of greening, initiated and implemented by local stakeholders. For example, Krasny and Tidball [18] define a framework of ‘civic ecology’, based on activities labelled as urban community greening. This term refers both to a diverse set of management/supervising environmental practices conducted by a community and to their role in a larger social-ecological system. Lovell and Taylor [13] examine community greening as a multifunctional element of GI, emphasizing its ecological importance for the resilience of socio-ecological systems perceived via innovation, adaptive management and social learning. The issue of community greening has been also studied in the context of Swedish cities by Colding and Barthel [19]. They described it as ’urban green commons’, important for urban resilience based on ecological and social diversity. Furthermore, the specificities of informal green spaces, especially their uncertain legal, socio-economic and ecological status, were tackled in recent studies [20]. In general, community green areas can be a result of different individual or collective actions located on private, common or public area. Their spatial configuration and relation to the built and natural surrounding could also vary, influencing the components which constitute GI. However, all forms of community greening are physically linked to the level of the neighbourhood/district or the individual plot/building. Since their elements contribute economically and ecologically to human well-being, inducing changes at higher spatial and management levels, they are eligible to become a part of the formal, strategically-planned network of GI [11,21]. Simultaneously, the involvement of public participation provides new opportunities for the empowerment of the local community. Community greening is also vital for the creation of urban spaces with polyvalent and multifunctional qualities [13], while small-scale greening projects could induce broader transformation of city’s GI, which might be more extensive and economical than the one achieved via the conventional top-down planning [11]. The implementation and upgrading of GI in Serbia has its own specificities which are the result of a comprehensive transitional process of an ex-socialist society shaken by the decade-long Balkan war conflicts, international sanctions, NATO bombing, and anti-governmental protests. Furthermore, the strict hierarchy of the Serbian planning system additionally complicates implementation of lower-ranged plans and documents. For example, the Master Plan of Belgrade 2021 [22] subordinates all other plans and regulations at lower spatial levels. Along with this legally-binding document, Sustainability 2017, 9, 1183 3 of 16 urban development is guided by the Strategic Development Plan of the City of Belgrade [23] and local environmental development plans (LEAP, Belgrade, Serbia), which recognize the importance of local community initiatives (including the greening activities), but do not have a legally-binding character [24]. Therefore, the possibility of implementation is significantly reduced due to the lack of adequate official mechanisms for inclusion of local greening. Furthermore, there are other problems underlined by the LEAP of the municipality Savski Venac (although applicable in the whole metropolitan area of Belgrade)—non-systematic and inconsistent management of green spaces; poorly maintained and degraded green areas; and functionally and visually unattractive green spaces [24]. An important step towards the successful implementation of plans represented the study Green Regulation of Belgrade [25], initiated in 2002 and conducted by the University of Belgrade—Faculty of Forestry and the Urban Planning Institute of Belgrade. It provided a comprehensive insight into green areas of Belgrade (GIS of biotopes), introduced contemporary principles of GI and enabled identification of so-called morphological units, according to the patch-corridor-matrix model of landscape structure [26–29]. Furthermore, the elements of the study were used in the Master Plan of Belgrade 2021 in which “the green core of Belgrade” was distinguished as a unique and comprehensive area of green and blue corridors, including the river courses of the Danube and the Sava [22]. The Plan indicates the components of GI on the metropolitan level—mainly river islands, coastal parks, forelands, lakes, ponds, and marshes, setting up a conceptual foundation for planning at the metropolitan/city scale. However, the strategies and plans on the local level do not recognize sufficiently the principles of the GI approach, although its importance could be identified in action plans, within the context of climate change adaptation and mitigation. For example, in early 2015, the city of Belgrade adopted the Action Plan for Climate Change Adaptation (hereinafter APCCA), emphasizing the planning and implementation of GI networks throughout the metropolitan territory as a measure of the highest priority [30]. Based on the concept defined by the Green Regulation of Belgrade, this action plan gradually introduces the preferred ecosystem approach to the level of metropolitan and municipality planning [25]. Considering all the benefits of community greening, as well as the local specificities of the Serbian socio-economic context, the article will focus on the case of Belgrade and two selected urban areas—Block 45 (municipality of Novi Beograd) and Savamala (occupying parts of municipalities—Stari Grad and Savski Venac). Representing two different epochs of Belgrade’s development, they are characterized by different typology, while the characteristics of community greening also differ in several aspects including purpose, model of organization and involved stakeholders/participants. The impact of community greening on the quality of local GI will be identified by comparing the green areas exposed to two different types of cultivation and maintenance—non-institutional (community greening) and institutional (provided by the public company). The analysis should provide data which will show the difference created by both approaches, especially related to the level of biodiversity, multi-functionality and maintenance of green spaces at the local scale. Furthermore, the possibilities of community greening will be elaborated, as future steps for achieving the formal GI standards at the neighborhood/district scale.

2. Case Studies

2.1. Methods The analysis of the selected study areas was conducted at the level of the urban matrix, defined according to the ’patch-corridor-matrix model’ [27]. It represents a dominant type of urban land cover in the terms of area, connectivity degree, continuity, and control over landscape [27,31]. Morphological units, as basic matrix elements composed of buildings with their immediate surrounding areas, are identified according to the Belgrade’s GIS (MapSoft, Belgrade, Serbia) of biotopes [26,29], and used for the analyses of the selected areas/matrices and the impact of two applied regimes of greening and maintenance. The evaluation of selected units is based on several criteria defined in the Green Sustainability 2017, 9, 1183 4 of 16

