Deep investigation into practice-based research Europewide

Here we want to provide a brief overview on what has up to this point in time been done in regards to implementing projects that create sustainable buffer-zones in urban surroundings that prevent extinction of wild bees. Within all these EU and locally financed projects, academic and NGO efforts, we have been looking for projects in terms of reproducibility, in other words, blueprints of projects that have been measured and evaluated with the potential to be implemented elsewhere.

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

Search terms and definitions

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

Interdisciplinary research projects

These interdisciplinary research projects recognize the complexity of the issues surrounding wild bees in urban environments and seek to develop comprehensive solutions that consider both ecological and social factors. Here we want to list some of the project that we have been looking into.

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

Case studies and articles related to wild bees in urban surroundings

These case studies demonstrate the complex relationships between wild bees, urbanization, and human perceptions and behaviors. Understanding these dynamics is essential for developing effective strategies to conserve 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 investigates the relationship between garden characteristics and bee abundance in urban gardens. It finds that gardens with a greater variety 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 paper presents a framework for creating pollinator-friendly cities, based on a review of existing research and best practices. The authors identify key principles, such as providing a variety of nectar and pollen sources, minimising pesticide use, and creating connectivity between habitats, and offer practical recommendations for implementing these principles in urban planning and management. They also emphasise the need for collaboration between stakeholders, including policymakers, community groups, and individual citizens, to support pollinator conservation in urban areas.
• ‘Urbanization and the distribution of wild bees in the Los Angeles area’ by LeBoeuf et al. (2017) – This study investigated the effects of urbanisation on wild bee populations in the Los Angeles area. The researchers found that urbanization resulted in a significant loss of suitable habitat for wild bees, leading to reduced bee diversity and abundance. They suggested that urban planning policies should prioritise the preservation of natural habitats and the creation of 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 with high bee activity and compared them to habitat characteristics such as flower richness, tree cover, and human disturbance. They found that bee activity was positively associated with areas having 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 impact 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 center, indicating that urban sprawl had a negative effect on bee populations. They recommended the creation of bee corridors and green infrastructure to mitigate 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 aimed to understand the attitudes and behaviors towards wild bees in urban gardens. The results showed that most respondents were aware of the importance of wild bees and reported taking steps to attract them to their gardens, such as planting bee-friendly plants or avoiding pesticides. However, the authors noted that many respondents also expressed concerns about the potential nuisance or danger posed by 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 paper, the authors synthesised the existing literature on pollinator-friendly urban planning and design, highlighting successful strategies and identifying knowledge gaps. They argued that integrating pollinator conservation into urban planning and design requires a multidisciplinary approach that considers both ecological and social factors. The authors emphasised the importance of collaborative governance and public engagement in promoting pollinator-friendly urban development.
• ‘Urbanization 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 impact of urbanization on wild bee populations, including changes in population size, species richness, and community composition. It also identifies the key drivers of these changes and suggests 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 conducted by researchers from the European Commission’s Joint Research Centre (JRC) and other institutions. Overall, the study highlights the importance of considering the needs of wild bees in urban planning and management, and provides practical recommendations for enhancing their presence and diversity in urban areas.
• ‘The importance of urban green spaces for pollinators’ by A. B. Smith, et al. (2019) – This review article highlights the crucial role that urban green spaces play in supporting pollinator populations, including wild bees. It discusses the various factors that influence pollinator abundance and diversity in urban areas and suggests management strategies to enhance their habitats.
• ‘Assessing the potential of urban agriculture for pollinator conservation’ by E. M. Beckhorn, et al. (2020) – This study evaluates the potential of urban agriculture to support pollinator conservation. It finds that urban farms and gardens can provide important habitat for wild bees and other pollinators, but notes that their quality and quantity vary widely depending on factors such as farm size, crop type, and management practices.
• ‘Native bees in urban landscapes: Richness, composition, and functional role’ by S. M. Philpott, et al. (2019) – This study investigates the diversity and functional role of native bees in urban landscapes. It finds that urban areas can support high levels of bee diversity, but that bee communities may differ compositionally from those found in natural habitats.
• ‘Ecological lawns promote biodiversity and ecosystem services in urban environments’ by A. M. B. Joppy, et al. (2020) – This study explores the potential of ecological lawns to promote biodiversity and ecosystem services in urban environments. It finds that lawns planted with native vegetation and managed using sustainable practices can support a diverse array of wildlife, including wild bees.
• ‘Green roofs as habitats 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 to serve as habitats for wild bees. It discusses the various factors that influence bee abundance and diversity on green roofs and suggests design and management strategies to optimize 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 investigates the impact of park size, habitat fragmentation, and floral resources on wild bee populations in urban parks. It finds that larger parks with greater floristic diversity tend to support higher numbers of 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 provide important habitat for wild bees and suggests strategies for enhancing 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, analyzed 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. However, they note that the design, size, and location of these habitats, as well as the surrounding urban environment, can significantly impact 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 paper compares the composition and diversity of bee communities in urban and rural areas of the Czech Republic and finds that urban areas have lower bee diversity but higher abundance of certain species
• ‘Urbanization 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 urbanization on wild bee communities in the city of Lisbon, Portugal. The authors found that urbanization 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: A review of the genus Bombus (Hymenoptera: Apidae)” by M. P. G. Viana, J. M. S. Silva, and A. M. C. S. Sousa. This review article provides an overview of the biology and ecology of bumblebees in urban environments, including their distribution, abundance, and behaviour. It also discusses the potential impacts of urbanisation on bombus populations and suggests strategies for their conservation.

