Research & reports

Horta das Corujas · Horta das Corujas (blog oficial) · Brazil

The official blog of Horta das Corujas, a volunteer-run community garden on Praça das Corujas in the Vila Beatriz neighborhood of São Paulo. Opened on September 29, 2012, the roughly 800 m² garden practices agroecological vegetable and herb cultivation, restores a local spring, keeps bees, and hosts school environmental-education visits. It operates without formal permits, run by volunteers, with about 10-15 people regularly active.

Hall D.M., Camilo G.R., Tonietto R.K., Ollerton J., Ahrné K., Arduser M., Ascher J.S., Baldock K.C.R., Fowler R., Frankie G., Goulson D., Gunnarsson B., Hanley M.E., Jackson J.I., Langellotto G., Lowenstein D., Minor E.S., Philpott S.M., Potts S.G., Sirohi M.H., Spevak E.M., Stone G.N., Threlfall C.G. · Conservation Biology, 31(1):24-29 · Global

A review by an international team arguing that, as pollinators decline globally under agricultural intensification and pesticide use, cities can serve as important refuges for insect pollinators including native bees. It highlights the conservation value of designing and managing urban green spaces such as gardens and community plots for pollinators, framing citizen urban agriculture as a contributor to biodiversity conservation.

Brenda B. Lin, Monika Egerer · · Global

Urban agriculture, the production of food and livestock in urban areas, is a key component of urban green infrastructure, supported for food security and biodiversity enhancement. While habitat management in urban agriculture aids local biodiversity and food production, the effect of native plants on beneficial insects and ecosystem function is debatable. Declines in urban bees are likely linked to increased impervious cover, which reduces habitat and restricts bee movement.

Monika Egerer, Courtney Arel, Michelle D. Otoshi, Robyn D. Quistberg, Peter Bichier, Stacy M. Philpott · Journal of Urban Ecology · United States (California)

This three-year study in 19 urban community gardens on the California central coast examined how urban landscape intensification and diversity influence the abundance and richness of five arthropod groups (ants, bees, ladybeetles, parasitoids, spiders) across six spatial scales (200 m to 5 km). All arthropod groups were influenced by landscape factors, but this influence varied with spatial scale and local habitat features, likely due to arthropod community interactions and life history strategies.

박진 · 한국양봉학회 학술대회 자료집 · Global

This report examines the global rise of urban beekeeping, noting its diverse approaches across countries like the UK, Japan, and Denmark. While South Korea has seen an increase in urban beekeeping since 2012, with government support initiated in 2016, the sector faces significant challenges. Urban beekeeping is still largely viewed as a derivative of conventional beekeeping, and a lack of ordinances or legal frameworks hinders its widespread adoption and recognition of its environmental, social, and economic value.

Edward Lagucki, Justin Burdine, Kevin E. McCluney · PeerJ · United States (Toledo, Ohio)

This study investigated associations between urbanization and flying arthropod communities in 30 gardens and parks in Toledo, Ohio, during July and August 2016, collecting 2,369 individuals across nine orders using elevated pan traps. Flying arthropod community composition was associated with percent impervious surface and canopy cover. Overall abundance was negatively associated with impervious surface and positively with distance to city center, with specific taxa showing similar responses, indicating urbanization reduces taxa important for urban agriculture.

Étienne Normandin, Nicolas J. Vereecken, Christopher M. Buddle, Valérie Fournier · PeerJ · Canada

This study collected 32,237 wild bee specimens (200 species, 6 families) from 46 sites in Montreal and Quebec City in 2012 and 2013, across cemeteries, community gardens, and urban parks. It demonstrated that cities are home to diverse communities of wild bees, which in turn affect bee community structure and dynamics. Community gardens specifically harbored high levels of functional trait diversity, suggesting a substantial contribution to urban pollination services.

M. Bare, Raymond M. Danner · Ecological Restoration · Global

A 2017 study surveyed bird communities in three forest sites with different restoration and natural revegetation histories, 20–40 years since clearing, within a tropical urban-agricultural landscape in the Ecuadorian Amazon, comparing manually restored and naturally revegetating forest. A diverse assemblage of birds was found visiting and occupying the forest fragments, including two IUCN-listed near-threatened species. Bird species richness was similar across sites with different management histories and species composition varied only slightly, but differences existed in the presence and occupancy of forest-dependent groups such as large frugivores and forest insectivores. In the manually restored site, bird diversity may have been limited by under-developed forest structure, though the effects of patch size and landscape matrix could not be isolated. The study suggests future restoration efforts consider forest structure alongside plant species diversity, and that future studies account for landscape and matrix parameters when evaluating restoration projects.