Regulation of Belgrade: the ratio of pervious surfaces, share of evapotranspirational surfaces, areas under treetops, vegetation structure of biotopes, multi-functionality, visual quality [32], as well as the condition of cultivation and maintenance. These criteria also match the parameters used in the GI methodologies applied in Berlin, Malmö, and Seattle [15–17]. The indicators used for calculating the ratio/percentageSustainability 2017, 9, 1183 ofpervious surfaces, evapotranspirational surfaces and the areas under4 of treetops 16 are quantitative and the data are available in the Belgrade’s GIS of biotopes. However, in order to criteria also match the parameters used in the GI methodologies applied in Berlin, Malmö, and Seattle achieve a higher accuracy, the high-resolution aerial images of the selected areas were also used, [15–17]. The indicators used for calculating the ratio/percentage of pervious surfaces, as wellevapotranspirational as the photos taken surfaces on-site. and Thethe areas data under related treetops to multi-functionality are quantitative and were the data gathered are available by regular monthlyin the observations Belgrade’s GIS and of biotopes. photographing, However, indicating in order to the achieve change a higher of the accuracy, number the and high-resolution type of activities. The informationaerial images describingof the selected the areas visual were quality, also used, as aas subjective well as the aestheticphotos taken category, on-site. representThe data related the result of theto descriptivemulti-functionality qualitative were gathered assessment by regular based monthly on the observations interviews and conducted photographing, in the indicating study areas. All selectedthe change criteria of the providenumber and a sufﬁcient type of activities. set for theThe evaluationinformation describing of the condition the visual and quality, quality as a of GI beforesubjective and after aesthetic community category, greening. represent Since the theresult selected of the descriptive data are also qualitative easily measurable, assessment based the methods on usedthe in thisinterviews research conducted are highly in applicable.the study areas. All selected criteria provide a sufficient set for the evaluation of the condition and quality of GI before and after community greening. Since the selected 2.2. Studydata are Areas also easily measurable, the methods used in this research are highly applicable.

The2.2. Study selected Areas areas of Belgrade represent two different planning approaches—Block 45 in New Belgrade wasThe selected designed areas in accordanceof Belgrade withrepresent the imperativestwo different of planning the 20th approaches—Block century Functionalist 45 in city,New while SavamalaBelgrade reﬂects was designed elements in of accordance the European with urbanismthe imperatives of the of 19th the century20th century (Figure Functionalist1). Consequently, city, theirwhile morphological, Savamala reflects ecological, elements and sociologicalof the European characteristics urbanism areof the drastically 19th century opposed. (Figure Plans 1). and regulationsConsequently, of the citytheir of morphological, Belgrade also ecological, recognize differencesand sociological between characteristics these two are areas, drastically both on the levelopposed. of built andPlans green and regulations areas (Table of1 the). According city of Belgrade to urban-morphological also recognize differences parameters, between these the Belgrade two Masterareas, Plan both 2021 on [22 the] identiﬁes level of theirbuilt urbanand green blocks areas as (1)(Table open/Modernist 1). According (dominantto urban-morphological in New Belgrade) and (2)parameters, perimeter the (dominant Belgrade Master in the traditionalPlan 2021 [22] city id core,entifies including their urban Savamala). blocks as However,(1) open/Modernist both selected areas(dominant are situated in inNew the Belgrade) same natural and (2) environment, perimeter (dom so-calledinant “Greenin the traditional core” of thecity city—along core, including the river Savamala). However, both selected areas are situated in the same natural environment, so-called Sava, as a dominant component of the urban ecosystem. Due to equal natural conditions, their different “Green core” of the city—along the river Sava, as a dominant component of the urban ecosystem. structuresDue to could equal be natural compared conditions, in order their to different determine structures their uniqueness could be compared and trace in theorder development to determine of GI at thetheir local uniqueness level. and trace the development of GI at the local level.

Figure 1. The position of Block 45 (A) and Savamala district (B) in relation to the Belgrade green core Figure 1. The position of Block 45 (A) and Savamala district (B) in relation to the Belgrade green core and the river Sava. Source: Master plan of Belgrade 2021. and the river Sava. Source: Master plan of Belgrade 2021.

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Table 1. The comparative review of basic urbo-morphological parameters of Block 45 (New Belgrade) and Savamala district (historical urban core).

Floor Space Index Population Density Building Coverage (%) Green Area (%) Block 45 1.2–2.2 300–600/ha 30 30 Savamala 3.5–4.5 400–800/ha 75 10

2.2.1. Block 45 Block 45 is located in the municipality of New Belgrade, which has the largest surface of intra-block green spaces among all Belgrade municipalities (396.6 hectares). The block of 32,000 inhabitants occupies a strip of land on the left bank of the Sava River and it was implemented in 1966 as a unique urban entity for the extended local community. Green areas were initially planned as a park and a recreational area complementing the built structures. Consistent with the principles of Le Corbusier embedded in the Functionalist design of New Belgrade, buildings were supposed to be ’immersed in greenery’ [33], providing a higher environmental quality. According to the Draft of the detailed regulation plan for blocks 45 and 70, the design of green spaces followed the standard of 22 m2/inhabitant [34], but their quality and differentiation after implementation remained at low levels [35]. Responding to the unfavourable condition of some green spaces, their revitalisation and differentiation have been included in new plans, along with the elements of the preferred GI network. For example, the Draft of the detailed regulation plan for blocks 45 and 70 specifies new values which include, inter alia, “the preservation and improvement of the achieved high standards of living and understanding of emerging residents’ needs” [34]. In terms of the GI development, the Action Plan for Climate Change Adaptation (APCCA) provides the foundation for the development of a network of green corridors along the promenade Lazaro Kardenas, which connects residents with the river Sava [30]. The green network is supposed to provide air-cooling by evapotranspiration, primarily via the avenue and small groups of trees. Setting permeable paving to reduce the outflow of atmospheric water, and constructing the canals and retention ponds along the dikes and banks should prevent floods. APCCA recommends use of local plant species, preservation, and improvement of urban forestation, promotion of ecological parks, and urban gardening, while recommending the introduction of green roofs and walls. All of these measures should increase the natural, cultural, and aesthetic values of targeted spaces, underlining their multiple role in creating a positive effect on mental and physical health and stimulating social interaction [30]. The plan also refers to administrative bodies and public companies as responsible for the implementation. Based on the patch-corridor-matrix model and the Belgrade’s GIS of biotopes, the elements of urban matrix were identified (Figure2a). The northern part of the block (Figure2b) consists of free-standing skyscrapers, whereas the southern part (Figure2c) consists of U-shaped residential buildings with a smaller number of floors. The shape of the built structures also caused a different configuration of greenery. The morphological units in the northern part include a narrow strip of greenery around the buildings and small residual areas around playgrounds and parking lots. All of them have been maintained by the public company—Belgrade’s City Greenery. The units of the southern part incorporate greenery within U-shaped buildings and the ground floor apartments have a narrow strip of secluded, quasi-private green space, while the remaining area, mainly covered with trees and shrubs, has a public character. The units of this part of Block 45 have been treated by two different greening approaches (community greening vs. institutional) and, therefore, represent the polygon of our analysis (options A and B—Figures3A and3B). Although identical in size and percentage of built area, the option A incorporates green space voluntarily maintained by residents, mostly owners of ground floor apartments, with a direct and easy access (Figure3A). Their high interest in individual greening is mainly expressed through the cultivation of small trees, flowers, and low vegetation, while their activities contribute to the bio-diversity and stronger feeling of privacy within a common green space. Although under the official jurisdiction of the city, the community Sustainability 2017, 9, 1183 6 of 16 greening has spontaneously started two decades ago, as a reaction to poor maintenance, as well as a form of hobby and leisure [36]. According to self-organized residents, there seems to be a tacit agreementSustainability with 2017 relevant, 9, 1183 city institutions/agencies of local inhabitants taking control over landscaping.6 of 16 Meanwhile,Sustainability the 2017 other, 9, 1183 morphological option (B) contains a public green space around buildings6 of 16 solely landscaping. Meanwhile, the other morphological option (B) contains a public green space around maintained by the public company—Belgrade’s City Greenery (Figure3B). buildingslandscaping. solely Meanwhile, maintained the by other the publicmorphological company—Belgrade’s option (B) contains City Greenery a public (Figuregreen space 3B). around buildings solely maintained by the public company—Belgrade’s City Greenery (Figure 3B).

