The future of urban agriculture and biodiversity-ecosystem services: Challenges and next steps

Integrating policy, data and technology in pursuing effective management of ecosystem services

With the growing concerns about the protection of ecosystem functions and services, governments have developed public policies and organizations have produced an awesome volume of digital data freely available through their websites. On the other hand, advances in data acquisition through remote sensed sources and processing through geographic information systems (GIS) and statistical tools, allowed an unprecedent capacity to manage ecosystems efficiently. However, the real-world scenario in that regard remains paradoxically challenging. The reasons can be many and diverse, but a strong candidate relates with the limited engagement among the interest parties that hampers bringing all these assets into action. The aim of the study is to demonstrate that management of ecosystem services can be significantly improved by integrating existing environmental policies with environmental big data and low-cost GIS and data processing tools. Using the Upper Rio das Velhas hydrographic basin located in the state of Minas Gerais (Brazil) as example, the study demonstrated how Principal Components Analysis based on a diversity of environmental variables assembled sub-basins into urban, agriculture, mining and heterogeneous profiles, directing management of ecosystem services to the most appropriate officially established conservation plans. The use of GIS tools, on the other hand, allowed narrowing the implementation of each plan to specific sub-basins. This optimized allocation of preferential management plans to priority areas was discussed for a number of conservation plans. A paradigmatic example was the so-called Conservation Use Potential (CUP) devoted to the protection of aquifer recharge (provision service) and control of water erosion (regulation service), as well as to the allocation of uses as function of soil capability (support service). In all cases, the efficiency gains in readiness for plans' implementation and economy of resources were prognosed as noteworthy.

Linking policies and regulations to sustainable finance for the promotion of urban agriculture: Evidence from micro and small businesses

Urban agriculture is closely tied to several of the Sustainable Development Goals. It can play a critical role in helping to achieve these goals by promoting sustainable food production and consumption, reducing greenhouse gas emissions, and creating more sustainable cities. It is also considered a pathway for overcoming food security in urban areas. However, this needs to be integrated with policies and regulations supported by sustainable finance. Due to COVID-19, conflict, and lack of infrastructure in Ethiopia, several challenges must be addressed to promote urban agriculture to aid food security. Hence, this study is conducted to examine how government policies and regulations promote urban agriculture through sustainable finance in Ethiopia. The study employed both an explanatory research design and a mixed research approach. Multi-stage sampling techniques that include (Simple random sampling techniques and judgmental sampling were used. The data was collected from selected micro and small enterprises engaged in urban agriculture. The structural and measurement model is estimated with the help of smart-pls software version 4. The study's finding implies that government policies and regulations have an insignificant effect on urban agriculture. At the same time, the study finding implies that sustainable finance has an important mediating role between urban agriculture and government policies. Hence, the impact of government policies and regulations on urban agriculture is found to have an indirect effect. Based on the study's findings, the study recommends that all stakeholders promote innovation and entrepreneurship that promote urban agriculture through sustainable finance.

Local Habitat Complexity and Its Effects on Herbivores and Predators in Urban Agroecosystems

In urban community gardens, cultivated vegetation provides variable levels of habitat complexity, which can suppress pests by promoting predator diversity and improving pest control. In this study, we examine three components of the structural complexity of garden vegetation (cover, diversity, and connectivity) to investigate whether higher garden vegetation complexity leads to fewer herbivores, more predators, and higher predation. We worked in eight community gardens where we quantified vegetation complexity, sampled the arthropod community, and measured predation on corn earworm eggs. We found that plots with high vegetation cover supported higher species richness and greater abundance of predatory insects. High vegetation cover also supported a greater abundance and species richness of spiders. In contrast, high vegetation diversity was negatively associated with predator abundance. While high predator abundance was positively associated with egg predation, greater predator species richness had a negative impact on egg predation, suggesting that antagonism between predators may limit biological control. Community gardeners may thus manipulate vegetation cover and diversity to promote higher predator abundance and diversity in their plots. However, the species composition of predators and the prevalence of interspecific antagonism may ultimately determine subsequent impacts on biological pest control.

Biotechnology and urban agriculture: A partnership for the future sustainability

The global population is growing rapidly, and with it, the demand for food. In the coming decades, more and more people will be living in urban areas, where land for traditional agriculture is scarce. Urban agriculture can help to meet this growing demand for food in a sustainable way. Urban agriculture is the practice of growing food in urban areas. It can be done on rooftops, balconies, vacant lots, and even in alleyways. Urban agriculture can produce a variety of crops, including fruits, vegetables, and herbs. It can also help to improve air quality, reduce stormwater runoff, and create jobs. Biotechnology can be used to improve the efficiency and sustainability of urban agriculture. Biotechnological tools can be used to develop crops that are resistant to pests and diseases, that are more tolerant of drought and heat, and that have higher yields. Biotechnology can also be used to improve the nutritional value of crops. This review article discusses the need for and importance of urban agriculture, biotechnology, and genome editing in meeting the growing demand for food in urban areas. It also discusses the potential of biotechnology to improve the sustainability of urban agriculture.

The effects of multilayer blue-green roof on the runoff water quality

In the context of climate changes, characterized by an increase of short but intense rainfall events and rise of the average temperature, the fast population growth and consequent urbanization require the implementation of innovative solutions to mitigate pluvial floods and, at the same time, reduce the water demand. Among the different nature-based solutions, multilayer blue-green roofs have been widely recognized for their high capacity of reducing runoff generation from rooftops, and their additional storage layer enables to collect water, which could be reused for different purposes. However, the quality of the collected water in a multilayer blue-green roof and the influence that the additional storage layer has on it have not been analysed yet. Following this knowledge gap, we investigated the potential benefits of a multilayer blue-green roof installed in Cagliari, with respect to a traditional roof. The outflow triggered by artificial irrigation and natural rainfall events was analysed, both from a quantitative and qualitative perspective. Results confirm the high contribution of multilayer blue-green roofs in mitigating runoff generation, which is however influenced by antecedent soil moisture and water level conditions. The outflow from the multilayer blue-green roof presents lower suspended solids and heavy metals concentrations than from a traditional roof. On the other hand, Carbon Oxigen Demand (COD) concentrations in the multilayer blue-green roof outflow exceed the limits defined by the Italian regulations (125 mg/l) for water discharge or reuse, partially due to the high residence time in the storage layer. Specific treatments could be planned to reuse the collected water for urban purposes.

ediblecity: an R package to model and estimate the benefits of urban agriculture

Urban agriculture is gaining attraction to become one of the pillars of the urban ecological transition and to increase food security in an urbanized planet. However, there is a lack of systematic quantification of the benefits provided by urban agriculture solutions. In this paper, we present an R package to estimate several indicators related to benefits of urban agriculture. The goal is to provide a tool for researchers and practitioners interested in the impacts of urban agriculture. The ediblecity package provides functions to calculate 8 indicators: urban heat island, runoff prevention, green areas accessibility, NO 2 sequestration, jobs created in commercial gardens, volunteers involved in community gardens, green per capita and, finally, food production. Moreover, the package also provides a function to generate scenarios with different implementations of urban agriculture. We illustrate the use of the package by comparing three scenarios in a neighborhood of Girona (Spain), which is included in the package as an example dataset. There, we compare scenarios with an increasing amount of urban agriculture solutions. The ediblecity package is open-source software. This allows other R developers to contribute to the package, providing new functionalities or improving the existing ones.

