Nature-Based Solutions 1 (2021) 100006 Contents lists available at ScienceDirect Nature-Based Solutions journal homepage: www.elsevier.com/locate/nbsj Nature-based solutions as nodes of green-blue infrastructure networks: A cross-scale, co-creation approach Johannes Langemeyer a,b,∗, Francesc Baró c,d,a a Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona (UAB), Edifici Z (ICTA-ICP), Carrer de les Columnes s/n, Campus de la UAB, 08193 Cerdanyola del Vallès, Spain b Department of Geography, Humboldt Universität zu Berlin, Germany c Vrije Universiteit Brussel (VUB), Geography Department, Pleinlaan 2, B-1050, Brussels, Belgium d Vrije Universiteit Brussel (VUB), Sociology Department, Pleinlaan 2, B-1050, Brussels, Belgium a r t i c l e i n f o a b s t r a c t Keywords: While nature-based solutions have become foundational to sustainable urban and landscape planning schemes Nature-based solutions at multiple landscape scales, there is a risk that previous progress in green-blue infrastructure planning will Ecosystem services be reversed as cross-scale integration increases single- and small-scale focus on nature-based solutions which, Green infrastructure in turn, impacts flows of ecosystem services. Considering successful applications of green-blue infrastructure in Spatial scales fostering cross-scale planning visions, we suggest here to conceptualize nature-based solutions as nodes in green- Co-creation Urban planning blue infrastructure networks in order to strengthen cross-scale considerations and improve ecosystem services. Addressing the three-tiered and nested regional, metropolitan and city scales of Barcelona, Spain, we apply a deliberative co-creation process to define nature-based solution priorities across landscape scales. Together with local stakeholders, we first prioritize nature-based solutions intervention areas by means of participatory map- ping. Secondly, we use a deliberative valuation approach to define ecosystem service priorities for nature-based solution planning. Our findings indicate strong difference in ecosystem service priorities at different scales which underpin the need for a stronger cross-scale spatial integration of planning goals addressed through nature-based solutions. We conclude that the transferability of ecosystem service and trade-offs between ecosystem services require stronger consideration in nature-based solution research and planning for which we base our study, ar- guing that a stronger integration of nature-based solutions into nested green and blue infrastructure planning would be a promising way forward in urban and landscape planning. 1. Introduction the important multi-scale holistic decision-making and planning out- comes that are claimed (for examples see Naturvation Urban Nature Atlas, The embracement of green and blue infrastructure (GBI) approaches https://una.city/). in the last decade has opened discussions of cross-scale landscape plan- In contrast, GBI is a systems-approach that addresses the interre- ning along urban-rural gradients [1,2]. Despite progress in GBI, consid- lated network of ecosystems (including natural and semi-natural areas) erations of cross-scale spatial relationships are at risk of losing momen- and puts explicit emphasis on scale issues. The consideration of cross- tum as focus shifts from integrated multi-scale GBI strategies to single- scale relationships in GBI planning is considered critical as many bene- scale nature-based solutions (NBS) [3–5,70]. fits provided or obtained from ecosystems coincide if single ecosystems NBS are defined as “actions to protect, sustainably manage and re- are linked with each other with aims to enhance biological connectiv- store natural and modified ecosystems in ways that address societal chal- ity, heat mitigation or recreation possibility. Furthermore, a multi-scale lenges effectively and adaptively, to provide both human well-being and approach such as GBI may account for cross-scale trade-offs which, in biodiversity benefits” (IUCN definition) [77]. The NBS concept develops the context of an increasingly urbanizing global society that demands its major strengths through capacity to explicitly address concrete soci- an always larger amount of ecosystem services (ES), can emerge as a etal challenges, not least climate change. While originally introduced result of strong land use competition, for instance between recreational as mechanisms that could be applied at multiple scales [6], the current uses and biodiversity protection [7,8]. The multifunctionality of ecosys- practical application of NBS as a single-scale solution does not achieve tems, understood as the simultaneous delivery of different ES, is limited ∗ Corresponding author. E-mail addresses: johannes.langemeyer@uab.cat (J. Langemeyer), francesc.baro@vub.be (F. Baró). https://doi.org/10.1016/j.nbsj.2021.100006 Received 25 June 2021; Received in revised form 19 October 2021; Accepted 20 October 2021 Available online 28 October 2021 2772-4115/© 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 1. Nature-based Solutions (and the gap thereof) as nodes in Green and Blue Infrastructure networks across different scales. and trade-offs tend to emerge especially if a single ES is maximized [9]. dependent, and with consideration of wider effects and functions of ES This constitutes a particular risk in the development of NBS that are flows from the GBI network across different scales. Considering the func- (per definition) targeted to specific human challenges. As an extreme tions of NBS within multi-scale GBI networks and gaps in these networks example, forest monoculture plantations for carbon sequestration and also allows for a strategic prioritization of NBS interventions in a land- climate change mitigation have been deployed despite known negative scape planning context. With similarity to its role in GBI planning, the long-term impacts on other ecosystems [10] producing inter-scale bar- ES concept might support the cross-scale consideration within NBS re- riers that hamper the flow of ES and accessibility elsewhere [11,12]. search and practice, and foster a systematic and cross-scale integration Cross-scale prioritizations of ES consider long-term ES needs in both of NBS into GBI planning (e.g. [25,26]). cities and their hinterland while also managing spatial relationships be- Beyond conceptual considerations, enhancing NBS scale-sensitivity tween ES providing areas and ES benefitting areas which simultaneously in praxis requires the collaboration of different stakeholders across help in sustaining a resilient ES supply [13,15,73,75]. The generation scales in NBS planning [12]. While participatory co-creation processes of specific ES thereby strongly depends (alongside people’s perceptions) have shown to be a strong tool for multiple stakeholder knowledge ex- on infrastructural and institutional configurations [16], and is thus to a change and creation in the context of ecosystem planning [27,28], delib- large extent subject to landscape and urban planning. erative approaches can add legitimacy to co-creation [29]. In engaging GBI planning has become an important vehicle for implementing with practice, various