Recent literature demonstrates the contribution of short food supply chains (SFSC) to regional economies and sustainable food systems, and acknowledges their role as drivers for sustainable development. Moreover, different types of SFSC have been supported by urban food policies (UFP) over the few last years and actors from the food chain became part of new institutional settings for urban food policies. However, evidence from the sustainability impact assessment (SIA) of these SFSC in urban contexts is limited. Our paper presents an approach for the development of an SIA framework for different SFSC types. In addition, a practical application of the tool in four metropolitan regions (Berlin, London, Ljubljana and Nairobi) is tested. The conceptual development of the SIA framework is based on an in-depth analysis of existing SIA frameworks and methods for assessing the sustainability of agriculture, food chains and food systems and adapted to the specific needs of analysing SFSC in metropolitan regions. The operational value and utility of the framework and the tool were tested with social and natural scientists and local stakeholders. The assessment results demonstrate that SFSC seems to be more sustainable than the baseline (long global food chains) in the social dimension, but also feature specific strengths and weaknesses concerning their economic and environmental sustainability. This might give an indication for regional adjusted strategies and food chain innovations that improve the sustainability performance may be required. We found the tool useful for framing the dialogue between food chain actors, consumers and policy, because it makes benefits and trade-offs of the chain types operating in an urban–rural context more visible and communicable.

Regional food systems and organic agriculture are both considered more sustainable than the conventional, globalized food system they provide an alternative to. The emergence and expansion of alternative forms of food supply are influenced by various factors on different scales. Using the food systems approach we aim to study potentials and limitations of regional organic food supply in the Berlin metropolitan region (BMR). Based on the literature, we developed an analytical framework and identified determinants of regional organic food provision along the three major levels of the supply chain: agricultural production, food chain organization, and consumption. Then, we examined a qualitative case study with two different types of alternative food networks (A) organic community supported agriculture (CSA) and (B) organic retail trade. Factors that hinder or promote the provision of regional organic food were identified through qualitative interviews and assessed by regional stakeholders in a workshop. Our findings show that demand for regional organic food is higher than regional supply, which could offer good possibilities for organic farmers. However, actors in these two food chains need to overcome some obstacles, including limited access to land, increasing renting prices, insufficient processing capacities, and unsupportive political environment for organic farming.

Aquaponics, the water-reusing production of fish and crops, is taken as an example to investigate the consequences of upscaling a nature-based solution in a circular city. We developed an upscaled-aquaponic scenario for the German metropolis of Berlin, analysed the impacts, and studied the system dynamics. To meet the annual fish, tomato, and lettuce demand of Berlin’s 3.77 million residents would require approximately 370 aquaponic facilities covering a total area of 224 hectares and the use of different combinations of fish and crops: catfish/tomato (56%), catfish/lettuce (13%), and tilapia/tomato (31%). As a predominant effect, in terms of water, aquaponic production would save about 2.0 million m³ of water compared to the baseline. On the supply-side, we identified significant causal link chains concerning the Food-Water-Energy nexus at the aquaponic facility level as well as causal relations of a production relocation to Berlin. On the demand-side, a ‘freshwater pescatarian diet’ is discussed. The new and comprehensive findings at different system levels require further investigations on this topic. Upscaled aquaponics can produce a relevant contribution to Berlin’s sustainability and to implement it, research is needed to find suitable sites for local aquaponics in Berlin, possibly inside buildings, on urban roofscape, or in peri-urban areas.

The implementation of eco-innovations can be a strategy to combine economic benefit and reduce negative environmental impact. German greenhouse production is highly energy intensive, as heating and energy account for the second largest cost factor. Thus, the sector wants to develop and implement eco-innovations to speed up the process towards increased sustainability. In this paper, a sectoral systems of innovation (SSI) analysis is presented to identify and describe interrelated systemic barriers for developing and implementing such innovations into the sector. The SSI was used as an analytical framework, which enabled covering different system levels and components in the research in order to draw a comprehensive picture of this specific innovation environment. A mixed-methods, explorative approach was used: a literature analysis, followed by an expert workshop and semi-structured expert interviews, was conducted to understand the barriers for development and implementation of such innovations. A SWOT workshop assisted in generalizing results from selected innovation examples. A complementary two-wave Delphi study was used to identify innovation activity, important actors, policies and drivers within horticulture. Based on these data, we were able to identify different barrier-types, showing how they are interconnected and affect innovation processes increasing ecological modernization of the sector.

Although the relevance of urban-rural interrelations is widely acknowledged in science and practice, there is as yet no feasible theoretical or theory-driven approach or model that addresses the multiple interconnections in urban-rural spaces at the regional level and makes them applicable to actors in policy and planning practice. In this chapter, we give a short overview of how the topic has developed; present core concepts for urban-rural interrelations; and discuss their applicability and potential improvements by integrating other concepts and connecting governance debates. In the process, we develop new ideas for the analysis and governance of regional functional interrelations in a bid to improve sustainable land management.

The food self-sufficiency assessment of Bristol and Vienna was developed by applying the Metropolitan Foodshed and Self-sufficiency scenario (MFSS) model [1] in the proposed respective foodsheds. In the case of Vienna 25 surrounding districts (i.e. Niederösterreich region) were selected, whereas for Bristol 5 districts surrounding the city were included. The model takes the consumption patterns as well as the available area for agriculture in the proposed foodsheds as the main inputs. Intermediate calculations are developed using data on population and yields. The outputs after applying the MFSS model are: (1) the area demand (i.e. surface needed to meet the population´s dietary requirements) in terms of surface and radius, and (2) the potential food self-sufficiency, at district level and for the whole foodshed area. The outputs are shown for 12 scenarios resulting after combining four variables: (1) production system (conventional vs organic), (2) dietary shifts (domestic vs current diet), (3) reducing food losses and waste, and (4) population growth 2015–2050. The analytical outputs from the MFSS model are converted in spatial data after applying GIS software. Whereas some of the supporting information on the inputs are shown spatially, the spatial outputs are shown in the co-submitted publication [2], as well as a summary of the datasets shown here. These data can be used to develop food policies in both city-regions as well as to test whether a specific policy is feasible. The data might be especially useful for policymakers and governance actors (e.g. food policy councils) when developing or assessing the food policies for both cities. The data can be used also by policymakers in other cities developing foodshed assessments. Furthermore, other stakeholders (e.g. education, NGOs) might use the data to increase the awareness of the impact of dietary patterns on the food land footprint.