Promoting Beneficial Arthropods in Urban Agroecosystems: Focus on Flowers, Maybe Not Native Plants

(1) Urbanization threatens biodiversity, yet urban native plants support native biodiversity, contributing to conservation and ecosystem services. Within urban agroecosystems, where non-native plants are abundant, native plants may boost the abundance and richness of beneficial arthropods. Nevertheless, current information focuses on pollinators, with little attention being paid to other beneficials, like natural enemies. (2) We examined how the species richness of native plants, garden management, and landscape composition influence the abundance and species richness of all, native, and non-native bees, ladybeetles, ants, and ground-foraging spiders in urban agroecosystems (i.e., urban community gardens) in California. (3) We found that native plants (~10% of species, but only ~2.5% of plant cover) had little influence on arthropods, with negative effects only on non-native spider richness, likely due to the low plant cover provided by native plants. Garden size boosted native and non-native bee abundance and richness and non-native spider richness; floral abundance boosted non-native spider abundance and native and non-native spider richness; and mulch cover and tree and shrub abundance boosted non-native spider richness. Natural habitat cover promoted non-native bee and native ant abundance, but fewer native ladybeetle species were observed. (4) While native plant richness may not strongly influence the abundance and richness of beneficial arthropods, other garden management features could be manipulated to promote the conservation of native organisms or ecosystem services provided by native and non-native organisms within urban agroecosystems.

Rewilding in Miniature: Suburban Meadows Can Improve Soil Microbial Biodiversity and Soil Health

Lawns are a ubiquitous, human-made environment created for human enjoyment, leisure, and aesthetics. While net positive for carbon storage, lawns can have negative environmental impacts. Lawns require frequent mowing, which produces high levels of CO₂ pollution and kills off native plants. Lawn fertilizing creates its own environmental pollution. One (presumed) ecologically-friendly alternative to lawns is restoration, or rewilding, of these spaces as meadows, which need less maintenance (e.g., infrequent mowing). However, little work has compared lawns against small-scale meadows for biodiversity outside of pollinator studies. Here, we tested the hypotheses that compared to lawns, meadows have (1) unique and higher levels of soil microbial biodiversity and (2) different soil physical and chemical characteristics. We conducted bacterial (16S) and fungal (ITS2) metabarcoding, and found that both bacteria and fungi are indeed more diverse in meadows (significantly so for bacteria). Species composition between meadows and lawns was significantly different for both types of microbes, including higher levels of mycorrhizal fungi in meadows. We also found that chemistry (e.g., potassium and metrics relating to pH) differed significantly between lawns and meadows and was more optimal for plant growth in the meadows. We believe these differences are caused by the different organisms dwelling in these habitats. In summary, these findings point to notable-positive-shifts in microbial and chemical compositions within meadows, further indicating that meadow restoration benefits biodiversity and soil health.

A sustainability scoring system to assess food initiatives in city regions

The City Region Food Systems approach has been proposed to achieve food system resilience and nutrition security while promoting the urgent ecological transition within urban and peri-urban areas, especially after the COVID-19 pandemic. However, the great diversity of the initiatives composing City Region Food Systems in Europe poses barriers to the assessment of their integrated sustainability. Hence, the present work is developed within the EU-H2020 project Food System in European Cities (FoodE), to build a consistent sustainability scoring system that allows comparative evaluation of City Region Food System Initiatives. Adopting a Life Cycle Thinking approach, it advances on existing knowledge and past projects, taking advantage of a participatory process, with stakeholders from multidisciplinary expertise. As a result, the research designs, and tests on 100 case studies a simplified and ready-to-use scoring mechanism based on a quali-quantitative appraisal survey tool, delivering a final sustainability score on a 1-5 points scale, to get insights on the social, economic, and environmental impacts. As in line with the needs of the UN Sustainable Development Goals, the outcome represents a step forward for the sustainable development and social innovation of food communities in cities and regions, providing a practical and empirical lens for improved planning and governance.

Multiple ecosystem service synergies and landscape mediation of biodiversity within urban agroecosystems

Ecosystem services (ESs) are essential for human well-being, especially in urban areas where 60% of the global population will live by 2030. While urban habitats have the potential to support biodiversity and ES, few studies have quantified the impact of local and landscape management across a diverse suite of services. We leverage 5 years of data (>5000 observations) across a network of urban community gardens to determine the drivers of biodiversity and ES trade-offs and synergies. We found multiple synergies and few trade-offs, contrasting previous assumptions that food production is at odds with biodiversity. Furthermore, we show that natural landscape cover interacts with local management to mediate services provided by mobile animals, specifically pest control and pollination. By quantifying the factors that support a diverse suite of ES, we highlight the critical role of garden management and urban planning for optimizing biodiversity and human benefit.

Vegetation complexity and nesting resource availability predict bee diversity and functional traits in community gardens

Urban gardens can support diverse bee communities through resource provision in resource poor environments. Yet the effects of local habitat and landscape factors on wild bee communities in cities is still insufficiently understood, nor is how this information could be applied to urban wildlife conservation. Here we investigate how taxonomic and functional diversity of wild bees and their traits in urban community gardens are related to garden factors and surrounding landscape factors (e.g., plant diversity, amount of bare ground, amount of nesting resources, amount of landscape imperviousness). Using active and passive methods in 18 community gardens in Berlin, Germany, we documented 26 genera and 102 species of bees. We found that higher plant species richness and plant diversity as well as higher amounts of deadwood in gardens leads to higher numbers of wild bee species and bee (functional) diversity. Furthermore, higher landscape imperviousness surrounding gardens correlates with more cavity nesting bees, whereas a higher amount of bare ground correlates with more ground-nesting bees. Pollen specialization was positively associated with plant diversity, but no factors strongly predicted the proportion of endangered bees. Our results suggest that, aside from foraging resources, nesting resources should be implemented in management for more pollinator-friendly gardens. If designed and managed using such evidence-based strategies, urban gardens can create valuable foraging and nesting habitats for taxonomically and functionally diverse bee communities in cities.

Urban agriculture in walkable neighborhoods bore fruit for health and food system resilience during the COVID-19 pandemic

Urban agriculture is the key to creating healthy cities and developing resilient urban food systems in uncertain times. However, relevant empirical evidence is limited. This study quantitatively verified the association of access to local food through urban agriculture with subjective well-being, physical activity, and food security concerns of neighborhood communities in the context of the COVID-19 pandemic. The target was Tokyo, Japan, where small-scale local food systems are widespread in walkable neighborhoods. We found that diversity in local food access, ranging from self-cultivation to direct-to-consumer sales, was significantly associated with health and food security variables. In particular, the use of allotment farms was more strongly associated with subjective well-being than the use of urban parks, and it was more strongly associated with the mitigation of food security concerns than the use of food retailers. These findings provide robust evidence for the effectiveness of integrating urban agriculture into walkable neighborhoods.

