Product, Service & Design Innovation
The Science of Tree Planting:
How Data Is Boosting Climate Resilience of Both Cities and Forests

When talking to Arbor Day Foundation CEO Dan Lambe about the potential for using trees as a direct pathway to post-wildfire and climate resiliency, the conversation always leads back to one thing: Health.

“Forests help to pull carbon from the air, reduce negative impacts of our climate; and in turn, create healthier, more climate-resilient forests,” he told Sustainable Brands®.

Of course, you’d expect the leader of the preeminent tree-planting advocacy group in the US (maybe the world) to say that. Arbor Day Foundation is on a mission to plant 500 million trees by 2027, focusing on areas where greenery and nature are needed most: areas recovering from wildfire; and traditionally underrepresented urban neighborhoods with lower socioeconomic standings, which often suffer from inequitable access to nature. Trees play a crucial role in human health; and science is now confirming the notion that people who live in areas with more greenery are generally healthier.

Arbor Day Foundation is working to understand how it can effectively direct resources to those areas around the country identified as nature deficient. Its Forest Priority Index (FPI) — a complex data collection tool that uses climate, biodiversity and Indigenous/community land data to understand areas where trees are needed most — focuses on rural areas; while a separate tool, developed by Oregon-based tech firm NatureQuant, pinpoints need in urban areas. According to NatureQuant CEO and co-founder Jared Hanley, the NatureScore tool collects from more than 5,000 air-quality sensors across the country on an hourly basis, but that information is aggregated monthly for the most practical use.

The mechanics of the Index

Across the US, Arbor Day Foundation uses the FPI to understand at a deeper level where trees are — and aren’t — making an impact in traditional forest lands. This becomes especially important in wildfire-prone areas, as air quality is one measurement used to decide where tree need is greatest.

“While trees aren’t the only part of it, it’s a guide for us to focus where we can make the biggest impact,” Lambe adds. “It doesn’t mean we stop planting in tree-rich neighborhoods.”

In one example, in the aftermath of 2021’s Dixie Fire in northern California, a burn scar of more than 963,000 acres in Lassen National Forest required significant reforestation. The project was designated as a 7 (high priority) through the FPI. Lambe says Arbor Day’s project with planting partner Aloma Land & Forest LLC helped to plant more than 646,000 seedlings to help to reestablish native conifer forest cover, restore important wildlife habitat, and improve the water quality in nearby Lake Almanor.

Image credit: NatureQuant

Meanwhile, NatureQuant’s NatureScore tool helps groups such as Arbor Day gather a high-level look at the level of nature within a given urban area (based on Census information) weighted against the potential health risks relative to that score. That overall score is one of several tools Arbor Day uses to help identify where trees need to be planted.

Responsible planting and wildfire management

Using data to inform effective tree planting could take on increased importance, as forest thinning gains steam across the US — the practice carries plenty of upsides; but trees also play a critical role in filtering the air from pollutants, including wildfire smoke.

“Trees aren’t a silver bullet; but they do help remove pollutants and advance climate resilience,” Lambe says.

“It’s not causal, but association is very strong,” Hanley adds. “The more nature in a given area, the better the air quality.”

Planting trees in the right areas after a wildfire gives forests a head start in regeneration by helping to protect animal diversity and revitalize damaged watersheds; replanting has also proven vital in areas stricken by hurricanes and tornadoes.

It all comes back to health

There’s a delicate balance to strike here: Obviously, it’s important to replant where trees have been decimated (either by nature or otherwise — as is the goal of a tool such as the FPI); but it’s also important to direct resources to nature-deprived urban areas, which is where NatureScore comes in.

Both Lambe and Hanley drive home the value of trees to human health. One of the most recent sources of evidence comes from a 2022 study, in which more than five million northern California Kaiser Permanente subscribers looked at their regular exposure to nature. Among other findings, it was clear that those living near the greenest spaces spent, on average, $374 less per person per year on healthcare-related expenses than those living in nature-deficient areas.

“This could save society trillions of dollars; but in America’s insurance system, it’s tough,” Hanley says.

Unsurprisingly, the greenest neighborhoods (and therefore, healthiest — in terms of air quality) also tend to be some of the wealthiest — adding yet another disadvantage for those living in lower socioeconomic areas — which is why we must invest to spread health-boosting tree wealth to the communities that need it most.