scholars have argued for the strength of deliber- scale-dependant ES priorities [17,18,66]. For instance, at the European ative valuation or prioritization of ES to inform land-use planning un- scale, the EU Green Infrastructure Strategy has created a policy frame- der trade-off assumptions, not least when dealing with different spatial work for the conservation and restoration of ES [19]. Alongside the de- scales [30,31]. Deliberative prioritization of ES helps to avoid both over- velopment of national and sub-national GBI strategies, the ES approach simplification of the complexity inherent to social-ecological systems has also found its way into urban domains [20,76] informing local GBI [32,33] and issues of incommensurability between different priorities planning in cities [68]. inherent to other methodologies, e.g. monetary valuation of ES [72]. Within the development of nested GBI strategies, the ES notion has In short, there is a lack of stronger cross-scale considerations and in- shown to be useful as a ‘boundary object’ (sensu [21]; see also [71]) tegration in the development of NBS strategies in praxis. As a means to that allows for the practical cross-scale integration of policy objectives foster cross-scale NBS planning, this paper offers a conceptualization of [12,22,23]. The ES concept describes beneficial relationships between NBS as nodes within wider GBI networks that support the flow of ES, people and nature in a single framework at multiple scales — from with emphasis on the need to understand ES trade-offs across different global climate regulation to in-situ appreciation of nature’s aesthetic. scales. Applying a deliberative co-creation process, we aim to establish Hence, ES relationships and trade-offs at different scales are already NBS planning targets in both spatial and ES provision metrics. Address- widely considered in GBI planning [24]; yet, given the growing rele- ing the three-tiered and nested regional, metropolitan and city scales of vance of NBS in research and practice, it seems timely and important to Barcelona, Spain, the specific objectives of our study are (1) to co-create develop and adopt similar inter-scale approaches for NBS. a spatial prioritization of NBS as nodes within a multi-scale GBI network, In order to foster cross-scale considerations in NBS research and and (2) to co-develop a cross-scale prioritization of specific ES. In do- praxis, we suggest taking advantage of the complementary strengths ing so, we support the development of an integrated cross-scale NBS of the GBI and NBS concepts. In this line of thinking we suggest to strategy. conceptualize NBS as nodes within nested GBI networks (Fig. 1). These This article begins with an explanation of the methodology, includ- NBS nodes can be tailored to a particular challenge, assumed as scale- ing the case study description (2.1) and the deliberative co-creation 2 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 process (2.2) for whichthe latter is divided into four sub-sections: the 2.2.2. Stakeholder engagement context in which the study took place and previous research conducted The ‘deliberative co-creation’ approach we follow in this study (2.2.1); a description of the stakeholder engagement process (2.2.2); [29] combines participatory co-creation practices [28] with principles the methodology for the spatial cross-scale prioritization of NBS (2.2.3); of deliberative participation which “involve weighing and reflecting on and, finally, the elicitation process to prioritize ES across the three case preferences, values, and interests […] under equal recognition, respect, study scales (2.2.4). The section following illustrates our results (3) and reciprocity, and sufficiently equal power for communicative influence provides the outcomes of the deliberative co-creation process, structured [[41]: 1]. We argue this methodology adds legitimacy to the experi- around the two specific study objectives. The discussion (4) and conclu- mental co-creation of knowledge in the context of a wicked real world- sion (5) sections finally highlight the major findings and indicate ways problem — the development of an NBS strategy under consideration of forward to plan NBS across different scales. multi-scale independencies as well as consequential trade-offs across ES. Commonly, the stakeholder events in our co-creation process are 2. Methodology championed by one of the participating stakeholder organizations. The collaboration with a ‘champion’ helps to align scientific interests, as 2.1. Case study area original objectives of the engagement was to shape the research foci in the Biodiversa-ENABLE and H2020-Naturvation projects (both 2016– Barcelona, situated in the region of Catalonia, was selected as case 2020), and planning objectives while also designing a stakeholder en- study for its multi-scalar (municipal, metropolitan, and regional) GBI de- velopment plans and implementation processes. While Spain and Catalo- gagement process in a meaningful way from a practitioners’ perspective. nia are currently developing GBI strategies responding to calls from the The champion, in this case the Barcelona Provincial Council, was chosen due to its outstanding experiences in GBI planning and implementation EU, both the Barcelona Province and the City of Barcelona are leaders in of an ES approach, as well as for holding a planning mandate that in- developing GBI strategies tailored to safeguard the provision of ES and biodiversity [17]. At the regional scale, the Barcelona Provincial Coun- cludes the entire study area (see 2.1). Together with the champion, we identified stakeholders from 16 or- cil (Diputació de Barcelona - a regional authority with an advisory role to ganizations including public administrations, public and private consul- landscape and urban planning/management), has developed the Terri- torial Information System on the Network of Open Spaces in the Province of tancies, international and national associations, and public and private research institutes (see Appendix A for a full list of the organizations that Barcelona (SITxell - www. sitxell.eu), which incorporates ES supply, flow were represented during the meetings). Results presented in the follow- and demand maps [2,17,34,14]. At the municipal scale, the Barcelona Biodiversity and Green Infrastructure Plan 2020 [35] (now replaced by ing section are based on two stakeholder meetings that took place on October 15th 2015 and on December 16th 2016, with 24 and 19 indi- the Barcelona Nature Plan 2021–2030), implemented through the Im- vidual participants, respectively. pulse Programme [36], provides the framing for the implementation of NBS in the city of Barcelona. Despite both organizations pioneering the For the deliberative co-creation exercises, workshop participants incorporation of ES in their strategic plans, the two approaches lack a were divided into three facilitated groups representing one for each of the three scales, (Fig. 2). The facilitators, environmental scientists common vision to bridge the scalar divide between the Barcelona mu- with long experiences in stakeholder engagement processes, ensured the nicipality and the regional Province. For