Functional diversity of farmland bees across rural-urban landscapes in a tropical megacity

Urbanization poses a major threat to biodiversity and food security, as expanding cities, especially in the Global South, increasingly compete with natural and agricultural lands. However, the impact of urban expansion on agricultural biodiversity in tropical regions is overlooked. Here we assess how urbanization affects the functional response of farmland bees, the most important pollinators for crop production. We sampled bees across three seasons in 36 conventional vegetable-producing farms spread along an urbanization gradient in Bengaluru, an Indian megacity. We investigated how landscape and local environmental drivers affected different functional traits (sociality, nesting behavior, body size, and specialization) and functional diversity (functional dispersion) of bee communities. We found that the functional responses to urbanization were trait specific with more positive than negative effects of gray area (sealed surfaces and buildings) on species richness, functional diversity, and abundance of most functional groups. As expected, larger, solitary, cavity-nesting, and, surprisingly, specialist bees benefited from urbanization. In contrast to temperate cities, the abundance of ground nesters increased in urban areas, presumably because larger patches of bare soil were still available beside roads and buildings. However, overall bee abundance and the abundance of social bees (85% of all bees) decreased with urbanization, threatening crop pollination. Crop diversity promotes taxonomic and functional diversity of bee communities. Locally, flower resources promote the abundance of all functional groups, and natural vegetation can maintain diverse pollinator communities throughout the year, especially during the noncropping season. However, exotic plants decrease functional diversity and bee specialization. To safeguard bees and their pollination services in urban farms, we recommend (1) preserving seminatural vegetation (hedges) around cropping fields to provide nesting opportunities for aboveground nesters, (2) promoting farm-level crop diversification of beneficial crops (e.g., pulses, vegetables, and spices), (3) maintaining native natural vegetation along field margins, and (4) controlling and removing invasive exotic plants that disrupt native plant-pollinator interactions. Overall, our results suggest that urban agriculture can maintain functionally diverse bee communities and, if managed in a sustainable manner, be used to develop win-win solutions for biodiversity conservation of pollinators and food security in and around cities.

Analysis of Urbanization and Climate Change Effects on Community Resilience in the Rio Grande Valley, South Texas

Disruptive development events have tested and will continue to test community resilience as people work to balance healthy living, economic growth, and environmental quality. Aspects of urbanization, if not designed and guided by healthy living strategies, convert natural areas into built environments, thus reducing the diversity of plant and animal species that are the foundation of resilience in communities. In this study, we attempted to answer the following question: What are the most effective ways to ensure that ongoing urbanization and climate change do not negatively affect ecological services and community resilience in the Rio Grande Valley (RGV)? The region is experiencing a high urban growth rate and is also one of the poorest regions in Texas. Thus, it has an inadequate capacity to prevent or mitigate climate change-related threats and take advantage of opportunities associated with urbanization. Using qualitative analysis, we consulted existing literature to identify relevant leverage points that can help foster regional resilience capacity. The findings show that there are very strong leverage points that can produce cumulative desired resilience outcomes, but these have not been incorporated into policy and natural systems in the RGV.

A Typology of Nature-Based Solutions for Sustainable Development: An Analysis of Form, Function, Nomenclature, and Associated Applications

This study presents a typology of nature-based solutions (NbS), addressing the need for a standardized source of definitions and nomenclature, and to facilitate communication in this interdisciplinary field of theory and practice. Growing usage of the umbrella phrase ‘nature-based solutions’ has led to a broad inclusion of terms. With the diversity of terminology used, the full potential of NbS may be lost in the confusion of misapplied terms. Standardization and definition of commonly used nature-based nomenclature are necessary to facilitate communication in this rapidly expanding field. Through objective systemization of applications, functions, and benefits, NbS can be embraced as a standard intervention to address societal challenges and support achievement of the UN SDGs.

Effectiveness of washing in reducing lead concentrations of lettuce grown in urban garden soils

Urban gardeners contribute to sustainable cities and often take great care to limit exposure to soil contaminants like lead (Pb). Although best management practices (BMPs) like mulching to reduce soil splash can limit crop contamination, they may not eliminate all contamination for leafy greens, which trap soil particles. How effective is washing at removing Pb contamination from leafy greens when using BMPs? Are certain washing techniques more effective than others? We present results from two experiments addressing these questions. We grew lettuce (Lactuca sativa L.) in homogenized high-Pb (∼1,150 mg kg-1 ) and low-Pb (∼90 mg kg-1 ) soils in Brooklyn, NY, and Ithaca, NY. Our results show that washing can remove 75-94% of Pb from lettuce, including that remaining after the use of contamination-reducing BMPs. It was estimated that washing removed 97% of Pb deposited by splash, which is the dominant source of Pb, and removed 91% deposited by downward deposition. All washing techniques were effective at reducing Pb levels, with differences in effectiveness ranked as: commercial soak > vinegar soak > water soak (and water rinse not significantly different from vinegar or water soak). Washing crops grown in low-Pb soils is also important. Without washing, lettuce grown in low-Pb soil may still have Pb levels above the European Commission comparison value. We offer these empirical findings and recommendations in support of urban growers.

Lowering the Temperature to Increase Heat Equity: A Multi-Scale Evaluation of Nature-Based Solutions in Toronto, Ontario, Canada

Nature-based solutions (NbS) present an opportunity to reduce rising temperatures and the urban heat island effect. A multi-scale study in Toronto, Ontario, Canada, evaluates the effect of NbS on air and land surface temperature through two field campaigns at the micro and meso scales, using in situ measurements and LANDSAT imagery. This research demonstrates that the application of NbS in the form of green infrastructure has a beneficial impact on urban climate regimes with measurable reductions in air and land surface temperatures. Broad implementation of green infrastructure is a sustainable solution to improve the urban climate, enhance heat and greenspace equity, and increase resilience.

Exploring connections between pollinator health and human health

Despite recent advances in understanding the role of biodiversity in ecosystem-service provision, the links between the health of ecosystem-service providers and human health remain more uncertain. During the past decade, an increasing number of studies have argued for the positive impacts of healthy pollinator communities (defined as functionally and genetically diverse species assemblages that are sustained over time) on human health. Here, we begin with a systematic review of these impacts, finding only two studies that concomitantly quantified aspects of pollinator health and human health. Next, we identify relevant research relating to four pathways linking pollinator health and human health: nutrition, medicine provisioning, mental health and environmental quality. These benefits are obtained through improved pollination of nutritious crops and an estimated approximately 28 000 animal-pollinated medicinal plants; the provisioning of pollinator-derived products such as honey; the maintenance of green spaces and biocultural landscapes that improve mental health; and cleaner air, water and food resulting from pollinator-centred initiatives to reduce agrochemical use. We suggest that pollinator diversity could be a proxy for the benefits that landscapes provide to human health. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.

