Doctoral Research
How does societal inequity influence the ecology of cities?
How does societal inequity influence the ecology of cities?
Cities are heterogeneous, dynamic habitats that have cascading effects on urban wildlife. However, these novel disturbances and pressures are not distributed equally within cities as a consequence of historical injustice and contemporary inequity. For my doctoral work at UC Berkeley, I'm interested in investigating the how societal inequity shapes the ecology of cities. Specifically, I'm researching how legacies of injustice underpin urban ecosystem heath, how urban heterogeneity shapes carnivore behavior, and how inequity limits our ability to understand urban biodiversity.
PDFs for published research can be found on the publication page of my website.
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Historical Redlining and Urban Ecosystem Health
Both the built and ecological components of cities are shaped by historical policies and actions, including racist and classist policies. For two chapters of my dissertation, I investigated the extent to which redlining - a historical policy that denied predominately Black residents access to credit and loans - undergirds urban ecosystem health. Specifically, I examined (1) how redlining was associated with contemporary environmental quality in California, and (2) how redlining was associated with contemporary wildlife biodiversity in California. I found that across eight California cities, previously redlined neighborhoods face disproportionately worse environmental quality. I then found that in four of the major cities in California (LA, Oakland, San Diego, and San Francisco) that redlined neighborhoods have the lowest species richness, altered community composition, and relative to greenlined neighborhoods, need more sampling effort to detect the same number of species. I also found that species richness was consistently lower across these cities for six taxonomic clades, including mammals, birds, and insects. These chapters were published in 2024 and can be found below: 1) Estien, Wilkinson, Morello-Frosch, & Schell (2024). Historical redlining is associated with disparities in environmental quality across California. Environmental Science & Technology Letters. https://doi.org/10.1021/acs.estlett.3c00870. 2) Estien, Fidino, Wilkinson, Morello-Frosch, & Schell (2024). Historical redlining is associated with disparities in wildlife biodiversity in four California cities. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.2321441121 |
Figure 1 from "Historical redlining is associated with disparities in environmental quality across California" (Estien et al. 2024)
Figure 2 from "Historical redlining is associated with disparities in wildlife biodiversity in four California cities" (Estien et al. 2024)
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Societal Inequity and Contributory Science Data
Cities and human societies are strongly characterized by inequity and biases (e.g., preference of using greenspace 1 for recreation, over greenspace 2), which can trickle down to shape where, and what kind, of data is reported to biodiversity platforms. For part of my dissertation, I was interested in investigating how biases arise in data sources like iNaturalist and eBird - two of the largest sources of biodiversity data today. This resulted in two publications: (1) A co-led a perspective article with Dr. Elizabeth Carlen describing how spatial and taxonomic biases arise in contributory science data, such as iNaturalist and eBird. We articulate how social and ecological factors drive biases in contributory science data. This work was published in People & Nature in 2024. Carlen & Estien et al. (2024). A framework for contextualizing social-ecological bias in contributory science data. People and Nature. https://doi.org/10.1002/pan3.10592 (2) A co-led manuscript investigating how the amount of reported observations within a census tract differs from what is expected based on population density or census tract area. We show that generally, census tracts that have higher income, more white people, and were previously given more favorable Home Owner Loan Corporation grades (e.g., given grade A and "greenlined") have smaller differences between what is reported and expected, and in some cases, have more data than you would expect. This work was published in Ecology & Society in 2024. Estien, Carlen, & Schell (2024). Examining the influence of sociodemographics, residential segregation, and historical redlining on eBird and iNaturalist data disparities in three US cities. Ecology and Society. https://doi.org/10.5751/ES-15263-290316 |
Figure 1 from "A framework for contextualizing social-ecological bias in contributory science data." (Carlen & Estien et al. 2024)
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Urban Heterogeneity and Carnivore Risk-taking
Cities concentrate environmental hazards, including elevated air pollution and water contamination. However, these environmental hazards are distributed unequally as a result of legacies of injustice and societal inequity. Given pollution has been shown to alter risk-taking behaviors, including boldness and exploration, in lab-based studies, it is probable that pollution may drive behavioral divergence within-cities. For this project, I'm investigating how within-city heterogeneity is associated with boldness and exploration in two urban mesocarnivores - coyotes and raccoons. The coyote portion of this work is currently available as a preprint. We found that human densities, not pollution, are uniformly associated with coyote risk-taking, with coyotes in more human dense areas being bolder and more exploratory. Check it out here! The raccoon portion of this work is under review. Stay tuned! |
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Header image by Kitundu