instance, the remote effects of Barcelona’s green space planning and potential shifts in the ES demands exercises were properly understood by every participant, encouraged engagement and representation of all stakeholders and their opinions at the Province level (e.g. food, recreation or air pollution mitigation) (sometimes with active limitation of dominant group members), and are not considered by the City planners; similarly, Province GBI plan- ners have yet to adapt conservation approaches to green areas in highly took notes that supported post-analysis of the gathered data. In addi- tion, all break-out group sessions were audio-recorded. urbanized areas, such as the Natural Park of Collserola. In most recent strategic action at the intermediate metropolitan scale, the Metropoli- tan Area of Barcelona, a union of 36 individual municipalities, including 2.2.3. Spatial prioritization of nature-based solutions Barcelona, operating on the principle of metropolitan authority, hopes In line with the conceptualization of NBS as nodes in a GBI network to achieve a stronger scalar integration through the development of the (Fig. 1), the first meeting was designed to determine gaps in the current Metropolitan Master Plan (PDU: https://urbanisme.amb.cat/en). A geo- GBI network which could be addressed by a cross-scale NBS strategy to graphical overview of the three scales is provided in Fig. 2. enhance the flow of ES. Adapting the NBS classifications by Eggermont et al. [42] and by 2.2. Deliberative co-creation process Cohen-Shacham et al. [77] (see Fig. 3), the spatial prioritization exercise aimed at identifying (a) areas for the improved management of existing 2.2.1. Study context NBS to maintain and ameloriate ES flows (type-I), (b) areas for NBS This study builds on a multi-scale and transdisciplinary stake- restoration in order to improve the flow of ES (type-II), and (c) areas holder engagement process established and coordinated by the au- where the creation of new NBS was needed to address specific challenges thors over several years and across different research projects (includ- (type-III). ing Biodiversa-URBES and Biodiversa-ENABLE, FP7-OpenNESS, H2020- At this stage of the co-creation process, the ES concept (as well as the Naturvation and ERC-URBAG). With one to three annual meetings be- GBI concept [see 2.1]) had already been introduced to the stakeholders tween 2013 and 2021 (ongoing), the stakeholder process has become through presentations of diverse ES mapping exercises (SITxell - www. an important forum for knowledge exchange, co-creation, and delib- sitxell.eu) [2,17,34,78] and had been discussed by the stakeholder group eration of objectives and strategies in the context of GBI planning in in previous meetings. Based on an extensive evaluation of the engage- the study area. Co-developed insights stemming from this process have ment process [40], we consider ES at this stage an established boundary informed local and regional planning initiatives, and are reported in object [21], and thus an accepted framework for the participants to con- several scientific publications [37–40]. The design of the process has duct a transdisciplinary workshop, in general (cf. [43,44,71]), and the received a consistently positive feedback by the stakeholders involved spatial prioritization of NBS, in particular. Participants were requested [40], while attracting in relevant meetings between 20 and 50 partic- to discuss and indicate which type of ES, i.e. supporting, provisioning, ipants, amongst them representatives from academia, urban and land- regulating, cultural (following MA, 2005, see also Table 1), they con- scape planners, small-scale business enterprises, and civic organizations. sidered particularly relevant in each priority area (whereby multiple The meetings generally entail a combination of presentations, discussion answers were possible). rounds, and individual or group exercises and deliberation workshops In this exercise, stakeholders were invited to choose the scale they [30]. felt most comfortable with, in order to discuss NBS priorities with en- 3 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 2. Case study area: Barcelona across municipal, metropolitan and regional scale. The population for the Municipality of Barcelona and Barcelona Metropolitan Area has been derived from www.amb.cat. The population for the Province of Barcelona is based on values derived from IDESCAT [74]. The areas are ‘nested’, meaning each geographical area is embedded within another larger area. 4 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 3. Classification of Nature-based Solutions. Adapted from Eggermont et al. [42] and Cohen-Shacham et al. [77]. Table 1 For this exercise, the attendees were again divided into three groups, Ecosystem services provided by green infrastructure used in the cross-scale ES one for each scale, but this time with aims to work towards a common prioritization workshop. cross-scale vision, the groups were predefined in order to mix represen- Ecosystem service type Ecosystem service group tatives of different scales and their respective knowledge. Each group received a list of 22 potentially relevant ES which had been estab- 1 Food provision Provisioning 2 Biomass / wood provision lished based on a review of previous ES research in the study area [45– 3 Water provision 47] (see Table 1). The prioritization exercise at each of the three scales 4 Provision of medical resources addressed the overarching question: ‘Which ES should be enhanced or pro- 5 Air pollution reduction Regulating tected within a green infrastructure strategy 2030?’ and was designed as a 6 Temperature regulation trade-off analysis using a pebble-distribution method [48]. The pebble- 7 Fire risk reduction 8 Flooding buffer distribution method combined with a Condorcet-ranking approach [49], 9 Global climate regulation particularly suitable to rank relative preferences if the underlying as- 10 Erosion control sumption is the existence of trade-offs was inherent. Each break-out 11 Pollination group was asked to select the five most important ES at each scale, and 12 Biological (pest) control 13 Biodiversity conservation Supporting then to distribute for each scale ten ‘pebbles’ (in this case coloured sticky 14 Water cycle points) across the five preselected ES, whereby a maximum of four peb- 15 Ecological support bles per ES where allowed (following Arrow & Raynaud [50], criteria 16 Ecological connectivity weights shall not exceed 50% in order to avoid dominant criteria). Each 17 Habitat for wild species break out group repeated the exercise three times at each of the scales 18 Outdoor recreation Cultural 19 Nature experiences consecutively. The results from the three groups were merged and nor- 20 Environmental education malized based on the overall amount of points (= 30 pebbles) for each 21 Tourism scale. 22 Landscape aesthetics 3. Results couragment for individuals from the same institution not to join the same group in order to create diversity in each of the break-out groups. 