Research & reports

· BMC Ecology and Evolution · Germany (Berlin, Munich)

In collaboration with 73 gardeners across 22 gardens in Berlin and Munich, measured fruit set of 150 crops to examine how bee diversity and urbanization affect pollination services, using a citizen science approach.

Della Rocca Francesca, Musiani Marco, Taioli Domitilla, Nardelli Edoardo, Milanesi Pietro · Biodiversity and Conservation · Italy (Bologna)

In Bologna, Italy, data on bird and butterfly communities were analyzed across an anthropogenic disturbance gradient encompassing urban, agricultural, and semi-natural contexts. The study found the highest species richness and diversity in peri-urban areas with natural and semi-natural habitats, while dense built-up areas supported fewer, mostly generalist species. Agricultural areas favored birds but not butterflies, and continuous urban cover, discontinuous high-density urban areas, distance to streets, and wood coverage were identified as main drivers of diversity.

Marcia Eugenio-Gozalbo, Inés Ortega-Cubero, Rafael Suárez-López · International explorations in outdoor and environmental education · Spain (Soria)

This chapter describes an educational project conducted with 8-year-old children in the Organic Learning Garden of the Faculty of Education of Soria, University of Valladolid, Spain. The project aimed to promote detailed observation and learning about insect morphology and diversity through scientific drawing. The use of school gardens is proposed to foster children's knowledge and appreciation of insect biodiversity.

Dagmar Haase, Dara V. Gaeva · Plant-Environment Interactions · Germany (Berlin)

An exploratory study conducted in allotment gardens in Berlin, Germany, from May to July 2019, investigated plant species richness and ecosystem services, particularly pollinator habitats and local food provision. Comparing 10 plots with varying management intensities, 376 plant species were identified. The study found that native species richness, weedy plant species richness, and the richness of species contributing to regulation and maintenance ecosystem services were significantly negatively correlated with garden management intensity. Urban allotments support pollinator populations due to a wide variety of nectar-producing plants, but this capacity is greatly affected by local gardener management.

Nicholas Balfour, Johnstone Caitlyn, Emma Bush · Zenodo (CERN European Organization for Nuclear Research) · United Kingdom

A 2025 survey of 31 green spaces in central Edinburgh, UK, including allotments, public gardens, cemeteries and roof gardens, assessed pollinator diversity and resource availability. The pollinator community was a generalist assemblage dominated by bumble bees (45%) and honey bees (26%), while butterflies, moths and beetles were notably scarce. Semi-natural areas, allotments and cemeteries sustained the highest pollinator diversity, linked to native vegetation and rich floral resources. Two-thirds of the plant species recorded were non-native horticultural varieties, yet 87% of recorded plants were visited by pollinators, and the three plant species attracting the widest range of pollinator taxa were all indigenous.

Stichting DakAkker · Stichting DakAkker (official) · Netherlands

The official site of DakAkker, a rooftop farm on top of the Schieblock building in Rotterdam. It describes itself as a 1,000-square-meter rooftop farm growing vegetables, edible flowers, and fruit and keeping bees, calling itself the largest open-air rooftop farm in the Netherlands and one of the largest in Europe. It is presented as an initiative of ZUS (Zones Urbaines Sensibles) and the Rotterdam Environmental Centre together with Optigrün Benelux and binder daktuinen, framed as part of Rotterdam's first city initiative 'de Luchtsingel.' The roof also hosts 'Slimdak,' a test site for smart rainwater management. 'Dakennie,' its environmental education program for Rotterdam primary schools, is financially supported by Watersensitive Rotterdam, the City of Rotterdam's nature and environmental education division, and the Hoogheemraadschap Schieland en de Krimpenerwaard water authority. The page itself does not state an opening year, which could not be confirmed here.

Plantlife · Plantlife · United Kingdom

An overview of Plantlife's 'No Mow May' campaign, urging people in the UK to stop mowing their lawns during May to let wildflowers grow and support bees and butterflies. The page states that approximately 97% of the UK's flower-rich meadows have been lost since the 1930s, and notes there are around 23 million gardens in the UK, meaning even small patches can add up. It encourages extending the practice beyond May into a year-round 'No Mow Movement' of managing lawns with mixed grass lengths for nature.

Buglife · Buglife · United Kingdom

An introduction to Buglife's 'B-Lines' initiative, which states that over 97% of the UK's flower-rich grasslands (an area the size of Wales) have been lost since the 1930s, and describes a nationwide network of flower-rich habitat 'stepping stones' linking existing wildlife areas across the countryside and towns. B-Lines have been mapped across England, Wales, Northern Ireland and Scotland, with a target to create and restore at least 150,000 hectares of flower-rich habitat across the UK.