Powerline Corridors Can Add Ecological Value to Suburban Landscapes When Not Maintained as Lawn

Electric powerline corridors are informal green spaces that encompass large areas of land and have the potential to support biodiversity in urban and suburban landscapes. However, the extent to which these corridors provide novel habitats compared to the surrounding landscape is unclear. Biodiversity in corridors is often compared to that of “natural” habitats despite the fact that the corridors are subject to frequent vegetation management. In urban and suburban landscapes, residential yards may provide a more appropriate comparison because they are a dominant type of green space and are also characterized by frequent vegetation management. We conducted a study of the biodiversity in suburban powerline corridors in northern Illinois, USA, and compared it to the biodiversity found in nearby residential yards. Our goal was to determine whether powerline corridors added ecological value to these suburban landscapes. We included three different management styles of powerline corridors: (1) frequently mowed and kept as lawn, (2) brush mowed on a five-year cycle (“old-field”), and (3) restored and/or maintained as native prairie. We measured the species richness and composition of plants, birds, and insect pollinators in corridors and yards. The corridor management types and comparison yards differed significantly in the richness of all three taxa, with old-field and/or prairie sites having greater species richness than mown corridors and/or comparison yards. Community composition also differed by management category. While the species richness of old-field sites tended to be high, prairie sites generally had more species of conservation interest. Our study shows that both old-field- and prairie-managed powerline corridors add habitat value to Midwestern U.S. suburban landscapes by providing alternative habitat types that support many species. Nonetheless, we suggest that managers looking to specifically support native and/or grassland specialist species in this region should manage sites as prairies when possible.

Making Green(s) With Black and White: Constructing Soils for Urban Agriculture Using Earthworms, Organic and Mineral Wastes

Urban agriculture has been of growing interest for a decade because it can address many economic and societal issues in the development of modern cities. However, urban agriculture is often limited by the availability of fertile and non-contaminated soils in the cities. Recycling excavated mineral wastes from building activities to construct fertile soils may be a more sustainable alternative than the importation of topsoils from rural zones. The present study aims to evaluate the possibility to grow green vegetables on soils made with excavated deep horizon of soils and green waste compost. During three consecutive seasons, we tested in situ the effects of different amounts of compost (10, 20, and 30%) and the addition of an earthworm species (Lumbricus terrestris) on the production of lettuce (Lactuca sativa L.), arugula (Eruca sativa Mill.), and spinach (Spinacia oleracea L.) in mono- and co-culture. Our results demonstrate that it is possible to reuse mineral and organic urban wastes to engineer soils adapted to agriculture. Here, we observed that higher doses of compost significantly increased plant biomass, especially when earthworms were introduced. For example, in the autumn, going from 10 to 30% of compost in the soil mixture allows to multiply by 2 the arugula biomass, and even by 4 in the presence of earthworms. These results were partly due to the positive effects of these two factors on soil physical properties (micro- and macro-porosity). This preliminary study also showed that some plants (arugula) are more adapted than others (lettuce) to the soil properties and that it only takes few months to get the highest yields. These promising results for the development of urban agricultures encourage to test many other combination of plant and earthworm species but also to conduct experiments over long-term periods.

Microclimatic and Environmental Improvement in a Mediterranean City through the Regeneration of an Area with Nature-Based Solutions: A Case Study

Dense urban areas are facing relevant issues related to their high vulnerability to the impacts of climate change and ecosystem health. The study presents a case study of a regeneration project with Nature-based Solutions in the city of Genoa (Italy) and, more specifically, in a neighbourhood characterised by relevant health and well-being issues. The performances of three design scenarios for a city hotspot, including plant species selected with a systemic approach and light pavements, are analysed in terms of improved microclimate by means of the ENVI-met software V4.4.5. The results show different benefits on the microclimate compared to the current state depending on the different scenarios: A UTCI decrease from 4.1 °C to 5.4 °C, a reduction of mean radiant temperature from 12.3 °C to 17.3 °C, a relative humidity increase from 3.8% to 5.6%, and a progressive decrease in wind speed are detected in a directly proportional way to the gradual increase in greenery inside the scenarios. In reverse, better results for air temperatures are detected for the scenario with less greening (Δt = 1.8 °C). The study relies on the re-parametrisation of plant species characteristics in the ENVI-met database to reach a high level of accuracy.

Application of UAV remote sensing and machine learning to model and map land use in urban gardens

Urban gardens are an integral part of urban agricultural systems, contributing to ecosystem services, biodiversity and human wellbeing. These systems occur at fine scales, can be highly complex and therefore offer the opportunity to test mechanisms of ecological patterns and processes. The capacity to confidently characterize urban gardens and their land uses is still lacking, while it could provide the basis for assessing ecosystem service provision. Land classifications from remote sensing platforms are common at the landscape scale, but imagery often lacks the resolution required to map differences in land use of fine-scale systems such as urban gardens. Here, we present a workflow to model and map land use in urban gardens using imagery from an unoccupied aerial vehicle (UAV) and machine learning. Due to high resolutions (<5 cm) from image acquisition at low altitudes, UAV remote sensing is better suited to characterize urban land use. We mapped six common land uses in 10 urban community gardens, exhibiting distinct spatial arrangements. Our models had good predictive performance, reaching 80% overall prediction accuracy in independent validation and up to 95% when assessing model performance per cover class. Extracting spatial metrics from these land use classifications, we found that at the garden and plot scale, plant species richness can be estimated by the total area and patchiness of crops. Land use classifications like these can offer an accessible tool to assess complex urban habitats and justify the importance of urban agriculture as a service-providing system, contributing to the sustainability and livability of cities.

Winter Bird Diversity and Abundance in Small Farmlands in a Megacity of Southern China

Urban expansion often accompanies a loss of natural habitats and arable lands but an increase in urban population. In China, vegetable-dominant small farmlands are common in urban/peri-urban areas. Some farmlands are also associated with government policy that aims to enhance local farmers’ livelihoods as well as increase food availability for city citizens. While small urban farmlands create open greenery cover that may provide birds with resources such as food and shelter, little attention has been given to understanding bird diversity in urban farmlands. Using two hierarchical models (multi-species occupancy model and N-mixture model), we examined how species richness and abundance of birds were associated with environmental characteristics within and surrounding urban farmlands in Guangzhou, one of the largest cities in China. We conducted crop and bird surveys at urban farmlands during two winter seasons between December 2019 and January 2021. Species richness increased with non-woody (herbaceous) vegetation cover within a farmland. Abundance of three species was also positively associated with the local non-woody vegetation variable. Two species were more abundant at farmlands with higher crop diversity. Compositional features of matrix surrounding a farmland (a 500-m circular area) did not affect species richness. However, species richness and abundance of one species tended to decrease with increasing farmland fragmentation (patch density of farmlands) within a 1-km circular area. These findings suggest that (1) birds could be more influenced by environmental features within farmlands than matrix features surrounding farmlands, (2) local uncultivated herbaceous vegetation is an important environmental feature, and (3) diverse crops in farmlands may benefit some birds. They also indicate that the landscape pattern of farmlands, such as degree of fragmentation, could affect bird diversity in urban farmlands.