3.1. Priority areas for nature-based solutions The exercise was designed as a ‘cross-scale assessment’ [12], looking deliberately for NBS intervention areas across three scales. The delib- The participatory mapping highlighted 20 different priority areas erative discussion culminated in a participatory mapping exercise. Ul- for NBS interventions across the three nested case study areas (Fig. 4). timately, the objective of this exercise consisted in the identification of Half of the proposed NBS can be categorized as type-II interventions, lacking nodes in the GBI network across the three scales, constituting focussing on the restoration of existing ecosystems, including, for ex- priority-areas for future NBS interventions. ample, the restoration of olive and wine plantations in Valls de l’Anoia For the participatory mapping exercise, each break-out group re- (intervention no. 5 in Fig. 2) or the river restoration in the Conca Besòs ceived an A1 topographic map of the respective geographic area (a) (no. 15). One-fourth of the proposed interventions belong to type-I NBS Municipality of Barcelona, (b) Barcelona Metropolitan Area, and (c) (management of existing ecosystems) and the remaining fourth to type- Province of Barcelona. Participants were then invited to discuss and III NBS (creation of new ecosystems). The vast majority of the proposed highlight priority areas for NBS interventions (e.g., management – I, type-III NBS are thereby located in the Municipality of Barcelona, such restoration – II, creation – III) by drawing zones on the map. Following as the creation of new green areas in the dense neighbourhood of Eix- the workshop, the participatory mapping results were digitized using ample (no. 18) — the renowned Barcelona superblocks programme has ArcGIS (version 10.6.1). been mentioned in this context. Type-I and type-II NBS proposals do not show a clear relationship with a particular scale. 2.2.4. Cross-scale ecosystem service prioritization The type of challenges to be addressed varied widely, from enhanced The second meeting aimed at a deliberative prioritization of specific fire resilience (no. 2 and 11), and improved water quality (no. 12 and ES that are to be enhanced by future NBS interventions under the ex- 15) to socio-ecological connectivity (no. 19). While most areas were plicit consideration of different scales. The particular objective was to prioritized under multiple challenges, a clear focus stands out on eco- create a better understanding of inter-scale mismatches in ES priorities, logical, multi-functional and mosaic Mediterranean landscapes (mixed especially for those cases a common cross-scale vision and NBS strategy agriculture and forestry) including the recovery of abandoned areas (e.g. was essential, to avoid cutting-off of flows of ES. no. 4, 5, 14), restoration and maintenance of existing agricultural areas 5 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 4. Priority areas for the implementation of NBS at three different scales. NBS types based on [42]. Map elaboration based on participatory mapping during stakeholder workshop. 6 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 4. Continued (e.g. no. 1, 3, 8), as well as the reduction of agricultural intensity (no. importance (16.7%) after food provision, followed by ecological connec- 6, 7, 9). None of these NBS priority areas, which were also the areas tivity (10.0%) as well as habitat for wildlife (10%) most ES prioritized where provisioning ES were prioritized, intersects with the Municipality at this scale belong to the overarching group of habitat ES. The only of Barcelona, while the other ES types (habitat, regulating and cultural) cultural ES which was given higher importance at the regional scale were seen as relevant for NBS interventions at all three scales. Cross- was landscape aesthetics (13.3%). As a general pattern, we observe an scale priorities for NBS interventions were primarily described for the increasing emphasis on provisioning ES and habitat ES with increasing main river basins, including Conca Llobregat (no. 12) and Conca Besòs scale, and a decreasing importance of cultural ES and regulating ES. (no. 15), but also for the maintenance of the traditional peri‑urban small- scale agriculture at Parc Agrari Llobregat (no. 1), and the management 4. Discussion of peri‑urban natural park of Collserola (no. 13). 4.1. Deliberative co-creation to foster cross-scale NBS strategies 3.2. Scale-based ecosystem service priorities Deliberative approaches have a long tradition in ecological eco- The prioritization of the provision of ES led to considerably diverg- nomics and environmental decision-making scholarship [30], but they ing outcomes for each of the three scales (see Fig. 5). At the municipal have not yet been widely and explicitly considered in participatory co- scale, eight ES were determined as priorities, with air pollution reduc- creation processes [29] that NBS research often relies on. Integrating tion (23%), urban cooling (23%), and outdoor recreation (20%) as most deliberative practices, as done here with the combination of the pebble- important. Water provision was the only provisioning ES highlighted distribution method and a Condorcet-ranking approach for the prioriti- at this scale, while food provision was not given any relevance at this zation of ES, enriches NBS co-creation and produces a targeted, rational scale. This changes fundamentally when looking at food provision at the and replicable study. metropolitan scale (20%) and especially at the regional scale where food Deliberative theory can also provide us an indication about the le- provision received the highest value (26.7%) of all ES across scales. At gitimacy of a co-creation process. Our study illustrates the difficulty the metropolitan scale we also find air pollution removal as a critical encountered in keeping up with deliberative principles, such as equal ES (16.7%), followed by biodiversity conservation (13.3%) and, again, recognition and communicative influence of different stakeholders, and recreation (13.3%). At this scale, stakeholders also put specific emphasis how this may act as a limitation of the co-creation process. For instance, on highlighting the critical importance of strategic planning, especially we relied on a champion organization to support the co-creation pro- of non-protected peri‑urban areas, as a means to maintain the provision cess which, for practical reasons of visibility and mandate, both helped of ES. At the regional scale, biodiversity conservation was of strongest to attract more high level stakeholders. While this can be considered 7 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 Fig. 5. ES values representing planning priorities for ES supply at different scales. Results based on a trade-off exercise during a stakeholder workshop using a Pebble Distribution method. The following ecosystem services were not given any priority: biomass / wood provision, provision of medical resources, global climate regulation, erosion control, pollination, biological control, and tourism. a successful strategy [16,40,51], the champion strongly influenced the ally produced in larger distance to cities due to its high transportability procedural dimension of the co-creation process [cf. 14] including its (livestock