Research & reports

Roedel J., Szendrei Z. · Urban Ecosystems · North America (urban-suburban gradient)

2025 research showing that squash bees are most abundant on suburban and urban farms compared to rural farms. Demonstrates that small-scale urban farms benefit from urban environment advantages (lower pesticide use, diverse floral resources, landscape heterogeneity), enabling bee and floral community responses to urbanization.

· 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.

· Landscape Ecology · Global

Ecological study examining how local garden features structure pollinator communities in urban agriculture. Links biodiversity conservation to food production success.

Chang X., Yan X., Lv F., Zhang Y., Breeze T. D., Li X. · Insects · Hanzhong, China

Documents pollinator resources and pollination networks in Hanzhong City, China, recording 80 pollinator species and 59 pollinated crop and wild nectar plant species, and evaluates the economic value of pollination services.

Alessio Russo, Manuel Esperon-Rodriguez, Annick St-Denis, Mark G. Tjoelker · Land · Global

Compares native and non-native plants in urban green spaces. Examines impacts on pollinator diversity, ecosystem services, and climate resilience. Analyzes conservation strategies and public preferences.

Emma Plant, Ria Dunkley, Davide M. Dominoni, Dominic J. McCafferty · Urban Ecosystems · Global

Empirical analysis of factors supporting pollinators in urban gardens. Demonstrates that floral richness and abundance are critical for pollinator diversity. Garden diversity prioritized over surrounding landscape influence.

Sergio Osorio Cañadas, Ek del Val de Gortari · Dialnet (Universidad de la Rioja) · Mexico (Morelia)

This study investigated pollinators in seven urban and periurban orchards in Morelia, Mexico, during an annual agricultural cycle from October 2022 to June 2023. Monthly 5-hour censuses at each site revealed a considerable diversity of pollinators, with an average of 60 different species including bees, wasps, flies, butterflies, beetles, and hummingbirds, visiting the orchard flowers. It was also observed that each plant species attracted different pollinators.

Lokesh Ramachandran, Keerthivasan Ragupathi, Nithishkumar Govindaraju, Ajay Raja Anandhan, Dinesh Devarajan · Zenodo (CERN European Organization for Nuclear Research) · Argentina

This chapter examines agroecology as a sustainable production paradigm for the horticultural sector, facing challenges like climate change and resource depletion. It reviews the conceptual foundations of agroecology, its application to horticulture, and advances in agroecological practices. Case studies, such as peri-urban horticulture in Argentina, illustrate its promise, but note that a full transition remains incomplete.

Celeus Baral, Hem Sagar Baral, Carol Inskipp, Rajana Maharjan · Our Nature · Nepal

This 14-day study examined Lepidoptera diversity in semi-urban agricultural landscapes around Lumbini, Nepal, documenting 30 moth species from six families and 39 butterfly species from five families across various habitats. Moth populations were dominated by Erebidae, and butterfly diversity by Nymphalidae, showing resilience in disturbed habitats. Statistical analyses revealed that shrubland and agricultural habitats supported the highest species richness and evenness, while grasslands hosted fewer species.

I Rabeena, Stankevich Sergey A., A Akash, G Nandhakumar, Deborah Mercy D · Journal of Scientific Research and Reports · Global

This article explores the potential, challenges, and opportunities of urban beekeeping as a sustainable response to declining bee biodiversity. It highlights urban beekeeping's role in pollination, sustainable urban agriculture, biodiversity enhancement, and income generation for urban communities, despite challenges like climate extremes and limited floral resources. The article suggests that urban green landscapes with high floral diversity and continuous bloom periods offer substantial support for urban pollinators, and responsible urban beekeeping can foster ecological citizenship.

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.

Diana Giurea, Vasile Gherheș, Claudiu Coman · Sustainability · Global

This paper explores temporary small-scale architecture as a catalyst for community-driven development of green urban spaces, using the Greenfeel Architecture wooden pavilion as a case study. The pavilion, built with reused materials, was designed to provide shelter and facilitate social interactions while protecting existing vegetation and enhancing biodiversity. Since its completion, it has hosted various outdoor activities and educational workshops, demonstrating the potential of temporary architecture for physical and socio-cultural sustainability in urban environments.

Rolf Morgenstern, Bernd Pölling · · Global

This chapter explores the economic benefits and challenges of integrating nature-based solutions (NBS), including urban farming, into circular economy frameworks in urban environments. Using the proGIreg framework and an Economic and Labour Market Questionnaire, it reveals financial impacts of NBS implementations. Case studies from Zagreb, Turin, and Dortmund illustrate diverse economic outcomes, demonstrating both direct financial returns and broader economic value created by NBS.

Kyla D. Schulte, Caleb J. Wilson, Anna Tawril, Mary A. Jamieson · Ecosphere · United States (Michigan)

A three-year study across 10 strawberry farms along a rural-urban gradient in Michigan, USA, characterized bee abundance, diversity, and community composition. The study found that urbanization, measured as impervious surface cover, had no consistent effect on overall bee abundance and diversity. While urbanization differentially influenced specific taxa (Halictini positively in year one, Ceratinini negatively in year three), the overall impact was limited, with wild bees, especially native species, being important pollinators in urban agriculture.

