Research & reports

Hojun Choi, Min Kim, Jinhyung Chon · Journal of the Korean Institute of Landscape Architecture · South Korea

A study structurally analyzed the socio-ecological system of honeybees, as pollinators, using systems thinking, in order to propose green space planning strategies to revitalize urban beekeeping. It analyzed the ecological structure of bees' foraging and pollination activities and the social-ecological structure of urban beekeeping through individual causal loop diagrams, then synthesized these into an integrated causal loop diagram. The resulting proposed strategies were citizen participation programs, local government investment, and the creation of urban parks and green spaces on idle land.

Chengxiang Zi, D. Winterbottom, Juanjuan Liu · Frontiers in Sustainable Food Systems · China

Focusing on a well-preserved village of the Dong ethnic group in southwest China that maintains traditional livelihoods and a local food system, a study used field surveys, interviews and participatory mapping to propose an edible green infrastructure (EGI) model for traditional villages. The model comprises the "rice-fish-duck" cycle as the core of traditional livelihoods, a hierarchical ecological structure of "households-groups-village," and corresponding management models. By theoretically analyzing the EGI of traditional villages shaped over China's millennia-old agricultural civilization, the study aims to inform sustainable food-system and natural-resource-management knowledge, applying it to the construction of bio-districts in rural China.

Angga Mahardika Syahrul Putra, Jafron Wasiq Hidayat, Kasiyati · Prosiding SNAST · Indonesia

Against the backdrop of Yogyakarta City, Indonesia (32.85 sq km) having only 23.52% green open space coverage versus the legally required 30%, this study used a literature review method (journal articles, proceedings, government documents, regulations, and spatial data) to analyze the form and role of the city's Lorong Sayur ("vegetable alley") program. It found Lorong Sayur to be a form of vertical urban agriculture using land along alleys and neighborhood roads, with an ecological effect of minimizing non-organic waste and contributions to changing residents' lifestyles and improving socio-economic life.

Putri Balqis, Riski Wulandari, Muhammad Zulfandi · Jurnal Teknologi Cerdas · Indonesia

Reducing carbon emissions is a critical task in addressing global climate change, and establishing rooftop gardens in urban areas is presented as one approach that could be adopted. This paper is a literature review examining the environmental advantages of rooftop gardens, with particular focus on their capacity to mitigate carbon emissions. It reviewed diverse sources concerning rooftop garden implementation for carbon mitigation. The review states that rooftop gardens possess significant capacity to mitigate carbon emissions and address the challenges posed by climate change, though successful installation requires careful planning and a thorough understanding of environmental and technological aspects. Rooftop gardens are described as enhancing CO2 absorption, lowering surface temperatures, and decreasing building energy needs by improving thermal insulation, as well as contributing to improved air quality and urban biodiversity. The review identified numerous designs and best practices that could optimize the ecological and economic advantages of rooftop gardens, and points to the possibility of incorporating them into urban planning as an approach to addressing climate change and enhancing urban quality of life.

Assyifa Fauzia, Evi Frimawaty, Hadi Susilo Arifin · Holistic Journal of Tropical Agriculture Sciences · Global

This literature review examines the role of urban agriculture as an ecosystem services provider in mitigating urban environmental deterioration. It states that urban agriculture adds various functions across different landscape scales and can provide numerous benefits when managed correctly. The review method compiled literature on urban agriculture and ecosystem services across provisioning, regulating, and cultural service categories. Results describe urban agriculture as taking diverse forms, from private gardens to community plots, addressing limited public funding and promoting greening initiatives; it is described as contributing to biodiversity conservation and to regulating the urban microclimate, including reduced urban heat island effects, wind protection, and pollutant absorption. It is also described as adding aesthetic value to urban spaces, promoting cultural integration, and functioning as a multifaceted strategy for sustainable urban development addressing food security, resilience, and well-being. Amid challenges including threats to urban biodiversity and the need for proper green-space management, the review frames urban agriculture as a holistic approach contributing to cities' visual, cultural, and environmental fabric.