moved into the cities alive on its own feed, while horticulture framing (e.g. the focus on ES) and the selection of stakeholders. This, in production was to take place within cities or in their direct surround- turn, may create a bias of influence on behalf of the champion who then ings due to the short storability), the temporal and especially spatial has a stronger influence on the process than other actors. This conflict distance between NBS as providing areas of ES and ES benefitting areas between theory and practice cannot be resolved easily, but deliberative (normally urban centres) must be considered as an important criterion theory permits us at least to see a situation that could arise as a limita- for prioritizing NBS in different locations along an urban-rural gradient. tion and to interpret our results with the appropriate caution. Many ES are limited in their transferability from the providing to the benefitting area. For example, air pollution removal depends on re- 4.2. Ecosystem services as systemic targets for NBS gional proximity [34], where as in situations of urban cooling, noise mit- igation, recreation or social cohesion, the benefitting area must overlap Similarly to what Scholes et al. [12] have shown, the ES concept used with the production areas as transfers of these ES across space are not as ‘boundary object’ [21] has helped to define spatial priorities for NBS possible or are user movement related [53]. That means beneficiaries interventions across the three-tiered and nested regional, metropolitan must either travel to the production area or, where mobility is ham- and city scales of Barcelona. Designing the ES prioritization exercise pered for physical, economic or other reasons, production must take in the form of a pebble-distribution method (with a maximum of peb- place close to the beneficiaries. Non-transferable ES, including heat is- bles and ES to be selected) forced the stakeholders to face a limited land reduction, recreation, and environmental education, were primar- multifunctionality of NBS and to trade-off ES objectives across different ily prioritized at the local city scale and the intermediate metropolitan scales. It thereby facilitated the elicitation of specific targets for NBS at scale. each scale. For instance, outdoor recreation decreased along an urban- Distinctively, the provision of food and raw materials from ecosys- rural gradient, while food provision increased. tems is perceived as widely decoupled in terms of spatial and tempo- The identification of such different targets at different scales and ral relationships between providing and benefitting areas. Although this along an urban-rural gradient reconfirms the need for a stronger con- understanding has previously been challenged from an urban resilience sideration of spatial relationships between ES providing areas (areas of perspective [54,55], it manifested as ’low priority’ in our study for these NBS interventions) and ES benefitting areas [13], including the stora- ES to be provided at the city scale. At the same time, food production bility, transportability or transferability of ES. Similarly as Von Thünen is prioritized at the regional scale. Similarly, a higher priority for NBS [52] demonstrated in the XIX century that livestock production was ide- planning at regional scale is also observed for supporting ES, such as 8 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 biodiversity conservation, ecological connectivity and habitat for wild tial relationships and cross-scale trade-offs in ES provision and demand species, which are intermediate ES and only indirectly coupled with ES might lead to simplistic NBS, which might not only hamper the flow of benefits, and thus benefitting areas. ES [65], but also foster social tensions and environmental conflict [46], An important finding from our study in this context is the strong pri- not least between urban and rural residents. ority for restorative NBS across all three scales, with a particular empha- sis on the recovery of agricultural areas and a decrease in agricultural 5. Conclusions intensity. The principal objective of these NBS is to foster the provision of habitat, regulatory and cultural ES alongside the production of food. Our study developed and applied a novel analytical framework that This finding drives a call to shift the current focus in NBS research from understands NBS as nodes within nested GBI networks. This framework the creation of new (often technically more sophisticated) type-I NBS to- promotes a systems-understanding of NBS with particular emphasis on wards restorative type-II NBS, while also reducing the maximization of ES as target objectives. A deliberative co-creation approach supported single ES and instead emphasizing the simultaneous generation of a va- the spatial prioritization of NBS across different scales and along an riety of ES while maintaining awareness of potential trade-offs between urban-rural gradient. Differences in the priorities at different scales pro- ES and limits to multifunctionality. vide evidence for the need for integrated NBS strategies across multiple scales with a prime example in food production, which was not given 4.3. NBS as nodes within GBI networks any importance at the city scale but was considered the most important ES from a regional scale perspective. To accommodate such competing While urban and regional land-use planning approaches continue to objectives across scales requires multi-scale integrated and holistic plan- have very different foci and priorities [56] ,GBI planning has brought ning approaches, which are currently underdeveloped in NBS research the multiple scales of urban development closer together. With NBS re- and practice. Conceptualizing NBS as nodes within GBI networks can be search and practice gaining momentum, we are at a turning point of a way forward, and would allow for novel NBS approaches to be aligned either reproducing the century-old urban-rural scalar divide in land-use with widely established GBI planning. planning,1 or further developing an integrated urban-rural vision and cohesive objectives. Acknowledgements Despite scholarly calls for choices and decisions about NBS “to con- sider larger temporal and spatial scales” [26,42,57,69], NBS approaches We would like to thank all workshop participants and co-organizers. and their uptake in planning are emphasizing narrow local,urban ob- This research was funded through the 2015–2016 BiodivERsA COFUND jectives [58,59,67], and tend to overlook urban-rural tele-connections call for research proposals, by the national funders: the Swedish Re- [54,60,61], cross-scale complexities in ES provision and demand, and search Council for Environment, Agricultural Sciences, and Spatial Plan- ES trade-offs [7]. ning, the Swedish Environmental Protection Agency, the German Aero- In response to this goal to foster integrated cross-scale NBS strategies, nautics and Space Research Centre, the National Science Centre (Poland) we presented a novel conceptual understanding of NBS as nodes within (grant no. 2016/22/Z/NZ8/00003), the Research Council of Norway, multi-scale GBI networks. GBI as an established