Drakhshanda Saeed, Areena Sohail, Mahnoor Munir, Khush Bakht · Physical Education Health and Social Sciences · Global

This study qualitatively reviewed 15 peer-reviewed studies published from 2015 to 2025 to evaluate the potential of rooftop and vertical gardens in providing ecosystem services and promoting urban plant diversity. Rooftop gardens primarily support pollinators, stormwater retention, thermal regulation, and spontaneous colonizers, fostering horizontal habitat connectivity. Vertical gardens, despite fewer species, provide essential vertical stratification, shade micro-niches, and air filtration, enhancing multi-dimensional habitat diversity. Design and management factors were found to strongly influence ecological outcomes.

Yiran Li, Chengweiran Liu, Yiran Wang, Muhan Li, Shasha Zou, Xiaona Hu, Zhiwei Chen, Mingrui Li, Changsheng Ma, C. Jennifer, Xin Zhou, Yi Zou, Min Tang · Insect Science · China (Suzhou)

This study investigated the survival status of mason bees (Osmia excavata) across 10 urban agricultural sites in Suzhou, China, using shotgun gut metagenome sequencing. It found that ingested pollen primarily came from Brassica crops and Plantanus, indicating limited plant diversity. The gut bacterial community was stable across 8 sites but perturbed at 2, and antibiotic resistance gene profiles varied widely. Virome analysis identified honeybee pathogens and unknown bacteriophages.

Elena Petelos, Danai Antonaki, Erasmia Angelaki, Christos Lemonakis, Alexandros Garefalakis · Sustainability · Global

This study explored how private sector initiatives in tourism can contribute to public health and SDG 3 through sustainable agricultural practices. Using a mixed-methods approach combining a systematic literature review and a case study, it examined how integrated strategies like pesticide-free farming reduce environmental health risks and improve nutritional quality. Findings indicate that business-led sustainability models can support systemic change when based on clear metrics and cross-sector collaboration. However, the absence of pre-2019 baseline data and direct health outcome measurements limits causal inference.

Riegel, Cameron · Maryland Shared Open Access Repository (USMAI Consortium) · United States (Baltimore)

This study investigated the motivations driving voluntary participation in urban community pollinator garden stewardship among residents of Baltimore, Maryland, USA. Six semi-structured interviews were conducted with volunteer gardeners and analyzed using a qualitative case study approach. Analysis revealed that gardeners are primarily motivated by environmental concerns, specifically an interest in and desire to give back to birds, an interest in trees and native plants, and a desire to interact with the urban natural environment. Social factors also shaped motivations but proved less influential than environmental factors in driving participation among most gardeners.

Emilie E. Ellis, S. Campbell, Jill L. Edmondson · Proceedings of the Royal Society B Biological Sciences · Global

A large-scale assessment across three cities found up to a 43% reduction in species richness of bees, hoverflies, and nocturnal moths in urban horticultural sites along urbanization gradients. These declines are driven by taxon-specific landscape changes like reduced tree canopy and semi-natural habitat. Moths and hoverflies were particularly sensitive to urbanization compared to bees, indicating a wide range of pollinators are under threat in urban landscapes.

Nicholas Sookhan, Thomas M. Onuferko, J. Scott MacIvor · Ecological Entomology · United States

This study measured pollination services across gradients of within-city urbanization and urban green space fragmentation at 10 community gardens in the United States, deploying four native indicator (phytometer) plant species and measuring visitor rate and alpha-diversity in relation to each species' reproductive outcomes. Although the researchers predicted a negative effect of urbanization, they found limited evidence of decline; contrary to expectation, Lobelia siphilitica showed increased visitor alpha-diversity and higher seed mass in more urbanized gardens, fragmentation effects were mixed -- edge density correlated positively with one species and negatively with another -- and local garden floral richness showed no influence, likely because richness was uniformly high across gardens.

Ibukun Balogun, James S. Pryke, Temitope Kehinde, Michael J. Samways · Landscape and Urban Planning · Africa

A 2025 study investigated how insect pollinator diversity differs between gardens, agricultural areas and natural areas within a southern African urban mosaic composed of an urban core, farms and natural areas, and examined how urban green spaces influence pollinator taxonomic diversity. Direct observation and pan traps were used to assess pollinator diversity alongside measured environmental, floral and landscape variables. Results showed similar pollinator diversity between agricultural and natural areas for some taxa, and between agricultural areas and urban gardens for other taxa. Floral variables were the most important predictors of pollinators, with greater floral diversity ameliorating the effects of urbanization and agricultural intensification, while landscape context was significant but less important. Although results varied considerably among taxa, the findings suggest agroecological farming may buffer natural areas from urbanization effects and reduce urbanization's impact on pollinators in urban gardens by providing needed resources. The study identifies floral variables as important for urban green planning, achievable through establishing more flowering plants in human-modified areas such as semi-urban agricultural areas and urban gardens.

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.