The activities are as follows:
We often imagine nature as being a place outside of cities. But within our cities, we are surrounded by nature – in fact, most human interactions with nature happen within urban areas. Picturing a tree, we might imagine it in a remote forest, yet many trees are planted by residents and local governments within cities. Trees provide important benefits, such as beauty and shade. The number and types of tree species that are planted in a neighborhood can increase the benefits received from trees in urban areas.
When Adrienne first moved to the Twin Cities in Minnesota, she started exploring Minneapolis and St. Paul by bike. Biking is done at a slow enough pace that she can travel long distances but still make observations about neighborhoods in these cities. As an ecologist, she naturally found herself looking for patterns in trees. For example, she noticed some older neighborhoods in St. Paul have a lot of large trees that provide plenty of shade and tree cover. In other neighborhoods, Adrienne saw fewer types of trees and noticed that she spent less time shaded by branches and leaves.
Adrienne started conversations with her colleagues about their observations of differences in urban landscapes. They discussed the ways in which laws, policies, and practices (“the way things are done”) give advantages to certain groups of people over others. These advantages are woven into our cultural systems.
Adrienne and her fellow researchers expected that neighborhoods with wealthier and more white residents would have benefited from a long history of greater investment.
Therefore, these neighborhoods were expected to have greater tree cover from the large old trees that have been growing there for many years. They also expected these neighborhoods would have more types of trees. In contrast, the researchers expected that less wealthy neighborhoods and those with a greater percentage of Black, Indigenous, and other People of Color (BIPOC) would have less tree cover and fewer types of trees because of chronic lower investment in these neighborhoods.
To research these ideas, Adrienne and her colleagues combined three different sources of publicly available data:
- U.S. Census data, used to estimate % BIPOC and average median household income per ‘Block Group’ (similar to a neighborhood).
- Satellite images, which are often used to estimate % tree cover, measure the percent of land area covered by the tree canopy. Adrienne looked at tree cover in the Block Group areas used in the Census.
- City data that include the location and species for each tree planted along public streets to calculate tree species richness in each Block Group. Tree species richness is the number of different tree species in an area and is a measure of tree biodiversity used by many ecologists.
Featured scientists: Adrienne Keller (she/her) from the University of Minnesota
The data in this activity are from the MSP Long-term Ecological Research Site. The focus of the research at this site is centered on ecological interactions in urban environments. You can learn more here.
Additional teacher resources related to this Data Nugget include:
- You can have students read more about environmental justice research from the MSP LTER in this peer-reviewed article (email us at firstname.lastname@example.org if you need a downloadable version):
- Rebecca H. Walker, Hannah Ramer, Kate D. Derickson & Bonnie L. Keeler (2023) Making the City of Lakes: Whiteness, Nature, and Urban Development in Minneapolis. Annals of the American Association of Geographers, DOI: 10.1080/24694452.2022.2155606
- This short video features Adrienne as she describes the motivation and process behind her research study.