Research Papers: Esther Marguiles

A Portable Sensor for the Determination of Tree Canopy Air Quality

By Esther Marguiles et al.

Environmental Science: Atmospheres


Using low-cost air quality sensors (PM2.5 , NO2, CO), air pumps, and a Raspberry Pi computer, we constructed a system by which air quality in tree canopies could be interrogated and quantified. The system involves pumping air into a sensor-containing box alternatively from tree canopy air and ambient air; repeating often enough to document if there are concentration differences between these two sources. By using the same set of sensors for air analysis from two sources, we eliminate issues such as sensor offset or drift and/or sensitivity to environmental conditions. True differences between tree canopy air and ambient air can be verified only after it has been established that the concentration difference between co-located inlet tubes is negligible. We’ve documented co-location results, described data summary protocol and as proof of concept, we show true differences in PM2.5 (production) and CO (consumption) between ambient air and tree canopies on the University of Southern California’s campus. In one tree tested, NO 2 between tree canopy and ambient air fluctuated as a function of day/night indicating periods of production and consumption…

Promoting Self-Determination, Minimizing Green Gentrification, and Maximizing Community Benefits in Urban Forestry Expansion: A Systematic Review

By Esther Marguiles et al.

Urban Forestry & Urban Greening


The purpose of this systematic review is to investigate how urban forest expansion processes can most equitably be carried out to improve environmental conditions in U.S. cities. In hopes of informing future environmental planning efforts that center racial and socioeconomic justice, this study examines existing literature in two ways. First, this study gathers existing research looking at associations between urban forest coverage and indicators of gentrification and residential displacement to better understand eco-gentrification risks. Second, this study assesses how participatory planning has been carried out in urban forest expansion projects and compiles descriptive findings and best practices noted in the literature. Findings show a need for further research looking specifically at associations between urban forest expansion and diverse indicators of gentrification and residential displacement, such as demographic shifts in neighborhood populations over time, and temporal changes in rental prices depending on a neighborhood’s proximity to different forms and magnitudes of urban forest expansion. Publications related to participatory urban forestry planning point to the importance of: (a) prioritizing the needs and goals of community members to best utilize local knowledge, rebuild trust in government, and repair historic harm; and (b) creating opportunities for community members to participate in planning processes that are accessible logistically, economically, and socially.

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