Research & reports

Juliane Forßmann, Simon Goebel · Zeitschrift für Flüchtlingsforschung · Germany

An urban gardening project in a residential facility for up to 230 refugees in Germany aims to counteract precarious living conditions. While the garden offers a low-threshold space for knowledge exchange on resource-saving cultivation, biodiversity, and health promotion, this paper also reflects on the project's limits.

Zhongxue Zhou, Fangze Zhao, Bingjie Song · Ecological Indicators · China

This study proposed the concept of agricultural comprehensive ecological effects (ACEE), developed an evaluation framework, and applied it to the Xi'an metropolitan zone, China. A key finding was the observed decrease in the comprehensive ecological effects of agriculture when transitioning from grain planting to urban agriculture due to unsuitable agricultural practices in urbanizing areas. This decline occurs because modern agricultural practices in urbanizing areas are ecologically detrimental compared with natural ecosystems.

James Mbugua · African Journal of Climate Change and Resource Sustainability · Global

Biochar is presented as a promising nature-based solution for urban resilience, applicable in soil remediation, stormwater management, and carbon sequestration within green infrastructure. However, its widespread adoption faces significant barriers, including inconsistent feedstock supply, high production costs, limited public awareness, and a lack of standardized quality and safety regulations. The study also identifies a critical need for policies that integrate biochar into urban planning frameworks and incentivize its production and application.

Mais Jafari, Rolf Morgenstern, Jonas Runte · · Germany

This chapter analyzed the co-creation pathway of Nature-based Solutions (NBS) in the Dortmund Living Lab, focusing on urban gardening, food forests, and biodiversity. It critically illustrated missing dimensions that hinder innovation, such as business opportunities, legal frameworks, and planning conditions. These identified gaps indicate challenges in governance and implementation for social innovation through NBS.

· The MIT Press eBooks · Global

This book examines community farms in Latin America, Australia, and China, highlighting tensions between local identities and global transformation. It finds that while industrial expansion in export agribusiness generates macroeconomic benefits, it incurs micro-level costs such as the replacement of peri-urban farms by plantations, loss of biodiversity, and groundwater contamination from pesticides and fertilizers. The study suggests that food system intermediaries are crucial in connecting rural migrants with urban farms and resources.

R Mohammadzadeh · Proceedings of International Structural Engineering and Construction · Global

This qualitative secondary study, based on a structured literature review, examined the role of green infrastructure (GI) integrated into buildings for urban sustainability. Findings indicate that GI supports climate change adaptation, improves air quality, promotes urban biodiversity, and enables energy-efficient design. However, the paper also recognizes limitations related to cost, maintenance, and structural requirements for implementing building-based GI.

Javier Rodrigo-Ilarri, Claudia P. Romero-Hernández, Sergio Salazar-Galán, María-Elena Rodrigo-Clavero · Sustainability · Spain (Valencia)

This article analyzes the impact of urban sprawl on the Valencia Plain aquifer system from 1990 to 2018 using the Weighted Environmental Index (WEI). Results show urban surfaces expanded by 70% and rainfed agricultural areas declined by over 59%, leading to a 9.2% reduction in environmental value (WEI decreased from 44.80 to 40.68). These changes threaten ecosystem sustainability and reduce the capacity to deliver ecosystem services.

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.

Alex Barimah Owusu, Collins Adjei Mensah, Clement Kwang, Gerald Albert Baeribameng Yiran, Ronald Reagan Gyimah, Dominic Edem Hotor, Princella Ofori Darko · International Planning Studies · Ghana

This paper analyzed the replacement of green spaces with brown spaces in Accra, Ghana, from 1991 to 2021 using Landsat satellite images. Brown areas increased from 24.5% in 1991 to 81% in 2021, while green areas decreased from 75.5% to 19% during the same period. The study found a significant reduction in green spaces due to urbanization.

Marcelo Silveira Badejo, Calebe de Hebrom Livistom da Silva, Joana Josiane Andriotte Oliveira Lima Nyland, Afonso Henrique da Silva Júnior, Juliano da Rosa Justim, Cassiano Ranzan · OBSERVATÓRIO DE LA ECONOMÍA LATINOAMERICANA · Brazil

In Santo Antônio da Patrulha, Brazil, a tree inventory was conducted in the Cidade Alta and Centro neighborhoods to support an urban afforestation project. The survey revealed a lack of trees in 5 out of 41 streets in Cidade Alta and 2 out of 28 streets in Centro, with high rates of unidentified trees (53% and 12% respectively). Furthermore, pedagogical practices tested in schools and universities raised challenges regarding the management of flowerbeds in urban areas.

