Boyle Heights II: Guide for Tree Planting Decisions

USC Trees analyzed data and prioritized community input to identify areas that are in greatest need and recommend increasing tree coverage on those streets first. The goal of additional tree planting is to reduce exposures to extreme heat and air pollution and produce lasting benefits for generations to come. 

Community input is foundational to the success of any tree planting project. This starts with an open dialogue between city officials, researchers and residents.

USC Trees spoke with Boyle Heights residents over several Zoom meetings and community events across all stages of development. Multiple rounds of feedback helped guide our analyses and designs, including decisions to prioritize school and transit routes. For example, after meeting with students and parents at Roosevelt High School in Boyle Heights, USC Trees revised the routes to the school to account for a new front entrance on campus. 

Please refer to our Community Conversations report to read more about our creative engagement events.  

Thank you to those who offered their time and shared their visions for their streets and neighborhoods. USC Trees strives to provide effective urban greening strategies that elevate your ideas and reflect your priorities. 

USC Trees compiled an inventory of existing trees in Boyle Heights. 

By the Numbers

1. Total number of trees: 28,263
2. Over half the trees — 14,982 total — are located on private property
3. There are roughly three residents for every tree

Figure 2 shows our comprehensive tree inventory. The map includes data from the 2020 City of L.A . Street Tree Inventory  , tree counts on private property conducted by USC Trees as of December 2021, and trees planted by L.A. Sanitation up to May 2022. USC Trees is happy to share these data upon request.

USC Trees divided Boyle Heights into blocks the same way that the U.S. Census does to determine priority locations for increased tree cover. The major factors considered included areas with low tree cover, high urban heat and poor air quality, as well as high percentages of youth and seniors, public transit users and low-income households. These groups of people are more vulnerable to the health problems associated with extreme heat and air pollution. 

Interpreting the Map

In Figure 3, the dark red areas are those that satisfy most of the equity criteria found in the legend. The dark red sites to the south and west met most of the criteria and were given higher priority for planting new trees. Drag and zoom to navigate the map. 

Following community suggestions to prioritize schools, USC Trees compared foot traffic to tree coverage on routes to elementary schools. With 39 schools in the area, sidewalks are important walking routes for children and their guardians. USC Trees used the LA Unified School District’s (LAUSD) maps showing school enrollment areas to match neighborhoods to the schools that serve them and then compared the estimated number of pedestrians along routes to these schools with the number of trees per 100 feet. The result is the model you see in Figure 4. Navigate the interactive map to explore pedestrian traffic on specific streets.

Interpreting the Map

Tree plantings should be prioritized in zones that are the darkest shade of blue, which indicates heavier foot traffic. Children currently using these routes likely experience higher levels of heat and sun exposure due to lack of shade. The orange dots indicate schools. This model uses elementary schools within LAUSD. 

USC Trees also estimated the foot traffic to and from train and bus stops to determine priority routes for those who walk to transit. Nearly one in five households in Boyle Heights do not own a personal vehicle and community members expressed great interest in prioritizing transit stops during our meetings.

Interpreting the Map

Dark red indicates routes with high pedestrian use and should be considered of higher priority for tree plantings. Blue dots indicate transit stops. 

USC Trees determined the location of overhead utility lines and the size of public parkways, which are the spaces between the curb and sidewalk under city jurisdiction. These measurements are important for defining the height and size of the tree species that can be planted as well as other factors that could constrain tree growth. For instance, it is not possible for the City and nonprofit planting partners to place a tree in the public parkway with less than 2 feet of space available.

Interpreting the Map

In Figure 6, areas with green dots represent sites with fewer constraints and purple dots represent sites with more constraints. Each dot shows a potential site for tree planting where there already is a tree or the City inventory has located where there could be a tree.  

USC Trees overlaid the maps above to identify the highest priority streets for planting trees. These areas include streets with higher foot traffic, fewer trees and higher scores meeting the equity criteria (as shown on the equity map). Overall, 58 street segments (equating to 4.1 miles) were identified as high priority in Boyle Heights based on the criteria met. Please note that several streets below the 60 freeway were not identified as high priority due to contamination in the soil from Exide Technologies, the former battery recycling facility. 

Interpreting the Map

The map identifies streets with high pedestrian foot traffic to and from elementary schools and transit stops, as well as streets with few trees per 100 ft. The yellow shading indicates street segments that met two or more criteria, and thus where new tree plantings would be most valuable. These suggestions do not reflect the only opportunities for additional tree canopy. 

USC Trees toured the field to verify the conditions of several high-priority streets and look for any unforeseen constraints. The reconnaissance confirmed that several of the selected street segments shown in the prior map were strong candidates, with minimal tree cover and few additional constraints. The slideshow below shows the three streets that were selected for further investigation by the USC Trees design team: Mariachi Plaza, Winter Street, and Kearney Street.

USC Trees created numerous design scenarios for how the City, County and nonprofit partners can thoughtfully plant trees on these high-priority streets. These designs can also be used by community members to advocate for improved urban greening in their neighborhoods and pursue more competitive funding opportunities. 

 Boyle Heights Storymap III   expands on the designs for the sample streets shown in this StoryMap.

For next steps, USC Trees has been meeting with planners and engineers from the City and County to ensure our designs meet current regulations. These meetings are also encouraging us to think about how regulations could be changed to promote a more expansive and vibrant urban tree canopy. 

USC Trees aims to inform the public and decision-makers about our research findings and subsequent recommendations. We are holding in-person and virtual meetings with community members and city officials, and welcome the opportunity to meet with you and your organization to share our data, methods and findings. Please reach out to project manager Marianna Babboni at   babboni@usc.edu   with any questions or to request more information. 

Today, the warming planet poses serious risks to Angelenos.The streets of L.A. can — and should — evolve to meet the needs of residents. The goal of the USC Urban Trees Initiative is to strategically and equitably expand tree cover to mitigate the harm that accompanies excessive heat and air pollution in Boyle Heights, provide ecosystem services, and improve the health and well-being of residents. Research and design guided by community input can help to determine how best to increase the urban tree cover, and thereby create benefits that will last for decades to come.

 _{StoryMap Author: Jillian Gorman}  

 _{Contributors: Dulce Acosta, Marianna Babboni, Will Berelson, Naman Casas, Eileen Chen, Tarana Chordia, Charlie Curtain, Monica Dean, Jackson FitzGerald, David Galaviz, Emma Johnson, Runzi Kang, Jinsol Kim, Carolyn Koh, Joan Lee, Yixuan Li, Beau MacDonald, Esther Margulies, Alyssa Ng, Eliana Ramirez, Melinda Ramos-Alatorre, Coleman Reardon, Nick Rollins, Katie Vega, Steve Wesson, John Wilson, Aviva Wolf-Jacobs}