Ensuring Urban Food Security in Malaysia during the COVID-19 Pandemic—Is Urban Farming the Answer? A Review

Urbanisation and related insufficiency of food sources is due to the high urban population, insufficient urban food sources, and inability of some urban communities to afford food due to rising costs. Food supply can also be jeopardised by natural and man-made disasters, such as warfare, pandemics, or any other calamities which result in the destruction of crop fields and disruption of food distribution. The COVID-19 pandemic exposed the impact of such calamities on the fresh food supply chain in Malaysia, especially when the Movement Control Order (MCO) policy was first implemented. The resulting panic buying caused some food shortage, while more importantly, the fresh food supply chain was severely disrupted, especially in urban areas, in the early stages of implementation. In this regard, urban farming, while a simple concept, can have a significant impact in terms of securing food sources for urban households. It has been used in several countries such as Canada, The Netherlands, and Singapore to ensure a continuous food supply. This paper thus attempted to review how the pandemic has affected Malaysian participation in urban farming and, in relation to that, the acceptance of urban farming in Malaysia and the initiatives and approaches of local governmental and non-governmental organisations in encouraging the urban community to participate in urban farming through peer-reviewed journal articles and other articles related to urban agriculture using the ROSES protocol. About 93 articles were selected after screening to ensure that the articles were related to the study. During the COVID-19 pandemic, the surge in Malaysians’ awareness of the importance of urban farming has offered great opportunities for the government to encourage more Malaysian urban communities to participate in urban farming activities. Limitations such as relevant knowledge, area, and space, however, are impediments to urban communities’ participation in these activities. Government initiatives, such as the Urban Community Garden Policy (Dasar Kebun Komuniti Bandar (DKKB)), are still inadequate as some issues are still not addressed. Permanent Food Production Parks (TKPM) and technology-driven practices are seen as possible solutions to the primary problem of land and space. Additionally, relevant stakeholders play a crucial role in disseminating relevant and appropriate knowledge and methodology applicable for urban farming. Partnerships between government agencies, the education sector, and the private sector are necessary to develop modern urban agricultural technologies as well as knowledge, knowhow, and supports to build and sustain urban community participation in urban farming activities.

An Ecosystem Service Approach to Assessing Agro-Ecosystems in Urban Landscapes

Creating sustainable urban landscapes in light of growing population pressures requires interdisciplinary multi-functional solutions. Alternative agro-ecosystems described as food forests, permaculture gardens, and/or edible landscapes among others could offer potential ways to address the social, economic, and ecological goals of various stakeholders simultaneously. Current research is lacking a comprehensive tool that can assess the performance of alternative agro-ecosystems that have both functional and aesthetic values. The present research uses a novel rubric, the Permaculture and Agro-ecosystems Sustainability Scorecard (PASS) that combines agricultural sustainability and ecosystem services (ES) indicators in order to assess alternative agro-ecosystems. The rubric evaluates provisioning, regulating, supporting, economic and cultural ES and includes benefits such as pollinator presence, increased biodiversity, alternative pesticides and fertilizer use, carbon sequestration, food security, and human interactions. Based on the concepts and principles drawn from four popular frameworks and sub-disciplines, namely, SAFE, SITES, permaculture, and agroecology, we identify sixteen broad ES indicators and 59 sub-indices and measure them using data collected through site observation, survey, interviews, and documentary research. For easy comparison across different urban agriculture sites, the above sub-indices are further aggregated into five ES criteria using stakeholder-informed weights. The weights are developed through pair-wise comparison of criteria by sample survey respondents. The PASS framework is used to score twelve sites in South Florida that meet specific criteria in the small farm, residential, and public space categories. Sample respondents place the highest weight on cultural services. Contrary to the popular notion of promoting urban agriculture for food security, the results show that the majority of the sites score highest in the supporting services provided, followed by regulating and cultural services, and lowest in the economic services category. The supporting service for most of the sample sites score consistently very high, close to the highest possible level of 5.0. There is a wide variation in provisioning and economic values across the study sites. The paper offers several ideas for mainstreaming the ES indicators into urban planning and decision-making and some of the practical difficulties one might face along the way. We conclude that in order to realize the broader ES benefits of urban agriculture in particular and agro-ecosystems in general, a multi-pronged policy and planning approach is necessary.

Land Cover Change and Its Impact in Crop Yield: A Case Study from Western Nepal

This study was conducted in Tanahun district of Gandaki Province, Nepal, to analyze the land cover change over two decades, the migration effect in land cover, and the impact caused in crop production by Rhesus macaque. Landsat TM/ETM+ for land use of 2000 and 2010 extracted by ICIMOD and Landsat 8 OLI/TIRS satellite images for land cover 2019 were downloaded from the USGS website. A purposive sample for household survey was carried out based on crops damaged by the monkey. Two hundred and fifty households were taken as samples. The Landsat images were analyzed by ArcGIS, and the social data were analyzed using SPSS and MS Excel. Land cover change data revealed increment of forest cover from 36.57% to 40.91% and drastic decrease in agriculture crops from 57.52% to 43.78% in the period of 20 years. The accuracy of the data showed overall classification accuracy of 86.11%, 81.08%, and 75% with overall kappa statistics 0.83, 0.77, and 0.74, respectively. The migration effect in the land cover was related to remittance and migrated members and found a significant positive relationship. Analyzing the trend of production with an increase in the forest cover, 21% decrease in paddy, 5% decrease in maize, and 26% decrease in millet were found as compared to the production in 2000. The econometric model concluded that the quantity of crop damage was negatively significant in relation to distance from forest and distance from water body while positively significant to distance from settlements and distance from owner's home. The quantity of crop damage was estimated 113.89 kg per household, and the cost was 78.82 USD. This study recommends active forest management; regular thinning, and weeding. Remittance generated should be invested in the agriculture field by the households. Damage relief should be made available for the damage cost by Rhesus macaque.

On-Farm Spatial Composition, Management Practices and Estimated Productivity of Urban Farms in the San Francisco Bay Area

Urban areas are the fastest growing land type worldwide. By 2060, it is expected that approximately 70% of the human population will live in cities. With increased urban population growth, food sovereignty and security issues have gained more attention, resulting in a drastic increase in urban food production activities including, urban farming and gardening. The extent to which urban farms function, their social, ecological and economic composition, and their overall impact on local food security has become an often overlooked, but important topic. From 2014 to 2017, we partnered with 29 urban farms in the San Francisco Bay Area for a broad-scale survey of urban farm characteristics. Findings reported in this research focused on local (on-farm) characteristics, including management practices, on-farm spatial composition, and estimated productivity. We implemented open-ended surveys for farm managers to better understand management practices, measured on-farm elements, including yields, crop biodiversity, weed composition and abundance, and measured spatial characteristics such as area of production, non-crop area, and proportion of infrastructure to better understand how urban farms were spatially configured. We found trends regarding spatial composition, including a large proportion of farm area dedicated to infrastructure and underutilized potential production space. All farms surveyed had adopted a breadth of agroecological management practices, including cover cropping, crop rotations, intercropping, and a range of soil conservation practices. Measured farms are incredibly productive, with estimated seasonal yields of 7.14 kg/square meter. Estimated yields were comparable with actual yields as measured at two participating farms.

