ASPEN BARTELS LIKES TO MOVE. The North Carolina-based arborist and competitive tree climber just finished his second year traversing California’s mountains, helping to gather cones from the state’s trees. Bartels drives his van up to four hours to reach each day’s designated collection site. The 2024 collection season particularly kept him on his toes.

“This year’s cone collection has been fast paced,” he said last fall. “You’re just kind of taking it as it comes. You almost don’t know where you’re going to be going until the end of the day, and then you’re packing up your stuff and driving there. It’s really exciting to see new places all the time.”

Bartels is one of dozens of climbers from across the country who make an annual migration to California to scale trees and collect cones to restock California’s seed supply — all in an effort to provide hope for the state’s forests.

When he’s in a tree, Bartels also likes to move. He starts at the top, up to 200 feet in the air, and hops side to side around the tree. For species with larger cones, like Ponderosa pine, he grabs the cones off the branches, dropping them to collectors on the ground below. He especially likes the freedom of being able to climb without a chainsaw, a tool he regularly uses for his residential tree work in North Carolina. He likens California’s conifers to a big jungle gym, and his favorite is the Ponderosa pine due to its spread-out cone clusters.

“You’re just jumping around and getting to move a lot in the tree, which I like a lot,” he says. “I don’t really want to stay in one spot. I want to be activating my body in that way.”

But amid all the movement, Bartels is dedicated to pausing and taking it all in: “I always get to the top, and I start to look around. I want to look at the views. It’s a different perspective that you really can’t get from the ground.”

This past fall, Bartels’ views were often of charred landscapes. His climbing and collecting efforts for several days were in Northern California’s Eldorado National Forest, where a decade earlier, the King Fire blazed through more than 63,000 acres of national forest, and an additional 34,000 acres of private timberlands, making it one of the first large-scale high-severity fires in the region. Then, in 2021, the Caldor Fire came through and scorched more than 220,000 total acres over a two-month span, more than double the area of the King Fire.

In recent years, the scale and severity of California’s wildfires have greatly escalated, deforesting millions of acres that, without human intervention, are unlikely to regenerate in our lifetimes. And the wildfire threat only stands to deepen as climate change intensifies. To help the restoration process, American Forests has spearheaded a collaborative effort with partners — including contractors like Bartels, who works with Sierra Cone, LLC, and other tree climbers — to collect the seeds in cones from the state’s existing trees and replant the landscape — with a focus on making the forests more resilient in the future.

THE NEED FOR SEED

When it comes to the urgency of cone collection, Melissa Paulsen, who manages Northern California’s reforestation efforts for American Forests, is clear: “The need for reforestation on our state’s public and private lands is huge — and we don’t have the seed in our seedbanks to do it.”

This seed shortage is directly tied to a lack of cone collection efforts robust enough to match the pace of reforestation needed after years of unprecedented, large-scale, high-severity wildfire events. These fires burn the cones and the seeds inside them, which would otherwise naturally regenerate those areas.

“The species of trees that we have in these forests can only spread their seeds themselves so far,” explains Leana Weissberg, American Forests’ California director. “So when we look at these patches of 30,000 acres or more, there really is no way for living trees at the edge of those patches to seed into the interior.”

Such wildfires are driving 81% of reforestation needs across the country. And California alone has more than 1.5 million acres that require restoration — a number that’s rapidly growing. California’s forests are invaluable, providing wide-ranging ecological, economic and recreational benefits. Critically, they are responsible for supplying 60% of the state’s water. To save these crucial resources, the state must quickly increase its rate of reforestation to address the backlog.

And they were certainly available this past fall: California’s trees, and its Ponderosa pines in particular, produced a large or “bumper” crop of cones. It was quite likely the best crop the state has seen in decades — and American Forests, along with the U.S. Forest Service, the California Department of Forestry and Fire Protection (CAL FIRE), and other partners, were ready for it. Thanks to their focus on coordination, education and workforce development over the past few years, they collected an incredible 11,330 bushels of cones across California in 2024, a 275% increase from the previous season. For context, that’s enough cones to grow around 57 million seedlings, enough to replant up to a quarter of the more than 1.5 million acres of forests the state lost to high-severity wildfires between 2019 and 2021. What’s more, voluntary reports show that private industry collected an additional 8,670 bushels of cones. Taken together, the 2024 totals have the potential to reforest close to 700,000 acres.

The cone collection process is an elaborate one, and it begins long before the tree climbers and cone gatherers ever set foot in the forest. In the months leading up to the narrow collection window when the cones are ripe for picking, restoration managers begin finding and mapping trees with significant numbers of cones. They then monitor the trees, aiming to gauge the quality of the cones, using a cone cutter to slice samples in half to determine if the seeds look healthy and viable, and assess their maturity. Green cones need to start browning — an indicator of ripeness — and the seeds inside need to be fully developed before they are ready for climbers to collect them from the trees. But if they wait too long, the cones will have opened on their own and released the seeds.

Cone collection crews send their bushels of cone to the nursery for processing and storage. Cones from the Eldorado National Forest end up at the Forest Service nursery in nearby Placerville, Calif. But Paulsen highlights the need for patience, especially after an exciting bumper crop year.

“It can be really easy to inundate your nursery with more cones than they can handle, so it’s important to coordinate a slow trickle of thousands of bushels of cones into our nurseries,” she says. Ultimately, many of the seedlings the Placerville nursery grows from the seeds sourced from Eldorado National Forest will help replant acres impacted by the Caldor Fire.