Sara-Charlotte Cayen, Kesnamelie-Ann Outha, Pierre Paul Audate · International Journal of Environmental Health Research · North America

This narrative review synthesized the ecosystem services of urban food forests and their contributions to urban health and food sustainability in North American cities. Based on 13 studies published between 2018 and 2023, it identified that food forests provide services such as sustainable food production and climate regulation. However, their implementation faces challenges including public space governance, maintenance costs, regulatory barriers, and ecological risks like invasive species.

Marina Abrão Ballak Dias · Revista Andaluza de Antropología · France (Paris)

This article explored how different conceptions of human-nature relationships shaped practices in two community gardens in Paris's Goutte d’Or neighborhood. Conceptions grounded in a human–nature divide prevailed, leading to a conservationist approach. Practices stemming from this perspective were found to be in constant tension with garden goals like increasing urban biodiversity and human socialization.

Mahacla Odongo, Caleb Mireri, Peter Mwangi · Environmental Technology and Science Journal · Kenya (Nairobi)

The Nairobi River riparian reserve in Kenya has undergone immense land use and land cover changes over the past 20 years due to urban development. A survey of 650 respondents revealed that urban agricultural activities dominated the upper segment at 69%, commercial ventures constituted 79% of the middle segment, and residential usage comprised 89% in the lower segment. These activities caused significant degradation from crop cultivation of river slopes, pollution infiltration, and loss of biodiversity, indicating a severe depletion of the riparian space's functions.

Marcus Robinson, Jacky Bowring, Shannon Davis, Sarah Edwards · Landscape Research · Global

This narrative review explored how urban expansion at the rural-urban fringe drives the loss of productive agricultural land, biodiversity, and ecosystem services. The review examined how these competing interests can be negotiated spatially, emphasizing the role of multifunctional green infrastructure to integrate both food production and ecological function across the urban-rural continuum.

Belma Soto-Fernández, Lurys Bourdett-Stanziola · Asian Journal of Agricultural and Horticultural Research · Latin America

A documentary review on the importance of urban gardening in Latin America revealed that urban gardening, when approached through the lens of agrobiodiversity, has become a key strategy for safe food production and environmental sustainability. However, it was found that several Latin American countries lack clear and established laws to regulate this activity. Preliminary evidence of rotavirus was detected in fresh vegetables from an urban garden in Panama, indicating that urban gardens can become infection foci capable of causing diseases of public health and veterinary importance.

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.

Jelena Salmi, Anna Krzywoszynska · Environmental Science & Policy · Finland

A discourse analysis of 103 governance and grey literature documents in Finland examined the politics of soil biodiversity indicators. The study found that eDNA is the preferred scientific basis for soil biodiversity governance in Finland due to alignment between scientific and policy groups. However, land workers' organizations criticize eDNA methods, arguing they risk obscuring local specificity and creating environmental and social injustice, potentially alienating land management groups.

Cristian Granados Martínez, Meyer Guevara-Mora, Eugenia López‐López, José Rincón Ramírez · Water · Colombia

This study evaluated aquatic macroinvertebrate community structure in the Ranchería River, Colombia, across conserved, urban/agricultural, and mining zones during the dry season (January–March 2021). Urban/agricultural zones showed the lowest richness (35 genera) and were characterized by disturbance-tolerant species, particularly Melanoides. Land use types constituted the primary driver of community structure, with a 24.1% pure effect, exceeding physical, chemical, and land cover variables.

Sergi Ventura, J.R. Armengol Miró, David Camacho-Caballero, Enric Casellas, Ricard Segura-Barrero, Alberto Martilli, gara villalba · Urban Climate · Spain (Barcelona)

This study used the Pseudo Global Warming method and WRF model to assess urban heat adaptation strategies in the Metropolitan Area of Barcelona. Three strategies were evaluated: increasing rooftop albedo, implementing irrigated sedum green roofs, and increasing peri-urban agriculture and urban parks. While increasing rooftop albedo provided the greatest daytime cooling (−1.75 °C), and green roofs and peri-urban agriculture showed moderate regulation, none of the strategies fully counterbalanced the projected 6 °C temperature increase by 2100, indicating a limited capacity of these adaptations under severe warming scenarios.