· Landscape Ecology · Germany (Berlin, Munich)

Recorded pollinators and garden features across 33 community gardens in Berlin and Munich over two summers, finding local-scale garden features—rather than landscape context—predominantly structured urban pollinator communities.

Silvia Barbero, Federica Larcher · · Italy (Turin)

This chapter explores the role of the Turin Living Lab in testing nature-based solutions (NBS) in the Mirafiori Sud district of Italy. Local schools play a significant role in testing these solutions. Seven NBS types have been implemented, including new soil, urban horticulture, aquaponics, green roofs and walls, and green corridors.

Hugo Rochard, Céline Clauzel, Nathalie Blanc · Urban Ecosystems · France (Paris)

The impact of civic-led hedgerow planting on landscape connectivity was assessed in the southern Paris periurban context. A graph modeling methodology was applied to 94 hedgerow sites, revealing that these sites strengthen landscape connectivity. This quantitative assessment was coupled with qualitative data collected from local civic leaders regarding their perception of social-ecological functions associated with hedgerow planting.

Johanna Bock, Márcio Zamboni Neske, Martin Krauß, Andrea Dombrowski, Jörg Oehlmann · Environmental Sciences Europe · Europe

Focusing on small water bodies in private urban gardens, this study examined whether chemical pollution limits insect diversity, given that gardens make up a significant share of urban green area and can serve as important habitats and stepping stones for insects, while pesticides, fertilizers and chemical run-off from building materials can strongly affect habitat quality and insect biodiversity. Garden pond toxicity was assessed using in vitro and in vivo methods and chemical screening. Of 17 ponds examined, only one water sample and one sediment sample were found non-toxic in a bioluminescence assay with Aliivibrio fischeri. Enhanced dioxin-like activity was measured in seven water and ten sediment samples using a reporter gene assay with Saccharomyces cerevisiae, and most water extracts showed mutagenic potential in the Ames fluctuation assay (Salmonella typhimurium strains YG1041 and YG1042), while most sediment extracts were not mutagenic. Increased larval mortality of Chironomus riparius occurred in five water-sediment systems built from pond samples, correlating positively with in vitro water toxicity and with concentrations of benzothiazole derivatives measured by LC-HRMS, likely originating from EPDM rubber pond liners. Substance composition differed significantly between house and allotment gardens, with higher concentrations measured in allotment ponds. The study concludes that chemical pollution in private urban gardens may have been underestimated to date, and that pond toxicity can severely affect insect populations, warranting further study.

Diego López-Collar, Pietro Agostini, Francisco J Cabrero-Sañudo · DIGITAL.CSIC (Spanish National Research Council (CSIC)) · Europe

This study reports the first records of two non-native ant species, Monomorium carbonarium (1858) and Cardiocondyla mauritanica (1890), within the urban area of Madrid, Spain, along with updated occurrence records for the Argentine ant (Linepithema humile). These detections are mostly associated with irrigated green spaces—public parks, private gardens, urban orchards, and landscaped medians—and confirm that Mo. carbonarium and C. mauritanica are established in the city, extending their known Iberian distributions beyond coastal areas into the interior, while new Li. humile records point to its persistent, patchy distribution across Madrid.

European Commission · European Commission, Directorate-General for Environment · Europe

The European Commission's official page on the EU Pollinators Initiative (adopted 2018, revised 2023). It reports that 1 in 3 European bee, butterfly and hoverfly species is in decline and 1 in 10 bee and butterfly species is threatened with extinction, while around 4 out of 5 crop and wild flowering plant species depend on animal pollination. Under Article 10 of the Nature Restoration Regulation (in force since 19 August 2024), Member States face a legally binding target to reverse pollinator decline by 2030. A delegated regulation establishing the EU Pollinator Monitoring Scheme (EU-PoMS) was adopted on 19 September 2025, to be implemented by Member States by 16 December 2026 at the latest.

Monika Egerer, Susan Karlebowski, David Schoo, Ulrike Sturm · Urban forestry & urban greening · Germany

This communication article presents a transdisciplinary research concept focused on developing, implementing, and testing biodiversity conservation interventions in urban community gardens in Berlin and Munich, Germany. The research aims to promote insect diversity with gardeners and neighborhood residents, engaging civil society and city actors to support biodiversity-based urban greening. It outlines participatory methods and experiences in translating research into practice, highlighting the role of city residents in implementing biodiversity interventions.

