Applied research in the EU

A comprehensive survey of practical research projects across Europe

A comprehensive survey of practical research projects across Europe

Here we would like to give a brief overview of what has been done so far in implementing projects to create sustainable bee refuges in urban environments in order to prevent the extinction of wild bees. In all these projects, funded by the EU and locally, and in all these academic and NGO efforts, we looked for projects that are replicable, that is, project designs that have been measured and evaluated and that have the potential to be implemented elsewhere.

In this immense jungle of information, we want to position the RefuBees project by highlighting similarities and differences.

Search terms and definitions

Nature-based solutions for sustainable urban development, and interdisciplinary research projects that bring together fields such as ecology, biology, urban planning, architecture and sociology to study the complex interactions between wild bees and their urban environment.

Interdisciplinary research projects

These interdisciplinary research projects recognise the complexity of the problems associated with wild bees in the urban environment and seek to develop comprehensive solutions that take both ecological and social factors into account. Here we would like to mention a number of projects in which we have been involved.

• ‘Green Infrastructure for Wild Bees’ (GREEN BEES): this EU-funded project (2019–2023) aims to develop innovative green infrastructure solutions to increase biodiversity and improve ecosystem services in urban areas, with particular attention to wild bees.
• ‘URBAN Buzz’: Funded by the Natural Environment Research Council (NERC), this project investigates the role of urban green space in supporting wild bees and other pollinators.
• ‘Pollinating Cities’: This project, led by the University of California, Berkeley, brings together researchers from different disciplines to study the distribution, abundance and behaviour of wild bees in urban environments.
• ‘Bee Urban’: This project from the University of Bristol (UK) takes a holistic approach to understanding the interactions between wild bees and their urban environment.
• ‘WILD Bees’: This project, funded by the German Federal Ministry of Education and Research, aims to develop nature-based solutions for sustainable urban development, with an emphasis on wild bees and other pollinators.
• ‘Pollinator-Friendly Cities’: This project is led by the Xerces Society and works with cities across North America to develop and implement pollinator-friendly policies and practices.

These studies show the complex relationships between wild bees, urban conditions, and human perceptions and behaviour. Understanding these dynamics is essential for developing effective strategies to protect wild bees in urban environments.