Figure 2. Aerial view of Block 45 (a), north (b), and south (c) part of urban matrix. Source: Google Figure 2. Aerial view of Block 45 (a), north (b), and south (c) part of urban matrix. Source: Google maps/BingFigure 2. Aerial maps. view of Block 45 (a), north (b), and south (c) part of urban matrix. Source: Google maps/Bing maps. maps/Bing maps.

Figure 3. The aerial view of the south urban matrix. Source: Google maps; morphological units (A) andFigure (B). 3. Source: The aerial Authors view own of the data. south urban matrix. Source: Google maps; morphological units (A) Figure 3. The aerial view of the south urban matrix. Source: Google maps; morphological and (B). Source: Authors own data. units2.2.2. (SavamalaA) and (B ). Source: Authors own data. 2.2.2. Savamala Savamala is located on a slope along the left bank of the river Sava, bounded on west by the 2.2.2. Savamala streetSavamala Gavrila isPrincipa located andon athe slope natural along borderthe left ofbank the of Sava. the riverThe Sava,plans boundedclassify Savamalaon west by as the a Savamalastreetcontinuously-built Gavrila is located Principa urban on and a fabric slope the alongcomposednatural the border leftof pe bank rimeterof the of the Sava.urban river Theblocks Sava, plans bounded[22]. classify Along on SavamalaKaradjordjeva west by as the a street Gavrilastreet,continuously-built Principa the urban and tissue the urban natural is homogene fabric border composedous, of thecomposed Sava.of perimeter The of five- plans urbanto seven-st classify blocksorey Savamala [2 buildings.2]. Along as a Urban continuously-builtKaradjordjeva fabric is urbanstreet,discontinued fabric the composed urban along tissue ofthe perimeteris riverbank,homogene urban ous,consisting composed blocks of [22low-rise of]. five- Along tourban seven-st Karadjordjeva blocksorey with buildings. street,services Urban the and urban fabricstorage tissue is is discontinuedfacilities. along the riverbank, consisting of low-rise urban blocks with services and storage facilities. Sustainability 2017, 9, 1183 7 of 16 homogeneous, composed of five- to seven-storey buildings. Urban fabric is discontinued along the riverbank, consisting of low-rise urban blocks with services and storage facilities. The course of development of this centrally-located area was set in the mid-19th century by Prince Miloš Obrenovićwho ordered relocation of trading activities to the new Abadžijski bazaar in Savamala. The establishment of a new commercial zone triggered the progress of this downtown area which had an intensive interaction with the river docks during its prosperous times. However, this connection, as well as the construction of representative buildings in Karadjordjeva Street was interrupted in the early 20th century after the construction of the railway and the railway station. Savamala lost its significance and Karadjordjeva Street became a high-frequency transit zone. The flux of people and greenery between the Sava River and Karadjordjeva Street was interrupted, leading to the gradual degradation of urban and environmental quality. Although ideas for the relief of road traffic and railway relocation have existed since the Master Plan of 1972, they have not been materialized. However, the construction of the new “Prokop” station represents an important step in improving the current condition, removing railway tracks and re-establishing a vital relationship between Savamala and the riverbank. Simultaneously, the interest in this part of the city has increased, since its degraded state is now perceived as a challenge for reactivation, especially in the civil sector, cultural, and artistic circles. The green areas of Savamala have had a partial planning treatment. Although recognized as an urban district, it officially belongs to two municipalities. The area under jurisdiction of the municipality Savski Venac is covered by the aforementioned Local Environmental Action Plan (LEAP) which suggests the initiation of new plans and projects for this area, as well as repurposing of the Sava amphitheatre and launching of the current relocation plan of the railway station [24]. The action plan also follows the planning concept of green areas formulated in the Green Regulation of Belgrade and the Biotope Map of Belgrade [25,37], defining basic aims, including the use of GIS and the introduction of modern forms of green areas—e.g., pocket parks, roofs, and vertical greenery, etc., [24]. The document also emphasizes the role of open cooperation with citizens, private and non-governmental organizations, and the importance of public participation. Stimulating the preparation of various events (forums, exhibitions) and advertising material, LEAP supports the raising of environmental awareness. However, similar to the previous case of Block 45, the plan does not provide possible models of participation, governance, and funding of these ’green’ projects. Considering the elements of this matrix, in which streets act as corridors, the current situation indicates an almost entirely unused potential, especially related to non-existing tree lines. The main street corridor is Karadjordjeva Street, with a higher urban significance and its connection to the riverbank, is achieved by a network of smaller streets. However, the railroad blocks the direct contact between street corridors and the riverbank. The urban matrix is characterized by a densely-built structure of perimeter blocks, covered by a high percentage of asphalt, concrete, and other impervious surfaces (Figure4). This condition implies fragmentation and low diversity of biotopes. The bits of nature are limited mainly to the small public green spaces between blocks. Consequently, the community greening of Savamala differs from Block 45. The combination of high density and mixed-use led to different models of community organization, focusing greening activities mainly toward implementation of pocket parks, conducted by local organizations. For example, in 2013 Mikser festival organized the “Blue-green dream” workshop, bringing together local community and professionals in an effort to initiate greening of public spaces, planting rows of trees and placing urban furniture for horticulture [38] (Figure5a,b). A public workshop on urban gardening “Zdravamala”—eng. Healthy-(Sava)mala, was held in 2015 in the space of the Spanish house (Figure5c), the abandoned and severely damaged building currently used as an informal public space [39]. During the same year, the workshop entitled “Moje parˇceSavamale”—eng. My Piece of Savamala (Figures4a,b and5d,e) brought together various stakeholders, focusing on the redesign of the pocket park in front of Mikser House [40]. This event represented a key point of transformation which is analysed and assessed in the next section. Sustainability 2017, 9, 1183 8 of 16 Sustainability 2017, 9, 1183 8 of 16 Sustainability 2017, 9, 1183 8 of 16