Consumers’ and Stakeholders’ Acceptance of Indoor Agritecture in Shanghai (China)

During recent decades, there has been increasing awareness of the development of “agritecture” (“agri”culture + archi“tecture”) as a means to transform and revolutionize the food supply of future cities. The different forms of agritecture include building-integrated agricultural concepts such as vertical farms or indoor farms. In this way, urban food production could take place in proximity to consumers while employing so-called “urban waste” products (such as wastewater, waste heat, and organic waste) as valuable production inputs. Although scholars frequently highlight the potential of vertical farming and other agritecture approaches for Asian megacities, there is still a lack of academic research and completed projects related to this field in China. This study uses a mixed-methods approach, combining quantitative and qualitative research in the study location of Shanghai, to reveal the social acceptance of indoor agritecture among consumers and experts. First, to explore the perceptions of consumers, a survey of 713 potential consumers was conducted in Shanghai. Second, these surveys were complemented by 20 expert interviews with academics and practitioners from Shanghai to frame the quantitative research results. Our results revealed that the surveyed consumers’ social acceptance of indoor agritecture and the expectations of the experts are high. Additionally, there is already a high level of demand and a potential market for indoor agritecture in Shanghai. This has been confirmed by the ongoing construction of the first moderate-scale vertical farm and several indoor farms, in combination with the increasing existence of edible landscape approaches and rooftop farms. This development can be viewed as the rise of urban agritecture in Shanghai. The interviews revealed that experts raise more doubts about the economic dimension, whereas its social and ecological dimensions and the contextual framework of indoor agritecture are considered to be positive.

Provision of Allotment Gardens and Its Influencing Factors: A Case Study of Tokyo, Japan

Allotment gardens (AGs) are widely used in metropolitan areas around the world to offer agricultural opportunities to urban residents. However, there are not enough individual plots for residents to rent for urban gardening, and research on AGs from a city-wide perspective is ongoing. In addition, AGs have a long history in Tokyo, yet few international studies on the current situation of AGs have addressed Asian cities. Thus, this study intends to analyze the provision of AGs and its influencing factors in Tokyo. Using ArcGIS combined the 472-points dataset created by geo-coordinate mapping with urban GIS data to reveal spatial characteristics in four dimensions. Results demonstrate that most AGs are in the urbanization promotion area; most municipalities have AGs; AGs are concentrated within 20 to 30 km from the center of Tokyo; the AGs’ clusters are located at the municipal boundaries. We conducted multiple regressions to determine the influencing factors at the municipal level, with the provision that AGs are related to population density, land price, and the ratio of productive green space. The policy implication of this study is that policymakers need to consider the siting strategy of AGs based on spatial characteristics of AGs.

Towards a More Sustainable Urban Food System—Carbon Emissions Assessment of a Diet Transition with the FEWprint Platform

The production, processing, and transportation of food, in particular animal-based products, imposes great environmental burden on the planet. The current food supply system often constitutes a considerable part of the total carbon emissions of urban communities in industrialised cities. Urban food production (UFP) is a method that can potentially diminish food emissions. In parallel, a shift towards a predominantly plant-based diet that meets the nutritional protein intake is an effective method to curtail carbon emissions from food. Considering the high land use associated with the production of animal-based products, such a shift will prompt a community food demand that is more inclined to be satisfied with local production. Therefore, during the design process of a future low-carbon city, the combined application of both methods is worth exploring. This work introduces, describes, and demonstrates the diet shift component of the FEWprint platform, a user friendly UFP assessment platform for designers that is constructed around the broader three-pronged strategy of evaluation, shift, and design. For three neighborhoods, in Amsterdam, Belfast, and Detroit, the contextual consumption and country-specific environmental footprint data are applied to simulate a theoretical community-wide diet shift from a conventional to a vegan diet, whilst maintaining protein intake equilibrium. The results show that in total terms, the largest carbon mitigation potential awaits in Detroit (−916 kg CO2eq/cap/year), followed by Belfast (−866 kg) and Amsterdam (−509 kg). In relative terms, the carbon reduction potential is largest in Belfast (−25%), followed by Amsterdam (−15%) and Detroit (−7%). The FEWprint can be used to generate preliminary figures on the carbon implications of dietary adaptations and can be employed to give a first indication of the potential of UFP in urban communities.

Nature-based cooling potential: a multi-type green infrastructure evaluation in Toronto, Ontario, Canada

The application of green infrastructure presents an opportunity to mitigate rising temperatures using a multi-faceted ecosystems-based approach. A controlled field study in Toronto, Ontario, Canada, evaluates the impact of nature-based solutions on near surface air temperature regulation focusing on different applications of green infrastructure. A field campaign was undertaken over the course of two summers to measure the impact of green roofs, green walls, urban vegetation and forestry systems, and urban agriculture systems on near surface air temperature. This study demonstrates that multiple types of green infrastructure applications are beneficial in regulating near surface air temperature and are not limited to specific treatments. Widespread usage of green infrastructure could be a viable strategy to cool cities and improve urban climate.

Agricultural land systems importance for supporting food security and sustainable development goals: A systematic review

Agriculture provides the largest share of food supplies and ensures a critical number of ecosystem services (e.g., food provisioning). Therefore, agriculture is vital for food security and supports the Sustainable Development Goal (SDGs) 2 (SDG 2 - zero hunger) as others SDG's. Several studies have been published in different world areas with different research directions focused on increasing food and nutritional security from an agricultural land system perspective. The heterogeneity of the agricultural research studies calls for an interdisciplinary and comprehensive systematization of the different research directions and the plethora of approaches, scales of analysis, and reference data used. Thus, this work aims to systematically review the contributions of the different agricultural research studies by systematizing the main research fields and present a synthesis of the diversity and scope of research and knowledge. From an initial search of 1151 articles, 260 meet the criteria to be used in the review. Our analysis revealed that most articles were published between 2015 and 2019 (59%), and most of the case studies were carried out in Asia (36%) and Africa (20%). The number of studies carried out in the other continents was lower. In the last 30 years, most of the research was centred in six main research fields: land-use changes (28%), agricultural efficiency (27%), climate change (16%), farmer's motivation (12%), urban and peri-urban agriculture (11%), and land suitability (7%). Overall, the research fields identified are directly or indirectly linked to 11 of the 17 SDGs. There are essential differences in the number of articles among research fields, and future efforts are needed in the ones that are less represented to support food security and the SDGs.

