Growing Gardens in Shrinking Cities: A Solution to the Soil Lead Problem?

Metagenomics: A Tool for Exploring Key Microbiome With the Potentials for Improving Sustainable Agriculture

Microorganisms are immense in nature and exist in every imaginable ecological niche, performing a wide range of metabolic processes. Unfortunately, using traditional microbiological methods, most microorganisms remain unculturable. The emergence of metagenomics has resolved the challenge of capturing the entire microbial community in an environmental sample by enabling the analysis of whole genomes without requiring culturing. Metagenomics as a non-culture approach encompasses a greater amount of genetic information than traditional approaches. The plant root-associated microbial community is essential for plant growth and development, hence the interactions between microorganisms, soil, and plants is essential to understand and improve crop yields in rural and urban agriculture. Although some of these microorganisms are currently unculturable in the laboratory, metagenomic techniques may nevertheless be used to identify the microorganisms and their functional traits. A detailed understanding of these organisms and their interactions should facilitate an improvement of plant growth and sustainable crop production in soil and soilless agriculture. Therefore, the objective of this review is to provide insights into metagenomic techniques to study plant root-associated microbiota and microbial ecology. In addition, the different DNA-based techniques and their role in elaborating plant microbiomes are discussed. As an understanding of these microorganisms and their biotechnological potentials are unlocked through metagenomics, they can be used to develop new, useful and unique bio-fertilizers and bio-pesticides that are not harmful to the environment.

Perspectives on Heavy Metal Soil Testing Among Community Gardeners in the United States: A Mixed Methods Approach

Community gardens offer numerous benefits, but there are also potential risks from exposure to chemical contaminants in the soil. Through the lens of the Theory of Planned Behavior, this mixed methods study examined community gardeners’ beliefs and intentions to conduct heavy metal soil testing. The qualitative component involved five focus groups of community garden leaders in Atlanta, Georgia. Qualitative analysis of the focus group data revealed that heavy metal soil contamination was not frequently identified as a common gardening hazard and several barriers limited soil testing in community gardens. The focus group results informed the development of a questionnaire that was administered to 500 community gardeners across the United States. Logistic regression analysis revealed that the soil testing intention was associated with attitude (aOR = 2.46, 95% CI: 1.34, 4.53), subjective norms (aOR = 3.39 95% CI: 2.07, 5.57), and perceived behavioral control (aOR = 1.81, 95% CI: 1.10, 2.99). Study findings have implications for interventions involving community garden risk mitigation, particularly gardens that engage children and vulnerable populations.

Modeling sustainability visions: A case study of multi-scale food systems in Southwestern Ontario

The process of systematically developing a sustainability vision is an important element of effective environmental management. Sustainability visions can, however, include contradictions and counterintuitive effects due to complex system behavior (e.g., feedback loops, multi-causality) and ambiguous system boundaries (e.g., choice of a scale, such as a regional or national scale). This paper proposes an innovative methodological framework for vision design and assessment (VDA) to analyze the sustainability of future visions on multiple scales with consideration of ecosystem services, and to test their plausibility based upon expert and local knowledge. First, requirements and functions of visionary system designs are identified. Second, a functional organizational analysis defines structures and processes that generate functions. Third, a literature review and participatory modeling process are conducted to analyze the system structures of visionary system designs using causal loop diagrams. Fourth, fuzzy cognitive mapping is used to assess visions based upon sustainability indicators. A case study on sustainable food systems in Southwestern Ontario, Canada, is provided to demonstrate the application of the methodology. Three designs of a sustainable food system were analyzed and tested: urban organic gardening, a local diversified organic food system and a globalized commodity-based organic food system. The results show the advantages and disadvantages of each system design and underline the sustainability benefits of a multi-scale food system based upon a combination of system designs.

Ecology for the Shrinking City

This article brings together the concepts of shrinking cities-the hundreds of cities worldwide experiencing long-term population loss-and ecology for the city. Ecology for the city is the application of a social-ecological understanding to shaping urban form and function along sustainable trajectories. Ecology for the shrinking city therefore acknowledges that urban transformations to sustainable trajectories may be quite different in shrinking cities as compared with growing cities. Shrinking cities are well poised for transformations, because shrinking is perceived as a crisis and can mobilize the social capacity to change. Ecology is particularly well suited to contribute solutions because of the extent of vacant land in shrinking cities that can be leveraged for ecosystem-services provisioning. A crucial role of an ecology for the shrinking city is identifying innovative pathways that create locally desired amenities that provide ecosystem services and contribute to urban sustainability at multiple scales.