Research & reports

Jennifer Roedel, Karma Thomas, Zsofia Szendrei · Renewable Agriculture and Food Systems · United States

This study surveyed 74 urban growers to evaluate how grower and farm characteristics influence the implementation of eight common pollinator management strategies and overall farm crop richness. It found that demographic variables had no impact; instead, growers' decisions were shaped most by their sources of educational information and by resource use and accessibility, with online materials appearing more effective than hard-copy formats. The authors conclude that more accessible educational resources are needed for these historically underserved urban growers.

Edith Gonzales, Brenda B. Lin, Heidi Liere, Shalene Jha, Stacy M. Philpott · Figshare · United States (California)

An online survey of community gardeners in California, United States, assessed their knowledge of arthropod ecological roles. Gardeners demonstrated high knowledge, correctly classifying 71–83% of arthropod images. Female gardeners more accurately classified pollinators, while those who participated in a Master Gardener program more accurately classified herbivores and natural enemies.

Subin Babu Neupane, Pedro F S Toledo, Katerina Velasco-Graham, Felipe N. Soto‐Adames, Arash Kheirodin · Journal of Integrated Pest Management · United States

This is the first report documenting the invasive thrips species Thrips parvispinus, native to Southeast Asia, in Texas, USA. Samples collected from 12 locations across Texas -- including greenhouse facilities, large retail outlets and community gardens -- from plants showing foliage injury confirmed the species' presence in November 2025, and detections across multiple counties suggest it has been introduced to multiple locations and may be widely distributed in the state.

Mary T Nguyen, Carleen Rauh, Shelby Gresch, Charlotte Correiro, Heidi Elmendorf, Adriane Fugh-Berman, Gina Wimp, Alexandra L. DeCandia · ODU Digital Commons (Old Dominion University) · United States

Plant, animal, bacterial and fungal diversity were examined across three distinct urban habitats — a turf lawn, a forb garden and a farming space — using bacterial 16S rRNA and fungal ITS2 sequencing, soil nutrient analyses, and vegetation and wildlife surveys. Bacterial community abundance was relatively even across garden types, but site-specific management style significantly shaped which fungal taxa dominated: Leotiomycetes in the farming space, Sordariomycetes in the forb garden, and Tremellomycetes in the turf lawn, indicating that distinct urban agricultural practices strongly shape fungal communities. Gardens with greater plant diversity also supported higher wildlife and fungal richness.

Santropol Roulant · Santropol Roulant · Canada

Santropol Roulant's rooftop farm in Montreal's Plateau neighbourhood combines intensive garden beds with container gardening and keeps beehives. Produce grown there feeds the organization's meals-on-wheels kitchen, and kitchen scraps are composted in the basement and returned to the rooftop farm, forming a closed food-waste loop.

Domanus A., Smith A., Roberts M., Schnorenberg R., Doane M., Minor E. · Cities and the Environment (CATE), 17(2):9 · United States (Chicago)

A study of 24 community gardens in Chicago measuring not only cultivated crops but also spontaneous (wild/native) plants, birds, butterflies and bees. Gardens supported many spontaneous plant species (mean 8.4 per garden) alongside crops, which underpinned diverse fauna (18 bird species, 13 bee genera, 10 lepidopteran species). Socio-ecological drivers such as management type (allotment vs. communal) significantly shaped cultivated richness, the volume of spontaneous vegetation, and tree/shrub density — showing that how gardens are managed governs urban biodiversity.

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.

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.

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.

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.

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.

Pierric Calenge, Maie Gérardot · Métropolitiques · United States (Cleveland)

The work by Max Rousseau and Vincent Béal illuminates the ambiguities of a policy that organizes urban decline and racial segregation in Cleveland. This policy promotes urban degrowth and racial segregation, balancing algorithmic management and urban greening. The study focuses on the Rust Belt region, which experiences de-urbanization marked by the subprime crisis, racism, and segregation.

L. Garcia Ferreira, M. E. F. CORREIA, M. C. UZEDA · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil (Rio de Janeiro)

This study evaluated the role of agroecological urban and peri-urban agriculture in preserving native bee communities in the western region of Rio de Janeiro, Brazil. Ten different bee species, nesting in soil and cavities, were identified. Generalized Linear Models (GLMs) indicated that the percentage of agricultural, natural, and built-up land cover was insufficient to explain the species composition regarding their nesting habits. The findings suggest the importance of assessing the quality of agricultural environments, as their association with urban landscapes could support a greater richness of species with diverse nesting habits.

Alexandra Zink, Paul J. CaraDonna, Kelly Larsen, Amy M. Iler · Ecosphere · United States (Chicago)

This study investigated how urbanization relates to pollination by growing 240 plants (squash and tomato) across six sites with varying urbanization levels in Chicago, Illinois. For tomatoes, the magnitude of pollen limitation increased with greater impervious surface, indicating more pronounced pollination deficits at highly urbanized sites. For squash, evidence of pollen limitation was found only at the most urban site, with a weak trend of pollen limitation of fruit set (but not seed set) increasing with impervious surface.

Karen R. Klinger, Aster F. Hasle, Karen S. Oberhauser · Frontiers in Ecology and Evolution · United States (New York City)

Working with community scientists in the Chicago metropolitan area, researchers monitored monarch butterfly (Danaus plexippus) eggs and caterpillars on milkweed patches in yards and community gardens. Peak egg counts per patch ranged from zero to 170 across observation years; patch age and the presence of common milkweed (Asclepias syriaca) affected whether eggs were present, and patches with the highest egg counts tended to have A. syriaca, more milkweed plants, and greater diversity of blooming nectar plants.