A STATE-WIDE EFFORT

The Eldorado National Forest is one of many locations across California that experienced the flurry of cone collecting activity last fall. CAL FIRE managed other collections, on both state and private forest lands, while the Forest Service and other partners carried out collection efforts in other California national forests.

Unlike the cones from the Eldorado National Forest, the state and private forest cones headed to the L.A. Moran Reforestation Center, CAL FIRE’s nursery in Davis, Calif., where the number of staff swelled with temporary workers to help process the cones and extract their seeds.

“We do our best to get the cones within the same collection day, or the next day,” says Reforestation Services Programs Operations Manager Kuldeep Singh, who helped reopen the facility in 2017 after it was shuttered for more than a decade. And when the trucks roll in with the cones, it’s “all hands on deck,” he says.

In 2024, CAL FIRE’s seed bank received 4,630 bushels — a major shift from the 230 bushels it processed in 2023. Once the bushels are unloaded, workers at L.A. Moran begin by laying the bushels of cones on racks to dry, flipping them every second day to provide even air flow and to prevent the cones from molding and damaging the seeds inside. After about a week on the racks, the cones go into a kiln to complete the drying process and help them flare out, before heading into big, green tumblers to spin until they release their seeds and separate. The seeds then enter small tumblers to remove any remaining debris (though the more delicate seeds of certain species, like incense cedar, require hand-cleaning instead). Finally, Singh and his team x-ray the seeds to ensure their embryos remain intact.

Seeds are transferred to long-term storage and only removed when needed for seedling orders. Singh explains that there is an intricate process of preparing the seeds for sowing and germination that includes mimicking their natural process using different temperatures as a proxy for various seasons. Nursery staff aim to find an exact seed zone match for requested seedlings and often employ a future climate-modeling tool that helps determine the best fit.

The L.A. Moran nursery’s seedling output has increased dramatically in recent years, from 5,000 seedlings in 2018 to 80,000 in 2020. These days, Singh reports that it’s growing 290,000 of them every year — and his team has a goal of eventually reaching 1 million seedlings annually.

“I think the main reason CAL FIRE, or the state, is into reforestation is we want to leave the legacy for our future generations,” Singh says. “We got it from our older generations, they got it from theirs. And I think we have no right to spoil the forest we have for the future generations.”

A COMMUNAL EFFORT TOWARD A COMMON GOAL

Back in Eldorado National Forest, Jesse Cone, a silviculturist with the Forest Service, stresses the importance of reforesting the Caldor burn scar with local seed from the trees that remain. The wildfire “burned a hole through the heart of the Eldorado National Forest,” he says. About 70,000 acres of the blaze was high-severity, which left very little tree canopy in its wake.

After the devastating 2021 wildfire season, a range of efforts by a variety of actors have started to address the massive need to restore California’s forests.

The REPLANT Act passed in November of that year, providing the Forest Service with additional resources to work towards reforesting 1.5 million acres in the state’s national forests over a 10-year period. A couple years later, American Forests joined forces with the agency through the REPLANT Act to help scale up its post-wildfire reforestation efforts.

Around the same time, the California Reforestation Pipeline Partnership, a strategic collaboration between CAL FIRE, the U.S. Forest Service Region 5 and American Forests, was created in 2022 to generate more cooperation amidst the groups and organizations working to increase the pace of reforestation on public and private lands, with a focus on closing critical knowledge gaps and expanding the reforestation workforce.

Coordinating cone collection is just one of the ways the members of the California Reforestation Pipeline Partnership have worked together to address and remove barriers to reforestation.

“American Forests has really done a marvelous job of bringing all the stakeholders together,” CAL FIRE’s Singh comments. “Before we were operating in silos.”

Indeed, collaboration and communication are key to successful reforestation, says Shelley Villalobos, manager of the Reforestation Pipeline Partnership with American Forests: “California’s forested landscapes have changed so much in recent years. It’s been heartbreaking. We are awash in wood from fire, and so many watersheds are drastically altered.

Emphasis on collecting cones and growing seed supply has diminished in recent decades, leading to a lack of expertise about the process and a generation of new foresters who have little understanding about it. Because of California’s vast reforestation needs and the critical cone collection windows that exist, the Reforestation Pipeline Partnership has committed to building up that knowledge base. Last year’s cone collection triumph would not have been possible without the people the partnership helped train to carry out the work.

In the summer of 2023, the Reforestation Pipeline Partnership hosted three Cone Camps across California — a first of its kind training initiative. Over two days — one in a classroom and one in the field — more than 200 participants learned from experts about the range of elements that go into the cone collection process, from surveying to tree climbing. Last year, Cone Camp held six training sessions in different forests across the state, with 170 participants total. Beyond the technical education, Cone Camp attendees have the opportunity to build community and share excitement about reforestation.

“Trying to figure out the timing of that sometimes seems more of an art than a science, because you can’t look inside the cones from afar,” she says. “Not only do people learn the skills, but they can also learn some of that insider knowledge.”

Workers like Lopez from the California Cone Corps played an important part in 2024’s momentous cone collection effort, their work supporting 30% of all the state and federal bushels collected during the season.

The reforestation-centered partnerships and training programs are inspiring, but CAL FIRE’s Singh encourages patience. “It’s not an overnight operation. It will take some time, but I think we are moving in the right direction.”

Singh’s outlook is hopeful. “If the cooperation is there, and the awareness is there, and the resources are made available, I’m pretty sure that California will be in the right spot within a few years to meet its obligation to maintain its natural forests.”

One thing is certain: Bartels and his fellow tree climbers will be ready, vans packed with gear, and waiting to do their part in making reforestation happen.

Nicole Greenfield is a New York-based freelance writer whose work focuses on the intersection of climate, environment and health.