Sowing Hope: Trees, Community, and Climate Resilience
In the heart of Los Angeles, our cherished trees are facing a daunting challenge: a vicious cycle of heat, water scarcity, dwindling immunity, and ultimately, demise due to thirst or pest invasions.
With each tree lost, the city becomes hotter, and the risks to human life soar, with people of color disproportionately bearing the brunt of this burden.
But here's the inspiring truth: there is a solution, and it's right at our fingertips – the simple act of planting and watering trees equitably and with care.
In this age of climate change, we're at a crossroads where our urban forests and our own well-being are deeply interconnected.
Tree stewardship—and equity—is our best bet for a more resilient Los Angeles. But don’t just take it from us. Here are the facts!
1. Trees in LA: Nature's Air Conditioning
When you stroll beneath the shade of LA's trees, you might not realize that they are working tirelessly to keep our city 9 degrees cooler than it would be without them (as reported by our partners, City Plants). This is a remarkable achievement and a testament to the power of nature.
Our city has set an ambitious goal to lower temperatures by 7 degrees to combat climate change and prevent deadly heatwaves. Trees are our best allies in achieving this goal, offering not just a respite from the heat but also protection against wildfires, a growing concern in our region.
2. The Lethal Threat of Extreme Heat
Extreme heat is currently the leading cause of weather-related deaths in the United States, even before we account for the effects of a warming climate (Source 1). Trees in urban areas, like Los Angeles, have the remarkable ability to reduce heat-related illnesses and deaths. Just three well-placed trees in an LA yard can provide enough shade and cooling to cut air conditioning needs by up to 50% (City Plants newsletter, 2023).
Yet, surviving heat in LA is far from equitable. Low-income urban communities and people of color are disproportionately affected by the heat, often residing in urban heat islands with older housing, limited cool spaces, and a scarcity of urban forest cover. Studies have shown that African American and Hispanic individuals are significantly more vulnerable during heatwaves, dying at significantly higher rates (Source 4).
When you stroll beneath the shade of LA's trees, you might not realize that they are working tirelessly to keep our city 9 degrees cooler than it would be without them. This is a remarkable achievement and a testament to the power of nature.
A spatial analysis of 108 urban areas, including LA, revealed that, in the vast majority of cases, previously redlined neighborhoods have 2-3 times less tree cover and can be up to 12.6°F hotter than their non-redlined counterparts (Source 3).
3. A Changing Landscape for Urban Trees
LA's urban trees face a growing challenge. Climate change exacerbates existing stressors such as poor soils, polluted air, contaminated runoff, and mechanical damage from cars and vandals (Source 1). Many of California's urban trees were planted when irrigation water was abundant, and these species aren't necessarily drought-tolerant or suited to our evolving climate (Source 2).
The longer, more intense hot and dry seasons we experience further strain these urban forests. Many of LA's trees struggle to find enough soil moisture to survive and require ongoing irrigation support during their establishment period.
Recycled water, commonly used during droughts, brings another challenge due to its high salinity, which reduces water uptake and can harm tree health (Source 1).
4. Nurturing Our Urban Forests
A staggering 90% of LA's urban forest resides on private property, emphasizing the significant role we play in caring for these vital assets (according to City Plants). Ensuring young trees receive adequate watering is essential to their growth, as they must establish roots deep enough to reach the underground water table for self-sufficiency.
It's disheartening to note that a significant number of trees distributed in city programs meet an untimely end due to insufficient care from residents. Prolonged drought not only decreases the water table, causing soil to lose moisture faster, but it also weakens trees' immune systems, rendering them susceptible to pests.
Drought, reduced irrigation, and pest infestations are linked to increased tree mortality, exemplified by the invasive shot hole borer beetle. Healthy trees can fend off pests, but stressed trees have compromised defenses, making them easy targets for invaders like the beetle. Approximately 23.2 million trees, or 32.8% of Southern California's urban trees, are at risk (Source 1).
As temperatures continue to rise, LA’s trees are key to our comfort, and our survival. By tending to and expanding our urban forests, we can forge a path towards a brighter, more inclusive, and resilient future for our city.
Together, we can create a thriving and harmonious city that stands strong against the rising heat and climate challenges that LA faces. Download the Dashboard.Earth app to get access to free trees and care guides, incentives, and a library of climate actions.
SOURCES:
Source 1: UC Davis Arboretum and Public Garden. (n.d.). Climate-Ready Tree Performance Testing. URL
Source 2: UC Davis Arboretum and Public Garden. (n.d.). Climate-Ready Tree Performance Testing. URL
Source 3: De Guzman, E. (2023). Hot Climate, Cool Shade: Community-Based Methods for Urban Forest Equity and Heat Health. eScholarship. URL
Source 4: Kalkstein, L. S., Sheridan, S. C., Kalkstein, A. J., & Vanos, J. K. (2014). The impact of oppressive weather on mortality across demographic groups in Los Angeles County and the potential impact of climate change. Department of Public Health Sciences, Miller School of Medicine, University of Miami; Department of Geography, Kent State University; Department of Geography and Environmental Engineering, U.S. Military Academy at West Point; Department of Geosciences, Texas Tech University.