multi-scale and systems and the Spanish Ministry of Economy and Competitiveness. It also re- concept facilitates the development of cross-scale NBS strategies. In this ceived funding through the EU’s Horizon 2020 framework program for context, the boundary character of the ES concept allowed for creating research and innovation (project NATURVATION, grant agreement ID: a common understanding of trade-offs and mutual consideration of con- 730243 and INTERLACE grant agreement: 869324). JL acknowledges flicting objectives amongst stakeholders. As our study shows, the latter additional funding from the European Research Council (ERC Consolida- can be promoted through the scalar prioritization of ES as objectives tor Grant: 818002-URBAG). FB’s contributions were also supported by for NBS within a larger GBI strategy. We highlight this finding as an the European Research Council (project GREENLULUs; grant agreement advancement towards a more integrated urban and landscape planning, ID: 678034). The manuscript was proof-edited by Emilia Oscilowicz. which in praxis requires more inclusive modes of NBS governance [62]. Aligning and implementing NBS interventions across multiple scales Appendix A is critical in fostering inter-scale collaboration and overcoming tradi- tional inter-scalar barriers in the provision of ES, thereby creating re- silient and equitable flows of ES which match resident’s needs and de- Primary sires without hampering the flourishment of others [15,63]. Organization Domain scale Understanding NBS as nodes within a cross-scale GBI planning Àrea Metropolitana de Barcelona1,2 Administration, public B framework can support integrated planning solutions, which are needed BCN-Ecologia1,2 Consultancy, public A to largely enable the multi-functional character of NBS. The visualiza- CREAF1,2 Research, public B,C Dep. de Territori i Sostenibilitat, Administration, public C tion of ES trade-offs thereby increases the stakeholders’ understanding Generalitat de Catalunya1,2 that there exist competing objectives in land-use decision-making that Dep. Espais Verds i Biodiversitat, Administration, public A contributes to a lack of ideal NBS. Simultaneously, it also triggers stake- Barcelona City Council1,2 holders to considering enhancing the provision of multiple ES from a Dep. Urbanisme, Barcelona City Council1 Administration, public A single NBS. This stands in sharp contrast to a still common functional Dipuatació de Barcelona1,2 Administration, public A, C Europarc España1,2 Consultancy, public C zoning in urban and landscape planning, for instance, often strictly di- Fedenatur1,2 Intern. association, public C viding agricultural land uses and protected natural areas. Institut Català d’Ornitologia1,2 Assoc., private C In short, the consideration of NBS within GBI networks might Institute of Environmental Science and Research, public A, B, C strengthen urban-rural ties, connecting cities to their hinterland, and Technolgy1,2 ISGlobal (former CREAL) 1,2 Research, private A help to create integrated urban-rural ‘landscape solutions’ [64]. Discor- Minuartia1,2 Consultancy, private B, C dantly, a lack of understanding and consideration of inter-scalar spa- School of Economics, Universitat de Research, public A, B, C Barcelona2 1 UNEP1 Intern. association, public A, B, C An increasing urban-rural divide can be traced back to the spatial decoupling Unió de Pagesos1 Assoc., private C of agricultural production areas from urban consumption areas in relation to improved transport and storage capacities since the mid 19th century. Before the 1 Participation in stakeholder meeting on October 15th 2015. 2 industrial revolution the urban-rural dependency was more evident and strongly Participation in stakeholder meeting on December 16th 2016; A: Municipal, considered in land-use planning (cf. [52]). B: Metropolitan, C: Regional. 9 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 References [29] M. Sonnberger, D. Lindner, Participation in real-world laboratories in a new light?!: Closing the gap between co-creative and deliberative participation, Spat. [1] F. Kroll, F. Müller, D. Haase, N. Fohrer, Rural–urban gradient analysis of ecosys- Res. Plann. 79 (4) (2021) 424–437 ISSN 1869-4179, Oekom Verlag, München- tem services supply and demand dynamics, Land Use Policy 29 (2012) 521–535 http://dx.doi.org/10.14512/rur.27. doi:http://dx.doi.org/10.1016/j.landusepol.2011.07.008. [30] J.O. Kenter, N. Jobstvogt, V. Watson, K.N. Irvine, M. Christie, R. Bryce, The im- [2] F. Baró, E. Gómez-Baggethun, D. Haase, Ecosystem service bundles along the urban- pact of information, value-deliberation and group-based decision-making on values rural gradient: insights for landscape planning and management, Ecosyst. Serv. 24 for ecosystem services: integrating deliberative monetary valuation and storytelling, (2017) 147–159, doi:10.1016/j.ecoser.2017.02.021. Ecosyst. Serv. 21 (2016) 270–290. [3] F. Boano, A. Caruso, E. Costamagna, L. Ridolfi, S. Fiore, F. Demichelis, . . . F. Masi, [31] J. Ainscough, M. Wilson, J.O. Kenter, Ecosystem services as a post-normal field of sci- A review of nature-based solutions for greywater treatment: applications, hydraulic ence, Ecosyst. Serv. 31 (Part A) (2018) 93–101, doi:10.1016/j.ecoser.2018.03.021. design, and environmental benefits, Sci. Total Environ. 711 (2020) 134731. [32] N. Kosoy, E. Corbera, Payments for ecosystem services as commodity fetishism, Ecol. [4] C. Davies, W.Y. Chen, G. Sanesi, R. Lafortezza, The European Union roadmap for im- Econ. 69 (6) (2010) 1228–1236. plementing nature-based solutions: a review, Environ. Sci. Policy 121 (2021) 49–67. [33] R.B. Norgaard, Ecosystem services: from eye-opening metaphor to complexity blin- [5] N. Faivre, M. Fritz, T. Freitas, B. de Boissezon, S. Vandewoestijne, Nature-Based der, Ecol. Econ. 69 (6) (2010) 1219–1227. Solutions in the EU: innovating with nature to address social, economic and envi- [34] F. Baró, I. Palomo, G. Zulian, P. Vizcaino, D. Haase, E. Gómez-Baggethun, Map- ronmental challenges, Environ. Res. 159 (2017) 509–518. ping ecosystem service capacity, flow and demand for landscape and urban plan- [6] IUCN - International Union for Conservation of Nature, No time to lose – make ning: a case study in the Barcelona metropolitan region, Land Use Policy 57 (2016) full use of nature-based solutions in the post-2012 climate change regimePosition 405–417. paper on the Fifteenth session of the Conference of the Parties to the United Nations [35] BCNBarcelona Green Infrastructure and Biodiversity Plan 2020, 2013 Ajuntament Framework Convention on Climate Change (COP 15), IUCN, 2009. de Barcelona. Available online: https://ajuntament.barcelona.cat/ecologiaurbana/ [7] F. Turkelboom, M. Leone, S. Jacobs, E. Kelemen, M. García-Llorente, et al., When we sites/default/files/Barcelona%20green%20infrastructure%20and%20biodiversity% cannot have it all: ecosystem services trade-offs in the context of spatial planning, 20plan%202020.pdf. Ecosyst. Serv. 29 (Part C) (2018) 566–578, doi:10.1016/j.ecoser.2017.10.011. [36] BCNStimulus Programme for the City’s Urban Green Infrastructure, 2017 Ajun- [8] T.O. Wiedmann, H. Schandl, M. Lenzen, D. Moran, S. Suh, J. West, K. Kanemoto, tament de Barcelona. Available online: https://bcnroc.ajuntament.barcelona.cat/ The material footprint of nations, PNAS 112 (20) (2015) 6271–6276. jspui/bitstream/11703/104928/1/eng_Mesura%20de%20govern%20increment% [9] R.S. De Groot, R. Alkemade, L. Braat, L. Hein, L. Willemen, Challenges in 20verd_08_06_2017.pdf. integrating the concept of ecosystem services and values in landscape plan- [37] C. De Luca, J. Langemeyer, S. Vano, F. Baró, E. Andersson, Adaptive resilience of ning, management and decision making, Ecol. Complex. 