Gerardo R. Camilo, Paige A. Muñiz, Michael Arduser, Edward M. Spevak · Journal of the Kansas Entomological Society · United States

A three-year survey (2013-2016 growing seasons) in St. Louis, Missouri, USA, sampled bees by aerial netting across vacant lots, city parks, community gardens and urban farms, collecting over 7,700 specimens, supplemented with BioBlitz data, personal collections, museum-collection records and the literature. The survey identified 198 bee species from five families in the city, of which only nine were non-native, and found St. Louis hosts nearly 45% of Missouri's bee diversity, a proportion the study describes as likely making it one of the most species-rich cities relative to its state's total bee fauna in the country.

Benjamin Iuliano, Alexandra Markiewicz, Paul Glaum · Michigan Journal of Sustainability · United States

A paper examining how community gardens have spread amid a decade of increased urban agriculture in American cities, and what effects this has on local ecosystems, with the title indicating a focus on potential effects on native pollinators. It states that socio-economic demographics may influence patterns of garden placement and quality, producing changes in biotic communities that urban ecologists are only beginning to understand. The available abstract breaks off while introducing a researcher hypothesis about increased floral resources, without stating further specific results.

Stacy M. Philpott, Peter Bichier · Ecological Applications · United States (California)

The influence of local, garden-scale factors (herbaceous and arboreal vegetation abundance and diversity, ground cover) and landscape-scale factors (landscape diversity and surrounding land use) on predation services was examined in 19 urban gardens on the California central coast. Sentinel pests — moth eggs and larvae and pea aphids — were placed on greenhouse-raised plants in open plots versus bagged, predator-exclosure plots. Predation rates were high, with 40% to 90% of prey items removed in open treatments. Predation services varied with local and landscape factors, but significant predictors differed by prey species: predation of eggs and aphids increased with vegetation complexity in gardens, while larval predation declined with vegetation complexity. Smaller gardens experienced higher predation, likely due to greater predator abundance, and several ground cover features influenced predation services. In contrast to patterns in rural agricultural landscapes, aphid predation declined as landscape diversity increased.

Fortel L., Henry M., Guilbaud L., Mouret H., Vaissiere B. E. · Journal of Insect Conservation · Lyon, France

Surveys use of human-made nesting structures (trap nests / bee hotels) by cavity-nesting wild bees in an urban setting, examining how artificial nesting aids may supplement scarce urban nesting resources.

Robyn D. Quistberg, Peter Bichier, Stacy M. Philpott · Environmental Entomology · United States (California)

This study investigated bee abundance and species richness in 19 urban community gardens on the California central coast using aerial nets and pan traps. Researchers found 55 bee species and identified that local factors, such as garden size, floral abundance, mulch cover, bare ground, and grass, were generally more important correlates than landscape factors. Medium bees were less abundant in areas with more medium-intensity developed land within 2 km.

Petites ruches · · France (Auxerre)

The shared garden of the Maison de Quartier des Piedalloues in Auxerre, France, features lawns intentionally left high to attract butterflies such as the 'demi-deuil', which pollinate knautia flowers. Residents have also participated in creating palisades or 'branch walls' using split acacia stakes within the garden.

J. Scott MacIvor, Laurence Packer · PLoS ONE · Global

This study modeled the occupancy probability of six solitary bee species using nest boxes set along an urbanization gradient over three consecutive years. Native M. pugnata showed decreased occupancy with increasing building footprint, and a similar but not significant pattern was found for native O. pumila. Conversely, introduced M. rotundata and M. centuncularis, along with native M. campanulae, exhibited increased occupancy with rising urbanization.

Andrea Burr · Consilience · United States (St. Louis, Missouri)

This interdisciplinary pilot study in St. Louis, Missouri, USA (2013-2015) investigated relationships between pollinator health and urban land-uses. Wild bees were sampled weekly at urban farms, community gardens, and prairie pockets, and ethnographic interviews were conducted with 30 decision-makers in summer 2015. Informants described bees' role in crop yield and reported planting to attract pollinators, suggesting the city is viable for pollinator habitat.

Monika Egerer, Peter Bichier, Stacy M. Philpott · Annals of the Entomological Society of America · Global

This study identified landscape and local habitat factors influencing lady beetle abundance and species richness in urban community gardens. Assessing 19 gardens over two years, it found that the amount of natural area surrounding gardens at 3 km was the strongest correlate of abundance and species richness. Gardens embedded in more urban landscapes had higher lady beetle abundance and richness, suggesting that urban landscape quality and local habitat management may interact to shape lady beetle communities within gardens.