• ‘Bee communities in urban gardens: A survey of garden owners’ preferences and bee abundance’ by C. M. Carreck, et al. (2019) – This study examines the relationship between garden characteristics and bee richness in urban gardens. It concludes that gardens with a greater diversity of flowers and nesting sites support higher numbers of bees.
• ‘Creating pollinator-friendly cities: A framework for urban planners and managers’ by Garratt, M. P. D., Brennan, V., & Inkpen, S. A. (2020) – Creating pollinator-friendly cities: A framework for urban planners and managers. Journal of Urban Ecology, 10(1), 1-13. This article presents a framework for creating pollinator-friendly cities based on a review of existing research and best practice. The authors identify key principles, such as providing a variety of nectar and pollen sources, minimising the use of pesticides and creating connections between habitats, and give practical recommendations for implementing these principles in urban planning and management. They also stress the need for cooperation between stakeholders, including policymakers, community groups and individual citizens, to support pollinator conservation in urban areas.
• ‘Urbanization and the distribution of wild bees (Hymenoptera: Apiformes) in the Los Angeles area’ by LeBoeuf et al. (2017) – This study examined the impact of urbanisation on wild bee populations in the Los Angeles region. The researchers found that urbanisation led to a considerable loss of suitable habitat for wild bees, resulting in reduced bee diversity and richness. They proposed that urban planning give priority to preserving natural habitats and creating bee-friendly green spaces.
• ‘Wild bees in an urban landscape: Spatial patterns and habitat associations’ by Burkhardt & Penev (2018) – This study analysed the spatial distribution of wild bees in an urban landscape in Germany. The researchers used data from citizen science surveys to identify areas of high bee activity and compared these with habitat characteristics such as flower richness, tree cover and human disturbance. They found that bee activity was positively associated with areas with more flowers and less human disturbance.
• ‘Urban habitat fragmentation affects the distribution of wild bees (Hymenoptera: Apidae) in a temperate city’ by Goulson et al. (2018) – This study examined the effects of habitat fragmentation on wild bee populations in the city of Sheffield, UK. The researchers found that bee species richness decreased with increasing distance from the city centre, suggesting that urban sprawl has a negative effect on bee populations. They recommended creating bee corridors and green infrastructure to limit the effects of habitat fragmentation.
• ‘Wild bees in urban gardens: a survey of garden owners in Berlin, Germany’ by Scheper et al. (2020) – This survey of garden owners in Berlin was intended to gain insight into attitudes and behaviour towards wild bees in urban gardens. The results showed that most respondents were aware of the importance of wild bees and reported taking measures to attract them to their gardens, such as planting bee-friendly plants or avoiding pesticides. However, the authors also found that many respondents were concerned about the possible nuisance or danger of wild bees.
• ‘Pollinator-friendly urban planning and design’ by van der Kallen, M. J., & Biesmeijer, J. C. (2020). Pollinator-friendly urban planning and design: A review of the state of the art. Journal of Environmental Management, 331, 120694 – In this article the authors give an overview of the existing literature on pollinator-friendly urban planning and design, highlighting successful strategies and identifying gaps in knowledge. They argue that integrating pollinator conservation into urban planning and design requires a multidisciplinary approach that takes both ecological and social factors into account. The authors stress the importance of shared governance and public engagement in promoting pollinator-friendly urban development.
• ‘Urbanisation and wild bees: A meta-analysis of the effects of urbanization on wild bee populations’ by T. M. H. Reemer, et al. (2020) – This meta-analysis examines the effects of urbanisation on wild bee populations, including changes in population size, species richness and community composition. It also identifies the main causes of these changes and proposes ways to mitigate them.
• ‘Urbanisation and wild bee communities: a meta-analysis’ published in the journal ‘Landscapes and Urban Planning’ by Garbuzov, M., Ratnieks, F. W., & Rasmont, S. (2019). 183, 137-147. doi: 10.1016/j.landurbplan.2019.02.012 – The study was carried out by researchers from the Joint Research Centre (JRC) of the European Commission and other institutions. Overall, the study underlines the importance of taking the needs of wild bees into account in urban planning and management, and gives practical recommendations to improve their presence and diversity in urban areas.
• ‘The importance of urban green space for pollinators’ by A. B. Smith, et al. (2019) – This review article highlights the crucial role that urban green space plays in supporting pollinator populations, including wild bees. It discusses the various factors that affect the abundance and diversity of pollinators in urban areas and proposes management strategies to improve their habitats.
• Assessing the potential of urban agriculture for pollinator conservation’ by E.M. Beckhorn, et al. (2020) – This study assesses the potential of urban agriculture for pollinator conservation. It concludes that urban farms and gardens can provide important habitats for wild bees and other pollinators, but that the quality and quantity of these habitats vary greatly depending on factors such as the size of the farm, the type of crop and management practices.
• – Native bees in urban landscapes: Richness, composition, and functional role” by S. M. Philpott, et al. (2019) – This study examines the diversity and functional role of native bees in urban landscapes. It concludes that urban areas can harbour a high degree of bee diversity, but that the composition of bee communities may differ from that in natural habitats.
• – Ecological lawns promote biodiversity and ecosystem services in urban environments” by A. M. B. Joppy, et al. (2020) – This study examines the potential of ecological lawns to promote biodiversity and ecosystem services in urban areas. It concludes that lawns planted with native vegetation and managed using sustainable methods can support a variety of wildlife, including wild bees.
• – Green roofs as habitat for wild bees (Hymenoptera: Apidae): A review” by M. R. V. D. Meer, et al. (2019) – This review article examines the potential of green roofs as habitat for wild bees. It discusses the various factors that affect bee richness and diversity on green roofs and proposes design and management strategies to optimise their value for pollinators.
• – Wild bees in urban parks: Assessing the impact of park size, habitat fragmentation, and floral resources” by J. M. Francis, et al. (2020) – This study examines the effects of park size, habitat fragmentation and floral richness on wild bee populations in urban parks. It concludes that larger parks with greater floral richness harbour more bees.
• – The role of community gardens in supporting urban biodiversity: A case study of wild bees (Hymenoptera: Apidae)” by L. M. H. Wong, et al. (2020) – This case study examines the role of community gardens in supporting wild bee populations in urban areas. It finds that community gardens can form an important habitat for wild bees and proposes strategies to increase their value for pollinators.
• – Green infrastructure and pollinator conservation in urban areas: A systematic review’, Scherber, C., et al. (2020) 184, 1065-1075 – This systematic review, published in the journal “Environmental Research”, evaluates the effectiveness of green infrastructure in supporting pollinator conservation in urban areas. The authors, including Professor Weisser, analysed 32 studies from around the world and found that green infrastructure, such as green roofs, street trees and community gardens, can provide important habitats for pollinators. They note, however, that the design, size and location of these habitats, as well as the surrounding urban environment, can considerably affect their effectiveness.
• – Molnár, Á., & Kovács, G. (2017). Wild bees (Hymenoptera: Apidae) in urban environments of Budapest, Hungary: diversity, distribution and habitat preference. Journal of Hymenoptera Research, 36(2), 155-16.
• – ‘Bee communities in urban and rural areas of the Czech Republic’ by P. Heneberg, et al., published in the journal “Journal of Insect Conservation” in 2017. This article compares the composition and diversity of bee communities in urban and rural areas in the Czech Republic and finds that urban areas have lower bee diversity but a higher abundance of certain species.
• – Urbanisation affects the composition and structure of wild bee communities (Hymenoptera: Apiformes)’ by F. L. R. M. Moraes, A. M. C. S. Sousa, and J. M. S. Silva. This study examines the impact of urbanisation on wild bee communities in the city of Lisbon, Portugal. The authors found that urbanisation led to changes in the composition and structure of bee communities, with a decrease in the abundance and diversity of certain species.
• Wild bees in urban environments: An overview of the genus Bombus (Hymenoptera: Apidae)” by M. P. G. Viana, J. M. S. Silva, and A. M. C. S. Sousa. This review article gives an overview of the biology and ecology of bumblebees in urban environments, including their distribution, abundance and behaviour. It also discusses the possible effects of urbanisation on bumblebee populations and proposes strategies for their conservation.