Vindication of Linking Social Capital Capacity to Urban Agriculture: A Paradigm of Participation Based on Social Empowerment in Klang Valley, Malaysia

With the rise of urbanization, the Malaysian government faces a tough challenge in ensuring food and nutrition security, especially for the disadvantaged urban populations. Urban agriculture (UA) seems to be a feasible approach to be undertaken by the government to overcome urban food insecurity. In distinguishing UA as a vital element of sustainable urban development, the primary challenge is to develop effective programs that engage urban dwellers and organizations through good design and implementation. Additionally, empowering communities through UA programs is challenging. Hence, the major aim of this study is to ascertain the assigned and underlying values of UA participation amongst communities that contribute to aspects of community social empowerment in Klang Valley, Malaysia. The dataset for the study was taken from the respondents (180) who were the participants of UA community programs authorized by the Department of Agriculture in Klang Valley area, and a Structural Equation Modelling using Partial Least Square (PLS-SEM) was utilized to integrate the interdependencies between multiple variables. The findings revealed the important role of participation in the planning, implementation, and evaluation of UA programs to ensure success. Participation should be seen through the roles of agencies, NGOs, and communities in order to build a strong network crucial to the enhancement of social empowerment among participants of UA programs.

Land sharing between cultivated and wild plants: urban gardens as hotspots for plant diversity in cities

Plant communities in urban gardens consist of cultivated species, including ornamentals and food crops, and wild growing species. Yet it remains unclear what significance urban gardens have for the plant diversity in cities and how the diversity of cultivated and wild plants depends on the level of urbanization. We sampled plants growing within 18 community gardens in Berlin, Germany to investigate the species diversity of cultivated and wild plants. We tested species diversity in relation to local and landscape-scale imperviousness as a measure of urbanity, and we investigated the relationship between cultivated and wild plant species within the gardens. We found that numbers of wild and cultivated plant species in gardens are high – especially of wild plant species – independent of landscape-scale imperviousness. This suggests that all community gardens, regardless of their urban contexts, can be important habitats for plant diversity along with their role in urban food provision. However, the number of all species was negatively predicted by local garden scale imperviousness, suggesting an opportunity to reduce imperviousness and create more habitats for plants at the garden scale. Finally, we found a positive relationship between the number of cultivated and wild growing species, which emphasizes that community gardens present a unique urban ecosystem where land sharing between cultivated and wild flora can transpire. As the urban agriculture movement is flourishing worldwide with gardens continuously and spontaneously arising and dissipating due to urban densification, such botanical investigations can support the argument that gardens are places for the reconciliation of plant conservation and food production.

Spatiotemporal dynamics of soil health in urban agriculture

There is a paucity of data on the state of urban agriculture soils. In order to develop efficient management practices, it is necessary to understand the seasonal dynamics of the soil health of these systems. This study sampled two community gardens, and one commercial urban agriculture site on a monthly basis over the span of one year. The dynamic analysis examined soil nutritional, chemical and microbial properties. Plant biodiversity was significantly higher in community gardens compared to commercial sites. Analysis of soil nutrients revealed fluctuations of mineral nitrogen with seasonal conditions and consistently high concentrations of plant-available phosphorus. We identified gradually decreasing soil total nitrogen and carbon concentrations throughout the year. Soils were abundant in arbuscular mycorrhizal fungi spores. Soil metabarcoding using 16S and ITS amplicons revealed a seasonal gradient of the microbial diversity and changes after the application of organic fertilizer. Soil-borne potential human pathogens were also detected in the soils. The results of this study provide relevant information about soil management principles in urban agriculture systems. These principles include mulching and the use of nutrient-balanced composts to counteract decreasing carbon pools and the excessive accumulation of phosphorus.

Enhancing climate resilience of irrigated agriculture: A review

Emerging evidence showing trends in climate change with a strong likelihood those changes will continue elevates the importance of finding affordable adaptations by irrigated agriculture. Successful climate adaptation measures are needed to affordably sustain irrigated agriculture in the face of elevated carbon emissions affecting the reliability of water supplies. Numerous potential adaptation options are available for adjusting irrigated agricultural systems to implement climate risk adaptation. This work focuses on addressing the gap in the literature defined by a scarcity of reviews on measures to elevate the capacity of irrigated agriculture to enhance its climate change resilience. Accordingly, the original contribution of this work is to review the literature describing measures for enhancing climate resilience by irrigated agriculture. In addition, it describes the role of economic analysis to discover affordable measures to enhance resilience by irrigated agriculture. It achieves those aims by posing the question "What principles, practices, and recent developments are available to guide discovery of measures to improve resilience by irrigated agriculture to adapt to ongoing evidence of climate change?" It addresses that question by reviewing several risk reduction measures to control the economic cost of losses to irrigators in the face of growing water supply unreliability. Following this review, a role for optimizing a portfolio of climate adaptation measures is described, followed by a discussion of potential contributions that can be made by the use of hydroeconomic analysis. Results provide a framework for economic analysis to discover economically attractive methods to elevate resilience of irrigated agriculture.

Enabling Nature-Based Solutions to Build Back Better—An Environmental Regulatory Impact Analysis of Green Infrastructure in Ontario, Canada

The application of green infrastructure in the built environment delivers a nature-based solution to address the impacts of climate change. This study presents a qualitative evidence synthesis that evaluates policy instruments which enable the use and implementation of green infrastructure, using Ontario, Canada as a case study. Unpacking the elements of the policy landscape that govern green infrastructure through environmental regulatory impact analysis can inform effective implementation of this nature-based solution and support decision-making in public policy. This environmental regulatory impact analysis is based on a systematic review of existing policy instruments, contextual framing in a continuum of coercion, and identification of alignment with relevant UN SDGs. Enabling widespread usage of green infrastructure in the built environment could be a viable strategy to build back better, localize the UN SDGs, and address multiple climate change impacts.

A Bibliometric and Visual Analysis of Global Urban Resilience Research in 2011–2020: Development and Hotspots

Urban resilience (UR), which promotes the implementation of resilient cities, has received widespread attention. The purpose of this study is to visualize the knowledge background, research status, and knowledge structure of relevant literatures by using a Citespace based scientometrics survey. The results show that UR is an increasingly popular topic, with 2629 articles published during the study period. (1) The most prolific publications and journals involved in the flourishment of UR research were identified by co-citation. The United States was the most productive contributor, with numerous publications and active institutions. Journal of Cleaner Production, Sustainability, International Journal of Disaster Risk Reduction were the three most cited journals. (2) Co-occurrence analysis was employed to determine the highly productive keywords, and subject categories in the UR domain, including “environmental science & ecology”, “environmental sciences, “science & technology”, “environmental studies”, “green & sustainable science & technology”, and “water resources”. (3) The diversity of highly cited authors in different countries and regions confirmed the evolution of UR studies. (4) Furthermore, the classification of UR knowledge was performed in the form of clusters and knowledge structure to achieve ten distinct sub-domains (e.g., Urban floods and stormwater management, Urban ecosystem services, Urban landscapes, and Trauma). This study provides an overview of UR research and research topics so that future researchers can identify their research topics and partners.