Figure 4. The aerial view of the Savamala urban matrix. Source: Google maps. The selected Figuremorphological 4.4.The The aerial aerial unit view viewbefore of the of(a Savamala) andthe afterSavamala urban (b) the matrix. workshopurban Source:matrix. “Moje Google parSource:če maps.Savamale” Google The and selected maps. the removal morphologicalThe selected of unitmorphological beforethe gas (station.a) andunit Source: afterbefore (b School )(a the) and workshop of afterurban ( bpractices.) “Moje the workshop parˇce Savamale” “Moje par andče Savamale” the removal and of the removal gas station. of Source:the gas station. School of Source: urban School practices. of urban practices.

Figure 5. Savamala—community greening actions: “Blue-green dream” (a,b), “Zdravamala” (c) Source: Mixer organization; “My piece of Savamala” (d,e) Source: School of urban practices.

Figure 5.5. Savamala—communitySavamala—community greening greening actions: actions: “Blue-green “Blue-green dream” dream” (a,b), “Zdravamala”(a,b), “Zdravamala” (c) Source: (c) MixerSource: organization; Mixer organization; “My piece “My of piece Savamala” of Savamala” (d,e) Source: (d,e) SchoolSource: of School urban of practices. urban practices.

Sustainability 2017, 9, 1183 9 of 16

3. Results The case of Block 45 and its southern part exposed to both greening approaches shows that, on the Sustainability 2017, 9, 1183 9 of 16 level ofSustainability morphological 2017, 9, 1183 units, both options (A and B) have the same proportion of impervious9 of 16 surfaces composed3. Results3. Results of the ﬂat roofs of three residential buildings (U-shape) and the access paths to building entrances and green area. In both options, the interventions which would give them higher levels TheThe case case of Blockof Block 45 and45 and its southernits southern part part expo exposedsed to bothto both greening greening approaches approaches shows shows that, that, on on of permeabilitythethe level level of morphologicalof (e.g., morphological installation units, units, ofboth greenboth options options roofs) (A (Aand have and B) nothaveB) have been the the same made. same proportion Accordingproportion of imperviousof to impervious the indicators of ecosystems’surfacessurfaces quality,composed composed the of gardening theof the flat flat roofs roofs activities of threeof three resi in residential thedential morphological buildings buildings (U-shape) (U-shape) option and A and havethe the access aaccess higher paths paths intensityto to and diversitybuildingbuilding than entrances theentrances usual and and setgreen green of area. activities area. In bothIn both conducted options, options, the bythe interventions theinterventions public which greening which would would company give give them them higher (Tables higher 2 and3). Plantedlevelslevels trees of ofpermeability large,permeability medium, (e.g., (e.g., installation and installation small of size ofgreen signiﬁcantlygreen roofs) roofs) have have increased not not been been themade. made. share According According of evapotranspirational to tothe the indicators of ecosystems’ quality, the gardening activities in the morphological option A have a surfaces,indicators comparing of ecosystems’ to the unit quality, B. The the area gardening under treesactivities has in also the increased, morphological while option an important A have a part of higherhigher intensity intensity and and diversity diversity than than the the usual usual set setof activitiesof activities conducted conducted by bythe the public public greening greening the greencompanycompany area (Tables (21.73%) (Tables 2 and 2 isand 3). transformed 3).Planted Planted trees trees intoof large,of gardens,large, medium, medium, contributing and and small small size tosize significantly higher significantly number increased increased of plantthe the species. The vegetativeshareshare of ofevapotranspirational structureevapotranspirational of the unitsurfaces, surfaces, B remained comparing comparing similar to theto the tounit theunit B. originalTheB. The area area ideaunder under of trees public trees has parks,has also also with the limitedincreased,increased, number while of while plant an animportant species important (mostly part part of originally ofthe the green green plantedarea area (21.73%) trees(21.73%) andis transformedis shrubs). transformed The into availableinto gardens, gardens, lawn space, due tocontributing itscontributing poor maintenance, to higherto higher number number monotonous of plantof plant species. appearance,species. The The vegetative vegetative and the structure lack structure of of visual theof the unit identity, unit B remainedB remained does not attract possiblesimilarsimilar users. to the to According the original original idea toidea of the public of public conducted parks, parks, with interviewswith the the limited limited of number local number inhabitants,of plant of plant species species the (mostly place(mostly originally does originally not instigate plantedplanted trees trees and and shrubs). shrubs). The The available available lawn lawn sp ace,space, due due to itsto itspoor poor maintenance, maintenance, monotonous monotonous any sense of belonging leaving the area without any trigger for the outdoor gatherings, as well as for appearance,appearance, and and the the lack lack of ofvisual visual identity, identity, do esdo esnot not attract attract possible possible users. users. According According to tothe the organizedconductedconducted and/or interviews interviews spontaneous of local of local inhabitants, activities. inhabitants, the the place place does does not not instigate instigate any any sense sense of belonging of belonging leaving leaving Thethethe area community area without without any any gardening trigger trigger for forthe in the outdoor the outdoor unit gather gather Aings, hasings, inducedas wellas well as foras many fororganized organized other and/or activities and/or spontaneous spontaneous related to open spacesactivities. suchactivities. as sports, relaxation, children’s play, etc. Although the visual quality of green space is a subjectiveTheThe community category, community itgardening should gardening in be the in noted the unit unit A that has A has induced the induced main many many drivers other other activities of activities spontaneous related related to open to interventions open spaces spaces were such as sports, relaxation, children’s play, etc. Although the visual quality of green space is a biophiliasuch and as thesports, need relaxation, for aesthetic children’s and play, social etc. enjoyment.Although the Givenvisual thequality fact of that green greenery space is hasa been subjectivesubjective category, category, it shouldit should be benoted noted that that the the main main drivers drivers of spontaneousof spontaneous interventions interventions were were cultivatedbiophiliabiophilia and and maintainedand the the need need for foraesthetic aesthetic more and than and social social 20 en years, joyment.enjoyment. itis Given expected Given the the fact thatfact that thatresidents’ greenery greenery has high has been been motivation will continuecultivatedcultivated theand and processmaintained maintained and for eventuallyformore more than than 20 lead years,20 years, toward it is it expected is expected continuous that that residents’ residents’ investment high high motivation in motivation local, will cost-effective will communitycontinuecontinue maintenance. the the process process and and eventually eventually lead lead toward toward continuous continuous investment investment in inlocal, local, cost-effective cost-effective communitycommunity maintenance. maintenance. Table 2. Block 45, morphological unit A. TableTable 2. Block 2. Block 45, 45,morphological morphological unit unit A. A.