Francesco Orsini, Giuseppina Pennisi, Giorgio Gianquinto, Michael Martin · International Journal of Vegetable Science · Global

This paper argues that widely publicized figures on urban agriculture's environmental impacts lack the methodologically sound evidence needed for valid comparison, before conclusions can be drawn. It addresses problems in comparatively assessing environmental performance between rural and urban farming and argues for the need for specifically designed indicators capable of comprehensively assessing multifunctional urban agriculture.

Francisco Tomatis, Monika Egerer, Luis Manuel Navas-Gracia · Horticulturae · Spain

A study of twelve plots across four urban allotment gardens in Valladolid, Spain (Horticulturae, 2024) examined food production, cooling effects, and gardener perspectives. Crop selection matched broader Global North urban-gardening trends, adapted to limited plot space and varying by season. The gardens provided more stable and cooler temperatures than urban gray spaces, though the cooling effect was smaller than that of urban parks, and was most pronounced in summer. Greater crop cover at the plot level produced a stronger cooling effect, while crop abundance and diversity showed only a weak correlation with cooling benefits. Gardener surveys found awareness of climate change and its perceived direct threat to crops, health, and the city, along with concern about future water availability for crop growth and garden development.

Brent F. Kim, Sara N. Lupolt, Raychel Santo, Grace H. Bachman, Xudong Zhu, Tianbao Yang, Naomi K. Fukagawa, Matthew L. Richardson, Carrie Green, Katherine M. Phillips, Keeve E. Nachman · PLoS ONE · United States

A pilot study (2024, PLoS ONE) planted Darkibor kale seedlings at three urban and four rural farms in and around Baltimore City, Maryland, had farmers grow them using their usual practices, and analyzed harvested kale for carotenoids, vitamins C and K1, ten nutritional elements, and eight non-essential metals. Sample sizes were in some cases too small to yield statistical significance, but the study identified potentially meaningful differences between urban and rural kale: mean carotenoid and vitamin concentrations were 22-38% higher in rural samples, while mean concentrations of eight nutritional elements were higher in urban samples, by as much as 413% for iron. Most of nine non-essential metals were higher on average in urban samples, though lead and cadmium concentrations across all samples stayed below public health guidelines; for six elements, variance within urban or within rural farms exceeded variance between the two groups, suggesting urbanicity may not be the primary driver of some differences, and some urban-rural gaps were more pronounced than in prior research.

J Resmi, K Vismaya, V. Chitra, S K Anjana, K V Sumiya · International Journal of Environment and Climate Change · India

Focusing on the role of trees and forested ecosystems in sustainable development and climate change adaptation and mitigation, this study compares Miyawaki forests — a high-density planting method developed by Japanese botanist Akira Miyawaki to intensify green cover and support local biodiversity — with food forests, planned and planted forests of food plants providing a variety of food year-round. The study sites were in Palakkad district, Kerala, India: Krishi Vigyan Kendra Palakkad, where a Miyawaki forest patch was established, and V.T. Bhattathiripad College in Sreekrishnapuram, where a food forest was established. While both approaches aim to restore ecosystems and enhance biodiversity, they differ in design, purpose and management: the Miyawaki forest reconnects with nature by supporting native flora and fauna for biodiversity conservation and habitat restoration, while the food forest reconnects with nature by providing a food source for pollinators and habitat for many animals, and is described as environmentally friendly because it requires no chemical pesticides. Both techniques are described as effective for establishing urban forests and converting unproductive wasteland into ecologically and socially beneficial productive land.

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.

CapitaLand · CapitaLand · Singapore

The rooftop of Singapore's Funan mixed-use development hosts an approximately 18,000-square-foot urban farm operated by Edible Garden City, growing more than 50 types of fruits and vegetables including mushrooms, edible flowers, and watermelon. CapitaLand frames this and its other greened properties as delivering functional benefits — reduced energy consumption, improved air quality, and enhanced employee wellness — beyond aesthetic appeal.

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.

Coulibaly S.F.M., Aubry C., Provent F., Rousset-Rouvière S., Joimel S. · Environmental Research Letters, 18(7) · Global

A review synthesizing existing research on how far green roofs can support urban biodiversity, framed by their design and modes of use. It finds green roofs can provide habitat for soil organisms and pollinators as well as plants, but that the effect depends strongly on design such as substrate depth and vegetation diversity, and recommends integrating soil communities into construction guidelines and increasing heterogeneity at roof and landscape scales.