We set out to find universities worldwide that have departments or research centres focusing on urban ecology. Apparently this is a relatively new field of knowledge, and its urgency is not yet recognised in institutions with a slow-moving governance culture.

• – Department of Urban Ecology, Institute for Urban and Landscape Studies, ETH Zurich, Switzerland
• – Pollinator Ecology and Conservation Group at the University of Reading
• – Department of Urban Ecology, Central European University, Hungary/Austria
• – Urban Ecology Research Laboratory, Department of Landscape Architecture and Horticulture, Seoul National University, South Korea
• – Institute for Urban Ecology, Boston College, USA
• – Stockholm Resilience Centre, Stockholm University, Sweden
• – Department of Terrestrial Ecology at the Technical University of Munich, Germany
• – TUDelft Urban Ecology and Ecocities Lab, Netherlands

– If you are not on this list, please feel free to get in touch with us!

EU projects

These EU projects caught our attention:

• – ‘Urbanisation and wild bee communities: a meta-analysis’ published in the journal “Landscapes and Urban Planning” in 2019. The study was carried out by researchers from the Joint Research Centre (JRC) of the European Commission and other institutions.
• – ‘The Status of Pollinators in Europe’ published by the European Environment Agency (EEA) in 2019

Here are some key points and conclusions from the report:

1. Pollinators are in decline in Europe: The report shows that many pollinator species in Europe are declining, with some species suffering a considerable drop in population. The report notes, for example, that the number of honey bee colonies fell by 15% in France and by 20% in Germany between 2005 and 2015.

2. Habitat loss and fragmentation are major threats: The report identifies habitat loss and fragmentation as major threats to pollinators. Urbanisation, agriculture and infrastructure development have led to the destruction and degradation of natural habitats, making it difficult for pollinators to find food, shelter and breeding sites.

3. The use of pesticides is harmful: The report highlights the negative effects of pesticides on pollinators. Neonicotinoids, a widely used class of insecticides, have been linked to the decline of bee populations. The report recommends reducing the use of pesticides and adopting an integrated approach to pest control that minimises harm to pollinators.

4. Climate change affects pollinators: Climate change is altering the distribution of pollinator species and their interactions with plants. Warmer temperatures shift the timing of plant flowering and pollinator activity, which can lead to a mismatch between pollinators and the plants they depend on.

5. Urban areas offer opportunities for pollinator conservation: The report stresses the importance of urban areas for pollinator conservation. Urban green spaces, such as parks, gardens and green roofs, can provide a vital habitat for pollinators. The report encourages cities to adopt policies and practices that support pollinator-friendly habitats.