Astrid E. Neumann, Felix Conitz, Susan Karlebowski, Ulrike Sturm, Julia M. Schmack, Monika Egerer · Basic and Applied Ecology · Germany (Munich)

This study recorded garden features and pollinators in 33 urban community gardens in Munich and Berlin, Germany, over two summer seasons to understand their impact on pollinator abundance. Findings showed that in more urbanized gardens, flower richness and bare substrate were less prevalent. Flower richness positively correlated with overall pollinator abundance, richness, and diversity, while landscape imperviousness negatively correlated with hoverfly and beetle abundances.

Julia M. Schmack, Monika Egerer, Susan Karlebowski, Astrid E. Neumann, Ulrike Sturm · Journal of Insect Conservation · Germany

A survey was conducted in urban community gardens in Berlin and Munich, Germany, to assess perceptions of social wasps and their ecosystem functions. Gardeners rated wasps as the least beneficial insect for urban gardens among other insect taxa, and predation was perceived as a negative function in insects and spiders. Knowledge of wasp ecology was positively associated with respondents' willingness to share gardens with wasps, suggesting negative perceptions are likely driven by a lack of knowledge and negative emotions.

Szczurek A., Maciejewska M., Batog P. · Applied Sciences, 13(1):597 · Poland (Wrocław)

Develops and evaluates an automated monitoring system for urban beekeeping's educational, greening and awareness benefits. Sensors, cameras and scales were deployed on hives on the roof of a four-storey university building in Wrocław; three months of operation confirmed the system works and that rooftop placement is a viable urban apiary model.

Nicholls E., Griffiths-Lee J., Basu P., Chatterjee S., Goulson D. · Plants, People, Planet · United Kingdom

Study of crop-pollinator interactions in UK urban and peri-urban farms, quantifying ecosystem services provided by pollinators in city farming systems.

· Frontiers in Sustainable Cities · Germany (Freising)

Developed a holistic assessment of bee and flowering-plant diversity in the medium-sized city of Freising using citizen science, identifying 22 bee-diversity hotspots and evaluating planted flower patches as stepping stones for oligolectic bees.

Felderhoff J. · Ecological Applications · Germany (Berlin)

Documented 26 genera and 102 bee species across 18 Berlin community gardens, finding that higher plant species richness and greater deadwood amounts increased wild bee species number and functional diversity.

Herrmann J., Buchholz S., Theodorou P. · Scientific Reports · Germany

In German urban dry grasslands, examined effects of local habitat quality, urbanisation (impervious surfaces), and 3D connectivity on flower visitors; bee and butterfly species richness declined with increasing impervious surface.

Nguyen H., Schmack J., Egerer M. · Basic and Applied Ecology · Germany (Munich)

Conducted a pollination-exclusion experiment with two cultivated and two wild plant species across 13 Munich community gardens, finding cultivated-plant fruit and seed mass positively correlated with temperature and pollinator diversity.

Shivant Jhagroe · Urban Studies · Netherlands

A study of the Gandhi-garden, a community garden in Rotterdam, the Netherlands, that is part of the global Transition Towns movement, drawing on participatory ethnography, interviews, and online documents. Challenging the anthropocentrism common in research on urban sustainability and resilience, the paper analyses everyday acts such as weeding and permacultural planting as "more-than-human assemblage" place-making practices involving insects, plants, soil, and fences that challenge urban neoliberalism. It also examines expressions of solidarity with Palestine through olive trees and non-violence thinking, alongside tensions between humans and non-humans over dog waste and birds that take harvested produce.

Emanuela Granata, Paolo Pedrini, Luigi Marchesi, Chiara Fedrigotti, Paolo Biella, Silvia Ronchi, Mattia Brambilla · Agriculture Ecosystems & Environment · Italy

This study investigated the environmental and management factors influencing bird communities, pollinating insects, and two ecosystem services — pollination and nature-based recreation — along an urban-natural gradient dominated by agricultural areas (vineyards, apple orchards, and grasslands) in northern Italy. Flower-visiting insects were mainly affected by management and environmental-climatic variables, with flowers at field margins and within vineyard and apple-orchard inter-rows best predicting pollinator and flower-visiting-insect abundance; sward height and grassland cover promoted insect abundance, while vineyards and apple orchards had a negative effect on it. Bird communities were mainly shaped by land-use/land-cover and management variables, with landscape heterogeneity and linear elements having a major positive effect; apple orchards negatively affected the richness and abundance of most bird species, and vineyards negatively affected overall bird abundance, while hedgerows had a positive effect on richness. Nature-based recreation was greater in areas with low or intermediate vineyard or urban cover, with apple orchards and intensively managed grasslands having negative effects and waterways a positive effect. The study concludes that apple orchards and large vineyards are largely unsuitable for biodiversity and ecosystem services.