N N

Built-upBuilt-up area area (%) (%) 38.46 38.46 Built-up area (%)MainlyMainly cultivated cultivated by self-organized by self-organized reside residents; nts;partially 38.46 partially maintained maintained by the by publicthe public CultivationCultivation and and maintenance maintenance Mainly cultivatedcompany—Belgrade’scompany—Belgrade’s by self-organized City City Greenery. residents; Greenery. partially maintained by the Cultivation and maintenance PerviousPervious surface surface (%) (%) public company—Belgrade’s 44.69 44.69 City Greenery. Evapotransp.Evapotransp. surface surface (%) (%) 17.04 17.04 PerviousTree-coveredTree-covered surface surface surface (%) (%) 12.61 12.61 44.69 ˃20 ˃cultivated20 cultivated species species including including large large trees trees (3), (3),medium medium size size trees trees (2), small(2), small trees trees (3), (3), Evapotransp.PlantPlant species species richness surface richness (n) (%) (n) 17.04 shrubsshrubs (3) and (3) and flowers flowers (5) (5) Tree-covered surface (%)GreaterGreater diversity diversity of greenery of greenery provides provides a nu amber number 12.61 of activities of activities related related to biophilia, to biophilia, Multi-functionalityMulti-functionality (n) (n) gardening,gardening, sport, sport, leisure, leisure, children’s children’s play, play, and and activities activities with with pets. pets. >20 cultivated species including large trees (3), medium size trees (2), small Plant speciesVisualVisual quality richness quality (n) Richness Richness of plant of plant and and animal animal species species meets meets the residents’the residents’ aesthetic aesthetic needs. needs. trees (3), shrubs (3) and ﬂowers (5)

Greater diversity of greenery provides a number of activities related to Multi-functionality (n) biophilia, gardening, sport, leisure, children’s play, and activities with pets. Visual quality Richness of plant and animal species meets the residents’ aesthetic needs. Sustainability 2017, 9, 1183 10 of 16

SustainabilitySustainability 2017 2017, 9, ,9 1183, 1183 1010 of of 16 16 Table 3. Block 45, morphological unit B. TableTable 3. 3. Block Block 45, 45, morphological morphological unit unit B. B.