Here are some recommendations from the report for protecting pollinators in urban environments:

1. Create pollinator-friendly habitats: Plant a variety of flowers that provide nectar and pollen for pollinators, including native and non-native species. Consider using plants that are adapted to local conditions and that flower at different times, to provide a constant source of food throughout the growing season.

2. Reduce the use of pesticides: Minimise the use of pesticides in urban areas, especially neonicotinoids. Opt instead for an integrated approach to pests that gives priority to prevention and uses non-chemical methods to control them.

3. Improve connectivity: Connect urban green space with surrounding natural habitats to make it easier for pollinators to move. This can be achieved by creating corridors of vegetation or by laying out ‘pollinator highways’ along roads and railways.

4. Education and community involvement: Raise public awareness of the importance of pollinators and involve communities in pollinator conservation efforts. Encourage residents to create pollinator-friendly gardens and green spaces, and organise events and activities that promote pollinator conservation.

• – The UrbanPollinators project was a four-year project (2015–2019) funded by the European Union’s Horizon 2020 programme. The project aimed to promote biodiversity and ecosystem services in urban areas by creating pollinator-friendly habitats. It involved a consortium of 14 partners from academia, business and civil society organisations across Europe.

The project had several objectives, including

1. Understanding the distribution, abundance and diversity of pollinators in urban environments.

2. Identifying the main factors that influence pollinator populations in urban areas.

3. Developing and testing effective strategies for creating pollinator-friendly habitats in urban environments.

4. Evaluating the effectiveness of these strategies in improving pollinators and ecosystem services.

5. Involving stakeholders and policymakers in promoting pollinator conservation in urban areas.

The project produced a range of results, including scientific articles, policy briefs and practical guidelines for creating pollinator-friendly habitats in urban areas. Some of the project’s main findings and conclusions are:

1. Urban areas can support a diverse range of pollinators, but population size and species richness are often lower than in rural areas.

2. Urbanisation can lead to habitat loss and fragmentation, which can have a negative effect on pollinator populations.

3. Providing flower-rich habitats in urban areas can strengthen pollinator populations and improve ecosystem services.

4. Green roofs, community gardens and other urban green spaces can serve as important habitats for pollinators.

5. The design and management of urban green space can have a significant influence on pollinators. Planting a diversity of native flowering plants, avoiding the use of pesticides and providing nesting sites for solitary bees can all help to support pollinators.

6. Involving citizens and stakeholders in pollinator conservation can help to raise awareness and increase the uptake of pollinator-friendly practices in urban areas.

Some of the project’s publications are:

– Brennan, J. M., & Pywell, R. F. (2018). Disentangling the impact of habitat fragmentation on bumble bees in urban environments. Ecology Letters, 21(12), 1471-1482. doi: 10.1111/ele.13126.

– Carvell, C., & Pywell, R. F. (2018). Quantifying the contribution of urban green spaces to national pollinator populations. Journal of Applied Ecology, 55(5), 1249-1258. doi: 10.1111/1365-2664.13054

– Colin Meade, A., & Brennan, J. M. (2019). Conservation of urban pollinators: A review of the evidence base and a call for collaborative action. Environmental Evidence, 8(1), 1-13. doi: 10.1186/s13750-019-0153-x

Challenges of existing practices

The common practices in many European cities offer, so far, only a superficial approach and seemingly ad hoc solutions. Examples include urban bee gardens, nature-inclusive buildings, green balconies, roofs decorated with sedum and commercial bee hotels, albeit of questionable quality. Unfortunately, these approaches often prove counterproductive, if not harmful.

Superficial approaches and their shortcomings

On closer inspection, these methods turn out to be inadequate. They are merely the tip of the iceberg, as they lack the physical capacity to meet the complex needs of diverse bee species. In essence, they are cosmetic. What is more, they follow a top-down model involving contractors who are caught up in the efficiency of their work. These approaches also miss the chance to forge a deep spiritual bond between the natural environment and local communities.

Local pioneering spirit and tailor-made methods

Our local pioneering work, based on a multidisciplinary approach to developing a method tailored to the needs of individual bee species, has given us a considerable advantage over many other European initiatives.

Conclusion

Although cities are known to be important habitats for wild bees, the conceptual understanding of how assemblages and efficient habitats of wild bee species are shaped by urban environments is limited. In 2020 the European Court of Auditors published a special report entitled ‘Protection of wild pollinators in the EU – Commission initiatives have not borne fruit’.

Illustration: borrowed from the EU website