7 (2010) 260–272, and through urban ecosystem services: a transdisciplinary approach to sustainability doi:10.1016/j.ecocom.2009.10.006. in Barcelona, Ecol. Soc. (2021) (in press). [10] Lewis, S.L., Wheeler, C.E., Mitchard, E.T., & Koch, A. (2019). Restoring natural [38] R. Dunford, P. Harrison, A. Smith, J. Dick, D.N. Barton, B. Martin-Lopez, E. Kele- forests is the best way to remove atmospheric carbon. men, S. Jacobs, H. Saarikoski, F. Turkelboom, W. Verheyden, J. Hauck, P. An- [11] C. Raudsepp-Hearne, G.D. Peterson, Scale and ecosystem services: how do observa- tunes, R. Aszalós, O. Badea, F. Baró, P. Berry, L. Carvalho, G. Conte, B. Czúcz, tion, management, and analysis shift with scale—Lessons from Québec, Ecol. Soc. G. Garcia Blanco, D. Howard, R. Giuca, E. Gomez-Baggethun, B. Grizetti, Z. Izakovi- 21 (3) (2016). cova, L. Kopperoinen, J. Langemeyer, S. Luque, D.M. Lapola, G. Martinez-Pastur, [12] R. Scholes, B. Reyers, R. Biggs, M. Spierenburg, A. Duriappah, Multi-scale and cross- R. Mukhopadhyay, S.B. Roy, J. Niemelä, et al., Integrating methods for ecosystem scale assessments of social–ecological systems and their ecosystem services, Curr. service assessment: experiences from real world situations, Ecosyst. Serv. 29 (2018) Opin. Environ. Sustain. 5 (2013) 16–25, doi:10.1016/j.cosust.2013.01.004. 499–514, doi:10.1016/j.ecoser.2017.10.014. [13] B. Fisher, R.K. Turner, P. Morling, Defining and classifying ecosystem services for [39] J. Langemeyer, D. Wedgwood, D. Barton, F. Baró, T. McPhearson, Creating urban decision making, Ecol. Econ. 68 (3) (2009) 643–653. green infrastructure where it is needed – a spatial ecosystem service-based de- [14] J. Langemeyer, F. Calcagni, F. Baró, Mapping the intangible: Using geolocated social cision analysis of green roofs in Barcelona, Sci. Total Environ. 707 (10) (2020), media data to examine landscape aesthetics, Land Use Policy 77 (2018) 542–552, doi:10.1016/j.scitotenv.2019.135487. doi:10.1016/j.landusepol.2018.05.049. [40] J. Dick, F. Turkelboom, H. Woods, I. Iniesta-Arandia, E. Primmer, S.-.R. Saarela, [15] J. Langemeyer, J.J.T. Connolly, Weaving notion of justice into urban ecosys- P. Bezák, P. Mederly, M. Leone, W. Verheyden, E. Kelemen, J. Hauck, C. An- tem service research and practice, Environ. Sci. Policy 109 (2020) (2020) 1–14, drews, P. Antunes, R. Aszalós, F. Baró, D.N. Barton, P. Berry, R. Bugter, L. Car- doi:10.1016/j.envsci.2020.03.021. valho, B. Czúcz, R. Dunford, G.G. Blanco, N. Geamănă, R. Giucă, B. Grizzetti, [16] E. Andersson, S. Borgström, D. Haase, J. Langemeyer, T. McPhearson, M. Wolff, Z. Izakovičová, M. Kertész, L. Kopperoinen, J. Langemeyer, D.M. Lapola, C. Li- Ensuring ecosystem service benefits over time - resilience thinking and practice for quete, S. Luque, G.M. Pastur, B. Martin-Lopez, R. Mukhopadhyay, J. Niemela, urban systems, Ecol. Soc. 26 (2) (2021) 35, doi:10.5751/ES-12411-260235. et al., Stakeholders’ perspectives on the operationalisation of the ecosystem ser- [17] C. Basnou, F. Baró, J. Langemeyer, C. Castell, C. Dalmases, J. Pino, Advancing green vice concept: results from 27 case studies, Ecosyst. Serv. 29 (2018) 552–565, infrastructure planning at a regional landscape scale: linking biodiversity, ecosystem doi:10.1016/j.ecoser.2017.09.015. functions and services in the province of Barcelona, Urban Forest. Urban Green. 55 [41] A. Bächtiger, J.S. Dryzek, J. Mansbridge, M.E. Warren, et al., Deliberative democ- (2020) 126797, doi:10.1016/j.ufug.2020.126797. racy: an introduction, in: Bächtiger, et al. (Eds.), The Oxford Handbook of Deliber- [18] G. Zulian, S. Ronchi, A. La Notte, S. Vallecillo, J. Maes, Adopting a cross-scale ap- ative Democracy, Oxford University Press, 2018, pp. 1–35. proach for the deployment of a green infrastructure, One Ecosyst. 6 (2021) e65578. [42] H. Eggermont, E. Balian, J.M.N. Azevedo, V. Beumer, T. Brodin, J. Claudet, B. Fady, [19] European CommissionGreen Infrastructure (GI)— Enhancing Europe’s Natural Cap- M. Grube, H. Keune, P. Lamarque, K. Reuter, M. Smith, C. van Ham, W.W. Weisser, ital, COM, Brussels, 2012 (2013)249. X. Le Roux, Nature-based solutions: new influence for environmental management [20] R.P. Remme, H. Frumkin, A.D. Guerry, A.C. King, L. Mandle, C. Sarabu, . . . and research in Europe, GAIA (2015) 24. G.C. Daily, An ecosystem service perspective on urban nature, physical activity, and [43] D.J. Abson, H. Von Wehrden, S. Baumgärtner, J. Fischer, J. Hanspach, W. Härdtle, health, PNAS 118 (22) (2021). . . . D. Walmsley, Ecosystem services as a boundary object for sustainability, Ecol. [21] S.L. Star, J. Griesemer, Institutional ecology, ‘Translations’, and Boundary objects: Econ. 103 (2014) 29–37. amateurs and professionals on Berkeley’s museum of vertebrate zoology, Soc. Stud. [44] C. Steger, S. Hirsch, C. Evers, B. Branoff, M. Petrova, M. Nielsen-Pincus, . . . C.J. Van Sci. 19 (1989) 387–420. Riper, Ecosystem services as boundary objects for transdisciplinary collaboration, [22] G.S. Cumming, P. Olsson, F.S. Chapin, C.S. Holling, Resilience, experimentation, Ecol. Econ. 143 (2018) 153–160. and scale mismatches in social-ecological landscapes, Landsc. Ecol. 28 (6) (2013) [45] F. Baró, L. Chaparro, E. Gómez-Baggethun, J. Langemeyer, D.J. Nowak, J. Terradas, 1139–1150. Assessing ecosystem services provided by urban forests in relation to air quality and [23] C. Schleyer, C. Görg, J. Hauck, K.J. Winkler, Opportunities and challenges for main- climate change mitigation policies in Barcelona, Spain, AMBIO 43 (2014) 466–479. streaming the ecosystem services concept in the multi-level policy-making within [46] E. Gómez-Baggethun, Å. Gren, D. Barton, J. Langemeyer, T. McPhearson, the EU, Ecosyst. Serv. 16 (2015) 174–181. P. O’Farrell, et al., Cities and biodiversity outlook 1. A global assessment of the [24] M. Demuzere, K. Orru, O. Heidrich, E. Olazabal, D. Geneletti, H. Orru, A.G. Bhave, links between urbanization, biodiversity and ecosystems, Convention on Biologi- N. Mittal, E. Feliu, M. Faehnle, Mitigating and adapting to climate change: multi- cal Diversity, UNEP, 2013 Role: ‘Urban Ecosystem Services’. Draft version available functional and multi-scale assessment of green urban infrastructure, J. Environ. Man- at http://www.cbd.int/en/subnational/partners-and-initiatives/cbo/cbo-scientific- age. 146 (2014) 107–115, doi:10.1016/j.jenvman.2014.07.025. analysis-and-assessment/cbo-saa_chapter-4_13-oct-2012. [25] E. Andersson, J. Langemeyer, S. Borgström, T. McPhearson, D. Haase, D. Barton, [47] J. Langemeyer, F. Baró, P. Roebeling, E. Gómez-Baggethun, Contrasting values of M. Davis, J. Kronenberg, S. Naumann, L. Röschel, E. Stange, F. Baró, Enabling