Research & reports

東京都 · 東京都例規集 · Japan

Article 14 of the Tokyo ordinance requires developers building or renovating on sites of 1,000 sqm or more (250 sqm or more for national/local government sites) to submit a greening plan covering both ground-level and building-top (e.g. rooftop) greening to the governor before starting work, to report completion of the greening afterward, and to properly maintain the resulting green space. Enacted December 22, 2000, with the most recent amendment taking effect June 1, 2025.

国土交通省 · 国土交通省 · Japan

According to this December 12, 2025 announcement by Japan's Ministry of Land, Infrastructure, Transport and Tourism, approximately 14.5 hectares of green roofs (equivalent to about two National Stadiums) and 4.6 hectares of green walls were newly installed nationwide in FY2024. Cumulative installations from FY2000 through FY2024 (25 years) reached about 633 hectares of green roofs and 131 hectares of green walls.

Bellini, A., Savo, V., Caneva, G., D'Amico, E., Casalini, R., Bartoli, F. · Plants (Basel) · Italy

This study analyzed vegetation on an unmaintained green roof in Rome. Spontaneous colonization produced 62 species across 18 families, with Asteraceae (19 species, 31%) and Poaceae (10 species, 16%) most represented. Therophytes (annuals) dominated the life-form spectrum at 35 species (56%). Geographically, cosmopolitan species made up 25%, Mediterranean species 38%, and alien species 15%. Some originally planted species, such as Thymus, thrived through summer without irrigation.

東京都環境局 · 東京都環境局 · Japan

This Tokyo Metropolitan Government Bureau of Environment page describes the Green Space Plan Notification System, which requires developers building or expanding structures on sites of 1,000 m2 or more (250 m2 or more for national/local government sites) to file a green space plan and meet a minimum greening standard, under the ordinance on nature protection and restoration in Tokyo. The system aims to restore lost green space and mitigate the urban heat island effect, requiring prior consultation and post-completion reporting.

東京都環境局 · 東京都環境局 · Japan

This Tokyo Metropolitan Government Bureau of Environment page compiles and publishes rooftop, wall, and balcony greening results based on green space plan filings from FY2000 through FY2024. The page text itself does not state cumulative totals; detailed figures are provided separately in downloadable Excel and PDF result tables.

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.

Bauer W., Titz A. · Nature-Based Solutions · Malawi (Lilongwe)

Urban Nature-based Solutions (NbS) are promoted globally as multifunctional and cost-effective, and municipal interest is growing in cities of the so-called Global South. Yet research remains clearly biased toward the Global North, with particularly few studies on cities in Sub-Saharan Africa — leaving a high risk that maladapted NbS, modelled on examples from elsewhere that do not meet local requirements, get adopted. This article examines the barriers to adopting urban NbS in Malawi's cities and the opportunities for successful implementation, drawing on qualitative data (workshops, narrative expert interviews, group discussions) gathered over five research stays in Lilongwe between 2022 and 2024, and analysing in detail the strategies used by those implementing the Lilongwe Ecological Corridor Initiative (LECI), a large-scale NbS in the capital.

Abdulhakeem Al-Qubati, Lulu Zhang, Matthias Forkel · Sustainable Cities and Society · Global

This 2024 global review examined 96 studies focusing on methods for estimating carbon sequestration (CS) and emissions in urban and peri-urban agriculture (UPA). The review found significant research gaps: most studies were in the global north, research in the global south is lacking, and there are fewer studies on CS compared to GHG emissions. Additionally, few studies jointly assessed water and carbon cycles, and spatiotemporal analysis, modeling, and remote sensing for GHG emissions are underutilized.

Ricard Segura, Johannes Langemeyer, Alba Badía, Sergi Ventura, Jaime Vila-Traver, Gara Villalba · The Science of The Total Environment · Spain (Barcelona)

A study in the Metropolitan Area of Barcelona, Spain, investigated the impacts of peri-urban agricultural expansion on the food-water-climate nexus using urban metabolism and atmospheric-biosphere models across four land-use scenarios. While expansion increased food production and irrigation water requirements, replacing natural non-forested and forest areas for peri-urban agriculture was predicted to reduce net ecosystem productivity by up to 18.5% and total carbon stocks by 3.3%. Irrigated peri-urban agriculture potentially reduced near-surface temperatures by 0.7°C, though reductions in the densest urban areas were minimal.

