Research & reports

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.

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.

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.

Catherine Oliver · Transactions of the Institute of British Geographers · United Kingdom (London)

This paper examines urban chicken-keeping in London, where urban spaces are transformed to accommodate chickens. It argues that the human-imposed design of urban barnyards is often impractical for chickens, leading to lawns being torn up, plants demolished, and vegetable patches consumed. Additionally, chickens are vulnerable to local foxes, highlighting that chickens' behaviors and territoriality often overflow their assigned space, challenging human design intentions.

Veronica Sebald, Julia M. Schmack, Monika Egerer · Renewable Agriculture and Food Systems · Germany

This study surveyed the occurrence of poisonous plant species in 30 urban community gardens across two German cities, Berlin and Munich, and examined concerns around poisonous and highly poisonous plants in urban garden settings. It found that plants producing substances toxic to humans occur in these gardens while also potentially holding ecosystem-functioning and biodiversity-conservation value, creating a trade-off with the ecosystem service of human health promotion, and concludes that poisonous plants should be carefully monitored and managed—depending on garden participants and the goals of the garden organization—to mitigate health risks while still supporting biodiversity conservation.

Marek Kopacki, Krystyna Rysiak, Mariusz Szmaraga · Annales Horticulturae · Poland (Lublin)

This 2014 study near Lublin, Poland, evaluated the decorative qualities and health of Tithonia rotundifolia in urban plantings, including a botanical garden and allotment gardens. Observations at the end of the vegetation period revealed disease symptoms, and mycological analysis of dead plant parts identified isolates of fungi from eleven genera. Dominant and dangerous pathogenic genera, Alternaria alternata and Botrytis cinerea, were found to affect T. rotundifolia.