green cultural ecosystem services in urban areas: the case of park Montjuïc in Barcelona, and blue infrastructure to improve contributions to human well-being and equity in Ecosyst. Serv. 12 (2015) 178–186, doi:10.1016/j.ecoser.2014.11.016. urban systems, Bioscience 69 (2019) 566–574, doi:10.1093/biosci/biz058. [48] D. Sheil, N. Liswanti, M. Van Heist, et al., Local priorities and biodiversity in tropical [26] C.M. Raymond, N. Frantzeskaki, N. Kabisch, P. Berry, M. Breil, M.R. Nita, . . . forestlandscapes:asking people what matters, Trop. For. Update (2003) 13. C. Calfapietra, A framework for assessing and implementing the co-benefits of na- [49] G. Munda, Social Multi-Criteria Evaluation For a Sustainable Economy (Vol. 17), ture-based solutions in urban areas, Environ. Sci. Policy 77 (2017) 15–24. Springer, Berlin, 2008. [27] N. Frantzeskaki, N. Kabisch, Designing a knowledge co-production operat- [50] K.J. Arrow, H. Raynaud, in: Social Choice and Multicriterion Decision-Making, MIT ing space for urban environmental governance – lessons from Rotterdam, Press Books, 1986, p. 1. Netherlands and Berlin, Germany, Environ. Sci. Policy 62 (2016) 90–98, [51] A. Mascarenhas, J. Langenmeyer, D. Haase, S. Borgström, E. Andersson, Assessing doi:10.1016/j.envsci.2016.01.010. the learning process in transdisciplinary research through a novel analytical ap- [28] S. Pauleit, B. Ambrose-Oji, E. Andersson, B. Anton, A. Buijs, D. Haase, . . . C.K. van proach, Ecol. Soc. (2021) (in press). den Bosch, Advancing urban green infrastructure in Europe: outcomes and reflec- [52] J.H. Von Thünen, The Isolated state in Relation to Land Use and National Economy, tions from the GREEN SURGE Project, Urban Forest. Urban Green. 40 (2019) 4–16. Schmaucher Zarchlin, Berlin, 1875. 10 J. Langemeyer and F. Baró Nature-Based Solutions 1 (2021) 100006 [53] R. Costanza, Ecosystem services: multiple classification systems are needed, Biol. [68] E. Gómez-Baggethun, D.N. Barton, Classifying and valuing ecosystem services for Conserv. 141 (2008) 350–352. urban planning, Ecol. Econ. 86 (2013) 235–245. [54] S. Barthel, C. Isendahl, B.N. Vis, A. Drescher, D.L. Evans, A. van Timmeren, Global [69] J. Maes, S. Jacobs, Nature-based solutions for Europe’s sustainable development, urbanization and food production in direct competition for land: leverage places Conserv. Lett. 10 (1) (2017) 121–124. to mitigate impacts on SDG2 and on the Earth System, Anthropocene Rev. 6 (1–2) [70] N. Nicolaidis, M.L. Denia Kolokotsa, G. Somarakis, S. Stagakis, F. Lemaitre, Clas- (2019) 71–97. sification of nature-based solutions, in: G. Somarakis, S. Stagakis, N. Chrysoulakis [55] J. Langemeyer, C. Madrid-Lopez, A. Mendoza Beltran, G. Villalba, Urban agriculture, (Eds.), Think Nature Nature-Based Solutions Handbook, 2019 ThinkNature project a necessary path to urban resiliency and global sustainability? Landsc Urban Plan. funded by the EU Horizon 2020 research and innovation programme under grant 210 (2021) 104055, doi:10.1016/j.landurbplan.2021.104055. agreement No. 730338, doi:10.26225/jerv-w202. [56] L. Hein, K. Van Koppen, R.S. De Groot, E.C. Van Ierland, Spatial scales, stakeholders [71] S.R. Saarela, J. Rinne, Knowledge brokering and boundary work for ecosystem and the valuation of ecosystem services, Ecol. Econ. 57 (2) (2006) 209–228. service indicators. An urban case study in Finland, Ecol. Indic. 61 (2016) 49–62, [57] C. Nesshöver, T. Assmuth, K.N. Irvine, G.M. Rusch, K.A. Waylen, B. Delbaere, doi:10.1016/j.ecolind.2015.07.016. H. Wittmer, The science, policy and practice of nature-based solutions: an inter- [72] H. Saarikoski, J. Mustajoki, D. Barton, D. Geneletti, J. Langemeyer, disciplinary perspective, Sci. Total Environ. 579 (2017) 1215–1227. E. Gómez-Baggethun, M. Marttunen, P. Antunes, H. Keune, R. Santos, Multi-criteria [58] N. Frantzeskaki, Seven lessons for planning nature-based solutions in cities, Environ. decision analysis and cost-benefit analysis: Comparing alternative frameworks for Sci. Policy 93 (2019) 101–111. integrated valuation of ecosystem services, Ecosyst. Serv. 22 (2016) 238–249. [59] N. Seddon, A. Chausson, P. Berry, C.A. Girardin, A. Smith, B. Turner, Understanding [73] R.-U. Syrbe, U. Walz, Spatial indicators for the assessment of ecosystem services: the value and limits of nature-based solutions to climate change and other global providing, benefiting and connecting areas and landscape metrics, Ecol. Indic. 21 challenges, Philos. Trans. R. Soc. B 375 (1794) (2020) 20190120. (2012) 80–88, doi:10.1016/j.ecolind.2012.02.013. [60] K.C. Seto, A. Reenberg, C.G. Boone, M. Fragkias, D. Haase, T. Langanke, . . . D. Simon, [74] IDESCATInstitut d’Estadística de Catalunya, 2020 Available online: Urban land teleconnections and sustainability, PNAS 109 (20) (2012) 7687–7692. https://www.idescat.cat/tema/xifpo . [61] D. Haase, B. Güneralp, B. Dahiya, X. Bai, T. Elmqvist, Global urbanization, Urban [75] Ralf-Uwe Syrbe, Ulrich Walz, Spatial indicators for the assessment of ecosystem Planet 19 (2018) 326–339. services: providing, benefiting and connecting areas and landscape metrics, Ecolog- [62] E. Primmer, P. Jokinen, M. Blicharska, D.N. Barton, R. Bugter, M. Potschin, Gover- ical Indicators 21 (2012) 80–88 https://www.researchgate.net/file.PostFileLoader. nance of ecosystem services: a framework for empirical analysis, Ecosyst. Serv. 16 html?id=5889965beeae3923243b1ef5&assetKey=AS%3A454664744378370%401 (2015) 158–166. 485411930924. [63] S.T. Borgström, T. Elmqvist, P. Angelstam, C. Alfsen-Norodom, Scale mismatches in [76] D. Haase, N. Larondelle, E. Andersson, M. Artmann , S. Borgström, J. Breuste, management of urban landscapes, Ecol. Soc. 11 (2) (2006) 16. E. Gomez-Baggethun, Å Gren, Z. Hamstead, R. Hansen, N. Kabisch, P. Kre- [64] S. Keesstra, J. Nunes, A. Novara, D. Finger, D. Avelar, Z. Kalantari, A. Cerdà, The su- mer, J. Langemeyer, E. Lorance, T. McPhearson, E. Rall, S. Pauleit, N. Qureshi, perior effect of nature based solutions in land management for enhancing ecosystem N. Schwarz, A. Voigt, D. Wurster, T. Elmqvist, Quantitative review of urban ecosys- services, Sci. Total Environ. 610 (2018) 997–1009. tem services assessment: Concepts, models and implementation, AMBIO (2014) [65] Wolff, Haase, Pushing the perception button - Unlocking barriers to recreational 413–433. benefits of urban green spaces, Ecol. Soc. (2021) (in press). [77] E. Cohen-Shacham, G. Walters, C. Janzen, S. Maginnis, Nature-based solutions to [66] W.L. Allen, A Green Infrastructure framework for vacant and underutilized urban address global societal challenges, IUCN: Gland, Switzerland (2016) 97. lands, J. Conserv. Plan. 10 (2014) 43–51. [78] Johannes Langemeyer, Marta Camps-Calvet, Laura Calvet-Mir, [67] N. Frantzeskaki, T. McPhearson, M.J. Collier, D. Kendal, H. Bulkeley, A. Dumitru, Erik Gomez-Baggethun, Stewardship of urban ecosystem services: Understand- . . . L. Pintér, Nature-based solutions for urban climate change adaptation: linking ing the value (s) of urban gardens in Barcelona, Landscape and Urban Planning 170 science, policy, and practice communities for evidence-based decision-making, Bio- (2018) 79–89. science 69 (6) (2019) 455–466. 11