Current Research

 By Debbie Hanson

Los Angeles is experiencing worsening urban heat, and the effects are not distributed equally. Low-income communities, particularly in the San Fernando Valley and other wildfire-prone areas, experience more intense heatwaves, limited tree cover, and poorer air quality. Research shows that these neighborhoods face up to 23 more days of extreme heat per year compared to wealthier areas, increasing risks of respiratory illness, heat stroke, and higher household energy costs (The Verge, 2023; UCLA Center for Healthy Climate Solutions, 2023).

Adding to this crisis, repeated wildfires have destroyed large areas of native tree cover, reducing biodiversity and leaving hillsides vulnerable to erosion and invasive species. According to the California Department of Fish and Wildlife (2022), many high-intensity fires now burn too severely for natural regrowth to occur. Studies confirm that seedling survival and vegetation regrowth after fire are increasingly uncertain in California’s conifer forests (ScienceDirect, 2024).

Tree canopy coverage in Los Angeles mirrors a history of environmental injustice. Underserved communities of color often have less than half the tree coverage of wealthier neighborhoods. This disparity translates into less shade, higher energy costs, and greater exposure to harmful air pollution (Los Angeles County Department of Public Health, 2023). Trees naturally filter particulate matter and reduce smog, wildfire smoke, and vehicle exhaust, but without them, residents face worsened respiratory health outcomes (TreePeople, 2023; Wired, 2022).

The Urban Tree Renewal for Resilience (UTRR) program addresses the loss of tree canopy across Los Angeles. At Wildfire Resilient Landscapes (WRL) and Wildfire Resilient Native Plants Nursery (WRN), we see urban tree renewal as essential to public health, climate justice, and long-term resilience. By removing sidewalk stumps and replanting with native, drought-tolerant, and fire-resilient trees grown locally at WRN, we aim to restore shade, reduce wildfire risk, and bring new life to neighborhoods disproportionately burdened by climate stress (The Nature Conservancy, 2021).

UTRR is more than a tree planting program—it is a community-powered strategy for climate resilience and recovery, designed to improve health, equity, and environmental sustainability across Los Angeles.

• California Department of Fish and Wildlife. (2022). Wildfire Impacts and Ecological Recovery in California.
• Los Angeles County Department of Public Health. (2023). Environmental Justice and Tree Canopy Inequity Report.
• ScienceDirect. (2024). Seedling Survival and Vegetation Regrowth in Burned Conifer Forests of California.
• The Nature Conservancy. (2021). Wildfire Resilience Funding and Community Benefits Report.
• The Verge. (2023). How Extreme Heat Disproportionately Affects Latino Neighborhoods in Los Angeles.
• TreePeople. (2023). Climate Gardening and Urban Canopy Restoration Programs in Los Angeles.
• UCLA Center for Healthy Climate Solutions. (2023). Heat and Public Health Impacts in Canopy Deficient Communities.
• Wired Magazine. (2022). City Trees Save Lives: How Urban Forestry Protects Public Health.