Built-upBuilt-up area area (%) (%) 38.46 38.46 Built-up area (%) 38.46 CultivationCultivation and and MaintainedMaintained by by the the public public comp company—Belgrade’sany—Belgrade’s City City Greenery. Greenery. Cultivationmaintenancemaintenance and maintenance Maintained by the public company—Belgrade’s City Greenery. Pervious surface (%) 45.10 PerviousPervious surface (%) (%) 45.10 45.10 Evapotransp.Evapotransp. surface surface (%) (%) 10.97 10.97 Evapotransp.Tree-coveredTree-covered surface surface surface (%) (%) 8.28 10.97 8.28 Tree-coveredPlantPlant species species richness surface richness (n) (%) (n) <10 <10 cultivated cultivated species: species: large large trees trees (3), (3), medium medium 8.28 size size trees trees (2), (2), small small trees trees (1), (1), shrubs shrubs (2) (2) ReducedReduced diversity diversity of of activities activities due due to to the the absence absence of of gardens gardens and and other other green green spaces spaces Multi-functionalityMulti-functionality (n) (n) <10 cultivated species: large trees (3), medium size trees (2), Plant species richness (n) requiringrequiring active active participation. participation. small trees (1), shrubs (2) TheThe lack lack of of low low vegetation, vegetation, flowers, flowers, edible edible pl plants.ants. Poorly-maintained Poorly-maintained trees trees contribute contribute to to VisualVisual quality quality Reduced diversity ofthe activitiesthe low low attractiveness attractiveness due to the of absenceof space. space. of gardens and other Multi-functionality (n) green spaces requiring active participation. InIn the the case case of of Savamala, Savamala, the theThe polygon polygon lack of of lowof the the vegetation, an analysisalysis flowers,was was a aperimeter edibleperimeter plants. bl block Poorly-maintainedock which which includes includes the the Visual quality buildingbuilding of of the the ’Mikser’ ’Mikser’ organization organization (moved (movedtrees out contribute out in in May May to 2017), the 2017), low focusing attractivenessfocusing on on a a ofsmall small space. park park in in front front of of it.it. The The quality quality of of greenery greenery is is comp comparedared before before and and after after the the campaign campaign of of community community greening greening entitled entitled In“My“My the piece casepiece of ofof Savamala”, Savamala,Savamala”, organized theorganized polygon as as a aworkshop of workshop the analysis in in June June was 2015. 2015. a Initiated perimeterInitiated and and block implemented implemented which includes by by NGOs NGOs ’Mixer’ and ’Urban Guerrilla’, it addressed new solutions for this public space in Karadjordjeva Street the building’Mixer’ and of the ’Urban ’Mikser’ Guerrilla’, organization it addressed (moved new soluti out inons May for this 2017), public focusing space in on Karadjordjeva a small park Street in (Figures(Figures 4a,b 4a,b and and 5d,e). 5d,e). The The applied applied participator participatoryy design design involved involved local local community, community, experts experts in in the the front of it. The quality of greenery is compared before and after the campaign of community fieldsfields of of urban urban planning, planning, architectu architecture,re, ecology ecology and and engineering, engineering, as as well well as as the the city city and and municipality municipality greening entitled “My piece of Savamala”, organized as a workshop in June 2015. Initiated and authorities,authorities, resulting resulting in in adopted adopted and and implemented implemented actions. actions. On On that that occasion, occasion, the the public-private public-private implemented by NGOs ’Mixer’ and ’Urban Guerrilla’, it addressed new solutions for this public partnershippartnership between between the the city city authorities, authorities, ’Mixer’ ’Mixer’ an andd ’Urban ’Urban Guerrilla’ Guerrilla’ has has been been established, established, as as a a space in Karadjordjeva Street (Figures4a,b and5d,e). The applied participatory design involved local foundationfoundation for for the the further further cultivation cultivation and and maintena maintenancence of of the the park. park. The The most most important important interventions interventions community,includedincluded experts the the removal removal in the fieldsof of a asmall small of urban gas gas station, station, planning, tree tree architecture,planting planting and and introduction ecology introduction and of engineering,of new new urban urban furnitureas furniture well as thefor cityfor flowers flowers and municipality and and green green walls. walls. authorities, These These arrangements arrangements resulting inhave have adopted formalized formalized and a implemented anew new mode mode of of cooperation, cooperation, actions. On leading leading that occasion,toto several theseveral public-private anticipatory anticipatory partnershipquantifiable quantifiable betweenconsequences consequences the city impacting impacting authorities, GI. GI. ’Mixer’ and ’Urban Guerrilla’ has been established,TheThe Tables Tables as a 4 foundation 4and and 5 5indicate indicate for thethe the furtherimprovement improvement cultivation of of the the and overall overall maintenance quality quality of ofof the the the selected selected park. Theunit/green unit/green most importantspace,space, interventions according according to to included the the criteria criteria the of removalof the the Green Green of aRegula Regula smalltion gastion of station, of Belgrade. Belgrade. tree The planting The share share and of of pervious introductionpervious surfaces surfaces of new urbanhashas increased increased furniture by forby 4.92% 4.92% flowers after after and the the green removal removal walls. of of the These the gas gas arrangementsstation. station. Planting Planting have three three formalized linden linden trees trees a new will will mode increase increase of cooperation,thethe evapotranspirational evapotranspirational leading to several surface anticipatorysurface by by 3.04% 3.04% quantifiable and, and, in in the the consequencesfuture, future, when when the impactingthe trees trees reach reach GI. their their full full diameter diameter Theofof 20 Tables20 m, m, the 4the and area area5 indicateunder under treetops treetops the improvement will will increase increase of from from the 39.26% overall 39.26% to qualityto 41.25%. 41.25%. of Urban theUrban selected design design unit/green interventions interventions space,(e.g., according(e.g., new new urban tourban the furniture criteriafurniture ofand and the pe pe Greenrviousrvious Regulationpavement) pavement) ofhave have Belgrade. made made spac spac Thee emore share more accessible ofaccessible pervious for for surfaces a agreater greater has increasednumbernumber of by of outdoor 4.92%outdoor after activities. activities. the removal Give Givenn that ofthat thecommunity community gas station. greening greening Planting represents represents three lindena arecent recent trees trend trend will in in Savamala, increase Savamala, the evapotranspirationalitit is is not not possible possible to to anticipate surfaceanticipate by the the 3.04% motivation motivation and, in and theand interest future,interest of when of the the local the local trees community community reach their in in the the full long-term. long-term. diameter of 20 m, the area under treetops will increase from 39.26% to 41.25%. Urban design interventions (e.g., new urban furniture and pervious pavement) have made space more accessible for a greater number of outdoor activities. Given that community greening represents a recent trend in Savamala, it is not possible to anticipate the motivation and interest of the local community in the long-term. Sustainability 2017, 9, 1183 11 of 16

SustainabilitySustainability 2017, 9 2017, 1183, 9 , 1183 11 of 1611 of 16 Table 4. Savamala, the selected morphological unit before the community action. Table Table4. Savamala, 4. Savamala, the selected the selected morphological morphological unit before unit before the community the community action. action.

SustainabilitySustainability 2017, 9 2017, 1183, 9 , 1183 11 of 1611 of 16 N N TableTable 4. Savamala, 4. Savamala, the selected the selected morphological morphological unit before unit before the community the community action. action.

N N

Built-upBuilt-up area (%) area (%) 2.40 2.40 Built-up area (%) 2.40 CultivationCultivation and maintenance and maintenance Maintained Maintained by the bypublic the publiccompany—Belgrade’s company—Belgrade’s City Greenery City Greenery CultivationPerviousPervious and surface maintenance surface (%) (%) Maintained by the public 49.35 company—Belgrade’s 49.35 City Greenery EvapotranspirationalPerviousEvapotranspirational surface surface (%) surface (%) (%) 41.63 41.63 49.35 Tree-coveredTree-coveredBuilt-up surfaceBuilt-up area surface (%) area (%)(%) 39.26 2.40 39.26 2.40 EvapotranspirationalCultivationCultivation and maintenance surface and maintenance (%) Six cultivatedSix cultivated Maintained species: Maintained species: large by treesth largee bypublic (2), thtreese medium public company—Belgrade’s (2), medium company—Belgrade’s41.63 size trees size (2), trees small City (2), trees Greenerysmall City (1), Greenerytrees shrubs (1), shrubs Plant speciesPlant species richness richness (n) (n) Tree-coveredPerviousPervious surface surface surface (%)(%) (%) (1) 49.35 39.26(1) 49.35 EvapotranspirationalEvapotranspirational surface surface (%) Gas (%) station Gas station limits thelimits potential the potential use of space;use 41.63of space;reduced 41.63 reduced diversity diversity of activities of activities due to due to Plant species richness (n) Six cultivated species: large trees (2), medium size trees (2), small trees (1), shrubs (1) Multi-functionalityTree-coveredMulti-functionalityTree-covered surface (n) surface (%) (n) (%)the absencethe absence of gardens of gardens and other and green other spacgreen 39.26es spacthat 39.26 esrequire that require active participationactive participation of of Six cultivatedSix cultivated species: species: large trees locallarge (2), community.treeslocal medium (2), community. medium size trees size (2), trees small (2), treessmall (1), trees shrubs (1), shrubs Plant speciesPlant species richness richness (n) (n) Gas station limits the potential use of space; reduced diversity of activities due to Multi-functionalityVisual Visualquality quality (n) the absence of gardens Disrupted and Disrupted other by greenpetrol(1) by station.petrol spaces(1) station. that require active participation of Gas stationGas station limits limitsthe potential the potential use localof usespace; community.of space;reduced reduced diversity diversity of activities of activities due to due to Multi-functionalityMulti-functionality (n) (n) the absencethe absence of gardens of gardens and other and greenother spacgreenes spac thates require that require active activeparticipation participation of of Table Table5. Savamala, 5. Savamala, the selected the selected morphological morphological unit after unit the after community the community action. action. Visual quality Disruptedlocal community.local by community. petrol station. VisualVisual quality quality Disrupted Disrupted by petrol by petrolstation. station. Table 5. Savamala, the selected morphological unit after the community action. TableTable 5. Savamala, 5. Savamala, the selected the selected morphological morphological unit after unit theafter community the community action. action. N N