Dong Wang, Peiyuan Xu, Bo-Wen An, Qiuping Guo · Frontiers in Ecology and Evolution · Global

This paper introduces a conceptual framework for urban green infrastructure (UGI) to integrate ecological principles, urban planning, and adaptive management for resilient urban landscapes. UGI aims to enhance ecological connectivity, restore ecosystem functions, and provide habitats, emphasizing multifunctionality, connectivity, diversity, and accessibility. Global case studies demonstrate UGI's effectiveness in biodiversity conservation and its contribution to sustainable urban development through ecosystem services. Challenges for UGI include funding constraints, institutional fragmentation, and equity issues, requiring innovative financing, community involvement, and policy innovations.

Aikaterini Kouloumprouka Zacharaki, James Monaghan, Jennifer R. Bromley, Laura H. Vickers · Plants People Planet · Global

This review identifies challenges for strawberry cultivation in urban production systems, noting that new urban farmers often lack the specialist knowledge of commercial growers. Common bottlenecks include plant physiology, pathogen management, choice of propagation material, fertigation, pollination, and environmental requirements. This knowledge gap appears to result in the abandonment of strawberries as a crop of choice in urban systems.

Amal Ibourk, Lauren Wagner, Deb Morrison, Syrena Young, Justin Milledge · Science and Children · Global

This article describes a fifth-grade climate change action project involving building a community garden, aligned with science standards. Students learned about monarch butterfly migration, life cycles, and greenhouse gases by planting milkweed. The article offers educators ideas and suggestions for implementing such a project within a school community.

Murali Krishna Pasupuleti · · Global

This chapter explores the transformative role of artificial intelligence (AI) in achieving a carbon-neutral future by enhancing sustainability in urban and agricultural systems. AI optimizes energy use, resource management, and disaster resilience in urban settings, and powers precision farming and reduces emissions in agriculture. The chapter also addresses challenges such as data privacy, economic barriers, and technological limitations.

Weonjung Sohn, Ibrahim El Saliby, Andrea Merenda, Sherub Phuntsho, Stefano Freguia, Jing Guan, Li Gao, Sungyun Lee, Ho Kyong Shon · Desalination and Water Treatment · Global

This study investigated the efficiency of urine-derived fertilizer compared to commercial fertilizers using three growing systems: nutrient film technique, pot-drench, and deep-water culture. The research found comparable growth responses in parsley, rhipsalis, coriander, and basil across various parameters like biomass and nutritional composition. Urine-derived fertilizers showed potential as a sustainable alternative to synthetic fertilizers.

Juan David Arosemena Polo, Susana Toboso‐Chavero, Biraj Adhikari, Gara Villalba · Waste Management · Spain (Barcelona)

This research determined the potential of organic municipal solid waste (OMSW) compost to supply nitrogen-phosphorus-potassium (NPK) demand for urban agriculture (UA) and its environmental benefits in the Metropolitan Area of Barcelona, Spain. Using spatial material flow analysis and life cycle assessment, it was found that the current waste management system could substitute 8% of total NPK demand with compost, reduce impacts by up to 39%, and yield 130% savings in global warming. A 2025 scenario could substitute 21% of NPK demand and reduce environmental impacts by up to 1,049%.

Brittany R. Kruger, Joshua Sackett · PLoS ONE · Global

This study assessed abiotic and biotic factors affecting sweet corn production in six arid urban agricultural plots with varying shade levels (n=18 plots). Corn successfully matured in 50% of the plots. Microbial richness and diversity were high and not a hindrance. Corn success metrics positively correlated with average daytime light intensity (r=0.74-0.84) and soil organic matter (r=0.77-0.89), but negatively correlated with soil calcium, magnesium, sodium, and sulfate (r=-0.71 to -0.90).

Mascha Gugganig · Science Technology & Human Values · Global

This paper explores the arguments and internal disagreements among experts popularizing vertical farming (VF), an emerging urban food production system. While VF is promoted for its space efficiency and independence from weather, it faces debates regarding its unsustainability and high energy costs for producing a limited range of perishable foods. Findings indicate that disagreements among vanguards reveal that VF is seen as one of many solutions, not the sole answer.

