The City of Boulder succeeds in making trees accessible, regardless of whether you rent or own
2020 Trends | Urban Land Cover
Studies conducted in cities throughout the United States have shown, over and over again, that areas with higher socioeconomic status have greater tree canopy cover. Here we investigate the distribution of tree cover in Boulder and ask whether there is a disparity in access to trees for those who rent versus own their home. We found that trees are abundant across the city, with the greatest tree cover actually found in neighborhoods with the highest proportion of renters.
The history of tree plantings in urban areas is fraught with environmental injustice. Studies conducted in cities throughout the United States have shown, over and over again, that areas with higher socioeconomic status have more tree cover. This relationship between income and tree cover is rooted in racially-based discriminatory city planning that started in the 1930’s (a practice known today as ‘redlining’), with historically Black neighborhoods still feeling the consequences today.
But trees are an increasingly important asset to keep cities liveable in the face of climate change. Tree cover has the ability to mitigate high temperatures in urban environments by providing shade, which in turn lowers energy bills and increases property values. Trees also limit the adverse health effects from ambient pollution and correlate with better health outcomes.
Here we investigate the distribution of tree canopy cover in Boulder and ask whether there is a disparity in access to trees for those who rent versus own their home. We hypothesized that there would be an inverse relationship between the proportion of rental properties and tree canopy cover, such that areas with a high proportion of renters would have lower tree cover. This hypothesis was based on the widespread relationship between socioeconomic status and tree canopy cover in cities.
The data did not support our hypothesis. Instead, the resulting distribution maps show that trees are abundant throughout Boulder, regardless of the proportion of renters (Figures 1 and 2). In fact, the neighborhood with the greatest tree cover also had the highest proportion of renters (University Hill, Table 1).
explore the data
Who has access to trees in Boulder? Answer: almost everybody, regardless of whether you rent or own.
Figure 1. Map of the city of Boulder, showing owner-occupied and rental housing types. Blue properties indicate all owner-occupied housing parcels, and gray properties indicate rental housing parcels that are currently licensed. Notice that Boulder’s older, central neighborhoods have more rental properties and tree cover than newer neighborhoods in the eastern parts of the city. Source: Data provided by the City of Boulder Open Data Catalog. The Rental Property List contains all residential rental properties that are currently licensed.
Figure 2. Map of the city of Boulder, showing canopy cover, including trees on both public and private lands. Notice that tree cover is widespread throughout the city of Boulder and not clustered in particular neighborhoods. Source: Data was collected through LiDAR and aerial images in 2013 by GIS Analysts at the city of Boulder Parks and Recreation department.
Comparing forest cover and housing across Boulder neighborhoods
Table 1. Percent forest cover and percent rental housing in neighborhoods throughout the City of Boulder. Interestingly, older neighborhoods have more tree cover than newer neighborhoods, which is the opposite of trends in many cities throughout the U.S. Rental housing data is provided by the City of Boulder Open Data Catalog.
The Rental Property List contains all residential rental properties that are currently licensed. Forest cover data was collected through LiDAR and aerial images in 2013 by GIS Analysts at the city of Boulder Parks and Recreation department.
recommendations
Boulder is doing a great job of keeping trees an equitable resource, so let’s continue this trend.
Boulder has been recognized as one of the “Tree Cities of the World”, a designation from the Food and Agriculture Organization of the United Nations that identifies cities that have shown a commitment to the responsible planning and management of urban trees and forests. This is a designation that we can all take pride in, and encourages us to continue building urban canopy in equitable ways.
Neighborhoods in the city of Boulder have abundant opportunities to access trees, and this is something to celebrate. Looking forward, we can continue efforts with the city of Boulder urban forestry program to maintain our valued green spaces, seek improvement projects for areas that could use more careful planning and management, and look towards bolstering neighborhoods that would benefit the most from future greening projects. Read our accompanying Urban Land Cover story to learn more about Boulder neighborhoods that could benefit from more trees.