Scaling Biodiversity Conservation Efforts: An Examination of the Relationship Between Global Biodiversity Targets and Local Plans

Cities have a critical role to play in meeting global-scale biodiversity targets. Urban socio-ecological systems connect human and ecological well-being. The outsized impact of cities reaches well-beyond their geographic borders through cultural, ecological, and economic interactions. Although cities account for just 2% of the earth's surface, they host over half of the human population and are responsible for 75% of consumption. The Parties to the Convention on Biological Diversity (CBD) and others have acknowledged the important role cities can play in achieving global targets. In response, at least 110 cities have produced plans focused on biodiversity, but we do not know the extent to which these city plans align with global targets or what role they play in achieving these targets. Here, we explore the relationship between global biodiversity conservation targets and local biodiversity plans to identify how elements at the two scales align or diverge. We compared the CBD Strategic Plan 2011–2020 (Aichi Targets) with 44 local biodiversity plans (often called LBSAPs) from cities around the world. We analyzed more than 2,800 actions from the local plans to measure the relationship with these global targets. Our results show how local approaches to biodiversity conservation can inform post-2020 global frameworks to improve coordination between global and local scale processes. We identify actions particular to the local scale that are critical to conserve global biodiversity and suggest a framework for improved coordination between actors at different scales that address their respective roles and spheres of influence.

Taxonomic and functional homogenization of farmland birds along an urbanization gradient in a tropical megacity

Urbanization is a major driver of land use change and biodiversity decline. While most of the ongoing and future urbanization hotspots are located in the Global South, the impact of urban expansion on agricultural biodiversity and associated functions and services in these regions has widely been neglected. Additionally, most studies assess biodiversity responses at local scale (α-diversity), however, ecosystem functioning is strongly determined by compositional and functional turnover of communities (β-diversity) at regional scales. We investigated taxonomic and functional β-diversity of farmland birds across three seasons on 36 vegetable farms spread along a continuous urbanization gradient in Bangalore, a South Indian megacity. Increasing amount of grey area in the farm surroundings was the dominant driver affecting β-diversity and resulting in taxonomic and functional homogenization of farmland bird communities. Functional diversity losses were higher than expected from species declines (i.e., urbanization acts as an environmental filter), with particular losses of functionally important groups such as insectivores of crop pests. Moreover, urbanization reduced functional redundancy of bird communities, which may further weaken ecosystems resilience to future perturbations. Our study underscores urbanization as a major driver of taxonomic and functional homogenization of species communities in agricultural systems, potentially threatening crucial ecosystem services for food production.

Nature-Based Resilience: A Multi-Type Evaluation of Productive Green Infrastructure in Agricultural Settings in Ontario, Canada

Nature-based solutions such as green infrastructure present an opportunity to reduce air pollutant concentrations and greenhouse gas emissions. This paper presents new findings from a controlled field study in Ontario, Canada, evaluating the impact of productive applications of green infrastructure on air pollution and carbon dioxide concentrations across different agricultural morphologies compared to other non-productive applications. This study demonstrates that productive green infrastructure applications are as beneficial as non-productive applications in reducing ozone, nitrogen dioxide, and carbon dioxide concentrations. Nature-based solutions present an opportunity to build climate resilience into agricultural systems through supply-side mitigation and adaptation. The implementation of productive green infrastructure could be a viable agricultural practice to address multiple climate change impacts.

Resilient Governance Regimes That Support Urban Agriculture in Sub-Saharan Cities: Learning From Local Challenges

Local governments in Sub-Saharan Africa face the daunting task of high urban growth and potentially devastating impacts of climate change across local communities and the economy. Urban and peri-urban food production can be among nature-based strategies planned for improving urban food security, reducing emissions, and climate adaptation. Co-operative governance, strategic planning, and accountable institutions are needed to support urban agriculture (UA), in the face of climate risks, unplanned urban development, the gendered nature of food provision, and the inability of urban farmers to self-organize toward optimal market and land access outcomes. Using a case study approach guided by qualitative content analysis with information derived from web analysis, we apply the Institutional Analysis and Development Framework to analyze underlying governance factors for UA in three selected Sub-Saharan African cities. Our three case cities of Kampala, Tamale and Cape Town reveal that UA is beginning to receive policy attention toward food security, and recognition for generating environmental, ecological, health, and human well-being benefits. Literature from specific cities however does not yet signal a local awareness and policy thrust regarding the associated and pertinent climate adaptation benefits of urban agriculture. We therefore recommend trans-disciplinary, locally-led, planning-based, and multi-sectoral approaches, involving a range of stakeholders toward recognizing and achieving the climate adaptation, environmental (ecologically restorative) and food security benefits of pursuing urban agriculture. This signals a larger role for the practice in sustainability discourse and SDGs 2 and 11, scaling out and up across large, medium and small towns, and cities of Sub-Saharan Africa.

Soil lead (Pb) and urban grown lettuce: Sources, processes, and implications for gardener best management practices

Urban community gardeners employ a range of best practices that limit crop contamination by toxicants like lead (Pb). While Pb root uptake is generally low, the relative significance of various Pb deposition processes and the effectiveness of best practices in reducing these processes have not been sufficiently characterized. This study compared leafy lettuce (Lactuca sativa) grown in high Pb (1150 mg/kg) and low Pb (90 mg/kg) soils, under three different soil cover conditions: 1) bare soil, 2) mulch cover to limit splash, and 3) mulch cover under hoophouses to limit splash and air deposition, in a New York City (NYC) community garden and a rural site in Ithaca, New York (NY). The lettuces were further compared to greenhouse (Ithaca) and supermarket (NYC) samples. Atmospheric deposition was monitored by passive trap collection through funnel samplers. Results show that in low Pb soils, splash and atmospheric deposition accounted for 84 and 78% of lettuce Pb in NYC and Ithaca, respectively. In high Pb soils, splash and atmospheric deposition accounted for 88 and 93% of Pb on lettuces, with splash being the dominant mechanism. Soil covers were shown to be effective at significantly (p < 0.05) reducing lettuce Pb contamination, and mulching is strongly recommended as a best practice.

Agricultural Production in Qatar’s Hot Arid Climate

Agriculture has played an essential role in the provision of food and has been a major factor in overall economic development for societies around the world for millennia. In the past, agriculture in hot, arid countries like Qatar faced many challenges, the primary one being a dearth of water for irrigation. Historically this severely limited Qatar’s economic development, which was based largely on resource exploitation, pearl fishing, and only more recently, on the exploitation of its oil and gas reserves which subsequently has led to Qatar’s great wealth. This paper gives an overview of the recent evolution of Qatar’s agricultural sector and investigates future trends that tackle the challenges of its hot arid climate and the limited availability of agricultural resources. Specifically, the review analyses Qatar’s potential to develop a national food security strategy based on a significant expansion of food production in the country. We review recent policy actions implemented to address challenges in the food supply chain caused by a 3.5-year blockade imposed by the adjacent Arab Gulf States, discussing the renewed interest in the potential that an enhanced agricultural sector must provide some aspects of food security and the implications for policymakers that would logically ensue.