AIPH (International Association of Horticultural Producers) · AIPH (International Association of Horticultural Producers) · Brazil

AIPH's Green City case study on Curitiba, Brazil (associated with the 2024 AIPH World Green City Awards), describes an urban agriculture program dating to the mid-1990s comprising 147 gardens — 47 community, 43 school, and 36 institutional — covering 17 hectares (177,000 m²). The gardens produce about 160 tons of vegetables per month and benefit 37,000 people; 89 beehives are also installed.

Riehn J.K., Fogel N.S., Hathaway J.N., Camilo G.R. · Frontiers in Sustainable Cities, 5:1100470 · United States (St. Louis, MO)

Surveyed bees on three urban rooftop food farms and two nearby ground-level community gardens in St. Louis during 2017–2018. Rooftops hosted 38 species—a nested subset of ground-level communities, with fewer bumblebees and more non-native Megachile—with implications for pollination services on rooftop food production.

Jha S., Egerer M., Bichier P., Cohen H., Liere H., Lin B., Lucatero A., Philpott S.M. · Ecology Letters, 26(3):369-383 · United States (California)

Using >5,000 observations over five years across a network of urban community gardens in California, this study quantifies trade-offs and synergies between biodiversity and multiple ecosystem services (e.g., pest control and pollination) in urban agroecosystems. Contrary to assumptions that food production conflicts with biodiversity, it finds many synergies and few trade-offs, and shows that surrounding natural landscape cover interacts with local management to mediate services from mobile animals — underscoring the role of garden management and urban planning in optimizing biodiversity and human benefit.

Gail MacInnis, Etienne Normandin, Carly D. Ziter · PeerJ · Canada (Montreal)

A study of wild bee communities across Montreal, Canada, greenspaces with differing honey bee densities, surveyed in 2020 and compared with 2013 baseline data. Sites with more honey bees had fewer wild bee species, and the negative association was strongest for small-bodied bees (inter-tegular span under 2.25 mm), whose shorter foraging ranges limit their access to floral resources under competition. Urban beekeeping is commonly promoted as environmentally beneficial, but this observational evidence indicates that high-density operations may pressure native pollinators through resource competition and pathogen transmission; the design is correlational rather than an experimental test of causation.

Sarah E. Orr · American Entomologist · United States

Community gardens are presented as a solution to food insecurity and a means to promote native bee conservation. They provide local fresh produce, affordable nutritious options, and foster education in gardening and nutrition. Additionally, community gardens support biodiversity, as roughly 35% of human food crops depend on animal pollination, with bees being primary pollinators for many crops.

Elda Míriam Aldasoro Maya, Ulises Rodríguez‐Robles, María Luisa Martínez Gutiérrez, Guelmy Anilú Chan Mutul, Teresita Avilez López, Helda Morales, Bruce G. Ferguson, Jorge Mérida‐Rivas · Frontiers in Sustainable Food Systems · Mexico (Tabasco)

Meliponiculture, or stingless bee breeding, in Mesoamerica serves as an effective tool for agroecological education, scaling, and pollinator conservation. In Tabasco, Mexico, activities included documenting contemporary knowledges, community agroecological workshops, guided visits to an institutional meliponary, and promoting school gardens, utilizing "knowledge dialogues" as a methodological approach. The study identified characteristics of stingless bees and their cultivation, such as their ecological and cultural importance, role as pollinators, association with community values, and productive potential, making them excellent mediators for biocultural conservation and agroecological education.

Tina McIntyre, Hamutahl Cohen, Rachel Gutner, Tiare Saracino, Esen Momol · EDIS · United States (Florida)

This is a five-page extension publication from the UF/IFAS Environmental Horticulture Department that provides a decision tree to help edible-landscape gardeners decide how to respond to wildlife in their growing areas. It states that while wild animals can damage crops, this need not require conflict, and aims to help gardeners become more accepting of wildlife species present in their managed area and coexist with them.

Mary Leou, Tania Goicoechea, Bethany Kogut · Catholic education/Catholic education (Dayton, Ohio. Online) · United States (New York City)

A report on "Bees Alive!", a civic ecology program run over three years by the NYU Wallerstein Collaborative for Urban Environmental Education & Sustainability in Greenpoint, Brooklyn, New York. A university, public schools, non-profit organizations and the Lentol Garden community garden collaborated to establish a native-plant pollinator garden, funded by EPA Region 2, using place-based education and experiential learning theory to create an outdoor classroom that supports wildlife and teaches the public about pollinators.

Rachel Bechtold, Catherine W. Shoulders, Jennie Popp, Donald M. Johnson, Lisa S. Wood · Natural sciences education · United States

This study evaluated the process and efficacy of installing a demonstration plot along a multiuse trail in Southeast Kansas to educate the community on rehabilitative plots. The greatest perceived challenges for this case study were the allotment of time and money for initial costs of the demonstration plot and addressing methodology for plant blindness in viewers.

Aaron Anderson, Lucas Costner, Lincoln R. Best, Gail Langellotto · Conservation Science and Practice · United States

This study compared the attractiveness of 23 native Pacific Northwest plant species to bees over three field seasons, using timed bee counts and vacuum sampling. It found that Douglas' aster, California poppy, varileaf phacelia, Canada goldenrod, farewell-to-spring, globe gilia, and Oregon sunshine consistently supported high bee abundance and species richness. These findings can inform urban pollinator conservation efforts in gardens and public spaces.