David M. Lowenstein, Maryam Gharehaghaji, David H. Wise · Environmental Entomology · United States

A study at 28 urban food-production sites in the Midwestern United States measured the removal of sentinel eggs and larvae of the cabbage looper (Trichoplusia ni) by predators over a 3-day period. Predators removed 50% of eggs and 25% of larvae, with mortality rates not predicted by landscape factors and similar across residential gardens, community gardens, and farms. Laboratory assays confirmed that lady beetles, spiders, and pirate bugs consumed eggs and larvae at high rates.

S.G. Potts, V.L. Imperatriz-Fonseca, H.T. Ngo · Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), Bonn, Germany · Global

IPBES's first international science assessment on pollinators, pollination and food production (552 pages), approved at its 4th Plenary session in Kuala Lumpur, Malaysia in February 2016. It covers animal pollination as a regulating ecosystem service underpinning food production, gene flow and ecosystem restoration, addressing the roles of native and exotic pollinators, status and trends in pollination networks, drivers of change, impacts on human well-being, and the effectiveness of policy responses. The Assessment was formally endorsed by the Convention on Biological Diversity's COP13 and prompted national pollinator strategies in countries including France, the Netherlands, Brazil, South Africa and the Republic of Korea.

Sakurai Shin · Nippon.com · Japan

A feature on the Ginza Honey Bee Project ('Ginpachi'), a nonprofit founded in March 2006 by Tanaka Atsuo, which installed beehives on the roof of the Kami Parupu Kaikan building in central Tokyo, drawing nectar from Hibiya Park and the Imperial Palace grounds within roughly a 3km radius. A decade on, the project has grown to 150 members, supplies honey products sold at the Matsuya Ginza department store and honey cocktails at nearby bars, and has inspired more than 100 urban beekeeping projects nationwide as well as projects in South Korea, Taiwan and elsewhere in Asia.

Lowenstein D.M., Matteson K.C., Minor E.S. · Oecologia, 179(3):811-821 · United States

A study measuring wild bee diversity and cucumber pollination (a pollination service) across urban Chicago. Sites with more bee species had better pollination, and even densely populated residential areas supported high bee richness. It demonstrates that growing diverse flowers in urban gardens sustains pollinators and directly benefits urban agricultural yields.

Misha Leong, Lauren C. Ponisio, Claire Kremen, Robbin W. Thorp, George Roderick · Global Change Biology · Global

This study investigated the impact of human-altered landscapes on the seasonal patterns of bee communities, using three years of data on the spatio-temporal distributions of 91 bee species in urban, agricultural, and natural landscapes. Seasonal patterns of abundance and species richness in human-altered landscapes varied significantly less compared to natural habitats, where floral resources are relatively scarce in the dry summer months. These findings demonstrate that anthropogenic environmental changes in urban and agricultural systems, mediated through changes in plant resources and water inputs, can alter the temporal dynamics of bee pollinators.

Braaker S., Ghazoul J., Obrist M.K., Moretti M. · Ecology, 95(4):1010-1021 · Switzerland (Zurich)

By sampling carabid beetles, spiders, weevils and bees on green roofs and ground-level green spaces in Zurich, this study compares community composition and tests the relative importance of local environment, microclimate and connectivity. Connectivity among roofs and to ground habitats emerged as a key driver of species composition, demonstrating that green roofs can act as stepping stones that support biodiversity in the surrounding urban ecosystem — a landmark case for connectivity-aware green-roof placement in city design.

Amanda E. Nelson, Andrew A. Forbes · PLoS ONE · Global

This study sampled two plant-herbivore-parasitoid systems across 250 sites in a 360 km2 urban/agricultural landscape to investigate the impact of human development on trophic interactions. It found that herbivorous insect densities were decoupled from host tree densities in urban landcover types at several spatial scales. Furthermore, a parasitoid species was absent from all urban/suburban landcover in one system, even where its herbivore host was common, indicating that human land use patterns limit specialist insect distributions due to dispersal constraints.

Misha Leong, Claire Kremen, George Roderick · PLoS ONE · United States (California)

This study investigated pollinator-plant interactions in a periurban landscape on the outskirts of the San Francisco Bay Area, California, where urban, agricultural, and natural land uses interface. Using standardized observations of floral visitation and measurement of seed set in yellow starthistle (Centaurea solstitialis), a common grassland invasive, it tested the hypothesis that increasing urbanization would decrease bee visitation rates, viable seed set, and pollination efficiency (the relationship between bee visitation and seed set). Contrary to expectation, bee visitation was found to be highest in urban and agricultural land use contexts. However, seed set rates in these human-altered landscapes were lower than in natural sites. The study attributes this mismatch between visitation and seed set to higher plant diversity in urban and agricultural areas — driven by more introduced species — which reduces pollinator efficiency. If consistent across other plant species, the novel plant communities and generalist bee species favored by human-altered landscapes would reduce pollination services.