Adriana de Paula Cavalcante Fraga, Ana Moraes Coelho, Jéssica Castro Chryssafidis, José Geraldo Barreto Monteiro de Andrade, Maíra Bombachini Silva, Maria Luiza Sevilha Seraphico de Assis Carvalho, Mariana Nicolletti, Nathan Debortoli, Samuel Santos de Souza Pinto · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil (Manaus)

A case study of urban and peri-urban agriculture in Manaus, Brazil, aimed to identify and characterize the benefits these agricultural initiatives provide to the territory. Using a hybrid methodology that combined biophysical modeling with listening to the voices of experienced protagonists, the study identified the significant potential of urban and peri-urban agriculture to contribute to city development. This research revealed the potential for urban agriculture to mitigate or solve typical urban problems.

Olivia M. Erskine, Alexa J. Lamm, Catherine E. Sanders, Kevan W. Lamm · Horticulturae · United States

This study investigated community garden coordinators' perceptions of the need for climate change adaptation, its attributes, and their position in the innovation-decision process in Georgia, North Carolina, and South Carolina, United States. Participants valued relative advantage and low complexity when adopting and implementing climate-smart practices. Community gardens were found to be implementing some form of climate-smart adaptations, even if not for climate-related reasons, but the largest barrier to adopting new practices was a lack of extra money.

Prajal Pradhan, Daya Raj Subedi, Kshitij Dahal, Yuanchao Hu, Prakriti Gurung, Sijal Pokharel, Sagar Kafle, Biplav Khatri, Sudeeksha Basyal, Monika Gurung, Aruna Joshi · Cell Reports Sustainability · Global

This systematic analysis of 1,450 urban agriculture publications examined its impacts on Sustainable Development Goals (SDGs). It found urban agriculture is linked to all SDGs, with 142 targets showing positive sentiments and 136 showing negative sentiments, with positive sentiments roughly double the negative. The study concludes that urban agriculture does not inherently contribute to sustainability, as its impacts depend on specific practices and require tackling identified hurdles.

Kamal Prasad Acharya, Kalpana Gyawali, Indra Raj Upadhyaya · Interdisciplinary Research in Education · Nepal

This article explores the contribution of garden-based activities to developing 21st-century skills in public schools in Nepal. Using participatory action research in three intervention schools, the study found that school gardening, involving flower and vegetable cultivation, enhances critical thinking, creativity, collaboration, and problem-solving skills. Students also viewed gardening as a valuable learning platform that encourages creative thinking, environmental sustainability, and lifelong learning competence.

Laura S. Tuominen, Heikki Helanterä, Patrik Karell, Lauri Rapeli, Timo Vuorisalo, Jon E. Brommer · npj Urban Sustainability · Finland (Turku)

This before-after study in Turku, Finland, examined the influence of the COVID-19 pandemic on urban box gardening from 2019 to 2021. While box gardening's importance for resilience increased and gardeners remained motivated, participants reported receiving fewer benefits from gardening during the pandemic. This suggests a negative influence of the pandemic on well-being, extending to urban gardening outcomes.

Ery Suhartanto, Mohammad Bisri, Ussy Andawayanti, Suwanto Marsudi, Evi Nur Cahya · TEKAD Teknik Mengabdi · Indonesia (Malang)

A 6-month "River Flow Conservation" activity was implemented in RW-01, Kasin Village, Klojen District, Malang City, Indonesia, to mitigate flood impact. Activities included river dredging, greening (urban farming), and establishing fish cages. This initiative resulted in RW-01 becoming a green, comfortable, and sustainable area, positively impacting flood reduction, environmental quality improvement, and water resource utilization.

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.

Goshu Desalegn, Anita Tangl, Mária Fekete‐Farkas, Girma Gudisa, Anita Boros · Heliyon · Ethiopia

A study of micro and small enterprises in Ethiopia showed that government policies and regulations have an insignificant direct effect on urban agriculture. However, sustainable finance plays an important mediating role between urban agriculture and government policies, indicating that the impact of government policies and regulations on urban agriculture is indirect.