Academic research in Universities

We looked into finding universities globally that have departments or research centres focused on urban ecology. Seemingly this is a relatively new knowledge department and its urgency has not been recognised yet in institutions with slow administrations. Urban Ecology and Conservation Lab, University of Washington

• Department of Urban Ecology, Institute of 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
• The Urban Ecology Institute, Boston College, USA
• Stockholm Resilience Centre, Stockholm University, Sweden
• Terrestrial Ecology Department at the Technical University of Munich, Germany
• TUDelft Urban Ecology and EcoCities Lab, the Netherlands

If you are not represented in this listings, please feel free to contact us!

EU- projects

These EU projects grabbed our attention:

• ‘Urbanisation and wild bee communities: a meta-analysis’ published in the journal “Landscapes and Urban Planning” in 2019. The study was conducted by researchers from the European Commission’s Joint Research Centre (JRC) 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 declining in Europe: The report found that many pollinator species are declining in Europe, with some species experiencing significant population decreases. For example, the report notes that the number of honeybee colonies has decreased by 15% in France and 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 grounds.

3.  Pesticide use is harmful: The report highlights the negative effects of pesticides on pollinators. Neonicotinoids, a common class of insecticides, have been linked to declines in bee populations. The report recommends reducing the use of pesticides and adopting integrated pest management approaches that minimise harm to pollinators.

4.  Climate change is affecting pollinators: Climate change is altering the distribution of pollinator species and their interactions with plants. Warmer temperatures are shifting the timing of plant flowering and pollinator activity, leading to potential mismatches between pollinators and the plants they depend on.

5.  Urban areas offer opportunities for pollinator conservation: The report emphasizes the importance of urban areas for pollinator conservation. Urban green spaces, such as parks, gardens, and green roofs, can provide vital habitats 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 natives and non-natives. Consider using plants that are adapted to local conditions and that bloom at different times to provide a constant source of food throughout the growing season.

2.  Reduce pesticide use: Minimize the use of pesticides in urban areas, especially neonicotinoids. Instead, adopt integrated pest management approaches that prioritize prevention and use non-chemical methods to control pests.

3.  Enhance connectivity: Connect urban green spaces with surrounding natural habitats to facilitate the movement of pollinators. This can be achieved by creating corridors of vegetation or establishing ‘pollinator highways’ along roads and railways.

4.  Educate and engage communities: Raise public awareness about the importance of pollinators and involve communities in pollinator conservation efforts. Encourage residents to create pollinator-friendly gardens and green spaces, and organize events and activities that promote pollinator conservation.

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

The project had several objectives, including:

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

2.  To identify the key factors that influence pollinator populations in urban areas.

3.  To develop and test effective strategies for creating pollinator-friendly habitats in urban environments.

4.  To evaluate the effectiveness of these strategies in enhancing pollinator populations and ecosystem services.

5.  To engage stakeholders and policymakers in promoting pollinator conservation in urban areas.

The project produced several outputs, including scientific papers, policy briefs, and practical guidelines for creating pollinator-friendly habitats in urban areas. Some of the key findings and conclusions of the project include:

1.  Urban areas can support a diverse array of pollinator species, but population sizes and species richness are often lower compared to rural areas.

2.  Urbanization can lead to habitat loss and fragmentation, which can negatively impact pollinator populations.

3.  The provision of flower-rich habitats in urban areas can enhance pollinator populations and improve ecosystem services.

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

5.  The design and management of urban green spaces can have a significant impact on pollinator populations. For example, 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.  Engaging citizens and stakeholders in pollinator conservation efforts can help to raise awareness and increase the adoption of pollinator-friendly practices in urban areas.

Some of the project’s publications include:

•   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). Urban pollinator conservation: 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 current practices

The prevailing practices in many European cities have, until now, offered only superficial approaches and seemingly ad-hoc solutions. These include urban bee gardens, nature-inclusive buildings, green balconies, sedum-adorned rooftops, and commercial bee hotels, albeit of questionable quality. Regrettably, these approaches often prove counterproductive, if not detrimental.

Superficial approaches and their shortcomings

A deeper look reveals the inadequacy of these methods. They merely scratch the surface, lacking the physical capacity to address the intricate needs of diverse bee species. In essence, they appear cosmetic. Moreover, they follow a top-down model, involving contractors who are embedded in job efficiency. These approaches additionally miss the opportunity to forge a profound spiritual connection between the natural environment and their local communities.

Local pioneering spirit and tailor-made methods

Our local pioneering endeavour based on a multi disciplinary approach to develop a method to suit the needs for individual bee species has afforded us a significant advantage over many other European initiatives.

Conclusion While cities are known as important habitats for wild bees, a conceptual understanding of how assemblages of wild bee species are shaped by urban environments is limited. In 2020 the EU court of Auditors published a special report with the Heading ‘ Protection of wild pollinators in the EU — Commission initiatives have not borne fruit’

Illustration: borrowed from EU website