Planting trees is a popular solution to carbon emissions. But where will all those seedlings come from?

Dean Swift has gotten really good at spotting where squirrels hide their seeds. In the forests of Colorado, Arizona, New Mexico, and South Dakota, he looks for a moist shaded area with a small grove of trees, sometimes near a ravine. Here, he will find a cache of chewed cones a few meters deep. On his hands and knees, he will dig through the mound searching for where the squirrels have hid full cones for the coming winter—the jackpot.

Swift is a seed collector. He takes the best cones and seeds he can find and sells them to nurseries. (Swift makes a point to mention that the squirrels don’t suffer because he never finds all the cones—and they have many other food sources.) This is the inception point for the United States’ reforestation efforts.

“Over the years, I’ve built up a network of people in the different collecting areas who helped me with seed collection,” Swift said. “I show them how to get started. Once they understand, it’s a lot of fun.”

Over the past decade, interest in reforestation has soared. Climate change, an increase in wildfires, and the need for huge carbon sinks to remove emissions from the atmosphere have increased the demand for trees and dense forests. Companies like CitiBank, Microsoft, Amazon and many others that have made net-zero carbon commitments; to fulfil these goals, they will have to buy carbon credits from organizations and nonprofits that protect or plant forests to offset emissions. In January, Elon Musk tweeted: “Am donating $100M towards a prize for best carbon capture technology.” Many of the responses can be summed up by designer Martin Darby, who tweeted in reply: “I have invented a concept called planting trees. Where do I send my bank details?”

But while there’s a huge focus on planting trees, there’s little on where those seedlings will come from. A study published in February in Frontiers in Forest and Global Change, authored by 17 environmental scientists, including ones from the Nature Conservancy, the USDA Forest Service, American Forests, and academic institutions, outlines that we are already short more than 2 billion seedlings per year—and that’s just to get halfway to meeting the reforesting potential of the lower 48 states. They estimated that there are 133 million acres to reforest by the year 2040, which would require 34 billion seedlings. According to the study, the US currently produces about 1.3 billion seedlings a year, which means a 2.4-fold increase is needed.

“There were increasing public calls for dramatically scaling up reforestation,” says Joseph Fargione, science director for the Nature Conservancy’s North America region and the study’s lead researcher. “The people that work in the industry were aware that would be hard to do because of the supply chain challenges. But most people outside the industry weren’t.”

Even nonprofit carbon offset project developers like the Arbor Day Foundation, who have access to private money from companies that have made net-zero pledges, know a squeeze is coming. “We’re going to have to increase the seedling production in order to meet the demand and the opportunities at hand,” says foundation president Dan Lambe. “We see that coming in the next couple of years.”

trees
Courtesy of Chuck Frank/USFS

So what happened to all the seedlings? The problem is a perfect storm of financial strains, labor issues, and climate change.

Budget cuts and an increase in wildfires that required the US Forest Service to put more of its resources toward fire mitigation have constrained replanting efforts. According to the National Forest Foundation, the service is only able to reforest about 20 percent of the national land that needs trees because the agency doesn’t have the resources to fund planting labor or site prep costs.

Another part of the problem is there aren’t enough folks like Dean Swift to steal from squirrels. Seed collecting is a profession on the verge of extinction. It is an extremely technical job: Seed collectors have to be arborists, be able to climb trees, understand how many seeds it’s okay to harvest without endangering the tree’s health, and what time of year each type of seed matures. Their industry has precise rules to avoid past mistakes; for example, campaigns a few decades ago used seeds from different geographic regions, resulting in weak, unhealthy growth of the replanted areas.

“They need to get a seed from that geographic area, from the right elevation, from the right species of tree, and grow those seeds in a nursery for a year or plus,” says Marcus Selig, vice president of field programs at the National Forest Foundation. “Then they take the seedlings back to that exact place to regenerate the trees. It’s just a really involved process.”

