Streetscape Green Infrastructure as Hot Spots in Urban Social-Ecological Systems

Background/Question/Methods

As rates of urbanization rise and a greater proportion of the world’s population lives in urban areas, the provision of ecosystem services become increasingly important to sustain human and environmental health in cities. Soil plays a key role in the healthy functioning of ecosystems and serve as natural capital that provides supporting, provisioning, regulating, preserving, and cultural ecosystem services. Despite this importance, urban soils are often degraded, and our understanding of how they function and are managed to provide ecosystem services is underdeveloped. This paper discusses how green infrastructure can provide critical functional hotspots and hot moments in urban social-ecological systems. Utilizing examples from Tucson, AZ, this talk illustrates how soils are focal points for biogeochemical function, ecohydrologic processes, community action and involvement, and policy and governance issues of green infrastructure. Field studies comparing a variety of green infrastructure installations (such as rain gardens and bioswales) assess soil properties, microbial function, plant performance, and biogeochemical cycling rates. 

Results/Conclusions

These studies show that by concentrating water flows in an arid urban center, green infrastructure can improve urban soil quality and their provision of ecosystem services, such as C-sequestration, nutrient retention, and shading.  Furthermore, studies comparing variation in design of green infrastructure highlight the importance of applying soil ecological knowledge to promote soil food web development and links to both nutrient retention and enhanced plant growth and function. Collaborations between academic researchers, non-profits, and city and county officials have fostered community engagement around urban environmental issues related to green infrastructure, including, the co-production of environmental knowledge, development of new policies related to water harvesting, and community programs to utilize soil stewardship to improve the urban environment.  Green infrastructure therefore serves as a nexus to improve soils and reconnect ecohydrologic flows in arid cities, contributing to the provision of ecosystem services and the resilience of cities.