Rueda, Ximena · Socio-Environmental Systems Modeling · Africa

A 2025 comparative analysis examines agricultural, economic, and biodiversity policy across Cameroon, Kenya, and Colombia in the context of agricultural expansion, using discourse analysis of policy documents via the Nature Futures Framework and Life Frames Framework, an evaluation of budgets allocated to major agricultural and biodiversity policies, and stakeholder interviews. It finds a shared struggle across all three countries to harmonize agricultural development with biodiversity conservation despite differing institutional capacities, historical pathways, and sociocultural contexts, with agriculture continuing to dominate policy agendas and resource allocation even as recognition of biodiversity's importance grows. Nature is framed primarily in instrumental terms, most strongly so in Colombia's utilitarian "Nature for Society" orientation, with intrinsic and relational values rooted in Indigenous cosmologies weakly reflected in implementation; funding for biodiversity-related ministries remains minimal relative to agriculture in all three countries — Kenya's environmental budget rarely exceeds 0.3% of national expenditure, with Cameroon showing similar disparities and Colombia's allocations continuing to favor agricultural expansion — and institutional fragmentation further undermines this governance.

Magboul M.S. Siddig, Stephen Boahen Asabere, Abdullah S. Al-Farraj, Eric C. Brevik, Daniela Sauer · Journal of Hazardous Materials Advances · Sudan

This systematic review and meta-analysis examined 76 publications on soil heavy metals in Sudan published between 1996 and 2024, assessing concentrations of 10 heavy metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Zn) and potential ecological risk index (PERI) across 9 land-use types including urban agricultural, industrial, roadside, tannery, waste dump, rural agricultural, coastal sediment, gold mining, and river sediment areas. Average heavy metal levels across all land uses exceeded common soil ranges, with Cd, Cr, Cu, Hg, Ni, and Pb surpassing WHO/FAO limits. In urban agricultural soils, Cd averaged about 158 times and Hg about 340 times typical background ranges, while industrial, gold mining, and waste dump land uses exceeded a serious ecological risk threshold (PERI greater than 900). Cd and Hg together accounted for over 70% of PERI in waste dump and gold mining sites.

Mwangi Kamau, Wanjiku Otieno · International Journal of Veterinary Sciences and Animal Husbandry · Kenya

This study characterized the physicochemical quality of untreated wastewater from three small-scale slaughterhouses on the outskirts of Nairobi, Kenya, and measured its effect on soil microbiology at 0, 50, and 200 meters from the discharge point during both wet and dry seasons. Wastewater biochemical oxygen demand (BOD5) ranged from 1,840 to 2,620 mg/L and chemical oxygen demand (COD) from 3,410 to 4,870 mg/L, exceeding Kenyan discharge standards by 6- to 10-fold. Total bacterial counts in soil at the discharge point were 2.7 times higher than at 200 m (p<0.001), and total coliform counts were 4.1 times higher (p<0.001). The Shannon-Wiener diversity index rose significantly with distance from the discharge point (1.42±0.14 at 0 m vs. 2.34±0.18 at 200 m; p<0.001), indicating that wastewater irrigation selects for a less diverse, coliform-dominated soil microbial community. Seasonal variation was significant for BOD5 and coliform loading but not for the diversity index.

Fetty Dwi Rahmayanti, Andi Gunawan, Anas Miftah Fauzi, Edi Santosa · Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) · Indonesia (Jakarta)

A mixed-methods study assessing biodiversity risk from urban agriculture activities in East Jakarta, Indonesia, combining a literature review with a field survey of questionnaires on respondents' perceptions of biodiversity risk to flora and fauna. The results showed the p-value exceeded the alpha level (0.05), indicating that urban agriculture in East Jakarta does not significantly affect biodiversity risks to flora and fauna.

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.

Ermias Debie · City and Environment Interactions · Ethiopia

A study in Bahir Dar, Ethiopia examined the integration of urban agriculture (UA) and green infrastructure (GI) through surveys and interviews with 99 stakeholders, supplemented by participatory observation. The main barriers to integration, based on multiple-response data, were a lack of supportive policies and regulatory frameworks (87%), limited awareness (57%), and space constraints (51%). Multicriteria decision analysis ranked integrated practices as the most effective strategy (score 16.81), followed by edible tree planting at garden centers (16.18), small gardens (13.83), and fence-edge greening (11.46). Structural equation modeling identified thermal regulation and access to fresh food as critical factors for planning sustainable urban systems.