Bell N.C.S., Ascher J.S., Hayes J.J.-M., Langellotto G.A. · Frontiers in Sustainable Cities, 5:1102360 · Global

A systematic review covering roughly five decades of bee research in urban and community gardens, analyzing 227 publications through early 2022. It clarifies the potential of gardens to support diverse bee communities, the role of citizen-tended green spaces in pollinator conservation, and existing research gaps, pointing toward future directions for urban pollinator conservation and participatory monitoring.

国土交通省 · 国土交通省（令和5年9月策定） · Japan

The core strategy of Japan's Ministry of Land, Infrastructure, Transport and Tourism aiming to mainstream and 'build in' green infrastructure across all sectors with the public and private sectors working in tandem. It sets out seven perspectives—collaboration, community, technology, evaluation, finance, global and digital—and positions a broad range of spaces, including urban farmland and everyday greenery, as multifunctional green social infrastructure for stormwater management, disaster risk reduction, biodiversity, health and community.

García-Vásquez R., Vera-Guzmán A.M., Carrillo-Rodríguez J.C., Pérez-Ochoa M.L., Aquino-Bolaños E.N., Alba-Jiménez J.E., Chávez-Servia J.L. · AIMS Agriculture and Food 8(3):832-850 · Mexico

Compared phenolics, vitamin C, carotenoids, capsaicinoids, and antioxidant activity in Oaxacan Huacle and De Agua pepper landraces versus commercial Jalapeño. Landraces showed higher flavonoid and carotenoid contents, underscoring indigenous germplasm value.

Shigita Gentaro, Tran Phuong Dung, Pervin Mst. Naznin, Duong Thanh-Thuy, Imoh Odirich Nnennaya, Monden Yuki, Nishida Hidetaka, Tanaka Katsunori, Sugiyama Mitsuhiro, Kawazu Yoichi, Tomooka Norihiko, Kato Kenji · Breeding Science, 73(3): 263-275 · Japan

Genotyping-by-sequencing of 755 melon accessions in the NARO Genebank identified ~39,000 SNPs to clarify genetic relationships and population structure and to construct a World Melon Core Collection, supporting conservation and use of genetic resources.

Hénaff E., Najjar D., Perez M., Mason C., McMeekin P. · Environmental Microbiome, 18:23 · United States (Brooklyn) / Australia / Italy / Japan

A pilot using three rooftop beehives in Brooklyn, NY, comparing hive substrates (honey, debris, swabs, bee bodies) to map surrounding urban metagenomes, then extending to hive debris from Sydney, Melbourne, Venice and Tokyo. Each city shows a distinct metagenomic profile, positioning rooftop beekeeping as a tool for reading the urban environment.

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.

大阪府摂津市, 農林水産省 · 農林水産省 農山漁村振興交付金事例 · Japan

Settsu City grant case installing signage for disaster-cooperation farmland, showing a municipal public-support model linking urban farmland's disaster and green functions with conservation of citizen farms.

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.

Kwartnik-Pruc A., Droj G. · Land (MDPI), 12(2):325 · Global

A systematic review of 162 peer-reviewed papers (1978–2022) organizing the role of allotments and community gardens into six themes (community, health, economics, pollution, urban planning, sustainable environment). Ecologically, it concludes that gardens create habitat mosaics that act as refugia for urban biodiversity and that urban agriculture enriches plant diversity, helping conserve native and agricultural biodiversity — and calls for planning and policy frameworks that treat gardens as part of urban green infrastructure alongside greenspace restoration and heat-island mitigation.

Sokolowski A.C., Álvarez V.E., Mangiarotti A., Gonçalves Vila Cova C. · Agroecology and Sustainable Food Systems · Argentina (Buenos Aires)

In Buenos Aires peri-urban family farms, TAPE surveys and soil measurements showed that self-defined agroecological farms outperformed conventional ones on soil health indicators including aggregate stability and organic carbon.

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.

Royer H., Yengue J., Bech N. · ScienceDirect · Global

Systematic review of biodiversity impacts of urban agriculture globally, comprehensively analyzing agriculture's role in urban ecosystems.