N N

Built-upBuilt-up area (%) area (%) 0 0 CultivationCultivation and and CultivatedCultivated and maintained and maintained by public-private by public-private partnership, partnership, i.e., the i.e., cooperation the cooperation between between the the maintenancemaintenance public publiccompany—Belgrade’s company—Belgrade’s City Greenery City Greenery and “Mixer” and “Mixer” organization. organization.

PerviousPervious surface surface (%) (%) 54.27 54.27 Built-upBuilt-up area (%) area (%) 0 0 EvapotranspirationalBuilt-upEvapotranspirational area (%) 0 CultivationCultivation and and CultivatedCultivated and maintained and maintained by public-private by public-private44.67 partnership,44.67 partnership, i.e., the i.e., cooperation the cooperation between between the the surfacesurface (%) (%) maintenancemaintenance Cultivatedpublicpublic company—Belgrade’s and company—Belgrade’s maintained by City public-private Greenery City Greenery and partnership, “Mixer” and “Mixer” organization. i.e., organization. the cooperation between Tree-coveredCultivationTree-covered surface and maintenance surface (%) (%) 41.25 41.25 PerviousPervious surface surface (%) (%) the public company—Belgrade’s 54.27 54.27 City Greenery and “Mixer” organization. Plant speciesPlant species richness richness (n) <10(n) cultivated <10 cultivated species: species: large trees large (2), trees medium (2), medium trees (3), trees small (3), trees small (1), trees shrubs (1), shrubs (1), flowers (1), flowers (2) (2) EvapotranspirationalEvapotranspirational Pervious surface (%)The removalThe removal of gas stationof gas station enabled enabled a number a number44.67 of activities 44.67 of 54.27 activities related related to the Mixerto the festival,Mixer festival, Multi-functionalityMulti-functionalitysurfacesurface (%) (n) (%) (n) workshops,workshops, public publicmeetings, meetings, recreation, recreation, children’s children’s activities. activities. etc. etc. EvapotranspirationalTree-coveredTree-covered surface surface surface (%) (%)(%) 41.25 41.25 44.67 The lackThe of lackmore of diverse more diverse low vegetation low vegetation and flowers, and flowers, as well as as well poorly-maintained as poorly-maintained trees, trees, Tree-coveredPlantVisual speciesPlant Visualquality species richness surface quality richness (n) (%) (n) <10 cultivated <10 cultivated species: species: large trees large (2), trees medium (2), medium trees (3), 41.25trees small (3), treessmall (1), trees shrubs (1), shrubs (1), flowers (1), flowers (2) (2) contributecontribute to the lowto the attractiveness low attractiveness of the park.of the park. The removalThe removal of gas ofstation gas station enabled enabled a number a number of activities of activities related related to the toMixer the Mixerfestival, festival, Multi-functionalityMulti-functionality (n) (n) <10 cultivated species: large trees (2), medium trees (3), small trees (1), Plant species richness (n) workshops,workshops, public public meetings, meetings, recreation, recreation, children’s children’s activities. activities. etc. etc. shrubs (1), ﬂowers (2) The lackThe of lack more of diversemore diverse low vegetation low vegetation and flowers, and flowers, as well as as well poorly-maintained as poorly-maintained trees, trees, VisualVisual quality quality The removal ofcontribute gascontribute station to the enabled tolow the attractiveness low a number attractiveness of of the activities ofpark. the park. related to the Mixer festival, Multi-functionality (n) workshops, public meetings, recreation, children’s activities. etc. The lack of more diverse low vegetation and ﬂowers, as well as poorly-maintained Visual quality trees, contribute to the low attractiveness of the park. Sustainability 2017, 9, 1183 12 of 16

4. Discussion The current socio-economic context in Serbia, resulting in a slow or non-existent implementation of plans, has triggered a number of informal/non-institutional greening initiatives which gradually contribute to the introduction of the contemporary GI concept formulated in the study Green Regulation of Belgrade. The comparative analysis, conducted on two morphologically and functionally different urban matrices in Belgrade, was focused on the level of basic morphological units, identifying the effects of two approaches—spontaneous/community greening and formal/institutional cultivation and maintenance. In residential Block 45, the residents of unit A undertook individual and collective greening activities, while unit B remained under the exclusive authority of the public greening company. In this case, the indicators showed the overall quality upgrading of green spaces and their environmental performances, i.e., the higher share of permeable and evapotranspiration surfaces, larger areas under the shadow and a higher number of plant species, improved biodiversity and visual attractiveness. As a result, the intensity and number of urban activities has increased. On the local level, the compatibility with the formal GI principles reflects in several elements. For example, the gardens situated between the U-shaped buildings correspond to the GI requirement for the bio-retention function of gardens [17]. The flowerpots added by tenants can take the role of planters for storm water collection. The accessible flat roofs of residential buildings are structurally suitable for adaptation to green roofs. The terraced form of the U-shaped buildings enables the greening of facades. Landscaping conducted by residents could be also extended beyond the existing limits, especially in vacant green spaces around buildings which could be activated. Savamala, as a mixed-use district, revealed a more complex structure of greening activities, both on the level of organizing and on the level of participants/involved stakeholders. In this case, the main generators of greening activities are local NGOs, local youth organizations, and associations. The selected polygon of the park in front of the Mikser house was activated by the community greening initiated by a public participatory workshop “My piece of Savamala”, which led to the more official channels of public-private partnership and cooperation between city’s institutions and local organizations. The results of analysis also indicate a moderate success of community greening on the level of vegetation parameters, general accessibility and urban activities. In the terms of compatibility with the formal GI principles and elements, greening of the public spaces in Savamala needs to be directed mainly towards tree planting (both in parks and sidewalks). Furthermore, greening should be extended to inner-block areas (e.g., common gardens with bio-retention) while sidewalks should be upgraded by water permeable features. Buildings with suitable structural properties could be adapted in order to provide green roofs and green facades, which could be jointly used and maintained by residents [17]. The selected cases reveal the importance of community involvement in achieving the higher level of sustainability (economic, social, and environmental) in/of public spaces, especially if they have a potential of becoming an integral part of GI. Although different in typology, contextual elements, and spatial capacity (in both units from Block 45 the public space covers 2984 m2 comparing to current 1232 m2 in the Savamala case), they also confirm that environmental quality represents both an aim and a generator of change. It raises general attractiveness and number of users, defines urban identity and sense of belonging simultaneously stimulating environmental consciousness and well-being of all stakeholders. This sensitive and complex relationship between users and public space could be also seen in two different approaches applied in Block 45, in which the urbo-morphological unit A developed an informal process of greening, unlike option B. Although the motives of this discrepancy were not a subject of this article and they need a comprehensive analysis, the conducted interviews reveal the importance of the sense of belonging to a neighbourhood (e.g., the status of home-ownership vs. renting/temporary stay) might have on developing community initiatives. Apart from the detected improvement of green areas, the selected polygons also showed the shortcomings of existing legislation related to GI, both on the city and the municipal level. Although Sustainability 2017, 9, 1183 13 of 16

