Supporting urban greenspace with microbial symbiosis

Abstract

Societal Impact StatementCities are stressful environments for plants, plagued by heat, pollution, and biodiversity loss. As a result, plant communities tend to suffer in green roofs, parks, and living walls. Finding solutions to help plants grow in stressful environments is a goal of the sustainable city. One solution is to better incorporate plant–microbe symbiosis in green architecture. Symbiotic fungi and bacteria can provide nutrients, water, and help plants to cope with urban stress. The reconceptualization of green infrastructure from a microbial‐focused perspective has the potential to improve plant health, growth, and diversity in cities.SummaryPlant communities in cities help maintain the health and stability of urban ecosystems and inhabitants. Ensuring that greenspace is healthy and productive is a key goal of green infrastructure and landscape architecture (GILA). However, cities are stressful environments for plants. In natural ecosystems, plants live in symbiosis with fungi, bacteria, and other microbes that can help alleviate stress. Microbial communities may also help with stress associated with urban environments. Incorporating mutualistic symbioses into GILA is a sustainable way to enhance urban greenspace. Here, we address key stressors for GILA in cities, including dependency on fertilizers, pathogens, drought, fewer pollinators, pollution, and reduced plant biodiversity. For each of these stressors, we discuss how symbiotic fungi and bacteria can help mitigate these issues, including case‐use scenarios. We conclude with new approaches to deliberately incorporate mutualisms in cities and open dialogues with stakeholders.

Impact of Plant–Microbe Interactions with a Focus on Poorly Investigated Urban Ecosystems—A Review

“…Plants play a central role in urban ecosystems by providing several ecological benefits. They -Promote flora and fauna conservation via habitat provision; -Contribute to environmental protection from soil and slope erosion, torrential floods, landslides, and strong winds; -Participate in the absorption/removal of pollutants, carbon uptake, oxygen release, air quality improvement, soil drainage, atmospheric cooling, temperature change moderation, and mitigation of extreme weather events [4,6,7].…”

“…In addition to being essential for the maintenance of healthy and stable urban ecosystems, several studies highlighted a correlation between urban green areas and human psychophysical well-being. Green spaces improve human wellness via engagement with nature, outdoor recreation, physical activity, enhancement in mental recovery and cognitive abilities, and reductions in stress, anxiety, depression, and violent behavior [6,8,9].…”

“…Although the benefits of green spaces within cities are well recognized, the ecosystemic role of "urban soil inhabitants" is often not adequately considered. Notably, microbial communities supporting urban green areas are largely overlooked, although they make important contributions to ecosystem services [3,6,36]. Therefore, the present review focused on plant-microbe dynamics within urban green areas, with special attention to the rhizosphere.…”

Urban horticulture: Building the evidence base to support integration into cities and towns

“…Whilst there is growing evidence that urban horticulture currently does and could further support more sustainable and resilient cities, there remain important scientific, engineering and socio-cultural challenges that must be overcome to successfully integrate food growing into cities more widely. This special collection for Plants, People, Planet brings together articles spanning mechanisms to engage urban communities with food cultivation (Sia et al, 2023); the benefit of urban horticulture to healthy diet and sustainability (Gulyas & Edmondson, 2023); the role of pollinators in supporting horticultural production (Nicholls et al, 2023); the importance of soil microbial communities for healthy and productive plants in urban green spaces (Stewart et al, 2024); experimental approaches to improve sustainability of aquaponically produced horticultural crops (Jones et al, 2023); the challenges to horticultural production of a specific crop, strawberry, in urban systems and the importance of knowledge exchange with rural producers (Zacharaki et al, 2024); and the role of institutions, such as the Royal Horticultural Society, in leading research into environmental horticulture at small scales in domestic gardens and community gardens (Gush et al, 2023). This collection of articles reflects the interdisciplinary nature of understanding the benefits of and the challenges to expansion of urban horticulture.…”