We are running out of people who know these nuances. “There are just a handful of people who know how to collect seeds for nurseries,” says Austin Rempel, one of the scientists involved in the study and the senior forest restoration manager at American Forests, a nonprofit conservation group. “And pretty much everyone we talked to says, ‘This might be my last year.’ No one is coming up behind them. They’re on the verge of retirement and they don’t really have a succession plan.”

Swift is one of the lucky ones who has built a business. During good harvest years, he employs almost 100 people across the western states to collect seeds to sell to nurseries in the US, China, Canada, and Europe, plus an assistant to handle the paperwork. After almost 50 years, he isn’t ready to stop yet. “Yes, seed collectors seem to be a dying breed,” he says. But, he adds, “I do not see retirement for me, as long as I can avoid the paperwork. Non-retirement tends to be the way of self-employed people.”

Still, there will be a point when the current generation of collectors will retire, and their institutional knowledge may be lost, partly because they are extremely secretive about where they harvest, and partly because there aren’t many places to learn except on the job from a mentor.

In addition, climate change is causing good seeds to become even more scarce. Years of drought can halt a tree’s energy-intensive cone production process. Warmer weather at lower elevations has also caused an increase in bugs that eat away at surviving seeds and cones. Forest fires are simultaneously increasing demand for seed while reducing the supply of trees to collect from.

“Every single seed collector I talked to says something along the lines of, ‘I’ve been doing this for 40 years and I have not seen this few mast years in my life,” Rempel says, referring to years when trees produce large crops of seeds. “Something’s changing. It’s not as predictable as it used to be. And then when they do produce crops, they’re not as great.”

Swift says he has a collecting area that hasn’t produced a heavy crop in nine years. “It’s no question in my mind” that it’s a result of climate change, he says. Overall, the crops are smaller and more sporadic than they were a few decades ago. “If this keeps up, I really don’t know what nurseries will do for seed in another 10 or 20 or 50 years,” he says.

Seed orchards—trees managed with the intent to harvest seed—are a contingency plan against lower yields from wild collecting. But they haven’t escaped climate change, either. Last year’s wildfires destroyed a sugar pine seed orchard in Klamath National Forest and another one on Oregon Bureau of Land Management land. That was a devastating blow, because orchards take a long time to set up, as the trees need time to mature.

After collecting, the seeds are sent to nurseries, where they are grown into seedlings for planting. The study’s authors interviewed over 120 nursery managers about obstacles to increasing their operations to fulfill reforestation needs. These problems range from spacing to staffing issues.

“We have no more greenhouse space,” Brian Morris, program manager at Webster Forest Nursery in Washington, told WIRED. “We’re having to actually work with outside growers to meet our demand. So over the last several years, we’ve been operating essentially at max capacity.”

Finding enough labor has already been a struggle for nurseries. According to Morris, his nursery hires its internal staff and seasonal contracts from farm labor, and those costs go up each year. Additionally, the study noted that immigration issues like visa restrictions often prevent migrant workers from coming into the US. Because of this, nursery operators and reforestation project managers are often uncertain about how many workers will be available and if their core team will be able to return. “Every year when we’re putting out those contracts, and going through the hiring process, it’s a very stressful time,” Morris says. “We don’t know what we’re going to get every year.”

Last summer, representative Bruce Westerman, a Republican from Arkansas, wrote in The Hill that without H-2B visa exemptions, in 2020 “1.6 million acres of forestland would go unplanted and nearly 1.12 billion seedlings would die.”

Nurseries, too, are struggling with the retirement issue. Many long-time growers are aging out of the business with few young people coming up behind them. There are only three forestry nursery training programs in the entire US, and increased urbanization has made rural nursery jobs less desirable. In fact, the program manager at Webster retired earlier this year; Morris is filling the role on an interim basis.

Fargione says that if nursery operators want to expand their infrastructure and hire more laborers, they’ll need a guarantee from the government or other large buyers that the investment will pay off. “They’ll need to add more land to grow, and that will require some long-term guarantees for them about the demand,” Fargione says. “So things like long term contracts or low-cost or forgivable loans to encourage them to make those investments.”