APCCA recognizes local community as one of the stakeholders and mentions some greening modes (urban gardens, eco-parks), the role of community greening within GI framework is vaguely defined, without a notion of possible models of organization, management and financing. Consequently, all detected initiatives remain insufficiently aligned with the regulations. The municipality of Novi Beograd still does not use Local ecological action plan (as the only relevant plan dealing with GI on the local level) and the community greening in Blok 45 remains legally unrecognized and unsupported. In Savamala, the ad hoc solution of public-private partnerships was created, aligning with city regulations. However, this approach is not consistent with LEAP, which fails to fully describe all of the aspects of community involvement in formal action plans of GI. The neighbouring countries could provide some examples of a successful interaction between community greening and official regulations, strategies and plans for the development of GI, both on city and municipal levels. The city of Budapest, which also had difficulties in including the local initiatives in GI strategies and plans, tackles the problem by engaging a well-organized civil sector, like in the case of the organization Contemporary Architecture Centre (KÉK), which has been a part of the dissemination process related to urban gardening in Hungary since 2010. KÉK represents a mediator between local initiatives and local governments in order to find the optimal models of cooperation. As a professional partner, they have contributed in setting up many community and school gardens, while operating four of them in Budapest [41]. In addition, Vienna, as a city with a long tradition in community gardening, has developed its own system which involves local initiatives in formal action plans. As a result, the local government encourages locals (individual gardeners, neighbourhood co-operatives, “guerrilla gardening”, etc.) to contribute to greening activities in public and private urban spaces. The community administration (Gebietsbetreuung) receives proposals for individual gardens and public urban spaces and considers the possibility of their implementation. The City of Vienna approved financial support for one community garden in each district, while ’neighbourhood plots’ represents a municipally-funded form of urban gardening [42]. A successful model, also applicable in Serbian case, has been conducted in Berlin. The link between individual greening and public GI infrastructure has been established through the process of the BAF implementation (BAF—Biotope Area Factor, used to estimate ecological effectiveness). If an individual parcel is not able to achieve the expected referent (BAF) standards, the greening of public spaces in immediate surroundings should compensate the imbalance [15]. In this way, plot-owners are engaged in greening activities in the public space, simultaneously improving GI at the local level.

5. Conclusions Based on the case studies, we conclude that, for the time being, the regulations and plans offer no comprehensive and harmonized solutions that recognize the contemporary approaches to green infrastructure, the role of participatory design with stakeholders, and the importance of community greening at the local level. This primarily outlines the need to establish a problem-specific approach in planning GI at the local level, which takes into account the specifics of greening activities defined and modified by different socio-economic and ecological circumstances, as well as morphological limitations. Therefore, the results may be applicable primarily in terms of further local-sensitive initiatives. It should be noted that the analysis was restricted only to certain elements concerning legislation, ecosystem performance and functionality, and did not consider the economic aspect which is also important for the development and implementation of GI. Considering the selected polygons, the results of the analysis could be very useful for the Belgrade’s areas with similar characteristics, and may apply in future studies, local plans, and urban design of GI. The analysis and assessment conducted in both cases reveal that the activities of community greening have significantly improved the condition of GI, previously maintained only by the public company (Belgrade’s City Greenery). The overall quality and quantity of greenery has been increased, as well as its variety and the intensity of use. Two different morphological units (Block 45 Sustainability 2017, 9, 1183 14 of 16 and Savamala), placed in different urban settings, have generated diverse approaches to community greening, with a specific structure and organization of actors, but their activities in both cases have contributed to the overall quality of GI. Furthermore, the identified activities of community greening have a potential which could be extended and used on the local level, as a channel for dissemination of environmentally friendly ideas and lifestyles, as well as for the improvement of environmental consciousness. The detected trend of urban gardening should be also upgraded in order to exceed its current scale, stimulate the practice of self-organization and intensify self-initiated refining of green areas in the immediate surroundings. Additionally, these cases could be used as examples for the countries in the Balkan region, with similar planning and legislative systems, social-economic contexts, and ex-socialist legacies reflected in the urban environment.

Acknowledgments: The article is realized as part of the project “Studying climate change and its influence on the environment: impacts, adaptation and mitigation” (43007) financed by the Ministry of Education and Science of the Republic of Serbia within the framework of integrated and interdisciplinary research for the period 2011–2017. Author Contributions: All three authors wrote the article, read, and approved the manuscript. Ivan Simić performed the literature review, collected and analysed the data, prepared the graphic material, and defined the methodology. Aleksandra Stupar, as the academic advisor, was in charge of the interdisciplinary approach, methodology, structure, and the article editing. Vladan Dokić,as the academic advisor related to the issues of urban morphology, contributed to interpreting the data and the article editing. Conflicts of Interest: The authors declare no conflict of interest.

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