Environmental Equity and Urban Forests

Environmental Equity and Urban Forests

The field of environmental justice is concerned with inequitable exposure to environmental harm and equitable access to environmental goods. Exposure and access is often studied with respect to race, ethnicity, and income. Urban forests provide many benefits to urban residents that live and work among them, but if residents have unequal access to urban forests, then they have unequal access to the benefits they provide. If inequity persists over time, over an array of public goods and services, inequity accrues and manifests in significant effects on health and well-being.

Sarah Mincey, BUFRG co-lead, was awarded an internal grant in January 2021 through IU's Racial Justice Research Fund for the project Access to Sustainable Urban Tree Benefits: A Statewide Assessment of Racial Equity and Urban Forest Ecosystem Services. This effort will investigate race-based inequity with respect to access to quality and quantity of urban forests throughout the state of Indiana. Work for the project has begun and is interdisciplinary, involving co-PIs Heather Reynolds (Biology) and Dana Habeeb (SICE) and collaborators Jeff Wilson (IUPUI Geography) and Sam Hamlin (Biology postdoctoral fellow). Also contributing to the project will be BUFRG collaborators Stephanie Freeman-Day, Hannah Gregory, and Clint McGill.

BUFRG researchers Donovan Moxley and Burney Fischer recently published a paper Exploring the ecological legacy of redlining maps used by the Home Owners' Loan Corporation in Indianapolis: 80 years later. In this project, they investigate the relationship between historic redlining status and greater presence of undesirable ecological factors such as nearby brownfields, Superfund sites, and interstate highways, but also a lower percentage of tree canopy cover. A future BUFRG project will entail doing a similar analysis of the other formerly redlined Indiana cities- Fort Wayne, Gary, Muncie, Terre Haute, Evansville, and South Bend.

Two completed projects led by former BUFRG researcher Shannon Lea Watkins examined environmental equity in the urban forest both by studying the distribution of the urban forest (see The relationship between urban forest and income: A meta-analysis (Gerrish and Watkins) and The relationship between urban forest and race: A meta-analysis (Watkins and Gerrish) and drivers of that distribution (Is Planting Equitable?: An Examination of the Spatial Distribution of Nonprofit Urban Tree Planting Programs by Canopy Cover, Income, Race, and Ethnicity (Watkins et al.)).

Meta-analysis

Many scholars have examined the distribution of urban forests to determine whether they are equitably distributed throughout cities and results differ across studies. Shannon and fellow SPEA PhD graduate Ed Gerrish have conducted a meta-analysis of previous studies using the following methodology:

  1. We employ a systematic literature search to identify original studies which examine this relationship
  2. We code all acceptable studies
  3. We estimate the average relationship across studies between urban forest cover and (i) race and (ii) income, and
  4. We identify some of the drivers of variation in the distribution of urban forest cover between studies.

This research process has resulted in the recent publications of two papers, "The relationship between urban forests and income: a meta-analysis" and "The relationship between urban forests and race: a meta-analysis".

Is Planting Equitable?

While there is a wealth of research about the distribution of the urban forest, few studies have considered the distributional impacts of current urban forestry activities (e.g. tree planting, tree maintenance).

In our recently published paper, "Is planting equitable? An examination of the spatial distribution of nonprofit urban tree-planting programs by canopy cover, income, race, and ethnicity", we examine the distribution of tree planting locations of our NUCFAC partners.