Morris wants even more specifics. Before he expands the business, he wants to know what tree species reforestation efforts will focus on next. Does that tree grow better in the ground or in a greenhouse? And what type of greenhouse? “There’s a lot of questions,” he says. “Trees are more than just trees. There’s a lot that goes into picking the right infrastructure for the crop you’re going to grow.”

Once the seedlings are grown, steep slopes and hazards from fires make replanting forest land extremely expensive. For example, according to the National Forest Foundation, a single project to plant 8,000 trees in California cost $300,000 just in site prep.

The study estimated it would cost $33 billion—about a dollar per tree—to plant 34 billion trees across public lands, national forests and reclaimed agricultural land. Selig thinks that the cost can only get that low if some trees are planted on cheap farmland, to subsidize more expensive forms of planting. “You can do machine planting, where you get a tractor and stick them into the ground really cheap,” he says. “But doing reforestation in ag land doesn’t have the same benefits of putting the trees back where they are right now.” In other words, it’s not just a matter of how many trees you plant—it also matters where you put them. For example, he says, while the carbon capture effect might be the same anywhere, replanting forests that have been destroyed by wildfire creates other environmental benefits, like protecting wildlife and the headwaters of rivers.

And the work doesn’t end after the trees are in the ground. Seedlings need to be cared for, managed, and protected from dry climates, wind, and animal foraging using tree shelters—plastic or metal mesh tubes. Fargione says that for some projects, up to 85 percent of seedlings die in the first year. “A plant-and-walk-away approach doesn’t work,” he says.

If seedlings die before becoming a thriving forest, we’ve not only lost their carbon sequestration potential, but all the money that was invested in growing and planting them. And with the shortage, planters can’t just go back to the nursery and get more seedlings, because there might not be any.

While the study outlined all the obstacles to reforesting US land, there are potential solutions on the horizon. The REPLANT Act was introduced into Congress last July; if passed it would quadruple the Forest Service’s Reforestation Trust Fund for forestry work and nursery development, which is currently $30 million a year—a figure that hasn’t changed since the 1980s. President Joe Biden’s planned Civilian Climate Corps could reinvigorate the nursery, planting, and seed collecting professions.

American Forests created a policy guide recommending 34 strategies to federal and state government agencies such as including trees and nurseries in infrastructure policy, investing in the tribal workforce because lands held in trust by the Bureau of Indian Affairs have significant reforestation potential, training new growers to stanch the loss of institutional knowledge, investing in seed orchards and climate-adapted seedlings that have been bred to survive in regions with severe drought, fire, or floods, establishing new collection networks by working with private landowners, and utilizing apps to help citizen scientists harvest seed.

Private money has also started pouring into reforestation investments and even nurseries. In 2020, Salesforce, the San Francisco-based sales software giant, worked with American Forests to hire a nursery technician at the Hakalau Forest National Wildlife Refuge to learn from Baron Horiuchi, the only person who knows how to grow a set of endangered Hawaiian tree and plant species, before he retires. In 2018, Bank of America helped invest in an urban nursery in Detroit. The Paul and June Rossetti Foundation, a frequent backer of America Forest projects including the recent seedling shortage study, is also funding a three-person crew to help build up seed banks in New Mexico and Colorado, a first in the world of private investment in seed collection. But right now most private money used to support forestry on public lands has to be philanthropic. According to Selig, the federal agencies in charge of the national forests haven’t authorized selling forestry credits on the carbon market.

Despite the difficulties nurseries and foresters are currently facing, a seedling shortage could signal something optimistic—a significant increase in reforestation investment to fight climate change. And Arbor Day Foundation president Lambe sees that as an opportunity. “We have to meet these demands and we have to overcome these challenges,” he says. “We need to figure out how to scale and find the labor, find the trees, find the land, in order to make the difference we’re hoping to make.”

Update 4-6-2021 1:05 PM: This story was updated to correct the definition of “mast years” and Austin Rempel’s job title


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